Merge changes from topics "action-in-apex-config", "apex-ready-event", "subcontext-for-vendor-apex"

* changes:
  Use subcontext for APEX configs from /{vendor, odm}
  add apex-ready event after post-fs-data
  APEX configs support 'on' as well
diff --git a/init/action.h b/init/action.h
index 1534bf9..eddc384 100644
--- a/init/action.h
+++ b/init/action.h
@@ -22,6 +22,8 @@
 #include <variant>
 #include <vector>
 
+#include <android-base/strings.h>
+
 #include "builtins.h"
 #include "keyword_map.h"
 #include "result.h"
@@ -79,6 +81,7 @@
     static void set_function_map(const BuiltinFunctionMap* function_map) {
         function_map_ = function_map;
     }
+    bool IsFromApex() const { return base::StartsWith(filename_, "/apex/"); }
 
   private:
     void ExecuteCommand(const Command& command) const;
diff --git a/init/action_manager.h b/init/action_manager.h
index b6f93d9..2746a7c 100644
--- a/init/action_manager.h
+++ b/init/action_manager.h
@@ -37,6 +37,10 @@
     size_t CheckAllCommands();
 
     void AddAction(std::unique_ptr<Action> action);
+    template <class UnaryPredicate>
+    void RemoveActionIf(UnaryPredicate predicate) {
+        actions_.erase(std::remove_if(actions_.begin(), actions_.end(), predicate), actions_.end());
+    }
     void QueueEventTrigger(const std::string& trigger);
     void QueuePropertyChange(const std::string& name, const std::string& value);
     void QueueAllPropertyActions();
diff --git a/init/builtins.cpp b/init/builtins.cpp
index 01db4f5..9e1d93c 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -1288,7 +1288,8 @@
         return Error() << "glob pattern '" << glob_pattern << "' failed";
     }
     std::vector<std::string> configs;
-    Parser parser = CreateServiceOnlyParser(ServiceList::GetInstance(), true);
+    Parser parser =
+            CreateApexConfigParser(ActionManager::GetInstance(), ServiceList::GetInstance());
     for (size_t i = 0; i < glob_result.gl_pathc; i++) {
         std::string path = glob_result.gl_pathv[i];
         // Filter-out /apex/<name>@<ver> paths. The paths are bind-mounted to
diff --git a/init/init.cpp b/init/init.cpp
index f8330bc..4955bc5 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -85,6 +85,10 @@
 #include "system/core/init/property_service.pb.h"
 #include "util.h"
 
+#ifndef RECOVERY
+#include "com_android_apex.h"
+#endif  // RECOVERY
+
 using namespace std::chrono_literals;
 using namespace std::string_literals;
 
@@ -293,13 +297,59 @@
     return parser;
 }
 
-// parser that only accepts new services
-Parser CreateServiceOnlyParser(ServiceList& service_list, bool from_apex) {
-    Parser parser;
+#ifndef RECOVERY
+template <typename T>
+struct LibXmlErrorHandler {
+    T handler_;
+    template <typename Handler>
+    LibXmlErrorHandler(Handler&& handler) : handler_(std::move(handler)) {
+        xmlSetGenericErrorFunc(nullptr, &ErrorHandler);
+    }
+    ~LibXmlErrorHandler() { xmlSetGenericErrorFunc(nullptr, nullptr); }
+    static void ErrorHandler(void*, const char* msg, ...) {
+        va_list args;
+        va_start(args, msg);
+        char* formatted;
+        if (vasprintf(&formatted, msg, args) >= 0) {
+            LOG(ERROR) << formatted;
+        }
+        free(formatted);
+        va_end(args);
+    }
+};
 
-    parser.AddSectionParser(
-            "service", std::make_unique<ServiceParser>(&service_list, GetSubcontext(), std::nullopt,
-                                                       from_apex));
+template <typename Handler>
+LibXmlErrorHandler(Handler&&) -> LibXmlErrorHandler<Handler>;
+#endif  // RECOVERY
+
+// Returns a Parser that accepts scripts from APEX modules. It supports `service` and `on`.
+Parser CreateApexConfigParser(ActionManager& action_manager, ServiceList& service_list) {
+    Parser parser;
+    auto subcontext = GetSubcontext();
+#ifndef RECOVERY
+    if (subcontext) {
+        const auto apex_info_list_file = "/apex/apex-info-list.xml";
+        auto error_handler = LibXmlErrorHandler([&](const auto& error_message) {
+            LOG(ERROR) << "Failed to read " << apex_info_list_file << ":" << error_message;
+        });
+        const auto apex_info_list = com::android::apex::readApexInfoList(apex_info_list_file);
+        if (apex_info_list.has_value()) {
+            std::vector<std::string> subcontext_apexes;
+            for (const auto& info : apex_info_list->getApexInfo()) {
+                if (info.hasPreinstalledModulePath() &&
+                    subcontext->PathMatchesSubcontext(info.getPreinstalledModulePath())) {
+                    subcontext_apexes.push_back(info.getModuleName());
+                }
+            }
+            subcontext->SetApexList(std::move(subcontext_apexes));
+        }
+    }
+#endif  // RECOVERY
+    parser.AddSectionParser("service",
+                            std::make_unique<ServiceParser>(&service_list, subcontext, std::nullopt,
+                                                            /*from_apex=*/true));
+    parser.AddSectionParser("on", std::make_unique<ActionParser>(&action_manager, subcontext));
+
     return parser;
 }
 
