diff --git a/cmds/atrace/atrace.cpp b/cmds/atrace/atrace.cpp
index 544e26c..8637a31 100644
--- a/cmds/atrace/atrace.cpp
+++ b/cmds/atrace/atrace.cpp
@@ -233,6 +233,7 @@
         { REQ,      "events/filemap/enable" },
     } },
     { "memory",  "Memory", 0, {
+        { OPT,      "events/mm_event/mm_event_record/enable" },
         { OPT,      "events/kmem/rss_stat/enable" },
         { OPT,      "events/kmem/ion_heap_grow/enable" },
         { OPT,      "events/kmem/ion_heap_shrink/enable" },
diff --git a/cmds/atrace/atrace.rc b/cmds/atrace/atrace.rc
index 6e460a0..040ddde 100644
--- a/cmds/atrace/atrace.rc
+++ b/cmds/atrace/atrace.rc
@@ -107,6 +107,8 @@
     chmod 0666 /sys/kernel/tracing/events/kmem/ion_heap_grow/enable
     chmod 0666 /sys/kernel/debug/tracing/events/kmem/ion_heap_shrink/enable
     chmod 0666 /sys/kernel/tracing/events/kmem/ion_heap_shrink/enable
+    chmod 0666 /sys/kernel/debug/tracing/events/mm_event/mm_event_record/enable
+    chmod 0666 /sys/kernel/tracing/events/mm_event/mm_event_record/enable
     chmod 0666 /sys/kernel/debug/tracing/events/signal/signal_generate/enable
     chmod 0666 /sys/kernel/tracing/events/signal/signal_generate/enable
     chmod 0666 /sys/kernel/debug/tracing/events/signal/signal_deliver/enable
diff --git a/cmds/dumpsys/dumpsys.cpp b/cmds/dumpsys/dumpsys.cpp
index a427c8d..1327cfd 100644
--- a/cmds/dumpsys/dumpsys.cpp
+++ b/cmds/dumpsys/dumpsys.cpp
@@ -230,7 +230,7 @@
     }
 
     const size_t N = services.size();
-    if (N > 1) {
+    if (N > 1 || showListOnly) {
         // first print a list of the current services
         std::cout << "Currently running services:" << std::endl;
 
diff --git a/cmds/dumpsys/tests/dumpsys_test.cpp b/cmds/dumpsys/tests/dumpsys_test.cpp
index b9395ba..3467898 100644
--- a/cmds/dumpsys/tests/dumpsys_test.cpp
+++ b/cmds/dumpsys/tests/dumpsys_test.cpp
@@ -206,10 +206,7 @@
     }
 
     void AssertRunningServices(const std::vector<std::string>& services) {
-        std::string expected;
-        if (services.size() > 1) {
-            expected.append("Currently running services:\n");
-        }
+        std::string expected = "Currently running services:\n";
         for (const std::string& service : services) {
             expected.append("  ").append(service).append("\n");
         }
@@ -263,6 +260,21 @@
     AssertRunningServices({"Locksmith", "Valet"});
 }
 
+TEST_F(DumpsysTest, ListServicesOneRegistered) {
+    ExpectListServices({"Locksmith"});
+    ExpectCheckService("Locksmith");
+
+    CallMain({"-l"});
+
+    AssertRunningServices({"Locksmith"});
+}
+
+TEST_F(DumpsysTest, ListServicesEmpty) {
+    CallMain({"-l"});
+
+    AssertRunningServices({});
+}
+
 // Tests 'dumpsys -l' when a service is not running
 TEST_F(DumpsysTest, ListRunningServices) {
     ExpectListServices({"Locksmith", "Valet"});
diff --git a/cmds/installd/CrateManager.cpp b/cmds/installd/CrateManager.cpp
index 6e079eb..b17cba1 100644
--- a/cmds/installd/CrateManager.cpp
+++ b/cmds/installd/CrateManager.cpp
@@ -86,7 +86,7 @@
 }
 
 void CrateManager::traverseAllPackagesForUser(
-        const std::unique_ptr<std::string>& uuid, userid_t userId,
+        const std::optional<std::string>& uuid, userid_t userId,
         std::function<void(FTSENT*)>& onHandlingPackage) {
     const char* uuid_ = uuid ? uuid->c_str() : nullptr;
 
@@ -96,21 +96,21 @@
 
 void CrateManager::createCrate(
         CratedFolder cratedFolder,
-        std::function<void(CratedFolder, std::unique_ptr<CrateMetadata>&)>& onCreateCrate) {
+        std::function<void(CratedFolder, CrateMetadata&&)>& onCreateCrate) {
     const char* path = cratedFolder->fts_path;
     if (path == nullptr || *path == '\0') {
         return;
     }
 
-    std::unique_ptr<CrateMetadata> crateMetadata = std::make_unique<CrateMetadata>();
-    crateMetadata->uid = cratedFolder->fts_statp->st_uid;
-    crateMetadata->packageName = mPackageName;
-    crateMetadata->id = getValidatedCratedPath(path);
+    CrateMetadata crateMetadata;
+    crateMetadata.uid = cratedFolder->fts_statp->st_uid;
+    crateMetadata.packageName = mPackageName;
+    crateMetadata.id = getValidatedCratedPath(path);
 
-    onCreateCrate(cratedFolder, crateMetadata);
+    onCreateCrate(cratedFolder, std::move(crateMetadata));
 }
 
-void CrateManager::traverseAllCrates(std::function<void(CratedFolder, std::unique_ptr<CrateMetadata>&)>& onCreateCrate) {
+void CrateManager::traverseAllCrates(std::function<void(CratedFolder, CrateMetadata&&)>& onCreateCrate) {
     std::function<void(FTSENT*)> onVisitCrateDir = [&](FTSENT* cratedFolder) -> void {
         createCrate(cratedFolder, onCreateCrate);
     };
@@ -118,11 +118,11 @@
 }
 
 #if CRATE_DEBUG
-void CrateManager::dump(std::unique_ptr<CrateMetadata>& CrateMetadata) {
+void CrateManager::dump(const CrateMetadata& CrateMetadata) {
     LOG(DEBUG) << "CrateMetadata = {"
-            << "uid : \"" << CrateMetadata->uid
-            << "\", packageName : \"" << CrateMetadata->packageName
-            << "\", id : \"" << CrateMetadata->id
+            << "uid : \"" << CrateMetadata.uid
+            << "\", packageName : \"" << CrateMetadata.packageName
+            << "\", id : \"" << CrateMetadata.id
             << "\"}";
 }
 #endif
diff --git a/cmds/installd/CrateManager.h b/cmds/installd/CrateManager.h
index 4332d4c..1f30b5d 100644
--- a/cmds/installd/CrateManager.h
+++ b/cmds/installd/CrateManager.h
@@ -25,7 +25,7 @@
 #include <sys/stat.h>
 #include <sys/types.h>
 
-#include <memory>
+#include <optional>
 #include <string>
 #include <vector>
 
@@ -55,18 +55,18 @@
     CrateManager(const char* uuid, userid_t userId, const std::string& packageName);
     ~CrateManager();
 
-    void traverseAllCrates(std::function<void(CratedFolder, std::unique_ptr<CrateMetadata>&)>& onCreateCrate);
+    void traverseAllCrates(std::function<void(CratedFolder, CrateMetadata&&)>& onCreateCrate);
 
     static void traverseChildDir(const std::string& targetDir,
             std::function<void(FTSENT*)>& onVisitChildDir);
 
     static void traverseAllPackagesForUser(
-        const std::unique_ptr<std::string>& uuid,
+        const std::optional<std::string>& uuid,
         userid_t userId,
         std::function<void(FTSENT*)>& onHandlingPackage);
 
 #if CRATE_DEBUG
-    static void dump(std::unique_ptr<CrateMetadata>& CrateMetadata);
+    static void dump(const CrateMetadata& CrateMetadata);
 #endif
 private:
     std::string mRoot;
@@ -75,7 +75,7 @@
 
     void createCrate(
         CratedFolder cratedFolder,
-        std::function<void(CratedFolder, std::unique_ptr<CrateMetadata>&)>& onCreateCrate);
+        std::function<void(CratedFolder, CrateMetadata&&)>& onCreateCrate);
 };
 
 } // namespace installd
diff --git a/cmds/installd/InstalldNativeService.cpp b/cmds/installd/InstalldNativeService.cpp
index c9b51b5..657409b 100644
--- a/cmds/installd/InstalldNativeService.cpp
+++ b/cmds/installd/InstalldNativeService.cpp
@@ -42,6 +42,7 @@
 
 #include <android-base/file.h>
 #include <android-base/logging.h>
+#include <android-base/parseint.h>
 #include <android-base/properties.h>
 #include <android-base/scopeguard.h>
 #include <android-base/stringprintf.h>
@@ -75,6 +76,7 @@
 #define LOG_TAG "installd"
 #endif
 
+using android::base::ParseUint;
 using android::base::StringPrintf;
 using std::endl;
 
@@ -164,7 +166,7 @@
     }
 }
 
-binder::Status checkArgumentUuid(const std::unique_ptr<std::string>& uuid) {
+binder::Status checkArgumentUuid(const std::optional<std::string>& uuid) {
     if (!uuid || is_valid_filename(*uuid)) {
         return ok();
     } else {
@@ -173,7 +175,7 @@
     }
 }
 
-binder::Status checkArgumentUuidTestOrNull(const std::unique_ptr<std::string>& uuid) {
+binder::Status checkArgumentUuidTestOrNull(const std::optional<std::string>& uuid) {
     if (!uuid || strcmp(uuid->c_str(), kTestUuid) == 0) {
         return ok();
     } else {
@@ -212,7 +214,7 @@
     return ok();
 }
 
-binder::Status checkArgumentPath(const std::unique_ptr<std::string>& path) {
+binder::Status checkArgumentPath(const std::optional<std::string>& path) {
     if (path) {
         return checkArgumentPath(*path);
     } else {
@@ -418,7 +420,7 @@
     return true;
 }
 
-binder::Status InstalldNativeService::createAppData(const std::unique_ptr<std::string>& uuid,
+binder::Status InstalldNativeService::createAppData(const std::optional<std::string>& uuid,
         const std::string& packageName, int32_t userId, int32_t flags, int32_t appId,
         const std::string& seInfo, int32_t targetSdkVersion, int64_t* _aidl_return) {
     ENFORCE_UID(AID_SYSTEM);
@@ -499,7 +501,7 @@
     return ok();
 }
 
-binder::Status InstalldNativeService::migrateAppData(const std::unique_ptr<std::string>& uuid,
+binder::Status InstalldNativeService::migrateAppData(const std::optional<std::string>& uuid,
         const std::string& packageName, int32_t userId, int32_t flags) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(uuid);
@@ -560,7 +562,7 @@
     return res;
 }
 
-binder::Status InstalldNativeService::clearAppData(const std::unique_ptr<std::string>& uuid,
+binder::Status InstalldNativeService::clearAppData(const std::optional<std::string>& uuid,
         const std::string& packageName, int32_t userId, int32_t flags, int64_t ceDataInode) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(uuid);
@@ -680,7 +682,7 @@
     return res;
 }
 
-binder::Status InstalldNativeService::destroyAppData(const std::unique_ptr<std::string>& uuid,
+binder::Status InstalldNativeService::destroyAppData(const std::optional<std::string>& uuid,
         const std::string& packageName, int32_t userId, int32_t flags, int64_t ceDataInode) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(uuid);
@@ -752,7 +754,7 @@
     return (gid != -1) ? gid : uid;
 }
 
-binder::Status InstalldNativeService::fixupAppData(const std::unique_ptr<std::string>& uuid,
+binder::Status InstalldNativeService::fixupAppData(const std::optional<std::string>& uuid,
         int32_t flags) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(uuid);
@@ -872,7 +874,7 @@
 }
 
 binder::Status InstalldNativeService::snapshotAppData(
-        const std::unique_ptr<std::string>& volumeUuid,
+        const std::optional<std::string>& volumeUuid,
         const std::string& packageName, int32_t user, int32_t snapshotId,
         int32_t storageFlags, int64_t* _aidl_return) {
     ENFORCE_UID(AID_SYSTEM);
@@ -999,7 +1001,7 @@
 }
 
 binder::Status InstalldNativeService::restoreAppDataSnapshot(
-        const std::unique_ptr<std::string>& volumeUuid, const std::string& packageName,
+        const std::optional<std::string>& volumeUuid, const std::string& packageName,
         const int32_t appId, const std::string& seInfo, const int32_t user,
         const int32_t snapshotId, int32_t storageFlags) {
     ENFORCE_UID(AID_SYSTEM);
@@ -1069,7 +1071,7 @@
 }
 
 binder::Status InstalldNativeService::destroyAppDataSnapshot(
-        const std::unique_ptr<std::string> &volumeUuid, const std::string& packageName,
+        const std::optional<std::string> &volumeUuid, const std::string& packageName,
         const int32_t user, const int64_t ceSnapshotInode, const int32_t snapshotId,
         int32_t storageFlags) {
     ENFORCE_UID(AID_SYSTEM);
@@ -1101,9 +1103,46 @@
     return ok();
 }
 
+binder::Status InstalldNativeService::destroyCeSnapshotsNotSpecified(
+        const std::optional<std::string> &volumeUuid, const int32_t user,
+        const std::vector<int32_t>& retainSnapshotIds) {
+    ENFORCE_UID(AID_SYSTEM);
+    CHECK_ARGUMENT_UUID_IS_TEST_OR_NULL(volumeUuid);
+    std::lock_guard<std::recursive_mutex> lock(mLock);
 
-binder::Status InstalldNativeService::moveCompleteApp(const std::unique_ptr<std::string>& fromUuid,
-        const std::unique_ptr<std::string>& toUuid, const std::string& packageName,
+    const char* volume_uuid = volumeUuid ? volumeUuid->c_str() : nullptr;
+
+    auto base_path = create_data_misc_ce_rollback_base_path(volume_uuid, user);
+
+    std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(base_path.c_str()), closedir);
+    if (!dir) {
+        return error(-1, "Failed to open rollback base dir " + base_path);
+    }
+
+    struct dirent* ent;
+    while ((ent = readdir(dir.get()))) {
+        if (ent->d_type != DT_DIR) {
+            continue;
+        }
+
+        uint snapshot_id;
+        bool parse_ok = ParseUint(ent->d_name, &snapshot_id);
+        if (parse_ok &&
+                std::find(retainSnapshotIds.begin(), retainSnapshotIds.end(),
+                          snapshot_id) == retainSnapshotIds.end()) {
+            auto rollback_path = create_data_misc_ce_rollback_path(
+                volume_uuid, user, snapshot_id);
+            int res = delete_dir_contents_and_dir(rollback_path, true /* ignore_if_missing */);
+            if (res != 0) {
+                return error(res, "Failed clearing snapshot " + rollback_path);
+            }
+        }
+    }
+    return ok();
+}
+
+binder::Status InstalldNativeService::moveCompleteApp(const std::optional<std::string>& fromUuid,
+        const std::optional<std::string>& toUuid, const std::string& packageName,
         int32_t appId, const std::string& seInfo,
         int32_t targetSdkVersion, const std::string& fromCodePath) {
     ENFORCE_UID(AID_SYSTEM);
@@ -1210,7 +1249,7 @@
     return res;
 }
 
-binder::Status InstalldNativeService::createUserData(const std::unique_ptr<std::string>& uuid,
+binder::Status InstalldNativeService::createUserData(const std::optional<std::string>& uuid,
         int32_t userId, int32_t userSerial ATTRIBUTE_UNUSED, int32_t flags) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(uuid);
@@ -1228,7 +1267,7 @@
     return ok();
 }
 
-binder::Status InstalldNativeService::destroyUserData(const std::unique_ptr<std::string>& uuid,
+binder::Status InstalldNativeService::destroyUserData(const std::optional<std::string>& uuid,
         int32_t userId, int32_t flags) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(uuid);
@@ -1265,13 +1304,13 @@
     return res;
 }
 
-binder::Status InstalldNativeService::freeCache(const std::unique_ptr<std::string>& uuid,
+binder::Status InstalldNativeService::freeCache(const std::optional<std::string>& uuid,
         int64_t targetFreeBytes, int64_t cacheReservedBytes, int32_t flags) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(uuid);
     std::lock_guard<std::recursive_mutex> lock(mLock);
 
-    auto uuidString = uuid ? *uuid : "";
+    auto uuidString = uuid.value_or("");
     const char* uuid_ = uuid ? uuid->c_str() : nullptr;
     auto data_path = create_data_path(uuid_);
     auto noop = (flags & FLAG_FREE_CACHE_NOOP);
@@ -1669,7 +1708,7 @@
     fts_close(fts);
 }
 
-binder::Status InstalldNativeService::getAppSize(const std::unique_ptr<std::string>& uuid,
+binder::Status InstalldNativeService::getAppSize(const std::optional<std::string>& uuid,
         const std::vector<std::string>& packageNames, int32_t userId, int32_t flags,
         int32_t appId, const std::vector<int64_t>& ceDataInodes,
         const std::vector<std::string>& codePaths, std::vector<int64_t>* _aidl_return) {
@@ -1709,7 +1748,7 @@
     memset(&stats, 0, sizeof(stats));
     memset(&extStats, 0, sizeof(extStats));
 
