adb: de-globalize fdevent context. (b0168bcb) · Commits · e / os / android_system_core

adb/fdevent/fdevent.cpp

+210 −142

Original line number	Diff line number	Diff line
		@@ -58,6 +58,30 @@
		#define FDE_PENDING 0x0200
		#define FDE_CREATED 0x0400

		static std::string dump_fde(const fdevent* fde) {
		std::string state;
		if (fde->state & FDE_ACTIVE) {
		state += "A";
		}
		if (fde->state & FDE_PENDING) {
		state += "P";
		}
		if (fde->state & FDE_CREATED) {
		state += "C";
		}
		if (fde->state & FDE_READ) {
		state += "R";
		}
		if (fde->state & FDE_WRITE) {
		state += "W";
		}
		if (fde->state & FDE_ERROR) {
		state += "E";
		}
		return android::base::StringPrintf("(fdevent %" PRIu64 ": fd %d %s)", fde->id, fde->fd.get(),
		state.c_str());
		}

		struct PollNode {
		fdevent* fde;
		adb_pollfd pollfd;
		@@ -74,90 +98,81 @@ struct PollNode {
		}
		};

		// All operations to fdevent should happen only in the main thread.
		// That's why we don't need a lock for fdevent.
		static auto& g_poll_node_map = *new std::unordered_map<int, PollNode>();
		static auto& g_pending_list = new std::list<fdevent>();
		static std::atomic<bool> terminate_loop(false);
		static bool main_thread_valid;
		static uint64_t main_thread_id;
		struct fdevent_context_poll : public fdevent_context {
		virtual ~fdevent_context_poll() = default;

		static uint64_t fdevent_id;
		virtual fdevent* Create(unique_fd fd, std::variant<fd_func, fd_func2> func, void* arg) final;
		virtual unique_fd Destroy(fdevent* fde) final;

		static bool run_needs_flush = false;
		static auto& run_queue_notify_fd = *new unique_fd();
		static auto& run_queue_mutex = *new std::mutex();
		static auto& run_queue GUARDED_BY(run_queue_mutex) = *new std::deque<std::function<void()>>();
		virtual void Set(fdevent* fde, unsigned events) final;
		virtual void Add(fdevent* fde, unsigned events) final;
		virtual void Del(fdevent* fde, unsigned events) final;
		virtual void SetTimeout(fdevent* fde, std::optional<std::chrono::milliseconds> timeout) final;

		void check_main_thread() {
		if (main_thread_valid) {
		CHECK_EQ(main_thread_id, android::base::GetThreadId());
		}
		}
		virtual void Loop() final;

		void set_main_thread() {
		main_thread_valid = true;
		main_thread_id = android::base::GetThreadId();
		}
		virtual void CheckMainThread() final;

		static std::string dump_fde(const fdevent* fde) {
		std::string state;
		if (fde->state & FDE_ACTIVE) {
		state += "A";
		}
		if (fde->state & FDE_PENDING) {
		state += "P";
		}
		if (fde->state & FDE_CREATED) {
		state += "C";
		}
		if (fde->state & FDE_READ) {
		state += "R";
		}
		if (fde->state & FDE_WRITE) {
		state += "W";
		virtual void Run(std::function<void()> fn) final;

		virtual void TerminateLoop() final;
		virtual size_t InstalledCount() final;
		virtual void Reset() final;

		// All operations to fdevent should happen only in the main thread.
		// That's why we don't need a lock for fdevent.
		std::unordered_map<int, PollNode> poll_node_map_;
		std::list<fdevent*> pending_list_;
		bool main_thread_valid_ = false;
		uint64_t main_thread_id_ = 0;
		uint64_t fdevent_id_ = 0;

		bool run_needs_flush_ = false;
		unique_fd run_queue_notify_fd_;
		std::mutex run_queue_mutex_;
		std::deque<std::function<void()>> run_queue_ GUARDED_BY(run_queue_mutex_);

		std::atomic<bool> terminate_loop_ = false;
		};

		static fdevent_context* g_ambient_fdevent_context = new fdevent_context_poll();