diff --git a/init/init.h b/init/init.h
index 4f686cb..5220535 100644
--- a/init/init.h
+++ b/init/init.h
@@ -29,7 +29,7 @@
 namespace init {
 
 Parser CreateParser(ActionManager& action_manager, ServiceList& service_list);
-Parser CreateServiceOnlyParser(ServiceList& service_list, bool from_apex);
+Parser CreateApexConfigParser(ActionManager& action_manager, ServiceList& service_list);
 
 bool start_waiting_for_property(const char *name, const char *value);
 
diff --git a/init/init_test.cpp b/init/init_test.cpp
index 8c19d5f..0dc6ff6 100644
--- a/init/init_test.cpp
+++ b/init/init_test.cpp
@@ -42,34 +42,34 @@
 using ActionManagerCommand = std::function<void(ActionManager&)>;
 
 void TestInit(const std::string& init_script_file, const BuiltinFunctionMap& test_function_map,
-              const std::vector<ActionManagerCommand>& commands, ServiceList* service_list) {
-    ActionManager am;
-
+              const std::vector<ActionManagerCommand>& commands, ActionManager* action_manager,
+              ServiceList* service_list) {
     Action::set_function_map(&test_function_map);
 
     Parser parser;
     parser.AddSectionParser("service",
                             std::make_unique<ServiceParser>(service_list, nullptr, std::nullopt));
-    parser.AddSectionParser("on", std::make_unique<ActionParser>(&am, nullptr));
+    parser.AddSectionParser("on", std::make_unique<ActionParser>(action_manager, nullptr));
     parser.AddSectionParser("import", std::make_unique<ImportParser>(&parser));
 
     ASSERT_TRUE(parser.ParseConfig(init_script_file));
 
     for (const auto& command : commands) {
-        command(am);
+        command(*action_manager);
     }
 
-    while (am.HasMoreCommands()) {
-        am.ExecuteOneCommand();
+    while (action_manager->HasMoreCommands()) {
+        action_manager->ExecuteOneCommand();
     }
 }
 
 void TestInitText(const std::string& init_script, const BuiltinFunctionMap& test_function_map,
-                  const std::vector<ActionManagerCommand>& commands, ServiceList* service_list) {
+                  const std::vector<ActionManagerCommand>& commands, ActionManager* action_manager,
+                  ServiceList* service_list) {
     TemporaryFile tf;
     ASSERT_TRUE(tf.fd != -1);
     ASSERT_TRUE(android::base::WriteStringToFd(init_script, tf.fd));
-    TestInit(tf.path, test_function_map, commands, service_list);
+    TestInit(tf.path, test_function_map, commands, action_manager, service_list);
 }
 
 TEST(init, SimpleEventTrigger) {
@@ -91,8 +91,9 @@
     ActionManagerCommand trigger_boot = [](ActionManager& am) { am.QueueEventTrigger("boot"); };
     std::vector<ActionManagerCommand> commands{trigger_boot};
 
+    ActionManager action_manager;
     ServiceList service_list;
-    TestInitText(init_script, test_function_map, commands, &service_list);
+    TestInitText(init_script, test_function_map, commands, &action_manager, &service_list);
 
     EXPECT_TRUE(expect_true);
 }
@@ -154,8 +155,9 @@
     ActionManagerCommand trigger_boot = [](ActionManager& am) { am.QueueEventTrigger("boot"); };
     std::vector<ActionManagerCommand> commands{trigger_boot};
 
+    ActionManager action_manager;
     ServiceList service_list;
-    TestInitText(init_script, test_function_map, commands, &service_list);
+    TestInitText(init_script, test_function_map, commands, &action_manager, &service_list);
     EXPECT_EQ(3, num_executed);
 }
 