-    auto uuidString = uuid ? *uuid : "";
+    auto uuidString = uuid.value_or("");
     const char* uuid_ = uuid ? uuid->c_str() : nullptr;
 
     if (!IsQuotaSupported(uuidString)) {
@@ -1896,7 +1935,7 @@
     return sizes;
 }
 
-binder::Status InstalldNativeService::getUserSize(const std::unique_ptr<std::string>& uuid,
+binder::Status InstalldNativeService::getUserSize(const std::optional<std::string>& uuid,
         int32_t userId, int32_t flags, const std::vector<int32_t>& appIds,
         std::vector<int64_t>* _aidl_return) {
     ENFORCE_UID(AID_SYSTEM);
@@ -1916,7 +1955,7 @@
     memset(&stats, 0, sizeof(stats));
     memset(&extStats, 0, sizeof(extStats));
 
-    auto uuidString = uuid ? *uuid : "";
+    auto uuidString = uuid.value_or("");
     const char* uuid_ = uuid ? uuid->c_str() : nullptr;
 
     if (!IsQuotaSupported(uuidString)) {
@@ -2028,7 +2067,7 @@
     return ok();
 }
 
-binder::Status InstalldNativeService::getExternalSize(const std::unique_ptr<std::string>& uuid,
+binder::Status InstalldNativeService::getExternalSize(const std::optional<std::string>& uuid,
         int32_t userId, int32_t flags, const std::vector<int32_t>& appIds,
         std::vector<int64_t>* _aidl_return) {
     ENFORCE_UID(AID_SYSTEM);
@@ -2043,7 +2082,7 @@
     LOG(INFO) << "Measuring external " << userId;
 #endif
 
-    auto uuidString = uuid ? *uuid : "";
+    auto uuidString = uuid.value_or("");
     const char* uuid_ = uuid ? uuid->c_str() : nullptr;
 
     int64_t totalSize = 0;
@@ -2145,9 +2184,9 @@
 }
 
 binder::Status InstalldNativeService::getAppCrates(
-        const std::unique_ptr<std::string>& uuid,
+        const std::optional<std::string>& uuid,
         const std::vector<std::string>& packageNames, int32_t userId,
-        std::unique_ptr<std::vector<std::unique_ptr<CrateMetadata>>>* _aidl_return) {
+        std::optional<std::vector<std::optional<CrateMetadata>>>* _aidl_return) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(uuid);
     for (const auto& packageName : packageNames) {
@@ -2156,15 +2195,15 @@
 #ifdef ENABLE_STORAGE_CRATES
     std::lock_guard<std::recursive_mutex> lock(mLock);
 
-    auto retVector = std::make_unique<std::vector<std::unique_ptr<CrateMetadata>>>();
+    auto retVector = std::vector<std::optional<CrateMetadata>>();
     const char* uuid_ = uuid ? uuid->c_str() : nullptr;
 
-    std::function<void(CratedFolder, std::unique_ptr<CrateMetadata> &)> onCreateCrate =
-            [&](CratedFolder cratedFolder, std::unique_ptr<CrateMetadata> &crateMetadata) -> void {
+    std::function<void(CratedFolder, CrateMetadata&&)> onCreateCrate =
+            [&](CratedFolder cratedFolder, CrateMetadata&& crateMetadata) -> void {
         if (cratedFolder == nullptr) {
             return;
         }
-        retVector->push_back(std::move(crateMetadata));
+        retVector.push_back(std::move(crateMetadata));
     };
 
     for (const auto& packageName : packageNames) {
@@ -2176,15 +2215,15 @@
     }
 
 #if CRATE_DEBUG
-    LOG(WARNING) << "retVector->size() =" << retVector->size();
-    for (auto iter = retVector->begin(); iter != retVector->end(); ++iter) {
-        CrateManager::dump(*iter);
+    LOG(WARNING) << "retVector.size() =" << retVector.size();
+    for (auto& item : retVector) {
+        CrateManager::dump(item);
     }
 #endif
 
     *_aidl_return = std::move(retVector);
 #else // ENABLE_STORAGE_CRATES
-    *_aidl_return = nullptr;
+    _aidl_return->reset();
 
     /* prevent compile warning fail */
     if (userId < 0) {
@@ -2195,18 +2234,18 @@
 }
 
 binder::Status InstalldNativeService::getUserCrates(
-        const std::unique_ptr<std::string>& uuid, int32_t userId,
-        std::unique_ptr<std::vector<std::unique_ptr<CrateMetadata>>>* _aidl_return) {
+        const std::optional<std::string>& uuid, int32_t userId,
+        std::optional<std::vector<std::optional<CrateMetadata>>>* _aidl_return) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(uuid);
 #ifdef ENABLE_STORAGE_CRATES
     std::lock_guard<std::recursive_mutex> lock(mLock);
 
     const char* uuid_ = uuid ? uuid->c_str() : nullptr;
-    auto retVector = std::make_unique<std::vector<std::unique_ptr<CrateMetadata>>>();
+    auto retVector = std::vector<std::optional<CrateMetadata>>();
 
-    std::function<void(CratedFolder, std::unique_ptr<CrateMetadata> &)> onCreateCrate =
-            [&](CratedFolder cratedFolder, std::unique_ptr<CrateMetadata> &crateMetadata) -> void {
+    std::function<void(CratedFolder, CrateMetadata&&)> onCreateCrate =
+            [&](CratedFolder cratedFolder, CrateMetadata&& crateMetadata) -> void {
         if (cratedFolder == nullptr) {
             return;
         }
@@ -2220,15 +2259,15 @@
     CrateManager::traverseAllPackagesForUser(uuid, userId, onHandingPackage);
 
 #if CRATE_DEBUG
-    LOG(DEBUG) << "retVector->size() =" << retVector->size();
-    for (auto iter = retVector->begin(); iter != retVector->end(); ++iter) {
-        CrateManager::dump(*iter);
+    LOG(DEBUG) << "retVector.size() =" << retVector.size();
+    for (auto& item : retVector) {
+        CrateManager::dump(item);
     }
 #endif
 
     *_aidl_return = std::move(retVector);
 #else // ENABLE_STORAGE_CRATES
-    *_aidl_return = nullptr;
+    _aidl_return->reset();
 
     /* prevent compile warning fail */
     if (userId < 0) {
@@ -2238,7 +2277,7 @@
     return ok();
 }
 
-binder::Status InstalldNativeService::setAppQuota(const std::unique_ptr<std::string>& uuid,
+binder::Status InstalldNativeService::setAppQuota(const std::optional<std::string>& uuid,
         int32_t userId, int32_t appId, int64_t cacheQuota) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(uuid);
@@ -2309,19 +2348,19 @@
     return ok();
 }
 
-static const char* getCStr(const std::unique_ptr<std::string>& data,
+static const char* getCStr(const std::optional<std::string>& data,
         const char* default_value = nullptr) {
-    return data == nullptr ? default_value : data->c_str();
+    return data ? data->c_str() : default_value;
 }
 binder::Status InstalldNativeService::dexopt(const std::string& apkPath, int32_t uid,
-        const std::unique_ptr<std::string>& packageName, const std::string& instructionSet,
-        int32_t dexoptNeeded, const std::unique_ptr<std::string>& outputPath, int32_t dexFlags,
-        const std::string& compilerFilter, const std::unique_ptr<std::string>& uuid,
-        const std::unique_ptr<std::string>& classLoaderContext,
-        const std::unique_ptr<std::string>& seInfo, bool downgrade, int32_t targetSdkVersion,
-        const std::unique_ptr<std::string>& profileName,
-        const std::unique_ptr<std::string>& dexMetadataPath,
-        const std::unique_ptr<std::string>& compilationReason) {
+        const std::optional<std::string>& packageName, const std::string& instructionSet,
+        int32_t dexoptNeeded, const std::optional<std::string>& outputPath, int32_t dexFlags,
+        const std::string& compilerFilter, const std::optional<std::string>& uuid,
+        const std::optional<std::string>& classLoaderContext,
+        const std::optional<std::string>& seInfo, bool downgrade, int32_t targetSdkVersion,
+        const std::optional<std::string>& profileName,
+        const std::optional<std::string>& dexMetadataPath,
+        const std::optional<std::string>& compilationReason) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(uuid);
     CHECK_ARGUMENT_PATH(apkPath);
@@ -2367,7 +2406,7 @@
 }
 
 binder::Status InstalldNativeService::linkNativeLibraryDirectory(
-        const std::unique_ptr<std::string>& uuid, const std::string& packageName,
+        const std::optional<std::string>& uuid, const std::string& packageName,
         const std::string& nativeLibPath32, int32_t userId) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(uuid);
@@ -2458,7 +2497,7 @@
     return res;
 }
 
-binder::Status InstalldNativeService::restoreconAppData(const std::unique_ptr<std::string>& uuid,
+binder::Status InstalldNativeService::restoreconAppData(const std::optional<std::string>& uuid,
         const std::string& packageName, int32_t userId, int32_t flags, int32_t appId,
         const std::string& seInfo) {
     ENFORCE_UID(AID_SYSTEM);
@@ -2576,7 +2615,7 @@
 }
 
 binder::Status InstalldNativeService::deleteOdex(const std::string& apkPath,
-        const std::string& instructionSet, const std::unique_ptr<std::string>& outputPath) {
+        const std::string& instructionSet, const std::optional<std::string>& outputPath) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_PATH(apkPath);
     CHECK_ARGUMENT_PATH(outputPath);
@@ -2728,7 +2767,7 @@
 
 binder::Status InstalldNativeService::reconcileSecondaryDexFile(
         const std::string& dexPath, const std::string& packageName, int32_t uid,
-        const std::vector<std::string>& isas, const std::unique_ptr<std::string>& volumeUuid,
+        const std::vector<std::string>& isas, const std::optional<std::string>& volumeUuid,
         int32_t storage_flag, bool* _aidl_return) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(volumeUuid);
@@ -2743,7 +2782,7 @@
 
 binder::Status InstalldNativeService::hashSecondaryDexFile(
         const std::string& dexPath, const std::string& packageName, int32_t uid,
-        const std::unique_ptr<std::string>& volumeUuid, int32_t storageFlag,
+        const std::optional<std::string>& volumeUuid, int32_t storageFlag,
         std::vector<uint8_t>* _aidl_return) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(volumeUuid);
@@ -2802,7 +2841,7 @@
 
 // Mount volume's CE and DE storage to mirror
 binder::Status InstalldNativeService::tryMountDataMirror(
-        const std::unique_ptr<std::string>& uuid) {
+        const std::optional<std::string>& uuid) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(uuid);
     if (!sAppDataIsolationEnabled) {
@@ -2866,7 +2905,7 @@
 
 // Unmount volume's CE and DE storage from mirror
 binder::Status InstalldNativeService::onPrivateVolumeRemoved(
-        const std::unique_ptr<std::string>& uuid) {
+        const std::optional<std::string>& uuid) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_UUID(uuid);
     if (!sAppDataIsolationEnabled) {
@@ -2910,7 +2949,7 @@
 }
 
 std::string InstalldNativeService::findDataMediaPath(
-        const std::unique_ptr<std::string>& uuid, userid_t userid) {
+        const std::optional<std::string>& uuid, userid_t userid) {
     std::lock_guard<std::recursive_mutex> lock(mMountsLock);
     const char* uuid_ = uuid ? uuid->c_str() : nullptr;
     auto path = StringPrintf("%s/media", create_data_path(uuid_).c_str());
@@ -2923,15 +2962,14 @@
 }
 
 binder::Status InstalldNativeService::isQuotaSupported(
-        const std::unique_ptr<std::string>& uuid, bool* _aidl_return) {
-    auto uuidString = uuid ? *uuid : "";
-    *_aidl_return = IsQuotaSupported(uuidString);
+        const std::optional<std::string>& uuid, bool* _aidl_return) {
+    *_aidl_return = IsQuotaSupported(uuid.value_or(""));
     return ok();
 }
 
 binder::Status InstalldNativeService::prepareAppProfile(const std::string& packageName,
         int32_t userId, int32_t appId, const std::string& profileName, const std::string& codePath,
-        const std::unique_ptr<std::string>& dexMetadata, bool* _aidl_return) {
+        const std::optional<std::string>& dexMetadata, bool* _aidl_return) {
     ENFORCE_UID(AID_SYSTEM);
     CHECK_ARGUMENT_PACKAGE_NAME(packageName);
     CHECK_ARGUMENT_PATH(codePath);
diff --git a/cmds/installd/InstalldNativeService.h b/cmds/installd/InstalldNativeService.h
index df01c3c..08be4d9 100644
--- a/cmds/installd/InstalldNativeService.h
+++ b/cmds/installd/InstalldNativeService.h
@@ -40,74 +40,76 @@
     static char const* getServiceName() { return "installd"; }
     virtual status_t dump(int fd, const Vector<String16> &args) override;
 
-    binder::Status createUserData(const std::unique_ptr<std::string>& uuid, int32_t userId,
+    binder::Status createUserData(const std::optional<std::string>& uuid, int32_t userId,
             int32_t userSerial, int32_t flags);
-    binder::Status destroyUserData(const std::unique_ptr<std::string>& uuid, int32_t userId,
+    binder::Status destroyUserData(const std::optional<std::string>& uuid, int32_t userId,
             int32_t flags);
 
-    binder::Status createAppData(const std::unique_ptr<std::string>& uuid,
+    binder::Status createAppData(const std::optional<std::string>& uuid,
             const std::string& packageName, int32_t userId, int32_t flags, int32_t appId,
             const std::string& seInfo, int32_t targetSdkVersion, int64_t* _aidl_return);
-    binder::Status restoreconAppData(const std::unique_ptr<std::string>& uuid,
+    binder::Status restoreconAppData(const std::optional<std::string>& uuid,
             const std::string& packageName, int32_t userId, int32_t flags, int32_t appId,
             const std::string& seInfo);
-    binder::Status migrateAppData(const std::unique_ptr<std::string>& uuid,
+    binder::Status migrateAppData(const std::optional<std::string>& uuid,
             const std::string& packageName, int32_t userId, int32_t flags);
-    binder::Status clearAppData(const std::unique_ptr<std::string>& uuid,
+    binder::Status clearAppData(const std::optional<std::string>& uuid,
             const std::string& packageName, int32_t userId, int32_t flags, int64_t ceDataInode);
-    binder::Status destroyAppData(const std::unique_ptr<std::string>& uuid,
+    binder::Status destroyAppData(const std::optional<std::string>& uuid,
             const std::string& packageName, int32_t userId, int32_t flags, int64_t ceDataInode);
 
-    binder::Status fixupAppData(const std::unique_ptr<std::string>& uuid, int32_t flags);
+    binder::Status fixupAppData(const std::optional<std::string>& uuid, int32_t flags);
 
-    binder::Status snapshotAppData(const std::unique_ptr<std::string>& volumeUuid,
+    binder::Status snapshotAppData(const std::optional<std::string>& volumeUuid,
             const std::string& packageName, const int32_t user, const int32_t snapshotId,
             int32_t storageFlags, int64_t* _aidl_return);
-    binder::Status restoreAppDataSnapshot(const std::unique_ptr<std::string>& volumeUuid,
+    binder::Status restoreAppDataSnapshot(const std::optional<std::string>& volumeUuid,
             const std::string& packageName, const int32_t appId, const std::string& seInfo,
             const int32_t user, const int32_t snapshotId, int32_t storageFlags);
-    binder::Status destroyAppDataSnapshot(const std::unique_ptr<std::string> &volumeUuid,
+    binder::Status destroyAppDataSnapshot(const std::optional<std::string> &volumeUuid,
             const std::string& packageName, const int32_t user, const int64_t ceSnapshotInode,
             const int32_t snapshotId, int32_t storageFlags);
+    binder::Status destroyCeSnapshotsNotSpecified(const std::optional<std::string> &volumeUuid,
+            const int32_t user, const std::vector<int32_t>& retainSnapshotIds);
 
-    binder::Status getAppSize(const std::unique_ptr<std::string>& uuid,
+    binder::Status getAppSize(const std::optional<std::string>& uuid,
             const std::vector<std::string>& packageNames, int32_t userId, int32_t flags,
             int32_t appId, const std::vector<int64_t>& ceDataInodes,
             const std::vector<std::string>& codePaths, std::vector<int64_t>* _aidl_return);
-    binder::Status getUserSize(const std::unique_ptr<std::string>& uuid,
+    binder::Status getUserSize(const std::optional<std::string>& uuid,
             int32_t userId, int32_t flags, const std::vector<int32_t>& appIds,
             std::vector<int64_t>* _aidl_return);
-    binder::Status getExternalSize(const std::unique_ptr<std::string>& uuid,
+    binder::Status getExternalSize(const std::optional<std::string>& uuid,
             int32_t userId, int32_t flags, const std::vector<int32_t>& appIds,
             std::vector<int64_t>* _aidl_return);
 
