Merge "libbinder: ProcessState warn on forked" am: a09c4ff2f1 (a147b019) · Commits · e / os / android_frameworks_native

libs/binder/ProcessState.cpp

+40 −2

Original line number	Diff line number	Diff line
		@@ -89,13 +89,23 @@ sp<ProcessState> ProcessState::selfOrNull()
		return init(nullptr, false /requireDefault/);
		}

		sp<ProcessState> ProcessState::init(const char *driver, bool requireDefault)
		{
		[[clang::no_destroy]] static sp<ProcessState> gProcess;
		[[clang::no_destroy]] static std::mutex gProcessMutex;

		static void verifyNotForked(bool forked) {
		if (forked) {
		ALOGE("libbinder does not support being forked");
		}
		}

		sp<ProcessState> ProcessState::init(const char *driver, bool requireDefault)
		{

		if (driver == nullptr) {
		std::lock_guard<std::mutex> l(gProcessMutex);
		if (gProcess) {
		verifyNotForked(gProcess->mForked);
		}
		return gProcess;
		}

		@@ -106,6 +116,14 @@ sp<ProcessState> ProcessState::init(const char *driver, bool requireDefault)
		driver = "/dev/binder";
		}

		// we must install these before instantiating the gProcess object,
		// otherwise this would race with creating it, and there could be the
		// possibility of an invalid gProcess object forked by another thread
		// before these are installed
		int ret = pthread_atfork(ProcessState::onFork, ProcessState::parentPostFork,
		ProcessState::childPostFork);
		LOG_ALWAYS_FATAL_IF(ret != 0, "pthread_atfork error %s", strerror(ret));

		std::lock_guard<std::mutex> l(gProcessMutex);
		gProcess = sp<ProcessState>::make(driver);
		});
		@@ -119,6 +137,7 @@ sp<ProcessState> ProcessState::init(const char *driver, bool requireDefault)
		gProcess->getDriverName().c_str(), driver);
		}

		verifyNotForked(gProcess->mForked);
		return gProcess;
		}

		@@ -137,6 +156,24 @@ sp<IBinder> ProcessState::getContextObject(const sp<IBinder>& /caller/)
		return context;
		}

		void ProcessState::onFork() {
		// make sure another thread isn't currently retrieving ProcessState
		gProcessMutex.lock();
		}

		void ProcessState::parentPostFork() {
		gProcessMutex.unlock();
		}

		void ProcessState::childPostFork() {
		// another thread might call fork before gProcess is instantiated, but after
		// the thread handler is installed
		if (gProcess) {
		gProcess->mForked = true;
		}
		gProcessMutex.unlock();
		}

		void ProcessState::startThreadPool()
		{
		AutoMutex _l(mLock);
		@@ -426,6 +463,7 @@ ProcessState::ProcessState(const char* driver)
		mWaitingForThreads(0),
		mMaxThreads(DEFAULT_MAX_BINDER_THREADS),
		mStarvationStartTimeMs(0),
		mForked(false),
		mThreadPoolStarted(false),
		mThreadPoolSeq(1),
		mCallRestriction(CallRestriction::NONE) {

libs/binder/include/binder/ProcessState.h

+5 −0

Original line number	Diff line number	Diff line
		@@ -94,6 +94,10 @@ public:
		private:
		static sp<ProcessState> init(const char* defaultDriver, bool requireDefault);

		static void onFork();
		static void parentPostFork();
		static void childPostFork();

		friend class IPCThreadState;
		friend class sp<ProcessState>;

		@@ -132,6 +136,7 @@ private:

		Vector<handle_entry> mHandleToObject;

		bool mForked;
		bool mThreadPoolStarted;
		volatile int32_t mThreadPoolSeq;