@@ -170,8 +172,9 @@
 
 )init";
 
+    ActionManager action_manager;
     ServiceList service_list;
-    TestInitText(init_script, BuiltinFunctionMap(), {}, &service_list);
+    TestInitText(init_script, BuiltinFunctionMap(), {}, &action_manager, &service_list);
     ASSERT_EQ(1, std::distance(service_list.begin(), service_list.end()));
 
     auto service = service_list.begin()->get();
@@ -237,13 +240,100 @@
     ActionManagerCommand trigger_boot = [](ActionManager& am) { am.QueueEventTrigger("boot"); };
     std::vector<ActionManagerCommand> commands{trigger_boot};
 
+    ActionManager action_manager;
     ServiceList service_list;
-
-    TestInit(start.path, test_function_map, commands, &service_list);
+    TestInit(start.path, test_function_map, commands, &action_manager, &service_list);
 
     EXPECT_EQ(6, num_executed);
 }
 
+BuiltinFunctionMap GetTestFunctionMapForLazyLoad(int& num_executed, ActionManager& action_manager) {
+    auto execute_command = [&num_executed](const BuiltinArguments& args) {
+        EXPECT_EQ(2U, args.size());
+        EXPECT_EQ(++num_executed, std::stoi(args[1]));
+        return Result<void>{};
+    };
+    auto load_command = [&action_manager](const BuiltinArguments& args) -> Result<void> {
+        EXPECT_EQ(2U, args.size());
+        Parser parser;
+        parser.AddSectionParser("on", std::make_unique<ActionParser>(&action_manager, nullptr));
+        if (!parser.ParseConfig(args[1])) {
+            return Error() << "Failed to load";
+        }
+        return Result<void>{};
+    };
+    auto trigger_command = [&action_manager](const BuiltinArguments& args) {
+        EXPECT_EQ(2U, args.size());
+        LOG(INFO) << "Queue event trigger: " << args[1];
+        action_manager.QueueEventTrigger(args[1]);
+        return Result<void>{};
+    };
+    BuiltinFunctionMap test_function_map = {
+            {"execute", {1, 1, {false, execute_command}}},
+            {"load", {1, 1, {false, load_command}}},
+            {"trigger", {1, 1, {false, trigger_command}}},
+    };
+    return test_function_map;
+}
+
+TEST(init, LazilyLoadedActionsCantBeTriggeredByTheSameTrigger) {
+    // "start" script loads "lazy" script. Even though "lazy" scripts
+    // defines "on boot" action, it's not executed by the current "boot"
+    // event because it's already processed.
+    TemporaryFile lazy;
+    ASSERT_TRUE(lazy.fd != -1);
+    ASSERT_TRUE(android::base::WriteStringToFd("on boot\nexecute 2", lazy.fd));
+
+    TemporaryFile start;
+    // clang-format off
+    std::string start_script = "on boot\n"
+                               "load " + std::string(lazy.path) + "\n"
+                               "execute 1";
+    // clang-format on
+    ASSERT_TRUE(android::base::WriteStringToFd(start_script, start.fd));
+
+    int num_executed = 0;
+    ActionManager action_manager;
+    ServiceList service_list;
+    BuiltinFunctionMap test_function_map =
+            GetTestFunctionMapForLazyLoad(num_executed, action_manager);
+
+    ActionManagerCommand trigger_boot = [](ActionManager& am) { am.QueueEventTrigger("boot"); };
+    std::vector<ActionManagerCommand> commands{trigger_boot};
+    TestInit(start.path, test_function_map, commands, &action_manager, &service_list);
+
+    EXPECT_EQ(1, num_executed);
+}
+
+TEST(init, LazilyLoadedActionsCanBeTriggeredByTheNextTrigger) {
+    // "start" script loads "lazy" script and then triggers "next" event
+    // which executes "on next" action loaded by the previous command.
+    TemporaryFile lazy;
+    ASSERT_TRUE(lazy.fd != -1);
+    ASSERT_TRUE(android::base::WriteStringToFd("on next\nexecute 2", lazy.fd));
+
+    TemporaryFile start;
+    // clang-format off
+    std::string start_script = "on boot\n"
+                               "load " + std::string(lazy.path) + "\n"
+                               "execute 1\n"
+                               "trigger next";
+    // clang-format on
+    ASSERT_TRUE(android::base::WriteStringToFd(start_script, start.fd));
+
+    int num_executed = 0;
+    ActionManager action_manager;
+    ServiceList service_list;
+    BuiltinFunctionMap test_function_map =
+            GetTestFunctionMapForLazyLoad(num_executed, action_manager);
+
+    ActionManagerCommand trigger_boot = [](ActionManager& am) { am.QueueEventTrigger("boot"); };
+    std::vector<ActionManagerCommand> commands{trigger_boot};
+    TestInit(start.path, test_function_map, commands, &action_manager, &service_list);
+
+    EXPECT_EQ(2, num_executed);
+}
+
 TEST(init, RejectsCriticalAndOneshotService) {
     if (GetIntProperty("ro.product.first_api_level", 10000) < 30) {
         GTEST_SKIP() << "Test only valid for devices launching with R or later";
diff --git a/init/reboot.cpp b/init/reboot.cpp
index 41cf748..4e4bfd8 100644
--- a/init/reboot.cpp
+++ b/init/reboot.cpp
@@ -892,7 +892,16 @@
         sub_reason = "ns_switch";
         return Error() << "Failed to switch to bootstrap namespace";
     }
-    // Remove services that were defined in an APEX.
+    ActionManager::GetInstance().RemoveActionIf([](const auto& action) -> bool {
+        if (action->IsFromApex()) {
+            std::string trigger_name = action->BuildTriggersString();
+            LOG(INFO) << "Removing action (" << trigger_name << ") from (" << action->filename()
+                      << ":" << action->line() << ")";
+            return true;
+        }
+        return false;
+    });
+    // Remove services that were defined in an APEX
     ServiceList::GetInstance().RemoveServiceIf([](const std::unique_ptr<Service>& s) -> bool {
         if (s->is_from_apex()) {
             LOG(INFO) << "Removing service '" << s->name() << "' because it's defined in an APEX";
diff --git a/init/subcontext.cpp b/init/subcontext.cpp
index 7aa4a9d..bb3967e 100644
--- a/init/subcontext.cpp
+++ b/init/subcontext.cpp
@@ -250,7 +250,14 @@
     Fork();
 }
 