-    binder::Status getAppCrates(const std::unique_ptr<std::string>& uuid,
+    binder::Status getAppCrates(const std::optional<std::string>& uuid,
             const std::vector<std::string>& packageNames,
             int32_t userId,
-            std::unique_ptr<std::vector<std::unique_ptr<android::os::storage::CrateMetadata>>>*
+            std::optional<std::vector<std::optional<android::os::storage::CrateMetadata>>>*
                     _aidl_return);
     binder::Status getUserCrates(
-            const std::unique_ptr<std::string>& uuid, int32_t userId,
-            std::unique_ptr<std::vector<std::unique_ptr<android::os::storage::CrateMetadata>>>*
+            const std::optional<std::string>& uuid, int32_t userId,
+            std::optional<std::vector<std::optional<android::os::storage::CrateMetadata>>>*
                     _aidl_return);
 
-    binder::Status setAppQuota(const std::unique_ptr<std::string>& uuid,
+    binder::Status setAppQuota(const std::optional<std::string>& uuid,
             int32_t userId, int32_t appId, int64_t cacheQuota);
 
-    binder::Status moveCompleteApp(const std::unique_ptr<std::string>& fromUuid,
-            const std::unique_ptr<std::string>& toUuid, const std::string& packageName,
+    binder::Status moveCompleteApp(const std::optional<std::string>& fromUuid,
+            const std::optional<std::string>& toUuid, const std::string& packageName,
             int32_t appId, const std::string& seInfo,
             int32_t targetSdkVersion, const std::string& fromCodePath);
 
     binder::Status dexopt(const std::string& apkPath, int32_t uid,
-            const std::unique_ptr<std::string>& packageName, const std::string& instructionSet,
-            int32_t dexoptNeeded, const std::unique_ptr<std::string>& outputPath, int32_t dexFlags,
-            const std::string& compilerFilter, const std::unique_ptr<std::string>& uuid,
-            const std::unique_ptr<std::string>& classLoaderContext,
-            const std::unique_ptr<std::string>& seInfo, bool downgrade,
-            int32_t targetSdkVersion, const std::unique_ptr<std::string>& profileName,
-            const std::unique_ptr<std::string>& dexMetadataPath,
-            const std::unique_ptr<std::string>& compilationReason);
+            const std::optional<std::string>& packageName, const std::string& instructionSet,
+            int32_t dexoptNeeded, const std::optional<std::string>& outputPath, int32_t dexFlags,
+            const std::string& compilerFilter, const std::optional<std::string>& uuid,
+            const std::optional<std::string>& classLoaderContext,
+            const std::optional<std::string>& seInfo, bool downgrade,
+            int32_t targetSdkVersion, const std::optional<std::string>& profileName,
+            const std::optional<std::string>& dexMetadataPath,
+            const std::optional<std::string>& compilationReason);
 
     binder::Status compileLayouts(const std::string& apkPath, const std::string& packageName,
                                   const std::string& outDexFile, int uid, bool* _aidl_return);
@@ -130,9 +132,9 @@
             const std::string& profileName);
 
     binder::Status rmPackageDir(const std::string& packageDir);
-    binder::Status freeCache(const std::unique_ptr<std::string>& uuid, int64_t targetFreeBytes,
+    binder::Status freeCache(const std::optional<std::string>& uuid, int64_t targetFreeBytes,
             int64_t cacheReservedBytes, int32_t flags);
-    binder::Status linkNativeLibraryDirectory(const std::unique_ptr<std::string>& uuid,
+    binder::Status linkNativeLibraryDirectory(const std::optional<std::string>& uuid,
             const std::string& packageName, const std::string& nativeLibPath32, int32_t userId);
     binder::Status createOatDir(const std::string& oatDir, const std::string& instructionSet);
     binder::Status linkFile(const std::string& relativePath, const std::string& fromBase,
@@ -140,27 +142,27 @@
     binder::Status moveAb(const std::string& apkPath, const std::string& instructionSet,
             const std::string& outputPath);
     binder::Status deleteOdex(const std::string& apkPath, const std::string& instructionSet,
-            const std::unique_ptr<std::string>& outputPath);
+            const std::optional<std::string>& outputPath);
     binder::Status installApkVerity(const std::string& filePath,
             android::base::unique_fd verityInput, int32_t contentSize);
     binder::Status assertFsverityRootHashMatches(const std::string& filePath,
             const std::vector<uint8_t>& expectedHash);
     binder::Status reconcileSecondaryDexFile(const std::string& dexPath,
         const std::string& packageName, int32_t uid, const std::vector<std::string>& isa,
-        const std::unique_ptr<std::string>& volumeUuid, int32_t storage_flag, bool* _aidl_return);
+        const std::optional<std::string>& volumeUuid, int32_t storage_flag, bool* _aidl_return);
     binder::Status hashSecondaryDexFile(const std::string& dexPath,
-        const std::string& packageName, int32_t uid, const std::unique_ptr<std::string>& volumeUuid,
+        const std::string& packageName, int32_t uid, const std::optional<std::string>& volumeUuid,
         int32_t storageFlag, std::vector<uint8_t>* _aidl_return);
 
     binder::Status invalidateMounts();
-    binder::Status isQuotaSupported(const std::unique_ptr<std::string>& volumeUuid,
+    binder::Status isQuotaSupported(const std::optional<std::string>& volumeUuid,
             bool* _aidl_return);
-    binder::Status tryMountDataMirror(const std::unique_ptr<std::string>& volumeUuid);
-    binder::Status onPrivateVolumeRemoved(const std::unique_ptr<std::string>& volumeUuid);
+    binder::Status tryMountDataMirror(const std::optional<std::string>& volumeUuid);
+    binder::Status onPrivateVolumeRemoved(const std::optional<std::string>& volumeUuid);
 
     binder::Status prepareAppProfile(const std::string& packageName,
             int32_t userId, int32_t appId, const std::string& profileName,
-            const std::string& codePath, const std::unique_ptr<std::string>& dexMetadata,
+            const std::string& codePath, const std::optional<std::string>& dexMetadata,
             bool* _aidl_return);
 
     binder::Status migrateLegacyObbData();
@@ -177,7 +179,7 @@
     /* Map from UID to cache quota size */
     std::unordered_map<uid_t, int64_t> mCacheQuotas;
 
-    std::string findDataMediaPath(const std::unique_ptr<std::string>& uuid, userid_t userid);
+    std::string findDataMediaPath(const std::optional<std::string>& uuid, userid_t userid);
 };
 
 }  // namespace installd
diff --git a/cmds/installd/binder/android/os/IInstalld.aidl b/cmds/installd/binder/android/os/IInstalld.aidl
index ca95cb3..e188807 100644
--- a/cmds/installd/binder/android/os/IInstalld.aidl
+++ b/cmds/installd/binder/android/os/IInstalld.aidl
@@ -114,6 +114,8 @@
             int userId, int snapshotId, int storageFlags);
     void restoreAppDataSnapshot(@nullable @utf8InCpp String uuid, in @utf8InCpp String packageName,
             int appId, @utf8InCpp String seInfo, int user, int snapshotId, int storageflags);
+    void destroyCeSnapshotsNotSpecified(@nullable @utf8InCpp String uuid, int userId,
+            in int[] retainSnapshotIds);
     void destroyAppDataSnapshot(@nullable @utf8InCpp String uuid, @utf8InCpp String packageName,
             int userId, long ceSnapshotInode, int snapshotId, int storageFlags);
     void tryMountDataMirror(@nullable @utf8InCpp String volumeUuid);
diff --git a/cmds/installd/dexopt.cpp b/cmds/installd/dexopt.cpp
index 1af6edd..5e87faf 100644
--- a/cmds/installd/dexopt.cpp
+++ b/cmds/installd/dexopt.cpp
@@ -2272,7 +2272,7 @@
 //   out_secondary_dex_exists will be set to false.
 bool reconcile_secondary_dex_file(const std::string& dex_path,
         const std::string& pkgname, int uid, const std::vector<std::string>& isas,
-        const std::unique_ptr<std::string>& volume_uuid, int storage_flag,
+        const std::optional<std::string>& volume_uuid, int storage_flag,
         /*out*/bool* out_secondary_dex_exists) {
     *out_secondary_dex_exists = false;  // start by assuming the file does not exist.
     if (isas.size() == 0) {
@@ -2293,7 +2293,7 @@
         /* child -- drop privileges before continuing */
         drop_capabilities(uid);
 
-        const char* volume_uuid_cstr = volume_uuid == nullptr ? nullptr : volume_uuid->c_str();
+        const char* volume_uuid_cstr = volume_uuid ? volume_uuid->c_str() : nullptr;
         if (!validate_secondary_dex_path(pkgname, dex_path, volume_uuid_cstr,
                 uid, storage_flag)) {
             LOG(ERROR) << "Could not validate secondary dex path " << dex_path;
@@ -2394,11 +2394,11 @@
 // the app.
 // For any other errors (e.g. if any of the parameters are invalid) returns false.
 bool hash_secondary_dex_file(const std::string& dex_path, const std::string& pkgname, int uid,
-        const std::unique_ptr<std::string>& volume_uuid, int storage_flag,
+        const std::optional<std::string>& volume_uuid, int storage_flag,
         std::vector<uint8_t>* out_secondary_dex_hash) {
     out_secondary_dex_hash->clear();
 
-    const char* volume_uuid_cstr = volume_uuid == nullptr ? nullptr : volume_uuid->c_str();
+    const char* volume_uuid_cstr = volume_uuid ? volume_uuid->c_str() : nullptr;
 
     if (storage_flag != FLAG_STORAGE_CE && storage_flag != FLAG_STORAGE_DE) {
         LOG(ERROR) << "hash_secondary_dex_file called with invalid storage_flag: "
@@ -2919,7 +2919,7 @@
                          appid_t app_id,
                          const std::string& profile_name,
                          const std::string& code_path,
-                         const std::unique_ptr<std::string>& dex_metadata) {
+                         const std::optional<std::string>& dex_metadata) {
     // Prepare the current profile.
     std::string cur_profile  = create_current_profile_path(user_id, package_name, profile_name,
             /*is_secondary_dex*/ false);
@@ -2930,7 +2930,7 @@
     }
 
     // Check if we need to install the profile from the dex metadata.
-    if (dex_metadata == nullptr) {
+    if (!dex_metadata) {
         return true;
     }
 
diff --git a/cmds/installd/dexopt.h b/cmds/installd/dexopt.h
index ef739ba..92b13c7 100644
--- a/cmds/installd/dexopt.h
+++ b/cmds/installd/dexopt.h
@@ -21,6 +21,8 @@
 
 #include <sys/types.h>
 
+#include <optional>
+
 #include <cutils/multiuser.h>
 
 namespace android {
@@ -98,17 +100,17 @@
                          appid_t app_id,
                          const std::string& profile_name,
                          const std::string& code_path,
-                         const std::unique_ptr<std::string>& dex_metadata);
+                         const std::optional<std::string>& dex_metadata);
 
 bool delete_odex(const char* apk_path, const char* instruction_set, const char* output_path);
 
 bool reconcile_secondary_dex_file(const std::string& dex_path,
         const std::string& pkgname, int uid, const std::vector<std::string>& isas,
-        const std::unique_ptr<std::string>& volumeUuid, int storage_flag,
+        const std::optional<std::string>& volumeUuid, int storage_flag,
         /*out*/bool* out_secondary_dex_exists);
 
 bool hash_secondary_dex_file(const std::string& dex_path,
-        const std::string& pkgname, int uid, const std::unique_ptr<std::string>& volume_uuid,
+        const std::string& pkgname, int uid, const std::optional<std::string>& volume_uuid,
         int storage_flag, std::vector<uint8_t>* out_secondary_dex_hash);
 
 int dexopt(const char *apk_path, uid_t uid, const char *pkgName, const char *instruction_set,
diff --git a/cmds/installd/tests/installd_cache_test.cpp b/cmds/installd/tests/installd_cache_test.cpp
index 5a5cb53..863cdfe 100644
--- a/cmds/installd/tests/installd_cache_test.cpp
+++ b/cmds/installd/tests/installd_cache_test.cpp
@@ -114,15 +114,14 @@
 class CacheTest : public testing::Test {
 protected:
     InstalldNativeService* service;
-    std::unique_ptr<std::string> testUuid;
+    std::optional<std::string> testUuid;
 
     virtual void SetUp() {
         setenv("ANDROID_LOG_TAGS", "*:v", 1);
         android::base::InitLogging(nullptr);
 
         service = new InstalldNativeService();
-        testUuid = std::make_unique<std::string>();
-        *testUuid = std::string(kTestUuid);
+        testUuid = kTestUuid;
         system("mkdir -p /data/local/tmp/user/0");
     }
 
diff --git a/cmds/installd/tests/installd_dexopt_test.cpp b/cmds/installd/tests/installd_dexopt_test.cpp
index 69fefa1..7d8cf1f 100644
--- a/cmds/installd/tests/installd_dexopt_test.cpp
+++ b/cmds/installd/tests/installd_dexopt_test.cpp
@@ -193,7 +193,7 @@
     const uid_t kTestAppGid = multiuser_get_shared_gid(kTestUserId, kTestAppId);
 
     InstalldNativeService* service_;
-    std::unique_ptr<std::string> volume_uuid_;
+    std::optional<std::string> volume_uuid_;
     std::string package_name_;
     std::string apk_path_;
     std::string empty_dm_file_;
@@ -221,7 +221,7 @@
         ASSERT_TRUE(init_selinux());
         service_ = new InstalldNativeService();
 
-        volume_uuid_ = nullptr;
+        volume_uuid_ = std::nullopt;
         package_name_ = "com.installd.test.dexopt";
         se_info_ = "default";
         app_apk_dir_ = android_app_dir + package_name_;
@@ -294,7 +294,7 @@
         }
 
         // Create a secondary dex file on CE storage
-        const char* volume_uuid_cstr = volume_uuid_ == nullptr ? nullptr : volume_uuid_->c_str();
+        const char* volume_uuid_cstr = volume_uuid_ ? volume_uuid_->c_str() : nullptr;
         app_private_dir_ce_ = create_data_user_ce_package_path(
                 volume_uuid_cstr, kTestUserId, package_name_.c_str());
         secondary_dex_ce_ = app_private_dir_ce_ + "/secondary_ce.jar";
@@ -353,36 +353,32 @@
         if (class_loader_context == nullptr) {
             class_loader_context = "&";
         }
-        std::unique_ptr<std::string> package_name_ptr(new std::string(package_name_));
         int32_t dexopt_needed = 0;  // does not matter;
-        std::unique_ptr<std::string> out_path = nullptr;  // does not matter
+        std::optional<std::string> out_path; // does not matter
         int32_t dex_flags = DEXOPT_SECONDARY_DEX | dex_storage_flag;
         std::string compiler_filter = "speed-profile";
-        std::unique_ptr<std::string> class_loader_context_ptr(
-                new std::string(class_loader_context));
-        std::unique_ptr<std::string> se_info_ptr(new std::string(se_info_));
         bool downgrade = false;
         int32_t target_sdk_version = 0;  // default
-        std::unique_ptr<std::string> profile_name_ptr = nullptr;
-        std::unique_ptr<std::string> dm_path_ptr = nullptr;
-        std::unique_ptr<std::string> compilation_reason_ptr = nullptr;
+        std::optional<std::string> profile_name;
+        std::optional<std::string> dm_path;
+        std::optional<std::string> compilation_reason;
 
         binder::Status result = service_->dexopt(path,
                                                  uid,
-                                                 package_name_ptr,
+                                                 package_name_,
                                                  kRuntimeIsa,
                                                  dexopt_needed,
                                                  out_path,
                                                  dex_flags,
                                                  compiler_filter,
                                                  volume_uuid_,
-                                                 class_loader_context_ptr,
-                                                 se_info_ptr,
+                                                 class_loader_context,
+                                                 se_info_,
                                                  downgrade,
                                                  target_sdk_version,
-                                                 profile_name_ptr,
-                                                 dm_path_ptr,
-                                                 compilation_reason_ptr);
+                                                 profile_name,
+                                                 dm_path,
+                                                 compilation_reason);
         ASSERT_EQ(should_binder_call_succeed, result.isOk()) << result.toString8().c_str();
         int expected_access = should_dex_be_compiled ? 0 : -1;
         std::string odex = GetSecondaryDexArtifact(path, "odex");
@@ -481,41 +477,35 @@
                            bool downgrade,
                            bool should_binder_call_succeed,
                            /*out */ binder::Status* binder_result) {
-        std::unique_ptr<std::string> package_name_ptr(new std::string(package_name_));
-        std::unique_ptr<std::string> out_path(
-                oat_dir == nullptr ? nullptr : new std::string(oat_dir));
-        std::unique_ptr<std::string> class_loader_context_ptr(new std::string("&"));
-        std::unique_ptr<std::string> se_info_ptr(new std::string(se_info_));
+        std::optional<std::string> out_path = oat_dir ? std::make_optional<std::string>(oat_dir) : std::nullopt;
+        std::string class_loader_context = "&";
         int32_t target_sdk_version = 0;  // default
-        std::unique_ptr<std::string> profile_name_ptr(new std::string("primary.prof"));
-        std::unique_ptr<std::string> dm_path_ptr = nullptr;
-        if (dm_path != nullptr) {
-            dm_path_ptr.reset(new std::string(dm_path));
-        }
-        std::unique_ptr<std::string> compilation_reason_ptr(new std::string("test-reason"));
+        std::string profile_name = "primary.prof";
+        std::optional<std::string> dm_path_opt = dm_path ? std::make_optional<std::string>(dm_path) : std::nullopt;
+        std::string compilation_reason = "test-reason";
 
