Merge "Improvements to SF's BackgroundExcecutor." into main (c4fe541e) · Commits · e / os / android_frameworks_native

services/surfaceflinger/BackgroundExecutor.cpp

+21 −3

Original line number	Diff line number	Diff line
		@@ -19,6 +19,9 @@
		#define LOG_TAG "BackgroundExecutor"
		#define ATRACE_TAG ATRACE_TAG_GRAPHICS

		#include <processgroup/sched_policy.h>
		#include <pthread.h>
		#include <sched.h>
		#include <utils/Log.h>
		#include <mutex>

		@@ -26,14 +29,24 @@

		namespace android {

		ANDROID_SINGLETON_STATIC_INSTANCE(BackgroundExecutor);
		namespace {

		BackgroundExecutor::BackgroundExecutor() : Singleton<BackgroundExecutor>() {
		void set_thread_priority(bool highPriority) {
		set_sched_policy(0, highPriority ? SP_FOREGROUND : SP_BACKGROUND);
		struct sched_param param = {0};
		param.sched_priority = highPriority ? 2 : 0 /* must be 0 for non-RT */;
		sched_setscheduler(gettid(), highPriority ? SCHED_FIFO : SCHED_NORMAL, &param);
		}

		} // anonymous namespace

		BackgroundExecutor::BackgroundExecutor(bool highPriority) {
		// mSemaphore must be initialized before any calls to
		// BackgroundExecutor::sendCallbacks. For this reason, we initialize it
		// within the constructor instead of within mThread.
		LOG_ALWAYS_FATAL_IF(sem_init(&mSemaphore, 0, 0), "sem_init failed");
		mThread = std::thread([&]() {
		mThread = std::thread([&, highPriority]() {
		set_thread_priority(highPriority);
		while (!mDone) {
		LOG_ALWAYS_FATAL_IF(sem_wait(&mSemaphore), "sem_wait failed (%d)", errno);
		auto callbacks = mCallbacksQueue.pop();
		@@ -45,6 +58,11 @@ BackgroundExecutor::BackgroundExecutor() : Singleton<BackgroundExecutor>() {
		}
		}
		});
		if (highPriority) {
		pthread_setname_np(mThread.native_handle(), "BckgrndExec HP");
		} else {
		pthread_setname_np(mThread.native_handle(), "BckgrndExec LP");
		}
		}

		BackgroundExecutor::~BackgroundExecutor() {

services/surfaceflinger/BackgroundExecutor.h

+14 −3

Original line number	Diff line number	Diff line
		@@ -18,7 +18,6 @@

		#include <ftl/small_vector.h>
		#include <semaphore.h>
		#include <utils/Singleton.h>
		#include <thread>

		#include "LocklessQueue.h"
		@@ -26,10 +25,20 @@
		namespace android {

		// Executes tasks off the main thread.
		class BackgroundExecutor : public Singleton<BackgroundExecutor> {
		class BackgroundExecutor {
		public:
		BackgroundExecutor();
		~BackgroundExecutor();

		static BackgroundExecutor& getInstance() {
		static BackgroundExecutor instance(true);
		return instance;
		}

		static BackgroundExecutor& getLowPriorityInstance() {
		static BackgroundExecutor instance(false);
		return instance;
		}

		using Callbacks = ftl::SmallVector<std::function<void()>, 10>;
		// Queues callbacks onto a work queue to be executed by a background thread.
		// This is safe to call from multiple threads.
		@@ -37,6 +46,8 @@ public:
		void flushQueue();

		private:
		BackgroundExecutor(bool highPriority);

		sem_t mSemaphore;
		std::atomic_bool mDone = false;