		static fdevent_context* fdevent_get_ambient() {
		return g_ambient_fdevent_context;
		}
		if (fde->state & FDE_ERROR) {
		state += "E";

		void fdevent_context_poll::CheckMainThread() {
		if (main_thread_valid_) {
		CHECK_EQ(main_thread_id_, android::base::GetThreadId());
		}
		return android::base::StringPrintf("(fdevent %" PRIu64 ": fd %d %s)", fde->id, fde->fd.get(),
		state.c_str());
		}

		template <typename F>
		static fdevent* fdevent_create_impl(int fd, F func, void* arg) {
		check_main_thread();
		CHECK_GE(fd, 0);
		fdevent* fdevent_context_poll::Create(unique_fd fd, std::variant<fd_func, fd_func2> func,
		void* arg) {
		CheckMainThread();
		CHECK_GE(fd.get(), 0);

		fdevent* fde = new fdevent();
		fde->id = fdevent_id++;
		fde->id = fdevent_id_++;
		fde->state = FDE_ACTIVE;
		fde->fd.reset(fd);
		fde->fd = std::move(fd);
		fde->func = func;
		fde->arg = arg;
		if (!set_file_block_mode(fd, false)) {
		if (!set_file_block_mode(fde->fd, false)) {
		// Here is not proper to handle the error. If it fails here, some error is
		// likely to be detected by poll(), then we can let the callback function
		// to handle it.
		LOG(ERROR) << "failed to set non-blocking mode for fd " << fd;
		LOG(ERROR) << "failed to set non-blocking mode for fd " << fde->fd.get();
		}
		auto pair = g_poll_node_map.emplace(fde->fd.get(), PollNode(fde));
		CHECK(pair.second) << "install existing fd " << fd;
		auto pair = poll_node_map_.emplace(fde->fd.get(), PollNode(fde));
		CHECK(pair.second) << "install existing fd " << fde->fd.get();

		fde->state \|= FDE_CREATED;
		return fde;
		}

		fdevent* fdevent_create(int fd, fd_func func, void* arg) {
		return fdevent_create_impl(fd, func, arg);
		}

		fdevent* fdevent_create(int fd, fd_func2 func, void* arg) {
		return fdevent_create_impl(fd, func, arg);
		}

		unique_fd fdevent_release(fdevent* fde) {
		check_main_thread();
		unique_fd fdevent_context_poll::Destroy(fdevent* fde) {
		CheckMainThread();
		if (!fde) {
		return {};
		}
		@@ -168,10 +183,10 @@ unique_fd fdevent_release(fdevent* fde) {

		unique_fd result = std::move(fde->fd);
		if (fde->state & FDE_ACTIVE) {
		g_poll_node_map.erase(result.get());
		poll_node_map_.erase(result.get());

		if (fde->state & FDE_PENDING) {
		g_pending_list.remove(fde);
		pending_list_.remove(fde);
		}
		fde->state = 0;
		fde->events = 0;
		@@ -181,14 +196,16 @@ unique_fd fdevent_release(fdevent* fde) {
		return result;
		}

		void fdevent_destroy(fdevent* fde) {
		// Release, and then let unique_fd's destructor cleanup.
		fdevent_release(fde);
		void fdevent_context_poll::Set(fdevent* fde, unsigned events) {
		CheckMainThread();
		events &= FDE_EVENTMASK;
		if ((fde->state & FDE_EVENTMASK) == events) {
		return;
		}
		CHECK(fde->state & FDE_ACTIVE);

		static void fdevent_update(fdevent* fde, unsigned events) {
		auto it = g_poll_node_map.find(fde->fd.get());
		CHECK(it != g_poll_node_map.end());
		auto it = poll_node_map_.find(fde->fd.get());
		CHECK(it != poll_node_map_.end());
		PollNode& node = it->second;
		if (events & FDE_READ) {
		node.pollfd.events \|= POLLIN;
		@@ -202,42 +219,31 @@ static void fdevent_update(fdevent* fde, unsigned events) {
		node.pollfd.events &= ~POLLOUT;
		}
		fde->state = (fde->state & FDE_STATEMASK) \| events;
		}