         bool prof_result;
         ASSERT_BINDER_SUCCESS(service_->prepareAppProfile(
-                package_name_, kTestUserId, kTestAppId, *profile_name_ptr, apk_path_,
-                dm_path_ptr, &prof_result));
+                package_name_, kTestUserId, kTestAppId, profile_name, apk_path_,
+                dm_path_opt, &prof_result));
         ASSERT_TRUE(prof_result);
 
         binder::Status result = service_->dexopt(apk_path_,
                                                  uid,
-                                                 package_name_ptr,
+                                                 package_name_,
                                                  kRuntimeIsa,
                                                  dexopt_needed,
                                                  out_path,
                                                  dex_flags,
                                                  compiler_filter,
                                                  volume_uuid_,
-                                                 class_loader_context_ptr,
-                                                 se_info_ptr,
+                                                 class_loader_context,
+                                                 se_info_,
                                                  downgrade,
                                                  target_sdk_version,
-                                                 profile_name_ptr,
-                                                 dm_path_ptr,
-                                                 compilation_reason_ptr);
+                                                 profile_name,
+                                                 dm_path_opt,
+                                                 compilation_reason);
         ASSERT_EQ(should_binder_call_succeed, result.isOk()) << result.toString8().c_str();
 
         if (!should_binder_call_succeed) {
@@ -953,7 +943,7 @@
         bool result;
         ASSERT_BINDER_SUCCESS(service_->prepareAppProfile(
                 package_name, kTestUserId, kTestAppId, profile_name, apk_path_,
-                /*dex_metadata*/ nullptr, &result));
+                /*dex_metadata*/ {}, &result));
         ASSERT_EQ(expected_result, result);
 
         if (!expected_result) {
diff --git a/cmds/installd/tests/installd_service_test.cpp b/cmds/installd/tests/installd_service_test.cpp
index a31d510..1e7559d 100644
--- a/cmds/installd/tests/installd_service_test.cpp
+++ b/cmds/installd/tests/installd_service_test.cpp
@@ -99,15 +99,14 @@
 class ServiceTest : public testing::Test {
 protected:
     InstalldNativeService* service;
-    std::unique_ptr<std::string> testUuid;
+    std::optional<std::string> testUuid;
 
     virtual void SetUp() {
         setenv("ANDROID_LOG_TAGS", "*:v", 1);
         android::base::InitLogging(nullptr);
 
         service = new InstalldNativeService();
-        testUuid = std::make_unique<std::string>();
-        *testUuid = std::string(kTestUuid);
+        testUuid = kTestUuid;
         system("mkdir -p /data/local/tmp/user/0");
 
         init_globals_from_data_and_root();
@@ -322,7 +321,7 @@
 
   // Request a snapshot of the CE content but not the DE content.
   int64_t ce_snapshot_inode;
-  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_unique<std::string>("TEST"),
+  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_optional<std::string>("TEST"),
           "com.foo", 0, 37, FLAG_STORAGE_CE, &ce_snapshot_inode));
   struct stat buf;
   memset(&buf, 0, sizeof(buf));
@@ -344,7 +343,7 @@
           0700, 10000, 20000, false /* follow_symlinks */));
 
   // Request a snapshot of the DE content but not the CE content.
-  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_unique<std::string>("TEST"),
+  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_optional<std::string>("TEST"),
           "com.foo", 0, 37, FLAG_STORAGE_DE, &ce_snapshot_inode));
   // Only DE content snapshot was requested.
   ASSERT_EQ(ce_snapshot_inode, 0);
@@ -365,7 +364,7 @@
           0700, 10000, 20000, false /* follow_symlinks */));
 
   // Request a snapshot of both the CE as well as the DE content.
-  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_unique<std::string>("TEST"),
+  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_optional<std::string>("TEST"),
           "com.foo", 0, 37, FLAG_STORAGE_DE | FLAG_STORAGE_CE, nullptr));
 
   ASSERT_TRUE(android::base::ReadFileToString(
@@ -407,10 +406,10 @@
           0700, 10000, 20000, false /* follow_symlinks */));
 
   // Request snapshot for the package com.foo.
-  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_unique<std::string>("TEST"),
+  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_optional<std::string>("TEST"),
           "com.foo", 0, 67, FLAG_STORAGE_DE | FLAG_STORAGE_CE, nullptr));
   // Now request snapshot with the same id for the package com.bar
-  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_unique<std::string>("TEST"),
+  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_optional<std::string>("TEST"),
           "com.bar", 0, 67, FLAG_STORAGE_DE | FLAG_STORAGE_CE, nullptr));
 
   // Check that both snapshots have correct data in them.
@@ -439,9 +438,9 @@
   ASSERT_EQ(0, delete_dir_contents_and_dir(fake_package_de_path, true));
 
   int64_t ce_snapshot_inode;
-  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_unique<std::string>("TEST"),
+  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_optional<std::string>("TEST"),
           "com.foo", 0, 73, FLAG_STORAGE_CE, &ce_snapshot_inode));
-  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_unique<std::string>("TEST"),
+  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_optional<std::string>("TEST"),
           "com.foo", 0, 73, FLAG_STORAGE_DE, nullptr));
   // No CE content snapshot was performed.
   ASSERT_EQ(ce_snapshot_inode, 0);
@@ -476,7 +475,7 @@
           "TEST_CONTENT_2_DE", fake_package_de_path + "/file2",
           0700, 10000, 20000, false /* follow_symlinks */));
 
-  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_unique<std::string>("TEST"),
+  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_optional<std::string>("TEST"),
           "com.foo", 0, 13, FLAG_STORAGE_DE | FLAG_STORAGE_CE, nullptr));
 
   // Previous snapshot (with data for file1) must be cleared.
@@ -497,7 +496,7 @@
   ASSERT_TRUE(mkdirs(rollback_ce_dir, 0700));
   ASSERT_TRUE(mkdirs(rollback_de_dir, 0700));
 
-  EXPECT_BINDER_FAIL(service->snapshotAppData(std::make_unique<std::string>("FOO"),
+  EXPECT_BINDER_FAIL(service->snapshotAppData(std::make_optional<std::string>("FOO"),
           "com.foo", 0, 17, FLAG_STORAGE_DE, nullptr));
 }
 
@@ -524,7 +523,7 @@
   ASSERT_TRUE(android::base::WriteStringToFile(
           "TEST_CONTENT_DE", fake_package_de_code_cache_path + "/file1",
           0700, 10000, 20000, false /* follow_symlinks */));
-  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_unique<std::string>("TEST"),
+  ASSERT_BINDER_SUCCESS(service->snapshotAppData(std::make_optional<std::string>("TEST"),
           "com.foo", 0, 23, FLAG_STORAGE_CE | FLAG_STORAGE_DE, nullptr));
   // The snapshot call must clear cache.
   struct stat sb;
@@ -558,7 +557,7 @@
           "TEST_CONTENT_DE", fake_package_de_path + "/file1",
           0700, 10000, 20000, false /* follow_symlinks */));
 
-  ASSERT_BINDER_SUCCESS(service->restoreAppDataSnapshot(std::make_unique<std::string>("TEST"),
+  ASSERT_BINDER_SUCCESS(service->restoreAppDataSnapshot(std::make_optional<std::string>("TEST"),
           "com.foo", 10000, "", 0, 239, FLAG_STORAGE_DE | FLAG_STORAGE_CE));
 
   std::string ce_content, de_content;
@@ -584,7 +583,7 @@
 
   int64_t ce_snapshot_inode;
   // Request a snapshot of both the CE as well as the DE content.
-  ASSERT_TRUE(service->snapshotAppData(std::make_unique<std::string>("TEST"),
+  ASSERT_TRUE(service->snapshotAppData(std::make_optional<std::string>("TEST"),
           "com.foo", 0, 57, FLAG_STORAGE_DE | FLAG_STORAGE_CE, &ce_snapshot_inode).isOk());
   // Because CE data snapshot was requested, ce_snapshot_inode can't be null.
   ASSERT_NE(0, ce_snapshot_inode);
@@ -594,7 +593,7 @@
   ASSERT_EQ(0, stat((rollback_de_dir + "/com.foo").c_str(), &sb));
 
 
-  ASSERT_TRUE(service->destroyAppDataSnapshot(std::make_unique<std::string>("TEST"),
+  ASSERT_TRUE(service->destroyAppDataSnapshot(std::make_optional<std::string>("TEST"),
           "com.foo", 0, ce_snapshot_inode, 57, FLAG_STORAGE_DE | FLAG_STORAGE_CE).isOk());
   // Check snapshot is deleted.
   ASSERT_EQ(-1, stat((rollback_ce_dir + "/com.foo").c_str(), &sb));
@@ -615,7 +614,7 @@
           "DE_RESTORE_CONTENT", rollback_de_dir + "/com.foo/file1",
           0700, 10000, 20000, false /* follow_symlinks */));
 
-  ASSERT_TRUE(service->destroyAppDataSnapshot(std::make_unique<std::string>("TEST"),
+  ASSERT_TRUE(service->destroyAppDataSnapshot(std::make_optional<std::string>("TEST"),
           "com.foo", 0, 0, 1543, FLAG_STORAGE_DE | FLAG_STORAGE_CE).isOk());
 
   // Check snapshot is deleted.
@@ -624,7 +623,7 @@
   ASSERT_EQ(-1, stat((rollback_de_dir + "/com.foo").c_str(), &sb));
 
   // Check that deleting already deleted snapshot is no-op.
-  ASSERT_TRUE(service->destroyAppDataSnapshot(std::make_unique<std::string>("TEST"),
+  ASSERT_TRUE(service->destroyAppDataSnapshot(std::make_optional<std::string>("TEST"),
           "com.foo", 0, 0, 1543, FLAG_STORAGE_DE | FLAG_STORAGE_CE).isOk());
 }
 
@@ -637,10 +636,50 @@
   ASSERT_TRUE(mkdirs(rollback_ce_dir, 0700));
   ASSERT_TRUE(mkdirs(rollback_de_dir, 0700));
 
-  ASSERT_FALSE(service->destroyAppDataSnapshot(std::make_unique<std::string>("BAR"),
+  ASSERT_FALSE(service->destroyAppDataSnapshot(std::make_optional<std::string>("BAR"),
           "com.foo", 0, 0, 43, FLAG_STORAGE_DE).isOk());
 }
 
+TEST_F(AppDataSnapshotTest, DestroyCeSnapshotsNotSpecified) {
+  auto rollback_ce_dir_in_1 = create_data_misc_ce_rollback_path("TEST", 0, 1543);
+  auto rollback_ce_dir_in_2 = create_data_misc_ce_rollback_path("TEST", 0, 77);
+  auto rollback_ce_dir_out_1 = create_data_misc_ce_rollback_path("TEST", 0, 1500);
+  auto rollback_ce_dir_out_2 = create_data_misc_ce_rollback_path("TEST", 0, 2);
+
+  // Create snapshots
+  ASSERT_TRUE(mkdirs(rollback_ce_dir_in_1 + "/com.foo/", 0700));
+  ASSERT_TRUE(android::base::WriteStringToFile(
+          "CE_RESTORE_CONTENT", rollback_ce_dir_in_1 + "/com.foo/file1",
+          0700, 10000, 20000, false /* follow_symlinks */));
+
+  ASSERT_TRUE(mkdirs(rollback_ce_dir_in_2 + "/com.foo/", 0700));
+  ASSERT_TRUE(android::base::WriteStringToFile(
+          "CE_RESTORE_CONTENT", rollback_ce_dir_in_2 + "/com.foo/file1",
+          0700, 10000, 20000, false /* follow_symlinks */));
+
+  ASSERT_TRUE(mkdirs(rollback_ce_dir_out_1 + "/com.foo/", 0700));
+  ASSERT_TRUE(android::base::WriteStringToFile(
+          "CE_RESTORE_CONTENT", rollback_ce_dir_out_1 + "/com.foo/file1",
+          0700, 10000, 20000, false /* follow_symlinks */));
+
+  ASSERT_TRUE(mkdirs(rollback_ce_dir_out_2 + "/com.foo/", 0700));
+  ASSERT_TRUE(android::base::WriteStringToFile(
+          "CE_RESTORE_CONTENT", rollback_ce_dir_out_2 + "/com.foo/file1",
+          0700, 10000, 20000, false /* follow_symlinks */));
+
+  ASSERT_TRUE(service->destroyCeSnapshotsNotSpecified(
+          std::make_optional<std::string>("TEST"), 0, { 1543, 77 }).isOk());
+
+  // Check only snapshots not specified are deleted.
+  struct stat sb;
+  ASSERT_EQ(0, stat((rollback_ce_dir_in_1 + "/com.foo").c_str(), &sb));
+  ASSERT_EQ(0, stat((rollback_ce_dir_in_2 + "/com.foo").c_str(), &sb));
+  ASSERT_EQ(-1, stat((rollback_ce_dir_out_1 + "/com.foo").c_str(), &sb));
+  ASSERT_EQ(ENOENT, errno);
+  ASSERT_EQ(-1, stat((rollback_ce_dir_out_2 + "/com.foo").c_str(), &sb));
+  ASSERT_EQ(ENOENT, errno);
+}
+
 TEST_F(AppDataSnapshotTest, RestoreAppDataSnapshot_WrongVolumeUuid) {
   // Setup rollback data to make sure that fails due to wrong volumeUuid being
   // passed, not because of some other reason.
@@ -650,7 +689,7 @@
   ASSERT_TRUE(mkdirs(rollback_ce_dir, 0700));
   ASSERT_TRUE(mkdirs(rollback_de_dir, 0700));
 
-  EXPECT_BINDER_FAIL(service->restoreAppDataSnapshot(std::make_unique<std::string>("BAR"),
+  EXPECT_BINDER_FAIL(service->restoreAppDataSnapshot(std::make_optional<std::string>("BAR"),
           "com.foo", 10000, "", 0, 41, FLAG_STORAGE_DE));
 }
 
diff --git a/libs/binder/Android.bp b/libs/binder/Android.bp
index e6cfeb4..bc241bf 100644
--- a/libs/binder/Android.bp
+++ b/libs/binder/Android.bp
@@ -73,9 +73,9 @@
     // or dessert updates. Instead, apex users should use libbinder_ndk.
     apex_available: [
         "//apex_available:platform",
-        // TODO(b/139016109) remove these three
+        // TODO(b/139016109) remove these
+        "com.android.media",
         "com.android.media.swcodec",
-        "test_com.android.media.swcodec",
     ],
 
     srcs: [
diff --git a/libs/binder/AppOpsManager.cpp b/libs/binder/AppOpsManager.cpp
index 2174ce2..1c6b491 100644
--- a/libs/binder/AppOpsManager.cpp
+++ b/libs/binder/AppOpsManager.cpp
@@ -91,12 +91,12 @@
 }
 
 int32_t AppOpsManager::noteOp(int32_t op, int32_t uid, const String16& callingPackage) {
-    return noteOp(op, uid, callingPackage, std::unique_ptr<String16>(),
+    return noteOp(op, uid, callingPackage, {},
             String16("Legacy AppOpsManager.noteOp call"));
 }
 
 int32_t AppOpsManager::noteOp(int32_t op, int32_t uid, const String16& callingPackage,
-        const std::unique_ptr<String16>& attributionTag, const String16& message) {
+        const std::optional<String16>& attributionTag, const String16& message) {
     sp<IAppOpsService> service = getService();
     int32_t mode = service != nullptr
             ? service->noteOperation(op, uid, callingPackage, attributionTag,
@@ -108,12 +108,12 @@
 
 int32_t AppOpsManager::startOpNoThrow(int32_t op, int32_t uid, const String16& callingPackage,
         bool startIfModeDefault) {
-    return startOpNoThrow(op, uid, callingPackage, startIfModeDefault, std::unique_ptr<String16>(),
+    return startOpNoThrow(op, uid, callingPackage, startIfModeDefault, {},
             String16("Legacy AppOpsManager.startOpNoThrow call"));
 }
 
 int32_t AppOpsManager::startOpNoThrow(int32_t op, int32_t uid, const String16& callingPackage,
-        bool startIfModeDefault, const std::unique_ptr<String16>& attributionTag,
+        bool startIfModeDefault, const std::optional<String16>& attributionTag,
         const String16& message) {
     sp<IAppOpsService> service = getService();
     int32_t mode = service != nullptr
@@ -125,11 +125,11 @@
 }
 
 void AppOpsManager::finishOp(int32_t op, int32_t uid, const String16& callingPackage) {
-    finishOp(op, uid, callingPackage, std::unique_ptr<String16>());
+    finishOp(op, uid, callingPackage, {});
 }
 
 void AppOpsManager::finishOp(int32_t op, int32_t uid, const String16& callingPackage,
-        const std::unique_ptr<String16>& attributionTag) {
+        const std::optional<String16>& attributionTag) {
     sp<IAppOpsService> service = getService();
     if (service != nullptr) {
         service->finishOperation(getClientId(), op, uid, callingPackage, attributionTag);
diff --git a/libs/binder/IAppOpsService.cpp b/libs/binder/IAppOpsService.cpp
index 0714723..cd78866 100644
--- a/libs/binder/IAppOpsService.cpp
+++ b/libs/binder/IAppOpsService.cpp
@@ -22,6 +22,8 @@
 #include <binder/Parcel.h>
 #include <utils/String8.h>
 
