Add RpcServer::shutdown. (1a235859) · Commits · e / os / android_frameworks_native

libs/binder/RpcServer.cpp

+63 −4

Original line number	Diff line number	Diff line
		@@ -16,19 +16,21 @@

		#define LOG_TAG "RpcServer"

		#include <poll.h>
		#include <sys/socket.h>
		#include <sys/un.h>

		#include <thread>
		#include <vector>

		#include <android-base/macros.h>
		#include <android-base/scopeguard.h>
		#include <binder/Parcel.h>
		#include <binder/RpcServer.h>
		#include <log/log.h>
		#include "RpcState.h"

		#include "RpcSocketAddress.h"
		#include "RpcState.h"
		#include "RpcWireFormat.h"

		namespace android {
		@@ -99,7 +101,7 @@ bool RpcServer::setupInetServer(unsigned int port, unsigned int* assignedPort) {

		void RpcServer::setMaxThreads(size_t threads) {
		LOG_ALWAYS_FATAL_IF(threads <= 0, "RpcServer is useless without threads");
		LOG_ALWAYS_FATAL_IF(mStarted, "must be called before started");
		LOG_ALWAYS_FATAL_IF(mJoinThreadRunning, "Cannot set max threads while running");
		mMaxThreads = threads;
		}

		@@ -126,16 +128,61 @@ sp<IBinder> RpcServer::getRootObject() {
		return ret;
		}

		std::unique_ptr<RpcServer::FdTrigger> RpcServer::FdTrigger::make() {
		auto ret = std::make_unique<RpcServer::FdTrigger>();
		if (!android::base::Pipe(&ret->mRead, &ret->mWrite)) return nullptr;
		return ret;
		}

		void RpcServer::FdTrigger::trigger() {
		mWrite.reset();
		}

		void RpcServer::join() {
		LOG_ALWAYS_FATAL_IF(!mAgreedExperimental, "no!");

		{
		std::lock_guard<std::mutex> _l(mLock);
		LOG_ALWAYS_FATAL_IF(!mServer.ok(), "RpcServer must be setup to join.");
		LOG_ALWAYS_FATAL_IF(mShutdownTrigger != nullptr, "Already joined");
		mJoinThreadRunning = true;
		mShutdownTrigger = FdTrigger::make();
		LOG_ALWAYS_FATAL_IF(mShutdownTrigger == nullptr, "Cannot create join signaler");
		}

		while (true) {
		(void)acceptOne();
		pollfd pfd[]{{.fd = mServer.get(), .events = POLLIN, .revents = 0},
		{.fd = mShutdownTrigger->readFd().get(), .events = POLLHUP, .revents = 0}};
		int ret = TEMP_FAILURE_RETRY(poll(pfd, arraysize(pfd), -1));
		if (ret < 0) {
		ALOGE("Could not poll socket: %s", strerror(errno));
		continue;
		}
		if (ret == 0) {
		continue;
		}
		if (pfd[1].revents & POLLHUP) {
		LOG_RPC_DETAIL("join() exiting because shutdown requested.");
		break;
		}

		(void)acceptOneNoCheck();
		}

		{
		std::lock_guard<std::mutex> _l(mLock);
		mJoinThreadRunning = false;
		}
		mShutdownCv.notify_all();
		}

		bool RpcServer::acceptOne() {
		LOG_ALWAYS_FATAL_IF(!mAgreedExperimental, "no!");
		LOG_ALWAYS_FATAL_IF(!hasServer(), "RpcServer must be setup to join.");
		LOG_ALWAYS_FATAL_IF(!hasServer(), "RpcServer must be setup to acceptOne.");
		return acceptOneNoCheck();
		}

		bool RpcServer::acceptOneNoCheck() {
		unique_fd clientFd(
		TEMP_FAILURE_RETRY(accept4(mServer.get(), nullptr, nullptr /length/, SOCK_CLOEXEC)));

		@@ -156,6 +203,18 @@ bool RpcServer::acceptOne() {
		return true;
		}

		bool RpcServer::shutdown() {
		LOG_ALWAYS_FATAL_IF(!mAgreedExperimental, "no!");
		std::unique_lock<std::mutex> _l(mLock);
		if (mShutdownTrigger == nullptr) return false;

		mShutdownTrigger->trigger();
		while (mJoinThreadRunning) mShutdownCv.wait(_l);

		mShutdownTrigger = nullptr;
		return true;
		}

		std::vector<sp<RpcSession>> RpcServer::listSessions() {
		std::lock_guard<std::mutex> _l(mLock);
		std::vector<sp<RpcSession>> sessions;

libs/binder/include/binder/RpcServer.h

+33 −2

Original line number	Diff line number	Diff line
		@@ -119,10 +119,21 @@ public:
		/**
		* You must have at least one client session before calling this.
		*
		* TODO(b/185167543): way to shut down?
		* If a client needs to actively terminate join, call shutdown() in a separate thread.
		*
		* At any given point, there can only be one thread calling join().
		*/
		void join();

