diff --git a/services/surfaceflinger/common/Android.bp b/services/surfaceflinger/common/Android.bp
new file mode 100644
index 0000000..5ef22b5
--- /dev/null
+++ b/services/surfaceflinger/common/Android.bp
@@ -0,0 +1,48 @@
+package {
+    // See: http://go/android-license-faq
+    // A large-scale-change added 'default_applicable_licenses' to import
+    // all of the 'license_kinds' from "frameworks_native_license"
+    // to get the below license kinds:
+    //   SPDX-license-identifier-Apache-2.0
+    default_applicable_licenses: ["frameworks_native_license"],
+}
+
+cc_defaults {
+    name: "libsurfaceflinger_common_defaults",
+    defaults: [
+        "android.hardware.graphics.composer3-ndk_shared",
+        "surfaceflinger_defaults",
+    ],
+    shared_libs: [
+        "libSurfaceFlingerProp",
+        "server_configurable_flags",
+    ],
+    static_libs: [
+        "librenderengine",
+    ],
+    srcs: [
+        "FlagManager.cpp",
+    ],
+    local_include_dirs: ["include"],
+    export_include_dirs: ["include"],
+}
+
+cc_library_static {
+    name: "libsurfaceflinger_common",
+    defaults: [
+        "libsurfaceflinger_common_defaults",
+    ],
+    static_libs: [
+        "libsurfaceflingerflags",
+    ],
+}
+
+cc_library_static {
+    name: "libsurfaceflinger_common_test",
+    defaults: [
+        "libsurfaceflinger_common_defaults",
+    ],
+    static_libs: [
+        "libsurfaceflingerflags_test",
+    ],
+}
diff --git a/services/surfaceflinger/common/FlagManager.cpp b/services/surfaceflinger/common/FlagManager.cpp
new file mode 100644
index 0000000..8da7d8e
--- /dev/null
+++ b/services/surfaceflinger/common/FlagManager.cpp
@@ -0,0 +1,203 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <common/FlagManager.h>
+
+#include <SurfaceFlingerProperties.sysprop.h>
+#include <android-base/parsebool.h>
+#include <android-base/parseint.h>
+#include <android-base/properties.h>
+#include <android-base/stringprintf.h>
+#include <log/log.h>
+#include <renderengine/RenderEngine.h>
+#include <server_configurable_flags/get_flags.h>
+#include <cinttypes>
+
+#include <com_android_graphics_surfaceflinger_flags.h>
+
+namespace android {
+using namespace com::android::graphics::surfaceflinger;
+
+static constexpr const char* kExperimentNamespace = "surface_flinger_native_boot";
+
+std::unique_ptr<FlagManager> FlagManager::mInstance;
+std::once_flag FlagManager::mOnce;
+
+FlagManager::FlagManager(ConstructorTag) {}
+FlagManager::~FlagManager() = default;
+
+namespace {
+std::optional<bool> parseBool(const char* str) {
+    base::ParseBoolResult parseResult = base::ParseBool(str);
+    switch (parseResult) {
+        case base::ParseBoolResult::kTrue:
+            return std::make_optional(true);
+        case base::ParseBoolResult::kFalse:
+            return std::make_optional(false);
+        case base::ParseBoolResult::kError:
+            return std::nullopt;
+    }
+}
+
+bool getFlagValue(std::function<bool()> getter, std::optional<bool> overrideValue) {
+    if (overrideValue.has_value()) {
+        return *overrideValue;
+    }
+
+    return getter();
+}
+
+} // namespace
+
+const FlagManager& FlagManager::getInstance() {
+    return getMutableInstance();
+}
+
+FlagManager& FlagManager::getMutableInstance() {
+    std::call_once(mOnce, [&] {
+        LOG_ALWAYS_FATAL_IF(mInstance, "Instance already created");
+        mInstance = std::make_unique<FlagManager>(ConstructorTag{});
+    });
+
+    return *mInstance;
+}
+
+void FlagManager::markBootCompleted() {
+    mBootCompleted = true;
+}
+
+void FlagManager::setUnitTestMode() {
+    mUnitTestMode = true;
+
+    // Also set boot completed as we don't really care about it in unit testing
+    mBootCompleted = true;
+}
+
+void FlagManager::dumpFlag(std::string& result, bool readonly, const char* name,
+                           std::function<bool()> getter) const {
+    if (readonly || mBootCompleted) {
+        base::StringAppendF(&result, "%s: %s\n", name, getter() ? "true" : "false");
+    } else {