+#include <optional>
+
 namespace android {
 
 // ----------------------------------------------------------------------
@@ -47,7 +49,7 @@
     }
 
     virtual int32_t noteOperation(int32_t code, int32_t uid, const String16& packageName,
-                const std::unique_ptr<String16>& attributionTag, bool shouldCollectAsyncNotedOp,
+                const std::optional<String16>& attributionTag, bool shouldCollectAsyncNotedOp,
                 const String16& message) {
         Parcel data, reply;
         data.writeInterfaceToken(IAppOpsService::getInterfaceDescriptor());
@@ -64,7 +66,7 @@
     }
 
     virtual int32_t startOperation(const sp<IBinder>& token, int32_t code, int32_t uid,
-                const String16& packageName, const std::unique_ptr<String16>& attributionTag,
+                const String16& packageName, const std::optional<String16>& attributionTag,
                 bool startIfModeDefault, bool shouldCollectAsyncNotedOp, const String16& message) {
         Parcel data, reply;
         data.writeInterfaceToken(IAppOpsService::getInterfaceDescriptor());
@@ -83,7 +85,7 @@
     }
 
     virtual void finishOperation(const sp<IBinder>& token, int32_t code, int32_t uid,
-            const String16& packageName, const std::unique_ptr<String16>& attributionTag) {
+            const String16& packageName, const std::optional<String16>& attributionTag) {
         Parcel data, reply;
         data.writeInterfaceToken(IAppOpsService::getInterfaceDescriptor());
         data.writeStrongBinder(token);
@@ -182,7 +184,7 @@
             int32_t code = data.readInt32();
             int32_t uid = data.readInt32();
             String16 packageName = data.readString16();
-            std::unique_ptr<String16> attributionTag;
+            std::optional<String16> attributionTag;
             data.readString16(&attributionTag);
             bool shouldCollectAsyncNotedOp = data.readInt32() == 1;
             String16 message = data.readString16();
@@ -198,7 +200,7 @@
             int32_t code = data.readInt32();
             int32_t uid = data.readInt32();
             String16 packageName = data.readString16();
-            std::unique_ptr<String16> attributionTag;
+            std::optional<String16> attributionTag;
             data.readString16(&attributionTag);
             bool startIfModeDefault = data.readInt32() == 1;
             bool shouldCollectAsyncNotedOp = data.readInt32() == 1;
@@ -215,7 +217,7 @@
             int32_t code = data.readInt32();
             int32_t uid = data.readInt32();
             String16 packageName = data.readString16();
-            std::unique_ptr<String16> attributionTag;
+            std::optional<String16> attributionTag;
             data.readString16(&attributionTag);
             finishOperation(token, code, uid, packageName, attributionTag);
             reply->writeNoException();
diff --git a/libs/binder/IMemory.cpp b/libs/binder/IMemory.cpp
index c2bb811..d8b44f9 100644
--- a/libs/binder/IMemory.cpp
+++ b/libs/binder/IMemory.cpp
@@ -82,10 +82,10 @@
     explicit BpMemoryHeap(const sp<IBinder>& impl);
     virtual ~BpMemoryHeap();
 
-    virtual int getHeapID() const;
-    virtual void* getBase() const;
-    virtual size_t getSize() const;
-    virtual uint32_t getFlags() const;
+    int getHeapID() const override;
+    void* getBase() const override;
+    size_t getSize() const override;
+    uint32_t getFlags() const override;
     off_t getOffset() const override;
 
 private:
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index beab270..5f1f682 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -751,6 +751,13 @@
     return NO_ERROR;
 }
 
+status_t Parcel::writeUtf8AsUtf16(const std::optional<std::string>& str) {
+  if (!str) {
+    return writeInt32(-1);
+  }
+  return writeUtf8AsUtf16(*str);
+}
+
 status_t Parcel::writeUtf8AsUtf16(const std::unique_ptr<std::string>& str) {
   if (!str) {
     return writeInt32(-1);
@@ -775,6 +782,12 @@
     return writeByteVectorInternal(val.data(), val.size());
 }
 
+status_t Parcel::writeByteVector(const std::optional<std::vector<int8_t>>& val)
+{
+    if (!val) return writeInt32(-1);
+    return writeByteVectorInternal(val->data(), val->size());
+}
+
 status_t Parcel::writeByteVector(const std::unique_ptr<std::vector<int8_t>>& val)
 {
     if (!val) return writeInt32(-1);
@@ -785,6 +798,12 @@
     return writeByteVectorInternal(reinterpret_cast<const int8_t*>(val.data()), val.size());
 }
 
+status_t Parcel::writeByteVector(const std::optional<std::vector<uint8_t>>& val)
+{
+    if (!val) return writeInt32(-1);
+    return writeByteVectorInternal(reinterpret_cast<const int8_t*>(val->data()), val->size());
+}
+
 status_t Parcel::writeByteVector(const std::unique_ptr<std::vector<uint8_t>>& val)
 {
     if (!val) return writeInt32(-1);
@@ -796,6 +815,11 @@
     return writeTypedVector(val, &Parcel::writeInt32);
 }
 
+status_t Parcel::writeInt32Vector(const std::optional<std::vector<int32_t>>& val)
+{
+    return writeNullableTypedVector(val, &Parcel::writeInt32);
+}
+
 status_t Parcel::writeInt32Vector(const std::unique_ptr<std::vector<int32_t>>& val)
 {
     return writeNullableTypedVector(val, &Parcel::writeInt32);
@@ -806,6 +830,11 @@
     return writeTypedVector(val, &Parcel::writeInt64);
 }
 
+status_t Parcel::writeInt64Vector(const std::optional<std::vector<int64_t>>& val)
+{
+    return writeNullableTypedVector(val, &Parcel::writeInt64);
+}
+
 status_t Parcel::writeInt64Vector(const std::unique_ptr<std::vector<int64_t>>& val)
 {
     return writeNullableTypedVector(val, &Parcel::writeInt64);
@@ -816,6 +845,11 @@
     return writeTypedVector(val, &Parcel::writeUint64);
 }
 
+status_t Parcel::writeUint64Vector(const std::optional<std::vector<uint64_t>>& val)
+{
+    return writeNullableTypedVector(val, &Parcel::writeUint64);
+}
+
 status_t Parcel::writeUint64Vector(const std::unique_ptr<std::vector<uint64_t>>& val)
 {
     return writeNullableTypedVector(val, &Parcel::writeUint64);
@@ -826,6 +860,11 @@
     return writeTypedVector(val, &Parcel::writeFloat);
 }
 
+status_t Parcel::writeFloatVector(const std::optional<std::vector<float>>& val)
+{
+    return writeNullableTypedVector(val, &Parcel::writeFloat);
+}
+
 status_t Parcel::writeFloatVector(const std::unique_ptr<std::vector<float>>& val)
 {
     return writeNullableTypedVector(val, &Parcel::writeFloat);
@@ -836,6 +875,11 @@
     return writeTypedVector(val, &Parcel::writeDouble);
 }
 
+status_t Parcel::writeDoubleVector(const std::optional<std::vector<double>>& val)
+{
+    return writeNullableTypedVector(val, &Parcel::writeDouble);
+}
+
 status_t Parcel::writeDoubleVector(const std::unique_ptr<std::vector<double>>& val)
 {
     return writeNullableTypedVector(val, &Parcel::writeDouble);
@@ -846,6 +890,11 @@
     return writeTypedVector(val, &Parcel::writeBool);
 }
 
+status_t Parcel::writeBoolVector(const std::optional<std::vector<bool>>& val)
+{
+    return writeNullableTypedVector(val, &Parcel::writeBool);
+}
+
 status_t Parcel::writeBoolVector(const std::unique_ptr<std::vector<bool>>& val)
 {
     return writeNullableTypedVector(val, &Parcel::writeBool);
@@ -856,6 +905,11 @@
     return writeTypedVector(val, &Parcel::writeChar);
 }
 
+status_t Parcel::writeCharVector(const std::optional<std::vector<char16_t>>& val)
+{
+    return writeNullableTypedVector(val, &Parcel::writeChar);
+}
+
 status_t Parcel::writeCharVector(const std::unique_ptr<std::vector<char16_t>>& val)
 {
     return writeNullableTypedVector(val, &Parcel::writeChar);
@@ -867,12 +921,23 @@
 }
 
 status_t Parcel::writeString16Vector(
+        const std::optional<std::vector<std::optional<String16>>>& val)
+{
+    return writeNullableTypedVector(val, &Parcel::writeString16);
+}
+
+status_t Parcel::writeString16Vector(
         const std::unique_ptr<std::vector<std::unique_ptr<String16>>>& val)
 {
     return writeNullableTypedVector(val, &Parcel::writeString16);
 }
 
 status_t Parcel::writeUtf8VectorAsUtf16Vector(
+                        const std::optional<std::vector<std::optional<std::string>>>& val) {
+    return writeNullableTypedVector(val, &Parcel::writeUtf8AsUtf16);
+}
+
+status_t Parcel::writeUtf8VectorAsUtf16Vector(
                         const std::unique_ptr<std::vector<std::unique_ptr<std::string>>>& val) {
     return writeNullableTypedVector(val, &Parcel::writeUtf8AsUtf16);
 }
@@ -997,6 +1062,15 @@
     return err;
 }
 
+status_t Parcel::writeString16(const std::optional<String16>& str)
+{
+    if (!str) {
+        return writeInt32(-1);
+    }
+
+    return writeString16(*str);
+}
+
 status_t Parcel::writeString16(const std::unique_ptr<String16>& str)
 {
     if (!str) {
@@ -1039,11 +1113,20 @@
     return writeTypedVector(val, &Parcel::writeStrongBinder);
 }
 
+status_t Parcel::writeStrongBinderVector(const std::optional<std::vector<sp<IBinder>>>& val)
+{
+    return writeNullableTypedVector(val, &Parcel::writeStrongBinder);
+}
+
 status_t Parcel::writeStrongBinderVector(const std::unique_ptr<std::vector<sp<IBinder>>>& val)
 {
     return writeNullableTypedVector(val, &Parcel::writeStrongBinder);
 }
 
+status_t Parcel::readStrongBinderVector(std::optional<std::vector<sp<IBinder>>>* val) const {
+    return readNullableTypedVector(val, &Parcel::readNullableStrongBinder);
+}
+
 status_t Parcel::readStrongBinderVector(std::unique_ptr<std::vector<sp<IBinder>>>* val) const {
     return readNullableTypedVector(val, &Parcel::readNullableStrongBinder);
 }
@@ -1142,6 +1225,10 @@
     return writeTypedVector(val, &Parcel::writeUniqueFileDescriptor);
 }
 
+status_t Parcel::writeUniqueFileDescriptorVector(const std::optional<std::vector<base::unique_fd>>& val) {
+    return writeNullableTypedVector(val, &Parcel::writeUniqueFileDescriptor);
+}
+
 status_t Parcel::writeUniqueFileDescriptorVector(const std::unique_ptr<std::vector<base::unique_fd>>& val) {
     return writeNullableTypedVector(val, &Parcel::writeUniqueFileDescriptor);
 }
@@ -1475,6 +1562,17 @@
     return readByteVectorInternal(val, size);
 }
 
+status_t Parcel::readByteVector(std::optional<std::vector<int8_t>>* val) const {
+    size_t size;
+    if (status_t status = reserveOutVector(val, &size); status != OK) return status;
+    if (!*val) {
+        // reserveOutVector does not create the out vector if size is < 0.
+        // This occurs when writing a null byte vector.
+        return OK;
+    }
+    return readByteVectorInternal(&**val, size);
+}
+
 status_t Parcel::readByteVector(std::unique_ptr<std::vector<int8_t>>* val) const {
     size_t size;
     if (status_t status = reserveOutVector(val, &size); status != OK) return status;
@@ -1486,6 +1584,17 @@
     return readByteVectorInternal(val->get(), size);
 }
 
+status_t Parcel::readByteVector(std::optional<std::vector<uint8_t>>* val) const {
+    size_t size;
+    if (status_t status = reserveOutVector(val, &size); status != OK) return status;
+    if (!*val) {
+        // reserveOutVector does not create the out vector if size is < 0.
+        // This occurs when writing a null byte vector.
+        return OK;
+    }
+    return readByteVectorInternal(&**val, size);
+}
+
 status_t Parcel::readByteVector(std::unique_ptr<std::vector<uint8_t>>* val) const {
     size_t size;
     if (status_t status = reserveOutVector(val, &size); status != OK) return status;
@@ -1497,6 +1606,10 @@
     return readByteVectorInternal(val->get(), size);
 }
 
+status_t Parcel::readInt32Vector(std::optional<std::vector<int32_t>>* val) const {
+    return readNullableTypedVector(val, &Parcel::readInt32);
+}
+
 status_t Parcel::readInt32Vector(std::unique_ptr<std::vector<int32_t>>* val) const {
     return readNullableTypedVector(val, &Parcel::readInt32);
 }
@@ -1505,6 +1618,10 @@
     return readTypedVector(val, &Parcel::readInt32);
 }
 
+status_t Parcel::readInt64Vector(std::optional<std::vector<int64_t>>* val) const {
+    return readNullableTypedVector(val, &Parcel::readInt64);
+}
+
 status_t Parcel::readInt64Vector(std::unique_ptr<std::vector<int64_t>>* val) const {
     return readNullableTypedVector(val, &Parcel::readInt64);
 }
@@ -1513,6 +1630,10 @@
     return readTypedVector(val, &Parcel::readInt64);
 }
 
+status_t Parcel::readUint64Vector(std::optional<std::vector<uint64_t>>* val) const {
+    return readNullableTypedVector(val, &Parcel::readUint64);
+}
+
 status_t Parcel::readUint64Vector(std::unique_ptr<std::vector<uint64_t>>* val) const {
     return readNullableTypedVector(val, &Parcel::readUint64);
 }
@@ -1521,6 +1642,10 @@
     return readTypedVector(val, &Parcel::readUint64);
 }
 
+status_t Parcel::readFloatVector(std::optional<std::vector<float>>* val) const {
+    return readNullableTypedVector(val, &Parcel::readFloat);
+}
+
 status_t Parcel::readFloatVector(std::unique_ptr<std::vector<float>>* val) const {
     return readNullableTypedVector(val, &Parcel::readFloat);
 }
@@ -1529,6 +1654,10 @@
     return readTypedVector(val, &Parcel::readFloat);
 }
 
+status_t Parcel::readDoubleVector(std::optional<std::vector<double>>* val) const {
+    return readNullableTypedVector(val, &Parcel::readDouble);
+}
+
 status_t Parcel::readDoubleVector(std::unique_ptr<std::vector<double>>* val) const {
     return readNullableTypedVector(val, &Parcel::readDouble);
 }
@@ -1537,6 +1666,28 @@
     return readTypedVector(val, &Parcel::readDouble);
 }
 
+status_t Parcel::readBoolVector(std::optional<std::vector<bool>>* val) const {
+    const int32_t start = dataPosition();
+    int32_t size;
+    status_t status = readInt32(&size);
+    val->reset();
+
+    if (status != OK || size < 0) {
+        return status;
+    }
+
+    setDataPosition(start);
+    val->emplace();
+
+    status = readBoolVector(&**val);
+
+    if (status != OK) {
+        val->reset();
+    }
+
+    return status;
+}
+
 status_t Parcel::readBoolVector(std::unique_ptr<std::vector<bool>>* val) const {
     const int32_t start = dataPosition();
     int32_t size;
@@ -1589,6 +1740,10 @@
     return OK;
 }
 
+status_t Parcel::readCharVector(std::optional<std::vector<char16_t>>* val) const {
+    return readNullableTypedVector(val, &Parcel::readChar);
+}
+
 status_t Parcel::readCharVector(std::unique_ptr<std::vector<char16_t>>* val) const {
     return readNullableTypedVector(val, &Parcel::readChar);
 }
@@ -1598,6 +1753,11 @@
 }
 
 status_t Parcel::readString16Vector(
+        std::optional<std::vector<std::optional<String16>>>* val) const {
+    return readNullableTypedVector(val, &Parcel::readString16);
+}
+
+status_t Parcel::readString16Vector(
         std::unique_ptr<std::vector<std::unique_ptr<String16>>>* val) const {
     return readNullableTypedVector(val, &Parcel::readString16);
 }
@@ -1607,6 +1767,11 @@
 }
 
 status_t Parcel::readUtf8VectorFromUtf16Vector(
+        std::optional<std::vector<std::optional<std::string>>>* val) const {
+    return readNullableTypedVector(val, &Parcel::readUtf8FromUtf16);
+}
+
+status_t Parcel::readUtf8VectorFromUtf16Vector(
         std::unique_ptr<std::vector<std::unique_ptr<std::string>>>* val) const {
     return readNullableTypedVector(val, &Parcel::readUtf8FromUtf16);
 }
@@ -1798,6 +1963,21 @@
     return NO_ERROR;
 }
 