		void fdevent_set(fdevent* fde, unsigned events) {
		check_main_thread();
		events &= FDE_EVENTMASK;
		if ((fde->state & FDE_EVENTMASK) == events) {
		return;
		}
		CHECK(fde->state & FDE_ACTIVE);
		fdevent_update(fde, events);
		D("fdevent_set: %s, events = %u", dump_fde(fde).c_str(), events);

		if (fde->state & FDE_PENDING) {
		// If we are pending, make sure we don't signal an event that is no longer wanted.
		fde->events &= events;
		if (fde->events == 0) {
		g_pending_list.remove(fde);
		pending_list_.remove(fde);
		fde->state &= ~FDE_PENDING;
		}
		}
		}

		void fdevent_add(fdevent* fde, unsigned events) {
		check_main_thread();
		CHECK(!(events & FDE_TIMEOUT));
		fdevent_set(fde, (fde->state & FDE_EVENTMASK) \| events);
		void fdevent_context_poll::Add(fdevent* fde, unsigned events) {
		Set(fde, (fde->state & FDE_EVENTMASK) \| events);
		}

		void fdevent_del(fdevent* fde, unsigned events) {
		check_main_thread();
		void fdevent_context_poll::Del(fdevent* fde, unsigned events) {
		CHECK(!(events & FDE_TIMEOUT));
		fdevent_set(fde, (fde->state & FDE_EVENTMASK) & ~events);
		Set(fde, (fde->state & FDE_EVENTMASK) & ~events);
		}

		void fdevent_set_timeout(fdevent* fde, std::optional<std::chrono::milliseconds> timeout) {
		check_main_thread();
		void fdevent_context_poll::SetTimeout(fdevent* fde,
		std::optional<std::chrono::milliseconds> timeout) {
		CheckMainThread();
		fde->timeout = timeout;
		fde->last_active = std::chrono::steady_clock::now();
		}
		@@ -257,12 +263,12 @@ static std::string dump_pollfds(const std::vector<adb_pollfd>& pollfds) {
		return result;
		}

		static std::optional<std::chrono::milliseconds> calculate_timeout() {
		static std::optional<std::chrono::milliseconds> calculate_timeout(fdevent_context_poll* ctx) {
		std::optional<std::chrono::milliseconds> result = std::nullopt;
		auto now = std::chrono::steady_clock::now();
		check_main_thread();
		ctx->CheckMainThread();

		for (const auto& [fd, pollnode] : g_poll_node_map) {
		for (const auto& [fd, pollnode] : ctx->poll_node_map_) {
		UNUSED(fd);
		auto timeout_opt = pollnode.fde->timeout;
		if (timeout_opt) {
		@@ -283,15 +289,15 @@ static std::optional<std::chrono::milliseconds> calculate_timeout() {
		return result;
		}

		static void fdevent_process() {
		static void fdevent_process(fdevent_context_poll* ctx) {
		std::vector<adb_pollfd> pollfds;
		for (const auto& pair : g_poll_node_map) {
		for (const auto& pair : ctx->poll_node_map_) {
		pollfds.push_back(pair.second.pollfd);
		}
		CHECK_GT(pollfds.size(), 0u);
		D("poll(), pollfds = %s", dump_pollfds(pollfds).c_str());

		auto timeout = calculate_timeout();
		auto timeout = calculate_timeout(ctx);
		int timeout_ms;
		if (!timeout) {
		timeout_ms = -1;
		@@ -328,8 +334,8 @@ static void fdevent_process() {
		events \|= FDE_READ \| FDE_ERROR;
		}
		#endif
		auto it = g_poll_node_map.find(pollfd.fd);
		CHECK(it != g_poll_node_map.end());
		auto it = ctx->poll_node_map_.find(pollfd.fd);
		CHECK(it != ctx->poll_node_map_.end());
		fdevent* fde = it->second.fde;

		if (events == 0) {
		@@ -348,7 +354,7 @@ static void fdevent_process() {
		fde->last_active = post_poll;
		D("%s got events %x", dump_fde(fde).c_str(), events);
		fde->state \|= FDE_PENDING;
		g_pending_list.push_back(fde);
		ctx->pending_list_.push_back(fde);
		}
		}
		}
		@@ -376,27 +382,28 @@ static void fdevent_call_fdfunc(fdevent* fde) {
		fde->func);
		}