+        base::StringAppendF(&result, "%s: in progress (still booting)\n", name);
+    }
+}
+
+void FlagManager::dump(std::string& result) const {
+#define DUMP_FLAG_INTERVAL(name, readonly) \
+    dumpFlag(result, (readonly), #name, std::bind(&FlagManager::name, this))
+#define DUMP_SERVER_FLAG(name) DUMP_FLAG_INTERVAL(name, false)
+#define DUMP_READ_ONLY_FLAG(name) DUMP_FLAG_INTERVAL(name, true)
+
+    base::StringAppendF(&result, "FlagManager values: \n");
+
+    /// Legacy server flags ///
+    DUMP_SERVER_FLAG(use_adpf_cpu_hint);
+    DUMP_SERVER_FLAG(use_skia_tracing);
+
+    /// Trunk stable server flags ///
+    DUMP_SERVER_FLAG(late_boot_misc2);
+    DUMP_SERVER_FLAG(dont_skip_on_early);
+    DUMP_SERVER_FLAG(refresh_rate_overlay_on_external_display);
+
+    /// Trunk stable readonly flags ///
+    DUMP_READ_ONLY_FLAG(connected_display);
+    DUMP_READ_ONLY_FLAG(enable_small_area_detection);
+    DUMP_READ_ONLY_FLAG(misc1);
+    DUMP_READ_ONLY_FLAG(vrr_config);
+    DUMP_READ_ONLY_FLAG(hotplug2);
+    DUMP_READ_ONLY_FLAG(hdcp_level_hal);
+    DUMP_READ_ONLY_FLAG(multithreaded_present);
+
+#undef DUMP_READ_ONLY_FLAG
+#undef DUMP_SERVER_FLAG
+#undef DUMP_FLAG_INTERVAL
+}
+
+std::optional<bool> FlagManager::getBoolProperty(const char* property) const {
+    return parseBool(base::GetProperty(property, "").c_str());
+}
+
+bool FlagManager::getServerConfigurableFlag(const char* experimentFlagName) const {
+    const auto value = server_configurable_flags::GetServerConfigurableFlag(kExperimentNamespace,
+                                                                            experimentFlagName, "");
+    const auto res = parseBool(value.c_str());
+    return res.has_value() && res.value();
+}
+
+#define FLAG_MANAGER_LEGACY_SERVER_FLAG(name, syspropOverride, serverFlagName)              \
+    bool FlagManager::name() const {                                                        \
+        LOG_ALWAYS_FATAL_IF(!mBootCompleted,                                                \
+                            "Can't read %s before boot completed as it is server writable", \
+                            __func__);                                                      \
+        const auto debugOverride = getBoolProperty(syspropOverride);                        \
+        if (debugOverride.has_value()) return debugOverride.value();                        \
+        return getServerConfigurableFlag(serverFlagName);                                   \
+    }
+
+#define FLAG_MANAGER_FLAG_INTERNAL(name, syspropOverride, checkForBootCompleted)                \
+    bool FlagManager::name() const {                                                            \
+        if (checkForBootCompleted) {                                                            \
+            LOG_ALWAYS_FATAL_IF(!mBootCompleted,                                                \
+                                "Can't read %s before boot completed as it is server writable", \
+                                __func__);                                                      \
+        }                                                                                       \
+        static std::optional<bool> debugOverride = getBoolProperty(syspropOverride);            \
+        static bool value = getFlagValue([] { return flags::name(); }, debugOverride);          \
+        if (mUnitTestMode) {                                                                    \
+            /*                                                                                  \
+             * When testing, we don't want to rely on the cached values stored in the static    \
+             * variables.                                                                       \
+             */                                                                                 \
+            debugOverride = getBoolProperty(syspropOverride);                                   \