+status_t Parcel::readUtf8FromUtf16(std::optional<std::string>* str) const {
+    const int32_t start = dataPosition();
+    int32_t size;
+    status_t status = readInt32(&size);
+    str->reset();
+
+    if (status != OK || size < 0) {
+        return status;
+    }
+
+    setDataPosition(start);
+    str->emplace();
+    return readUtf8FromUtf16(&**str);
+}
+
 status_t Parcel::readUtf8FromUtf16(std::unique_ptr<std::string>* str) const {
     const int32_t start = dataPosition();
     int32_t size;
@@ -1874,6 +2054,29 @@
     return String16();
 }
 
+status_t Parcel::readString16(std::optional<String16>* pArg) const
+{
+    const int32_t start = dataPosition();
+    int32_t size;
+    status_t status = readInt32(&size);
+    pArg->reset();
+
+    if (status != OK || size < 0) {
+        return status;
+    }
+
+    setDataPosition(start);
+    pArg->emplace();
+
+    status = readString16(&**pArg);
+
+    if (status != OK) {
+        pArg->reset();
+    }
+
+    return status;
+}
+
 status_t Parcel::readString16(std::unique_ptr<String16>* pArg) const
 {
     const int32_t start = dataPosition();
@@ -2079,6 +2282,10 @@
     return OK;
 }
 
+status_t Parcel::readUniqueFileDescriptorVector(std::optional<std::vector<base::unique_fd>>* val) const {
+    return readNullableTypedVector(val, &Parcel::readUniqueFileDescriptor);
+}
+
 status_t Parcel::readUniqueFileDescriptorVector(std::unique_ptr<std::vector<base::unique_fd>>* val) const {
     return readNullableTypedVector(val, &Parcel::readUniqueFileDescriptor);
 }
diff --git a/libs/binder/ProcessState.cpp b/libs/binder/ProcessState.cpp
index 4b773e8..f3861bb 100644
--- a/libs/binder/ProcessState.cpp
+++ b/libs/binder/ProcessState.cpp
@@ -328,6 +328,8 @@
 }
 
 status_t ProcessState::setThreadPoolMaxThreadCount(size_t maxThreads) {
+    LOG_ALWAYS_FATAL_IF(mThreadPoolStarted && maxThreads < mMaxThreads,
+           "Binder threadpool cannot be shrunk after starting");
     status_t result = NO_ERROR;
     if (ioctl(mDriverFD, BINDER_SET_MAX_THREADS, &maxThreads) != -1) {
         mMaxThreads = maxThreads;
diff --git a/libs/binder/include/binder/AppOpsManager.h b/libs/binder/include/binder/AppOpsManager.h
index 6afcd77..6d04f13 100644
--- a/libs/binder/include/binder/AppOpsManager.h
+++ b/libs/binder/include/binder/AppOpsManager.h
@@ -21,6 +21,8 @@
 
 #include <utils/threads.h>
 
+#include <optional>
+
 #ifdef __ANDROID_VNDK__
 #error "This header is not visible to vendors"
 #endif
@@ -143,18 +145,18 @@
     //              const String16&) instead
     int32_t noteOp(int32_t op, int32_t uid, const String16& callingPackage);
     int32_t noteOp(int32_t op, int32_t uid, const String16& callingPackage,
-            const std::unique_ptr<String16>& attributionTag, const String16& message);
+            const std::optional<String16>& attributionTag, const String16& message);
     // @Deprecated, use startOpNoThrow(int32_t, int32_t, const String16&, bool, const String16&,
     //              const String16&) instead
     int32_t startOpNoThrow(int32_t op, int32_t uid, const String16& callingPackage,
             bool startIfModeDefault);
     int32_t startOpNoThrow(int32_t op, int32_t uid, const String16& callingPackage,
-            bool startIfModeDefault, const std::unique_ptr<String16>& attributionTag,
+            bool startIfModeDefault, const std::optional<String16>& attributionTag,
             const String16& message);
     // @Deprecated, use finishOp(int32_t, int32_t, const String16&, bool, const String16&) instead
     void finishOp(int32_t op, int32_t uid, const String16& callingPackage);
     void finishOp(int32_t op, int32_t uid, const String16& callingPackage,
-            const std::unique_ptr<String16>& attributionTag);
+            const std::optional<String16>& attributionTag);
     void startWatchingMode(int32_t op, const String16& packageName,
             const sp<IAppOpsCallback>& callback);
     void stopWatchingMode(const sp<IAppOpsCallback>& callback);
diff --git a/libs/binder/include/binder/BpBinder.h b/libs/binder/include/binder/BpBinder.h
index 8e871b8..378a911 100644
--- a/libs/binder/include/binder/BpBinder.h
+++ b/libs/binder/include/binder/BpBinder.h
@@ -137,7 +137,6 @@
             volatile int32_t    mObitsSent;
             Vector<Obituary>*   mObituaries;
             ObjectManager       mObjects;
-            Parcel*             mConstantData;
     mutable String16            mDescriptorCache;
             int32_t             mTrackedUid;
 
diff --git a/libs/binder/include/binder/IAppOpsService.h b/libs/binder/include/binder/IAppOpsService.h
index 1ffb8de..a4a20c8 100644
--- a/libs/binder/include/binder/IAppOpsService.h
+++ b/libs/binder/include/binder/IAppOpsService.h
@@ -21,6 +21,8 @@
 #include <binder/IAppOpsCallback.h>
 #include <binder/IInterface.h>
 
+#include <optional>
+
 #ifdef __ANDROID_VNDK__
 #error "This header is not visible to vendors"
 #endif
@@ -36,13 +38,13 @@
 
     virtual int32_t checkOperation(int32_t code, int32_t uid, const String16& packageName) = 0;
     virtual int32_t noteOperation(int32_t code, int32_t uid, const String16& packageName,
-            const std::unique_ptr<String16>& attributionTag, bool shouldCollectAsyncNotedOp,
+            const std::optional<String16>& attributionTag, bool shouldCollectAsyncNotedOp,
             const String16& message) = 0;
     virtual int32_t startOperation(const sp<IBinder>& token, int32_t code, int32_t uid,
-            const String16& packageName, const std::unique_ptr<String16>& attributionTag,
+            const String16& packageName, const std::optional<String16>& attributionTag,
             bool startIfModeDefault, bool shouldCollectAsyncNotedOp, const String16& message) = 0;
     virtual void finishOperation(const sp<IBinder>& token, int32_t code, int32_t uid,
-            const String16& packageName, const std::unique_ptr<String16>& attributionTag) = 0;
+            const String16& packageName, const std::optional<String16>& attributionTag) = 0;
     virtual void startWatchingMode(int32_t op, const String16& packageName,
             const sp<IAppOpsCallback>& callback) = 0;
     virtual void stopWatchingMode(const sp<IAppOpsCallback>& callback) = 0;
diff --git a/libs/binder/include/binder/IBinder.h b/libs/binder/include/binder/IBinder.h
index 64604b7..eea0e89 100644
--- a/libs/binder/include/binder/IBinder.h
+++ b/libs/binder/include/binder/IBinder.h
@@ -173,6 +173,10 @@
      * The @a cookie is optional -- if non-NULL, it should be a
      * memory address that you own (that is, you know it is unique).
      *
+     * @note When all references to the binder being linked to are dropped, the
+     * recipient is automatically unlinked. So, you must hold onto a binder in
+     * order to receive death notifications about it.
+     *
      * @note You will only receive death notifications for remote binders,
      * as local binders by definition can't die without you dying as well.
      * Trying to use this function on a local binder will result in an
diff --git a/libs/binder/include/binder/IPCThreadState.h b/libs/binder/include/binder/IPCThreadState.h
index 4818889..b4e4a42 100644
--- a/libs/binder/include/binder/IPCThreadState.h
+++ b/libs/binder/include/binder/IPCThreadState.h
@@ -39,12 +39,28 @@
             
             status_t            clearLastError();
 
+            /**
+             * Returns the PID of the process which has made the current binder
+             * call. If not in a binder call, this will return getpid. If the
+             * call is oneway, this will return 0.
+             */
             pid_t               getCallingPid() const;
-            // nullptr if unavailable
-            //
-            // this can't be restored once it's cleared, and it does not return the
-            // context of the current process when not in a binder call.
+
+            /**
+             * Returns the SELinux security identifier of the process which has
+             * made the current binder call. If not in a binder call this will
+             * return nullptr. If this isn't requested with
+             * IBinder::setRequestingSid, it will also return nullptr.
+             *
+             * This can't be restored once it's cleared, and it does not return the
+             * context of the current process when not in a binder call.
+             */
             const char*         getCallingSid() const;
+
+            /**
+             * Returns the UID of the process which has made the current binder
+             * call. If not in a binder call, this will return 0.
+             */
             uid_t               getCallingUid() const;
 
             void                setStrictModePolicy(int32_t policy);
diff --git a/libs/binder/include/binder/MemoryHeapBase.h b/libs/binder/include/binder/MemoryHeapBase.h
index 3fccddc..edada3d 100644
--- a/libs/binder/include/binder/MemoryHeapBase.h
+++ b/libs/binder/include/binder/MemoryHeapBase.h
@@ -57,14 +57,14 @@
     virtual ~MemoryHeapBase();
 
     /* implement IMemoryHeap interface */
-    virtual int         getHeapID() const;
+    int         getHeapID() const override;
 
     /* virtual address of the heap. returns MAP_FAILED in case of error */
-    virtual void*       getBase() const;
+    void*       getBase() const override;
 
-    virtual size_t      getSize() const;
-    virtual uint32_t    getFlags() const;
-            off_t       getOffset() const override;
+    size_t      getSize() const override;
+    uint32_t    getFlags() const override;
+    off_t       getOffset() const override;
 
     const char*         getDevice() const;
 
diff --git a/libs/binder/include/binder/Nullable.h b/libs/binder/include/binder/Nullable.h
index b605bd3..a98583d 100644
--- a/libs/binder/include/binder/Nullable.h
+++ b/libs/binder/include/binder/Nullable.h
@@ -15,7 +15,7 @@
  */
 #pragma once
 
-#include <memory>
+#include <optional>
 #include <utility>
 
 namespace android {
@@ -32,11 +32,11 @@
 //     c = std::move(a);
 
 template <typename T>
-using nullable = std::unique_ptr<T>;
+using nullable = std::optional<T>;
 
 template <typename T, typename... Args>
 inline nullable<T> make_nullable(Args&&... args) {
-    return std::make_unique<T>(std::forward<Args>(args)...);
+    return std::make_optional<T>(std::forward<Args>(args)...);
 }
 
 } // namespace aidl
diff --git a/libs/binder/include/binder/Parcel.h b/libs/binder/include/binder/Parcel.h
index 4b1a758..97f1aee 100644
--- a/libs/binder/include/binder/Parcel.h
+++ b/libs/binder/include/binder/Parcel.h
@@ -120,6 +120,7 @@
     status_t            writeCString(const char* str);
     status_t            writeString8(const String8& str);
     status_t            writeString16(const String16& str);
+    status_t            writeString16(const std::optional<String16>& str);
     status_t            writeString16(const std::unique_ptr<String16>& str);
     status_t            writeString16(const char16_t* str, size_t len);
     status_t            writeStrongBinder(const sp<IBinder>& val);
@@ -131,33 +132,48 @@
 
     // Take a UTF8 encoded string, convert to UTF16, write it to the parcel.
     status_t            writeUtf8AsUtf16(const std::string& str);
+    status_t            writeUtf8AsUtf16(const std::optional<std::string>& str);
     status_t            writeUtf8AsUtf16(const std::unique_ptr<std::string>& str);
 
+    status_t            writeByteVector(const std::optional<std::vector<int8_t>>& val);
     status_t            writeByteVector(const std::unique_ptr<std::vector<int8_t>>& val);
     status_t            writeByteVector(const std::vector<int8_t>& val);
+    status_t            writeByteVector(const std::optional<std::vector<uint8_t>>& val);
     status_t            writeByteVector(const std::unique_ptr<std::vector<uint8_t>>& val);
     status_t            writeByteVector(const std::vector<uint8_t>& val);
+    status_t            writeInt32Vector(const std::optional<std::vector<int32_t>>& val);
     status_t            writeInt32Vector(const std::unique_ptr<std::vector<int32_t>>& val);
     status_t            writeInt32Vector(const std::vector<int32_t>& val);
+    status_t            writeInt64Vector(const std::optional<std::vector<int64_t>>& val);
     status_t            writeInt64Vector(const std::unique_ptr<std::vector<int64_t>>& val);
     status_t            writeInt64Vector(const std::vector<int64_t>& val);
+    status_t            writeUint64Vector(const std::optional<std::vector<uint64_t>>& val);
     status_t            writeUint64Vector(const std::unique_ptr<std::vector<uint64_t>>& val);
     status_t            writeUint64Vector(const std::vector<uint64_t>& val);
+    status_t            writeFloatVector(const std::optional<std::vector<float>>& val);
     status_t            writeFloatVector(const std::unique_ptr<std::vector<float>>& val);
     status_t            writeFloatVector(const std::vector<float>& val);
+    status_t            writeDoubleVector(const std::optional<std::vector<double>>& val);
     status_t            writeDoubleVector(const std::unique_ptr<std::vector<double>>& val);
     status_t            writeDoubleVector(const std::vector<double>& val);
+    status_t            writeBoolVector(const std::optional<std::vector<bool>>& val);
     status_t            writeBoolVector(const std::unique_ptr<std::vector<bool>>& val);
     status_t            writeBoolVector(const std::vector<bool>& val);
+    status_t            writeCharVector(const std::optional<std::vector<char16_t>>& val);
     status_t            writeCharVector(const std::unique_ptr<std::vector<char16_t>>& val);
     status_t            writeCharVector(const std::vector<char16_t>& val);
     status_t            writeString16Vector(
+                            const std::optional<std::vector<std::optional<String16>>>& val);
+    status_t            writeString16Vector(
                             const std::unique_ptr<std::vector<std::unique_ptr<String16>>>& val);
     status_t            writeString16Vector(const std::vector<String16>& val);
     status_t            writeUtf8VectorAsUtf16Vector(
+                            const std::optional<std::vector<std::optional<std::string>>>& val);
+    status_t            writeUtf8VectorAsUtf16Vector(
                             const std::unique_ptr<std::vector<std::unique_ptr<std::string>>>& val);
     status_t            writeUtf8VectorAsUtf16Vector(const std::vector<std::string>& val);
 
+    status_t            writeStrongBinderVector(const std::optional<std::vector<sp<IBinder>>>& val);
     status_t            writeStrongBinderVector(const std::unique_ptr<std::vector<sp<IBinder>>>& val);
     status_t            writeStrongBinderVector(const std::vector<sp<IBinder>>& val);
 
@@ -166,14 +182,20 @@
     template<typename T, std::enable_if_t<std::is_enum_v<T> && std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool> = 0>
     status_t            writeEnumVector(const std::vector<T>& val);
     template<typename T, std::enable_if_t<std::is_enum_v<T> && std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool> = 0>
+    status_t            writeEnumVector(const std::optional<std::vector<T>>& val);
+    template<typename T, std::enable_if_t<std::is_enum_v<T> && std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool> = 0>
     status_t            writeEnumVector(const std::unique_ptr<std::vector<T>>& val);
     // Write an Enum vector with underlying type != int8_t.
     template<typename T, std::enable_if_t<std::is_enum_v<T> && !std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool> = 0>
     status_t            writeEnumVector(const std::vector<T>& val);
     template<typename T, std::enable_if_t<std::is_enum_v<T> && !std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool> = 0>
+    status_t            writeEnumVector(const std::optional<std::vector<T>>& val);
+    template<typename T, std::enable_if_t<std::is_enum_v<T> && !std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool> = 0>
     status_t            writeEnumVector(const std::unique_ptr<std::vector<T>>& val);
 
     template<typename T>
+    status_t            writeParcelableVector(const std::optional<std::vector<std::optional<T>>>& val);
+    template<typename T>
     status_t            writeParcelableVector(const std::unique_ptr<std::vector<std::unique_ptr<T>>>& val);
     template<typename T>
     status_t            writeParcelableVector(const std::shared_ptr<std::vector<std::unique_ptr<T>>>& val);
@@ -181,6 +203,8 @@
     status_t            writeParcelableVector(const std::vector<T>& val);
 
     template<typename T>
+    status_t            writeNullableParcelable(const std::optional<T>& parcelable);
+    template<typename T>
     status_t            writeNullableParcelable(const std::unique_ptr<T>& parcelable);
 
     status_t            writeParcelable(const Parcelable& parcelable);
@@ -194,6 +218,8 @@
     template<typename T>
     status_t            writeVectorSize(const std::vector<T>& val);
     template<typename T>
+    status_t            writeVectorSize(const std::optional<std::vector<T>>& val);
+    template<typename T>
     status_t            writeVectorSize(const std::unique_ptr<std::vector<T>>& val);
 