		static void fdevent_run_flush() EXCLUDES(run_queue_mutex) {
		static void fdevent_run_flush(fdevent_context_poll* ctx) EXCLUDES(ctx->run_queue_mutex_) {
		// We need to be careful around reentrancy here, since a function we call can queue up another
		// function.
		while (true) {
		std::function<void()> fn;
		{
		std::lock_guard<std::mutex> lock(run_queue_mutex);
		if (run_queue.empty()) {
		std::lock_guard<std::mutex> lock(ctx->run_queue_mutex_);
		if (ctx->run_queue_.empty()) {
		break;
		}
		fn = run_queue.front();
		run_queue.pop_front();
		fn = ctx->run_queue_.front();
		ctx->run_queue_.pop_front();
		}
		fn();
		}
		}

		static void fdevent_run_func(int fd, unsigned ev, void* /* userdata */) {
		static void fdevent_run_func(int fd, unsigned ev, void* data) {
		CHECK_GE(fd, 0);
		CHECK(ev & FDE_READ);

		bool* run_needs_flush = static_cast<bool*>(data);
		char buf[1024];

		// Empty the fd.
		@@ -405,13 +412,13 @@ static void fdevent_run_func(int fd, unsigned ev, void* /* userdata */) {
		}

		// Mark that we need to flush, and then run it at the end of fdevent_loop.
		run_needs_flush = true;
		*run_needs_flush = true;
		}

		static void fdevent_run_setup() {
		static void fdevent_run_setup(fdevent_context_poll* ctx) {
		{
		std::lock_guard<std::mutex> lock(run_queue_mutex);
		CHECK(run_queue_notify_fd.get() == -1);
		std::lock_guard<std::mutex> lock(ctx->run_queue_mutex_);
		CHECK(ctx->run_queue_notify_fd_.get() == -1);
		int s[2];
		if (adb_socketpair(s) != 0) {
		PLOG(FATAL) << "failed to create run queue notify socketpair";
		@@ -421,23 +428,23 @@ static void fdevent_run_setup() {
		PLOG(FATAL) << "failed to make run queue notify socket nonblocking";
		}

		run_queue_notify_fd.reset(s[0]);
		fdevent* fde = fdevent_create(s[1], fdevent_run_func, nullptr);
		ctx->run_queue_notify_fd_.reset(s[0]);
		fdevent* fde = ctx->Create(unique_fd(s[1]), fdevent_run_func, &ctx->run_needs_flush_);
		CHECK(fde != nullptr);
		fdevent_add(fde, FDE_READ);
		ctx->Add(fde, FDE_READ);
		}

		fdevent_run_flush();
		fdevent_run_flush(ctx);
		}

		void fdevent_run_on_main_thread(std::function<void()> fn) {
		std::lock_guard<std::mutex> lock(run_queue_mutex);
		run_queue.push_back(std::move(fn));
		void fdevent_context_poll::Run(std::function<void()> fn) {
		std::lock_guard<std::mutex> lock(run_queue_mutex_);
		run_queue_.push_back(std::move(fn));

		// run_queue_notify_fd could still be -1 if we're called before fdevent has finished setting up.
		// In that case, rely on the setup code to flush the queue without a notification being needed.
		if (run_queue_notify_fd != -1) {
		int rc = adb_write(run_queue_notify_fd.get(), "", 1);
		if (run_queue_notify_fd_ != -1) {
		int rc = adb_write(run_queue_notify_fd_.get(), "", 1);

		// It's possible that we get EAGAIN here, if lots of notifications came in while handling.
		if (rc == 0) {
		@@ -448,7 +455,7 @@ void fdevent_run_on_main_thread(std::function<void()> fn) {
		}
		}

		static void fdevent_check_spin(uint64_t cycle) {
		static void fdevent_check_spin(fdevent_context_poll* ctx, uint64_t cycle) {
		// Check to see if we're spinning because we forgot about an fdevent
		// by keeping track of how long fdevents have been continuously pending.
		struct SpinCheck {
		@@ -456,6 +463,8 @@ static void fdevent_check_spin(uint64_t cycle) {
		android::base::boot_clock::time_point timestamp;
		uint64_t cycle;
		};