+            value = getFlagValue([] { return flags::name(); }, debugOverride);                  \
+        }                                                                                       \
+        return value;                                                                           \
+    }
+
+#define FLAG_MANAGER_SERVER_FLAG(name, syspropOverride) \
+    FLAG_MANAGER_FLAG_INTERNAL(name, syspropOverride, true)
+
+#define FLAG_MANAGER_READ_ONLY_FLAG(name, syspropOverride) \
+    FLAG_MANAGER_FLAG_INTERNAL(name, syspropOverride, false)
+
+/// Legacy server flags ///
+FLAG_MANAGER_LEGACY_SERVER_FLAG(test_flag, "", "")
+FLAG_MANAGER_LEGACY_SERVER_FLAG(use_adpf_cpu_hint, "debug.sf.enable_adpf_cpu_hint",
+                                "AdpfFeature__adpf_cpu_hint")
+FLAG_MANAGER_LEGACY_SERVER_FLAG(use_skia_tracing, PROPERTY_SKIA_ATRACE_ENABLED,
+                                "SkiaTracingFeature__use_skia_tracing")
+
+/// Trunk stable readonly flags ///
+FLAG_MANAGER_READ_ONLY_FLAG(connected_display, "")
+FLAG_MANAGER_READ_ONLY_FLAG(enable_small_area_detection, "")
+FLAG_MANAGER_READ_ONLY_FLAG(misc1, "")
+FLAG_MANAGER_READ_ONLY_FLAG(vrr_config, "debug.sf.enable_vrr_config")
+FLAG_MANAGER_READ_ONLY_FLAG(hotplug2, "")
+FLAG_MANAGER_READ_ONLY_FLAG(hdcp_level_hal, "")
+FLAG_MANAGER_READ_ONLY_FLAG(multithreaded_present, "debug.sf.multithreaded_present")
+
+/// Trunk stable server flags ///
+FLAG_MANAGER_SERVER_FLAG(late_boot_misc2, "")
+FLAG_MANAGER_SERVER_FLAG(refresh_rate_overlay_on_external_display, "")
+
+/// Exceptions ///
+bool FlagManager::dont_skip_on_early() const {
+    // Even though this is a server writable flag, we do call it before boot completed, but that's
+    // fine since the decision is done per frame. We can't do caching though.
+    return flags::dont_skip_on_early();
+}
+
+} // namespace android
diff --git a/services/surfaceflinger/common/include/common/FlagManager.h b/services/surfaceflinger/common/include/common/FlagManager.h
new file mode 100644
index 0000000..e3e4f80
--- /dev/null
+++ b/services/surfaceflinger/common/include/common/FlagManager.h
@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <cstdint>
+#include <mutex>
+#include <optional>
+#include <string>
+
+namespace android {
+// Manages flags for SurfaceFlinger, including default values, system properties, and Mendel
+// experiment configuration values. Can be called from any thread.
+class FlagManager {
+private:
+    // Effectively making the constructor private, while allowing std::make_unique to work
+    struct ConstructorTag {};
+
+public:
+    static const FlagManager& getInstance();
+    static FlagManager& getMutableInstance();
+
+    FlagManager(ConstructorTag);
+    virtual ~FlagManager();
+
+    void markBootCompleted();
+    void dump(std::string& result) const;
+
+    void setUnitTestMode();
+
+    /// Legacy server flags ///
+    bool test_flag() const;
+    bool use_adpf_cpu_hint() const;
+    bool use_skia_tracing() const;
+
+    /// Trunk stable server flags ///
+    bool late_boot_misc2() const;
+    bool dont_skip_on_early() const;
+    bool refresh_rate_overlay_on_external_display() const;
+
+    /// Trunk stable readonly flags ///
+    bool connected_display() const;
+    bool enable_small_area_detection() const;
+    bool misc1() const;
+    bool vrr_config() const;
+    bool hotplug2() const;
+    bool hdcp_level_hal() const;
+    bool multithreaded_present() const;
+
+protected:
+    // overridden for unit tests
+    virtual std::optional<bool> getBoolProperty(const char*) const;
+    virtual bool getServerConfigurableFlag(const char*) const;
+
+private:
+    friend class TestableFlagManager;
+
+    FlagManager(const FlagManager&) = delete;
+
+    void dumpFlag(std::string& result, bool readonly, const char* name,
+                  std::function<bool()> getter) const;
+
+    std::atomic_bool mBootCompleted = false;
+    std::atomic_bool mUnitTestMode = false;
+
+    static std::unique_ptr<FlagManager> mInstance;
+    static std::once_flag mOnce;
+};
+} // namespace android