     // Place a native_handle into the parcel (the native_handle's file-
@@ -229,6 +255,8 @@
     // Place a vector of file desciptors into the parcel. Each descriptor is
     // dup'd as in writeDupFileDescriptor
     status_t            writeUniqueFileDescriptorVector(
+                            const std::optional<std::vector<base::unique_fd>>& val);
+    status_t            writeUniqueFileDescriptorVector(
                             const std::unique_ptr<std::vector<base::unique_fd>>& val);
     status_t            writeUniqueFileDescriptorVector(
                             const std::vector<base::unique_fd>& val);
@@ -278,6 +306,7 @@
 
     // Read a UTF16 encoded string, convert to UTF8
     status_t            readUtf8FromUtf16(std::string* str) const;
+    status_t            readUtf8FromUtf16(std::optional<std::string>* str) const;
     status_t            readUtf8FromUtf16(std::unique_ptr<std::string>* str) const;
 
     const char*         readCString() const;
@@ -285,27 +314,34 @@
     status_t            readString8(String8* pArg) const;
     String16            readString16() const;
     status_t            readString16(String16* pArg) const;
+    status_t            readString16(std::optional<String16>* pArg) const;
     status_t            readString16(std::unique_ptr<String16>* pArg) const;
     const char16_t*     readString16Inplace(size_t* outLen) const;
     sp<IBinder>         readStrongBinder() const;
     status_t            readStrongBinder(sp<IBinder>* val) const;
     status_t            readNullableStrongBinder(sp<IBinder>* val) const;
 
-
     // Read an Enum vector with underlying type int8_t.
     // Does not use padding; each byte is contiguous.
     template<typename T, std::enable_if_t<std::is_enum_v<T> && std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool> = 0>
     status_t            readEnumVector(std::vector<T>* val) const;
     template<typename T, std::enable_if_t<std::is_enum_v<T> && std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool> = 0>
     status_t            readEnumVector(std::unique_ptr<std::vector<T>>* val) const;
+    template<typename T, std::enable_if_t<std::is_enum_v<T> && std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool> = 0>
+    status_t            readEnumVector(std::optional<std::vector<T>>* val) const;
     // Read an Enum vector with underlying type != int8_t.
     template<typename T, std::enable_if_t<std::is_enum_v<T> && !std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool> = 0>
     status_t            readEnumVector(std::vector<T>* val) const;
     template<typename T, std::enable_if_t<std::is_enum_v<T> && !std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool> = 0>
     status_t            readEnumVector(std::unique_ptr<std::vector<T>>* val) const;
+    template<typename T, std::enable_if_t<std::is_enum_v<T> && !std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool> = 0>
+    status_t            readEnumVector(std::optional<std::vector<T>>* val) const;
 
     template<typename T>
     status_t            readParcelableVector(
+                            std::optional<std::vector<std::optional<T>>>* val) const;
+    template<typename T>
+    status_t            readParcelableVector(
                             std::unique_ptr<std::vector<std::unique_ptr<T>>>* val) const;
     template<typename T>
     status_t            readParcelableVector(std::vector<T>* val) const;
@@ -313,6 +349,8 @@
     status_t            readParcelable(Parcelable* parcelable) const;
 
     template<typename T>
+    status_t            readParcelable(std::optional<T>* parcelable) const;
+    template<typename T>
     status_t            readParcelable(std::unique_ptr<T>* parcelable) const;
 
     template<typename T>
@@ -321,31 +359,45 @@
     template<typename T>
     status_t            readNullableStrongBinder(sp<T>* val) const;
 
+    status_t            readStrongBinderVector(std::optional<std::vector<sp<IBinder>>>* val) const;
     status_t            readStrongBinderVector(std::unique_ptr<std::vector<sp<IBinder>>>* val) const;
     status_t            readStrongBinderVector(std::vector<sp<IBinder>>* val) const;
 
+    status_t            readByteVector(std::optional<std::vector<int8_t>>* val) const;
     status_t            readByteVector(std::unique_ptr<std::vector<int8_t>>* val) const;
     status_t            readByteVector(std::vector<int8_t>* val) const;
+    status_t            readByteVector(std::optional<std::vector<uint8_t>>* val) const;
     status_t            readByteVector(std::unique_ptr<std::vector<uint8_t>>* val) const;
     status_t            readByteVector(std::vector<uint8_t>* val) const;
+    status_t            readInt32Vector(std::optional<std::vector<int32_t>>* val) const;
     status_t            readInt32Vector(std::unique_ptr<std::vector<int32_t>>* val) const;
     status_t            readInt32Vector(std::vector<int32_t>* val) const;
+    status_t            readInt64Vector(std::optional<std::vector<int64_t>>* val) const;
     status_t            readInt64Vector(std::unique_ptr<std::vector<int64_t>>* val) const;
     status_t            readInt64Vector(std::vector<int64_t>* val) const;
+    status_t            readUint64Vector(std::optional<std::vector<uint64_t>>* val) const;
     status_t            readUint64Vector(std::unique_ptr<std::vector<uint64_t>>* val) const;
     status_t            readUint64Vector(std::vector<uint64_t>* val) const;
+    status_t            readFloatVector(std::optional<std::vector<float>>* val) const;
     status_t            readFloatVector(std::unique_ptr<std::vector<float>>* val) const;
     status_t            readFloatVector(std::vector<float>* val) const;
+    status_t            readDoubleVector(std::optional<std::vector<double>>* val) const;
     status_t            readDoubleVector(std::unique_ptr<std::vector<double>>* val) const;
     status_t            readDoubleVector(std::vector<double>* val) const;
+    status_t            readBoolVector(std::optional<std::vector<bool>>* val) const;
     status_t            readBoolVector(std::unique_ptr<std::vector<bool>>* val) const;
     status_t            readBoolVector(std::vector<bool>* val) const;
+    status_t            readCharVector(std::optional<std::vector<char16_t>>* val) const;
     status_t            readCharVector(std::unique_ptr<std::vector<char16_t>>* val) const;
     status_t            readCharVector(std::vector<char16_t>* val) const;
     status_t            readString16Vector(
+                            std::optional<std::vector<std::optional<String16>>>* val) const;
+    status_t            readString16Vector(
                             std::unique_ptr<std::vector<std::unique_ptr<String16>>>* val) const;
     status_t            readString16Vector(std::vector<String16>* val) const;
     status_t            readUtf8VectorFromUtf16Vector(
+                            std::optional<std::vector<std::optional<std::string>>>* val) const;
+    status_t            readUtf8VectorFromUtf16Vector(
                             std::unique_ptr<std::vector<std::unique_ptr<std::string>>>* val) const;
     status_t            readUtf8VectorFromUtf16Vector(std::vector<std::string>* val) const;
 
@@ -358,10 +410,15 @@
     template<typename T>
     status_t            resizeOutVector(std::vector<T>* val) const;
     template<typename T>
+    status_t            resizeOutVector(std::optional<std::vector<T>>* val) const;
+    template<typename T>
     status_t            resizeOutVector(std::unique_ptr<std::vector<T>>* val) const;
     template<typename T>
     status_t            reserveOutVector(std::vector<T>* val, size_t* size) const;
     template<typename T>
+    status_t            reserveOutVector(std::optional<std::vector<T>>* val,
+                                         size_t* size) const;
+    template<typename T>
     status_t            reserveOutVector(std::unique_ptr<std::vector<T>>* val,
                                          size_t* size) const;
 
@@ -397,6 +454,8 @@
 
     // Retrieve a vector of smart file descriptors from the parcel.
     status_t            readUniqueFileDescriptorVector(
+                            std::optional<std::vector<base::unique_fd>>* val) const;
+    status_t            readUniqueFileDescriptorVector(
                             std::unique_ptr<std::vector<base::unique_fd>>* val) const;
     status_t            readUniqueFileDescriptorVector(
                             std::vector<base::unique_fd>* val) const;
@@ -490,6 +549,9 @@
     status_t            unsafeReadTypedVector(std::vector<T>* val,
                                               status_t(Parcel::*read_func)(U*) const) const;
     template<typename T>
+    status_t            readNullableTypedVector(std::optional<std::vector<T>>* val,
+                                                status_t(Parcel::*read_func)(T*) const) const;
+    template<typename T>
     status_t            readNullableTypedVector(std::unique_ptr<std::vector<T>>* val,
                                                 status_t(Parcel::*read_func)(T*) const) const;
     template<typename T>
@@ -499,9 +561,15 @@
     status_t            unsafeWriteTypedVector(const std::vector<T>& val,
                                                status_t(Parcel::*write_func)(U));
     template<typename T>
+    status_t            writeNullableTypedVector(const std::optional<std::vector<T>>& val,
+                                                 status_t(Parcel::*write_func)(const T&));
+    template<typename T>
     status_t            writeNullableTypedVector(const std::unique_ptr<std::vector<T>>& val,
                                                  status_t(Parcel::*write_func)(const T&));
     template<typename T>
+    status_t            writeNullableTypedVector(const std::optional<std::vector<T>>& val,
+                                                 status_t(Parcel::*write_func)(T));
+    template<typename T>
     status_t            writeNullableTypedVector(const std::unique_ptr<std::vector<T>>& val,
                                                  status_t(Parcel::*write_func)(T));
     template<typename T>
@@ -689,6 +757,15 @@
 }
 
 template<typename T>
+status_t Parcel::writeVectorSize(const std::optional<std::vector<T>>& val) {
+    if (!val) {
+        return writeInt32(-1);
+    }
+
+    return writeVectorSize(*val);
+}
+
+template<typename T>
 status_t Parcel::writeVectorSize(const std::unique_ptr<std::vector<T>>& val) {
     if (!val) {
         return writeInt32(-1);
@@ -713,6 +790,22 @@
 }
 
 template<typename T>
+status_t Parcel::resizeOutVector(std::optional<std::vector<T>>* val) const {
+    int32_t size;
+    status_t err = readInt32(&size);
+    if (err != NO_ERROR) {
+        return err;
+    }
+
+    val->reset();
+    if (size >= 0) {
+        val->emplace(size_t(size));
+    }
+
+    return OK;
+}
+
+template<typename T>
 status_t Parcel::resizeOutVector(std::unique_ptr<std::vector<T>>* val) const {
     int32_t size;
     status_t err = readInt32(&size);
@@ -745,6 +838,25 @@
 }
 
 template<typename T>
+status_t Parcel::reserveOutVector(std::optional<std::vector<T>>* val, size_t* size) const {
+    int32_t read_size;
+    status_t err = readInt32(&read_size);
+    if (err != NO_ERROR) {
+        return err;
+    }
+
+    if (read_size >= 0) {
+        *size = static_cast<size_t>(read_size);
+        val->emplace();
+        (*val)->reserve(*size);
+    } else {
+        val->reset();
+    }
+
+    return OK;
+}
+
+template<typename T>
 status_t Parcel::reserveOutVector(std::unique_ptr<std::vector<T>>* val,
                                   size_t* size) const {
     int32_t read_size;
@@ -839,6 +951,30 @@
 }
 
 template<typename T>
+status_t Parcel::readNullableTypedVector(std::optional<std::vector<T>>* val,
+                                         status_t(Parcel::*read_func)(T*) const) const {
+    const size_t start = dataPosition();
+    int32_t size;
+    status_t status = readInt32(&size);
+    val->reset();
+
+    if (status != OK || size < 0) {
+        return status;
+    }
+
+    setDataPosition(start);
+    val->emplace();
+
+    status = unsafeReadTypedVector(&**val, read_func);
+
+    if (status != OK) {
+       val->reset();
+    }
+
+    return status;
+}
+
+template<typename T>
 status_t Parcel::readNullableTypedVector(std::unique_ptr<std::vector<T>>* val,
                                          status_t(Parcel::*read_func)(T*) const) const {
     const size_t start = dataPosition();
@@ -899,6 +1035,16 @@
 }
 
 template<typename T>
+status_t Parcel::writeNullableTypedVector(const std::optional<std::vector<T>>& val,
+                                          status_t(Parcel::*write_func)(const T&)) {
+    if (!val) {
+        return this->writeInt32(-1);
+    }
+
+    return unsafeWriteTypedVector(*val, write_func);
+}
+
+template<typename T>
 status_t Parcel::writeNullableTypedVector(const std::unique_ptr<std::vector<T>>& val,
                                           status_t(Parcel::*write_func)(const T&)) {
     if (val.get() == nullptr) {
@@ -909,6 +1055,16 @@
 }
 
 template<typename T>
+status_t Parcel::writeNullableTypedVector(const std::optional<std::vector<T>>& val,
+                                          status_t(Parcel::*write_func)(T)) {
+    if (!val) {
+        return this->writeInt32(-1);
+    }
+
+    return unsafeWriteTypedVector(*val, write_func);
+}
+
+template<typename T>
 status_t Parcel::writeNullableTypedVector(const std::unique_ptr<std::vector<T>>& val,
                                           status_t(Parcel::*write_func)(T)) {
     if (val.get() == nullptr) {
@@ -924,6 +1080,30 @@
 }
 
 template<typename T>
+status_t Parcel::readParcelableVector(std::optional<std::vector<std::optional<T>>>* val) const {
+    const size_t start = dataPosition();
+    int32_t size;
+    status_t status = readInt32(&size);
+    val->reset();
+
+    if (status != OK || size < 0) {
+        return status;
+    }
+
+    setDataPosition(start);
+    val->emplace();
+
+    using NullableT = std::optional<T>;
+    status = unsafeReadTypedVector<NullableT, NullableT>(&**val, &Parcel::readParcelable);
+
+    if (status != OK) {
+        val->reset();
+    }
+
+    return status;
+}
+
+template<typename T>
 status_t Parcel::readParcelableVector(std::unique_ptr<std::vector<std::unique_ptr<T>>>* val) const {
     const size_t start = dataPosition();
     int32_t size;
@@ -937,7 +1117,8 @@
     setDataPosition(start);
     val->reset(new std::vector<std::unique_ptr<T>>());
 
-    status = unsafeReadTypedVector(val->get(), &Parcel::readParcelable<T>);
+    using NullableT = std::unique_ptr<T>;
+    status = unsafeReadTypedVector<NullableT, NullableT>(val->get(), &Parcel::readParcelable);
 
     if (status != OK) {
         val->reset();
@@ -947,6 +1128,29 @@
 }
 
 template<typename T>
+status_t Parcel::readParcelable(std::optional<T>* parcelable) const {
+    const size_t start = dataPosition();
+    int32_t present;
+    status_t status = readInt32(&present);
+    parcelable->reset();
+
+    if (status != OK || !present) {
+        return status;
+    }
+
+    setDataPosition(start);
+    parcelable->emplace();
+
+    status = readParcelable(&**parcelable);
+
+    if (status != OK) {
+        parcelable->reset();
+    }
+
+    return status;
+}
+
+template<typename T>
 status_t Parcel::readParcelable(std::unique_ptr<T>* parcelable) const {
     const size_t start = dataPosition();
     int32_t present;
@@ -970,6 +1174,11 @@
 }
 
 template<typename T>
+status_t Parcel::writeNullableParcelable(const std::optional<T>& parcelable) {
+    return writeRawNullableParcelable(parcelable ? &*parcelable : nullptr);
+}
+
+template<typename T>
 status_t Parcel::writeNullableParcelable(const std::unique_ptr<T>& parcelable) {
     return writeRawNullableParcelable(parcelable.get());
 }
@@ -980,6 +1189,16 @@
 }
 
 template<typename T>
+status_t Parcel::writeParcelableVector(const std::optional<std::vector<std::optional<T>>>& val) {
+    if (!val) {
+        return this->writeInt32(-1);
+    }
+
+    using NullableT = std::optional<T>;
+    return unsafeWriteTypedVector<NullableT, const NullableT&>(*val, &Parcel::writeNullableParcelable);
+}
+
+template<typename T>
 status_t Parcel::writeParcelableVector(const std::unique_ptr<std::vector<std::unique_ptr<T>>>& val) {
     if (val.get() == nullptr) {
         return this->writeInt32(-1);
@@ -994,7 +1213,8 @@
         return this->writeInt32(-1);
     }
 
