Merge "libbinder - avoid pthread_cond_broadcast per call" (ff30b34c) · Commits · e / devices / smdk4412 / android_frameworks_native

libs/binder/IPCThreadState.cpp

+8 −1

Original line number	Diff line number	Diff line
		@@ -489,12 +489,14 @@ void IPCThreadState::flushCommands()
		void IPCThreadState::blockUntilThreadAvailable()
		{
		pthread_mutex_lock(&mProcess->mThreadCountLock);
		mProcess->mWaitingForThreads++;
		while (mProcess->mExecutingThreadsCount >= mProcess->mMaxThreads) {
		ALOGW("Waiting for thread to be free. mExecutingThreadsCount=%lu mMaxThreads=%lu\n",
		static_cast<unsigned long>(mProcess->mExecutingThreadsCount),
		static_cast<unsigned long>(mProcess->mMaxThreads));
		pthread_cond_wait(&mProcess->mThreadCountDecrement, &mProcess->mThreadCountLock);
		}
		mProcess->mWaitingForThreads--;
		pthread_mutex_unlock(&mProcess->mThreadCountLock);
		}

		@@ -534,7 +536,12 @@ status_t IPCThreadState::getAndExecuteCommand()
		}
		mProcess->mStarvationStartTimeMs = 0;
		}

		// Cond broadcast can be expensive, so don't send it every time a binder
		// call is processed. b/168806193
		if (mProcess->mWaitingForThreads > 0) {
		pthread_cond_broadcast(&mProcess->mThreadCountDecrement);
		}
		pthread_mutex_unlock(&mProcess->mThreadCountLock);
		}

+1 −0

Original line number	Diff line number	Diff line
		@@ -399,6 +399,7 @@ ProcessState::ProcessState(const char *driver)
		, mThreadCountLock(PTHREAD_MUTEX_INITIALIZER)
		, mThreadCountDecrement(PTHREAD_COND_INITIALIZER)
		, mExecutingThreadsCount(0)
		, mWaitingForThreads(0)
		, mMaxThreads(DEFAULT_MAX_BINDER_THREADS)
		, mStarvationStartTimeMs(0)
		, mThreadPoolStarted(false)

+4 −1

Original line number	Diff line number	Diff line
		@@ -107,11 +107,14 @@ private:
		int mDriverFD;
		void* mVMStart;

		// Protects thread count variable below.
		// Protects thread count and wait variables below.
		pthread_mutex_t mThreadCountLock;
		// Broadcast whenever mWaitingForThreads > 0
		pthread_cond_t mThreadCountDecrement;
		// Number of binder threads current executing a command.
		size_t mExecutingThreadsCount;
		// Number of threads calling IPCThreadState::blockUntilThreadAvailable()
		size_t mWaitingForThreads;
		// Maximum number for binder threads allowed for this process.
		size_t mMaxThreads;
		// Time when thread pool was emptied