		// TODO: Move this into the base fdevent_context.
		static auto& g_continuously_pending = *new std::unordered_map<uint64_t, SpinCheck>();
		static auto last_cycle = android::base::boot_clock::now();

		@@ -468,7 +477,7 @@ static void fdevent_check_spin(uint64_t cycle) {
		}
		last_cycle = now;

		for (auto* fde : g_pending_list) {
		for (auto* fde : ctx->pending_list_) {
		auto it = g_continuously_pending.find(fde->id);
		if (it == g_continuously_pending.end()) {
		g_continuously_pending[fde->id] =
		@@ -503,51 +512,110 @@ static void fdevent_check_spin(uint64_t cycle) {
		}
		}

		void fdevent_loop() {
		set_main_thread();
		fdevent_run_setup();
		void fdevent_context_poll::Loop() {
		this->main_thread_id_ = android::base::GetThreadId();
		this->main_thread_valid_ = true;
		fdevent_run_setup(this);

		uint64_t cycle = 0;
		while (true) {
		if (terminate_loop) {
		if (terminate_loop_) {
		return;
		}

		D("--- --- waiting for events");

		fdevent_process();
		fdevent_process(this);

		fdevent_check_spin(cycle++);
		fdevent_check_spin(this, cycle++);

		while (!g_pending_list.empty()) {
		fdevent* fde = g_pending_list.front();
		g_pending_list.pop_front();
		while (!pending_list_.empty()) {
		fdevent* fde = pending_list_.front();
		pending_list_.pop_front();
		fdevent_call_fdfunc(fde);
		}

		if (run_needs_flush) {
		fdevent_run_flush();
		run_needs_flush = false;
		if (run_needs_flush_) {
		fdevent_run_flush(this);
		run_needs_flush_ = false;
		}
		}
		}

		void fdevent_context_poll::TerminateLoop() {
		terminate_loop_ = true;
		}

		size_t fdevent_context_poll::InstalledCount() {
		return poll_node_map_.size();
		}

		void fdevent_context_poll::Reset() {
		poll_node_map_.clear();
		pending_list_.clear();

		std::lock_guard<std::mutex> lock(run_queue_mutex_);
		run_queue_notify_fd_.reset();
		run_queue_.clear();

		main_thread_valid_ = false;
		terminate_loop_ = false;
		}

		fdevent* fdevent_create(int fd, fd_func func, void* arg) {
		unique_fd ufd(fd);
		return fdevent_get_ambient()->Create(std::move(ufd), func, arg);
		}

		fdevent* fdevent_create(int fd, fd_func2 func, void* arg) {
		unique_fd ufd(fd);
		return fdevent_get_ambient()->Create(std::move(ufd), func, arg);
		}

		unique_fd fdevent_release(fdevent* fde) {
		return fdevent_get_ambient()->Destroy(fde);
		}

		void fdevent_destroy(fdevent* fde) {
		fdevent_get_ambient()->Destroy(fde);
		}

		void fdevent_set(fdevent* fde, unsigned events) {
		fdevent_get_ambient()->Set(fde, events);
		}

		void fdevent_add(fdevent* fde, unsigned events) {
		fdevent_get_ambient()->Add(fde, events);
		}

		void fdevent_del(fdevent* fde, unsigned events) {
		fdevent_get_ambient()->Del(fde, events);
		}

		void fdevent_set_timeout(fdevent* fde, std::optional<std::chrono::milliseconds> timeout) {
		fdevent_get_ambient()->SetTimeout(fde, timeout);
		}

		void fdevent_run_on_main_thread(std::function<void()> fn) {
		fdevent_get_ambient()->Run(std::move(fn));
		}