-    return unsafeWriteTypedVector(*val, &Parcel::writeNullableParcelable<T>);
+    using NullableT = std::unique_ptr<T>;
+    return unsafeWriteTypedVector<NullableT, const NullableT&>(*val, &Parcel::writeNullableParcelable);
 }
 
 template<typename T, std::enable_if_t<std::is_same_v<typename std::underlying_type_t<T>,int32_t>, bool>>
@@ -1011,6 +1231,11 @@
     return writeByteVectorInternal(reinterpret_cast<const int8_t*>(val.data()), val.size());
 }
 template<typename T, std::enable_if_t<std::is_enum_v<T> && std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool>>
+status_t Parcel::writeEnumVector(const std::optional<std::vector<T>>& val) {
+    if (!val) return writeInt32(-1);
+    return writeByteVectorInternal(reinterpret_cast<const int8_t*>(val->data()), val->size());
+}
+template<typename T, std::enable_if_t<std::is_enum_v<T> && std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool>>
 status_t Parcel::writeEnumVector(const std::unique_ptr<std::vector<T>>& val) {
     if (!val) return writeInt32(-1);
     return writeByteVectorInternal(reinterpret_cast<const int8_t*>(val->data()), val->size());
@@ -1020,6 +1245,10 @@
     return writeTypedVector(val, &Parcel::writeEnum);
 }
 template<typename T, std::enable_if_t<std::is_enum_v<T> && !std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool>>
+status_t Parcel::writeEnumVector(const std::optional<std::vector<T>>& val) {
+    return writeNullableTypedVector(val, &Parcel::writeEnum);
+}
+template<typename T, std::enable_if_t<std::is_enum_v<T> && !std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool>>
 status_t Parcel::writeEnumVector(const std::unique_ptr<std::vector<T>>& val) {
     return writeNullableTypedVector(val, &Parcel::writeEnum);
 }
@@ -1051,6 +1280,17 @@
     return readByteVectorInternal(val, size);
 }
 template<typename T, std::enable_if_t<std::is_enum_v<T> && std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool>>
+status_t Parcel::readEnumVector(std::optional<std::vector<T>>* val) const {
+    size_t size;
+    if (status_t status = reserveOutVector(val, &size); status != OK) return status;
+    if (!*val) {
+        // reserveOutVector does not create the out vector if size is < 0.
+        // This occurs when writing a null Enum vector.
+        return OK;
+    }
+    return readByteVectorInternal(&**val, size);
+}
+template<typename T, std::enable_if_t<std::is_enum_v<T> && std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool>>
 status_t Parcel::readEnumVector(std::unique_ptr<std::vector<T>>* val) const {
     size_t size;
     if (status_t status = reserveOutVector(val, &size); status != OK) return status;
@@ -1066,6 +1306,10 @@
     return readTypedVector(val, &Parcel::readEnum);
 }
 template<typename T, std::enable_if_t<std::is_enum_v<T> && !std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool>>
+status_t Parcel::readEnumVector(std::optional<std::vector<T>>* val) const {
+    return readNullableTypedVector(val, &Parcel::readEnum);
+}
+template<typename T, std::enable_if_t<std::is_enum_v<T> && !std::is_same_v<typename std::underlying_type_t<T>,int8_t>, bool>>
 status_t Parcel::readEnumVector(std::unique_ptr<std::vector<T>>* val) const {
     return readNullableTypedVector(val, &Parcel::readEnum);
 }
diff --git a/libs/binder/include/binder/ParcelFileDescriptor.h b/libs/binder/include/binder/ParcelFileDescriptor.h
index 4635ad8..2ede6c4 100644
--- a/libs/binder/include/binder/ParcelFileDescriptor.h
+++ b/libs/binder/include/binder/ParcelFileDescriptor.h
@@ -32,6 +32,7 @@
     ParcelFileDescriptor();
     explicit ParcelFileDescriptor(android::base::unique_fd fd);
     ParcelFileDescriptor(ParcelFileDescriptor&& other) : mFd(std::move(other.mFd)) { }
+    ParcelFileDescriptor& operator=(ParcelFileDescriptor&& other) = default;
     ~ParcelFileDescriptor() override;
 
     int get() const { return mFd.get(); }
diff --git a/libs/binder/ndk/include_ndk/android/binder_parcel_utils.h b/libs/binder/ndk/include_ndk/android/binder_parcel_utils.h
index df5df13..09949ea 100644
--- a/libs/binder/ndk/include_ndk/android/binder_parcel_utils.h
+++ b/libs/binder/ndk/include_ndk/android/binder_parcel_utils.h
@@ -831,34 +831,34 @@
 }
 
 /**
- * Writes a vector of int8_t to the next location in a non-null parcel.
+ * Writes a vector of uint8_t to the next location in a non-null parcel.
  */
-inline binder_status_t AParcel_writeVector(AParcel* parcel, const std::vector<int8_t>& vec) {
-    return AParcel_writeByteArray(parcel, vec.data(), vec.size());
+inline binder_status_t AParcel_writeVector(AParcel* parcel, const std::vector<uint8_t>& vec) {
+    return AParcel_writeByteArray(parcel, reinterpret_cast<const int8_t*>(vec.data()), vec.size());
 }
 
 /**
- * Writes an optional vector of int8_t to the next location in a non-null parcel.
+ * Writes an optional vector of uint8_t to the next location in a non-null parcel.
  */
 inline binder_status_t AParcel_writeVector(AParcel* parcel,
-                                           const std::optional<std::vector<int8_t>>& vec) {
+                                           const std::optional<std::vector<uint8_t>>& vec) {
     if (!vec) return AParcel_writeByteArray(parcel, nullptr, -1);
     return AParcel_writeVector(parcel, *vec);
 }
 
 /**
- * Reads a vector of int8_t from the next location in a non-null parcel.
+ * Reads a vector of uint8_t from the next location in a non-null parcel.
  */
-inline binder_status_t AParcel_readVector(const AParcel* parcel, std::vector<int8_t>* vec) {
+inline binder_status_t AParcel_readVector(const AParcel* parcel, std::vector<uint8_t>* vec) {
     void* vectorData = static_cast<void*>(vec);
     return AParcel_readByteArray(parcel, vectorData, AParcel_stdVectorAllocator<int8_t>);
 }
 
 /**
- * Reads an optional vector of int8_t from the next location in a non-null parcel.
+ * Reads an optional vector of uint8_t from the next location in a non-null parcel.
  */
 inline binder_status_t AParcel_readVector(const AParcel* parcel,
-                                          std::optional<std::vector<int8_t>>* vec) {
+                                          std::optional<std::vector<uint8_t>>* vec) {
     void* vectorData = static_cast<void*>(vec);
     return AParcel_readByteArray(parcel, vectorData, AParcel_nullableStdVectorAllocator<int8_t>);
 }
diff --git a/libs/binderthreadstate/Android.bp b/libs/binderthreadstate/Android.bp
index c186110..9e50729 100644
--- a/libs/binderthreadstate/Android.bp
+++ b/libs/binderthreadstate/Android.bp
@@ -20,6 +20,10 @@
     vendor_available: true,
     host_supported: true,
 
+    apex_available: [
+        "com.android.media",
+    ],
+
     shared_libs: [
         "libbinder",
         "libhidlbase",  // libhwbinder is in here
diff --git a/libs/dumputils/dump_utils.cpp b/libs/dumputils/dump_utils.cpp
index fd557b7..2e14408 100644
--- a/libs/dumputils/dump_utils.cpp
+++ b/libs/dumputils/dump_utils.cpp
@@ -56,6 +56,10 @@
         "android.hardware.audio@4.0::IDevicesFactory",
         "android.hardware.audio@5.0::IDevicesFactory",
         "android.hardware.audio@6.0::IDevicesFactory",
+        "android.hardware.automotive.audiocontrol@1.0::IAudioControl",
+        "android.hardware.automotive.audiocontrol@2.0::IAudioControl",
+        "android.hardware.automotive.evs@1.0::IEvsCamera",
+        "android.hardware.automotive.vehicle@2.0::IVehicle",
         "android.hardware.biometrics.face@1.0::IBiometricsFace",
         "android.hardware.biometrics.fingerprint@2.1::IBiometricsFingerprint",
         "android.hardware.bluetooth@1.0::IBluetoothHci",
@@ -67,16 +71,12 @@
         "android.hardware.media.c2@1.0::IComponentStore",
         "android.hardware.media.omx@1.0::IOmx",
         "android.hardware.media.omx@1.0::IOmxStore",
+        "android.hardware.neuralnetworks@1.0::IDevice",
         "android.hardware.power@1.3::IPower",
         "android.hardware.power.stats@1.0::IPowerStats",
         "android.hardware.sensors@1.0::ISensors",
         "android.hardware.thermal@2.0::IThermal",
         "android.hardware.vr@1.0::IVr",
-        "android.hardware.automotive.audiocontrol@1.0::IAudioControl",
-        "android.hardware.automotive.audiocontrol@2.0::IAudioControl",
-        "android.hardware.automotive.vehicle@2.0::IVehicle",
-        "android.hardware.automotive.evs@1.0::IEvsCamera",
-        "android.hardware.neuralnetworks@1.0::IDevice",
         NULL,
 };
 
diff --git a/libs/fakeservicemanager/Android.bp b/libs/fakeservicemanager/Android.bp
index de32ff4..6909637 100644
--- a/libs/fakeservicemanager/Android.bp
+++ b/libs/fakeservicemanager/Android.bp
@@ -1,5 +1,6 @@
 cc_defaults {
     name: "fakeservicemanager_defaults",
+    host_supported: true,
     srcs: [
         "ServiceManager.cpp",
     ],
diff --git a/libs/gralloc/OWNERS b/libs/gralloc/OWNERS
index 67743cd..4a95778 100644
--- a/libs/gralloc/OWNERS
+++ b/libs/gralloc/OWNERS
@@ -1,2 +1,2 @@
-marissaw@google.com
+chrisforbes@google.com
 vhau@google.com
diff --git a/libs/gui/OWNERS b/libs/gui/OWNERS
index c13401d..b77dfda 100644
--- a/libs/gui/OWNERS
+++ b/libs/gui/OWNERS
@@ -1,10 +1,9 @@
 adyabr@google.com
 akrulec@google.com
 alecmouri@google.com
+chrisforbes@google.com
 jessehall@google.com
-jwcai@google.com
 lpy@google.com
-marissaw@google.com
 mathias@google.com
 racarr@google.com
 steventhomas@google.com
diff --git a/libs/gui/sysprop/Android.bp b/libs/gui/sysprop/Android.bp
index e7f7c1f..e090c49 100644
--- a/libs/gui/sysprop/Android.bp
+++ b/libs/gui/sysprop/Android.bp
@@ -1,5 +1,9 @@
 sysprop_library {
     name: "LibGuiProperties",
+    apex_available: [
+        "com.android.media",
+        "com.android.media.swcodec",
+    ],
     srcs: ["*.sysprop"],
     api_packages: ["android.sysprop"],
     property_owner: "Platform",
diff --git a/libs/ui/OWNERS b/libs/ui/OWNERS
index 97ead21..203a739 100644
--- a/libs/ui/OWNERS
+++ b/libs/ui/OWNERS
@@ -1,7 +1,6 @@
+chrisforbes@google.com
 lpy@google.com
-marissaw@google.com
 mathias@google.com
 romainguy@google.com
 stoza@google.com
-jwcai@google.com
-tianyuj@google.com
+vhau@google.com
diff --git a/libs/vr/libpdx_uds/service_endpoint.cpp b/libs/vr/libpdx_uds/service_endpoint.cpp
index ecbfdba..9bc70ea 100644
--- a/libs/vr/libpdx_uds/service_endpoint.cpp
+++ b/libs/vr/libpdx_uds/service_endpoint.cpp
@@ -535,13 +535,13 @@
   *message = Message{info};
   auto* state = static_cast<MessageState*>(message->GetState());
   state->request = std::move(request);
-  if (request.send_len > 0 && !request.is_impulse) {
-    state->request_data.resize(request.send_len);
+  if (state->request.send_len > 0 && !state->request.is_impulse) {
+    state->request_data.resize(state->request.send_len);
     status = ReceiveData(channel_fd, state->request_data.data(),
                          state->request_data.size());
   }
 
-  if (status && request.is_impulse)
+  if (status && state->request.is_impulse)
     status = ReenableEpollEvent(channel_fd);
 
   if (!status) {
diff --git a/opengl/tools/glgen/gen b/opengl/tools/glgen/gen
index 41fcf1b..9efd38f 100755
--- a/opengl/tools/glgen/gen
+++ b/opengl/tools/glgen/gen
@@ -1,6 +1,18 @@
 #!/bin/bash
 set -u
 set -e
+
+if [ -z "$ANDROID_BUILD_TOP" ] ; then
+    echo "ANDROID_BUILD_TOP is not set, did you run lunch?"
+    exit 1
+fi
+
+# Avoid spewing files in any location other than the intended one.
+if [ ! -x "$PWD/gen" ] ; then
+    echo "Run this script from its parent directory".
+    exit 1
+fi
+
 rm -rf out generated
 
 mkdir out
@@ -92,7 +104,7 @@
 
 # Add UnsupportedAppUsage.java to known sources.
 mkdir -p out/android/compat/annotation
-cp ../../../../../tools/platform-compat/annotation/src/java/android/compat/annotation/UnsupportedAppUsage.java out/android/compat/annotation
+cp ${ANDROID_BUILD_TOP}/tools/platform-compat/java/android/compat/annotation/UnsupportedAppUsage.java out/android/compat/annotation
 
 pushd out > /dev/null
 mkdir classes
@@ -153,23 +165,23 @@
     fi
 }
 
-compareGenerated ../../../../base/core/jni generated/C com_google_android_gles_jni_GLImpl.cpp
-compareGenerated ../../../../base/opengl/java/com/google/android/gles_jni generated/com/google/android/gles_jni GLImpl.java
+compareGenerated ${ANDROID_BUILD_TOP}/frameworks/base/core/jni generated/C com_google_android_gles_jni_GLImpl.cpp
+compareGenerated ${ANDROID_BUILD_TOP}/frameworks/base/opengl/java/com/google/android/gles_jni generated/com/google/android/gles_jni GLImpl.java
 
 for x in GL.java GL10.java GL10Ext.java GL11.java GL11Ext.java GL11ExtensionPack.java
 do
-    compareGenerated ../../../../base/opengl/java/javax/microedition/khronos/opengles generated/javax/microedition/khronos/opengles $x
+    compareGenerated ${ANDROID_BUILD_TOP}/frameworks/base/opengl/java/javax/microedition/khronos/opengles generated/javax/microedition/khronos/opengles $x
 done
 
 for x in EGL14 EGL15 EGLExt GLES10 GLES10Ext GLES11 GLES11Ext GLES20 GLES30 GLES31 GLES31Ext GLES32
 do
-    compareGenerated ../../../../base/opengl/java/android/opengl generated/android/opengl ${x}.java
-    compareGenerated ../../../../base/core/jni generated/C android_opengl_${x}.cpp
+    compareGenerated ${ANDROID_BUILD_TOP}/frameworks/base/opengl/java/android/opengl generated/android/opengl ${x}.java
+    compareGenerated ${ANDROID_BUILD_TOP}/frameworks/base/core/jni generated/C android_opengl_${x}.cpp
 done
 
 for x in EGLConfig EGLContext EGLDisplay EGLObjectHandle EGLSurface EGLImage EGLSync
 do
-    compareGenerated ../../../../base/opengl/java/android/opengl generated/android/opengl ${x}.java
+    compareGenerated ${ANDROID_BUILD_TOP}/frameworks/base/opengl/java/android/opengl generated/android/opengl ${x}.java
 done
 
 if [ $KEEP_GENERATED == "0" ] ; then
diff --git a/opengl/tools/glgen/stubs/egl/EGL14Header.java-if b/opengl/tools/glgen/stubs/egl/EGL14Header.java-if
index 9932556..951ecff 100644
--- a/opengl/tools/glgen/stubs/egl/EGL14Header.java-if
+++ b/opengl/tools/glgen/stubs/egl/EGL14Header.java-if
@@ -21,8 +21,8 @@
 import android.compat.annotation.UnsupportedAppUsage;
 import android.graphics.SurfaceTexture;
 import android.view.Surface;
-import android.view.SurfaceView;
 import android.view.SurfaceHolder;
+import android.view.SurfaceView;
 
 /**
  * EGL 1.4
diff --git a/opengl/tools/glgen/stubs/jsr239/GLImplHeader.java-impl b/opengl/tools/glgen/stubs/jsr239/GLImplHeader.java-impl
index afcc3eb..32c9d7d 100644
--- a/opengl/tools/glgen/stubs/jsr239/GLImplHeader.java-impl
+++ b/opengl/tools/glgen/stubs/jsr239/GLImplHeader.java-impl
@@ -19,6 +19,7 @@
 package com.google.android.gles_jni;
 
 import android.app.AppGlobals;
+import android.compat.annotation.UnsupportedAppUsage;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.IPackageManager;
 import android.os.Build;
@@ -26,6 +27,7 @@
 import android.util.Log;
 
 import java.nio.Buffer;
+
 import javax.microedition.khronos.opengles.GL10;
 import javax.microedition.khronos.opengles.GL10Ext;
 import javax.microedition.khronos.opengles.GL11;
@@ -55,6 +57,7 @@
     private boolean have_OES_framebuffer_object;
     private boolean have_OES_texture_cube_map;
 
+    @UnsupportedAppUsage
     public GLImpl() {
     }
 
diff --git a/services/surfaceflinger/OWNERS b/services/surfaceflinger/OWNERS
index f2bc65d..6bb999c 100644
--- a/services/surfaceflinger/OWNERS
+++ b/services/surfaceflinger/OWNERS
@@ -3,7 +3,6 @@
 alecmouri@google.com
 chaviw@google.com
 lpy@google.com
-marissaw@google.com
 racarr@google.com
 steventhomas@google.com
 stoza@google.com