		/**
		* Shut down any existing join(). Return true if successfully shut down, false otherwise
		* (e.g. no join() is running). Will wait for the server to be fully
		* shutdown.
		*
		* TODO(b/185167543): wait for sessions to shutdown as well
		*/
		[[nodiscard]] bool shutdown();

		/**
		* Accept one connection on this server. You must have at least one client
		* session before calling this.
		@@ -142,14 +153,31 @@ public:
		void onSessionTerminating(const sp<RpcSession>& session);

		private:
		/** This is not a pipe. */
		struct FdTrigger {
		static std::unique_ptr<FdTrigger> make();
		/**
		* poll() on this fd for POLLHUP to get notification when trigger is called
		*/
		base::borrowed_fd readFd() const { return mRead; }
		/**
		* Close the write end of the pipe so that the read end receives POLLHUP.
		*/
		void trigger();

		private:
		base::unique_fd mWrite;
		base::unique_fd mRead;
		};

		friend sp<RpcServer>;
		RpcServer();

		void establishConnection(sp<RpcServer>&& session, base::unique_fd clientFd);
		bool setupSocketServer(const RpcSocketAddress& address);
		[[nodiscard]] bool acceptOneNoCheck();

		bool mAgreedExperimental = false;
		bool mStarted = false; // TODO(b/185167543): support dynamically added clients
		size_t mMaxThreads = 1;
		base::unique_fd mServer; // socket we are accepting sessions on

		@@ -159,6 +187,9 @@ private:
		wp<IBinder> mRootObjectWeak;
		std::map<int32_t, sp<RpcSession>> mSessions;
		int32_t mSessionIdCounter = 0;
		bool mJoinThreadRunning = false;
		std::unique_ptr<FdTrigger> mShutdownTrigger;
		std::condition_variable mShutdownCv;
		};

		} // namespace android

libs/binder/tests/binderRpcTest.cpp

+50 −0

Original line number	Diff line number	Diff line
		@@ -40,6 +40,8 @@
		#include "../RpcState.h" // for debugging
		#include "../vm_sockets.h" // for VMADDR_*

		using namespace std::chrono_literals;

		namespace android {

		TEST(BinderRpcParcel, EntireParcelFormatted) {
		@@ -970,6 +972,54 @@ TEST_P(BinderRpcServerRootObject, WeakRootObject) {
		INSTANTIATE_TEST_CASE_P(BinderRpc, BinderRpcServerRootObject,
		::testing::Combine(::testing::Bool(), ::testing::Bool()));

		class OneOffSignal {
		public:
		// If notify() was previously called, or is called within \|duration\|, return true; else false.
		template <typename R, typename P>
		bool wait(std::chrono::duration<R, P> duration) {
		std::unique_lock<std::mutex> lock(mMutex);
		return mCv.wait_for(lock, duration, [this] { return mValue; });
		}
		void notify() {
		std::unique_lock<std::mutex> lock(mMutex);
		mValue = true;
		lock.unlock();
		mCv.notify_all();
		}

		private:
		std::mutex mMutex;
		std::condition_variable mCv;
		bool mValue = false;
		};

		TEST(BinderRpc, Shutdown) {
		auto addr = allocateSocketAddress();
		unlink(addr.c_str());
		auto server = RpcServer::make();
		server->iUnderstandThisCodeIsExperimentalAndIWillNotUseItInProduction();
		ASSERT_TRUE(server->setupUnixDomainServer(addr.c_str()));
		auto joinEnds = std::make_shared<OneOffSignal>();

		// If things are broken and the thread never stops, don't block other tests. Because the thread
		// may run after the test finishes, it must not access the stack memory of the test. Hence,
		// shared pointers are passed.
		std::thread([server, joinEnds] {
		server->join();
		joinEnds->notify();
		}).detach();

		bool shutdown = false;
		for (int i = 0; i < 10 && !shutdown; i++) {
		usleep(300 * 1000); // 300ms; total 3s
		if (server->shutdown()) shutdown = true;
		}
		ASSERT_TRUE(shutdown) << "server->shutdown() never returns true";

		ASSERT_TRUE(joinEnds->wait(2s))
		<< "After server->shutdown() returns true, join() did not stop after 2s";
		}

		} // namespace android

		int main(int argc, char** argv) {