		void fdevent_loop() {
		fdevent_get_ambient()->Loop();
		}

		void check_main_thread() {
		fdevent_get_ambient()->CheckMainThread();
		}

		void fdevent_terminate_loop() {
		terminate_loop = true;
		fdevent_get_ambient()->TerminateLoop();
		}

		size_t fdevent_installed_count() {
		return g_poll_node_map.size();
		return fdevent_get_ambient()->InstalledCount();
		}

		void fdevent_reset() {
		g_poll_node_map.clear();
		g_pending_list.clear();

		std::lock_guard<std::mutex> lock(run_queue_mutex);
		run_queue_notify_fd.reset();
		run_queue.clear();

		main_thread_valid = false;
		terminate_loop = false;
		return fdevent_get_ambient()->Reset();
		}

adb/fdevent/fdevent.h

+40 −17

Original line number	Diff line number	Diff line
		@@ -36,6 +36,43 @@
		typedef void (fd_func)(int fd, unsigned events, void userdata);
		typedef void (fd_func2)(struct fdevent fde, unsigned events, void* userdata);

		struct fdevent;

		struct fdevent_context {
		virtual ~fdevent_context() = default;

		// Allocate and initialize a new fdevent object.
		virtual fdevent* Create(unique_fd fd, std::variant<fd_func, fd_func2> func, void* arg) = 0;

		// Deallocate an fdevent object, returning the file descriptor that was owned by it.
		virtual unique_fd Destroy(fdevent* fde) = 0;

		// Change which events should cause notifications.
		virtual void Set(fdevent* fde, unsigned events) = 0;
		virtual void Add(fdevent* fde, unsigned events) = 0;
		virtual void Del(fdevent* fde, unsigned events) = 0;

		// Set a timeout on an fdevent.
		// If no events are triggered by the timeout, an FDE_TIMEOUT will be generated.
		// Note timeouts are not defused automatically; if a timeout is set on an fdevent, it will
		// trigger repeatedly every \|timeout\| ms.
		virtual void SetTimeout(fdevent* fde, std::optional<std::chrono::milliseconds> timeout) = 0;

		// Loop forever, handling events.
		virtual void Loop() = 0;

		// Assert that the caller is running on the context's main thread.
		virtual void CheckMainThread() = 0;

		// Queue an operation to be run on the main thread.
		virtual void Run(std::function<void()> fn) = 0;

		// Test-only functionality:
		virtual void TerminateLoop() = 0;
		virtual size_t InstalledCount() = 0;
		virtual void Reset() = 0;
		};

		struct fdevent {
		uint64_t id;

		@@ -51,31 +88,18 @@ struct fdevent {
		void* arg = nullptr;
		};

		// Allocate and initialize a new fdevent object
		// TODO: Switch these to unique_fd.
		// Backwards compatibility shims that forward to the global fdevent_context.
		fdevent* fdevent_create(int fd, fd_func func, void* arg);
		fdevent* fdevent_create(int fd, fd_func2 func, void* arg);

		// Deallocate an fdevent object that was created by fdevent_create.
		void fdevent_destroy(fdevent *fde);

		// fdevent_destroy, except releasing the file descriptor previously owned by the fdevent.
		unique_fd fdevent_release(fdevent* fde);
		void fdevent_destroy(fdevent* fde);

		// Change which events should cause notifications
		void fdevent_set(fdevent *fde, unsigned events);
		void fdevent_add(fdevent *fde, unsigned events);
		void fdevent_del(fdevent *fde, unsigned events);

		// Set a timeout on an fdevent.
		// If no events are triggered by the timeout, an FDE_TIMEOUT will be generated.
		// Note timeouts are not defused automatically; if a timeout is set on an fdevent, it will
		// trigger repeatedly every \|timeout\| ms.
		void fdevent_set_timeout(fdevent* fde, std::optional<std::chrono::milliseconds> timeout);

		// Loop forever, handling events.
		void fdevent_loop();

		void check_main_thread();

		// Queue an operation to run on the main thread.
		@@ -85,6 +109,5 @@ void fdevent_run_on_main_thread(std::function<void()> fn);
		void fdevent_terminate_loop();
		size_t fdevent_installed_count();
		void fdevent_reset();
		void set_main_thread();

		#endif