-bool Subcontext::PathMatchesSubcontext(const std::string& path) {
+bool Subcontext::PathMatchesSubcontext(const std::string& path) const {
+    static const std::string kApexDir = "/apex/";
+    if (StartsWith(path, kApexDir)) {
+        auto begin = kApexDir.size();
+        auto end = path.find('/', begin);
+        auto apex_name = path.substr(begin, end - begin);
+        return std::find(apex_list_.begin(), apex_list_.end(), apex_name) != apex_list_.end();
+    }
     for (const auto& prefix : path_prefixes_) {
         if (StartsWith(path, prefix)) {
             return true;
@@ -259,6 +266,10 @@
     return false;
 }
 
+void Subcontext::SetApexList(std::vector<std::string>&& apex_list) {
+    apex_list_ = std::move(apex_list);
+}
+
 Result<SubcontextReply> Subcontext::TransmitMessage(const SubcontextCommand& subcontext_command) {
     if (auto result = SendMessage(socket_, subcontext_command); !result.ok()) {
         Restart();
diff --git a/init/subcontext.h b/init/subcontext.h
index cb4138e..8acc032 100644
--- a/init/subcontext.h
+++ b/init/subcontext.h
@@ -46,7 +46,8 @@
     Result<void> Execute(const std::vector<std::string>& args);
     Result<std::vector<std::string>> ExpandArgs(const std::vector<std::string>& args);
     void Restart();
-    bool PathMatchesSubcontext(const std::string& path);
+    bool PathMatchesSubcontext(const std::string& path) const;
+    void SetApexList(std::vector<std::string>&& apex_list);
 
     const std::string& context() const { return context_; }
     pid_t pid() const { return pid_; }
@@ -56,6 +57,7 @@
     Result<SubcontextReply> TransmitMessage(const SubcontextCommand& subcontext_command);
 
     std::vector<std::string> path_prefixes_;
+    std::vector<std::string> apex_list_;
     std::string context_;
     pid_t pid_;
     android::base::unique_fd socket_;
diff --git a/rootdir/init.rc b/rootdir/init.rc
index dcaaa4b..caed4e1 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -534,6 +534,10 @@
     # /data, which in turn can only be loaded when system properties are present.
     trigger post-fs-data
 
+    # APEXes are ready to use. apex-ready is a public trigger similar to apexd.status=ready which
+    # is a system-private property.
+    trigger apex-ready
+
     # Should be before netd, but after apex, properties and logging is available.
     trigger load_bpf_programs
 
@@ -1290,6 +1294,7 @@
 on userspace-reboot-resume
   trigger userspace-reboot-fs-remount
   trigger post-fs-data
+  trigger apex-ready
   trigger zygote-start
   trigger early-boot
   trigger boot