Merge "Partial Revert "audio: Add addtl permission sync behavior"" into main (9d7d08e6) · Commits · e / os / android_frameworks_base

core/jni/android_media_AudioSystem.cpp

+27 −35

Original line number	Diff line number	Diff line
		@@ -45,6 +45,7 @@
		#include <sys/system_properties.h>
		#include <utils/Log.h>

		#include <thread>
		#include <optional>
		#include <sstream>
		#include <memory>
		@@ -3378,46 +3379,36 @@ static jboolean android_media_AudioSystem_isBluetoothVariableLatencyEnabled(JNIE
		class JavaSystemPropertyListener {
		public:
		JavaSystemPropertyListener(JNIEnv* env, jobject javaCallback, std::string sysPropName) :
		mCallback {javaCallback, env},
		mPi {__system_property_find(sysPropName.c_str())},
		mListenerThread([this](mediautils::stop_token stok) mutable {
		static const struct timespec close_delay = { .tv_sec = 1 };
		while (!stok.stop_requested()) {
		uint32_t old_serial = mSerial.load();
		uint32_t new_serial;
		if (__system_property_wait(mPi, old_serial, &new_serial, &close_delay)) {
		while (new_serial > old_serial) {
		if (mSerial.compare_exchange_weak(old_serial, new_serial)) {
		fireUpdate();
		break;
		}
		mCallback(env->NewGlobalRef(javaCallback)),
		mCachedProperty(android::base::CachedProperty{std::move(sysPropName)}) {
		mListenerThread = std::thread([this]() mutable {
		JNIEnv* threadEnv = GetOrAttachJNIEnvironment(gVm);
		while (!mCleanupSignal.load()) {
		using namespace std::chrono_literals;
		// 1s timeout so this thread can read the cleanup signal to (slowly) be able to
		// be destroyed.
		std::string newVal = mCachedProperty.WaitForChange(1000ms) ?: "";
		if (newVal != "" && mLastVal != newVal) {
		threadEnv->CallVoidMethod(mCallback, gRunnableClassInfo.run);
		mLastVal = std::move(newVal);
		}
		}
		});
		}
		}) {}

		void triggerUpdateIfChanged() {
		uint32_t old_serial = mSerial.load();
		uint32_t new_serial = __system_property_serial(mPi);
		while (new_serial > old_serial) {
		if (mSerial.compare_exchange_weak(old_serial, new_serial)) {
		fireUpdate();
		break;
		}
		}
		~JavaSystemPropertyListener() {
		mCleanupSignal.store(true);
		mListenerThread.join();
		JNIEnv* env = GetOrAttachJNIEnvironment(gVm);
		env->DeleteGlobalRef(mCallback);
		}

		private:
		void fireUpdate() {
		const auto threadEnv = GetOrAttachJNIEnvironment(gVm);
		threadEnv->CallVoidMethod(mCallback.get(), gRunnableClassInfo.run);
		}

		// Should outlive thread object
		const GlobalRef mCallback;
		const prop_info * const mPi;
		std::atomic<uint32_t> mSerial = 0;
		const mediautils::jthread mListenerThread;
		jobject mCallback;
		android::base::CachedProperty mCachedProperty;
		std::thread mListenerThread;
		std::atomic<bool> mCleanupSignal{false};
		std::string mLastVal = "";
		};

		// A logical set keyed by address
		@@ -3441,7 +3432,8 @@ static void android_media_AudioSystem_triggerSystemPropertyUpdate(JNIEnv *env,
		const auto iter = std::find_if(gSystemPropertyListeners.begin(), gSystemPropertyListeners.end(),
		[nativeHandle](const auto& x) { return reinterpret_cast<jlong>(x.get()) == nativeHandle; });
		if (iter != gSystemPropertyListeners.end()) {
		(*iter)->triggerUpdateIfChanged();
		// TODO(b/363548816) resolve performance issue
		// (*iter)->triggerUpdateIfChanged();
		} else {
		jniThrowException(env, "java/lang/IllegalArgumentException", "Invalid handle");
		}