| /* http://frotznet.googlecode.com/svn/trunk/utils/fdevent.c |
| ** |
| ** Copyright 2006, Brian Swetland <swetland@frotz.net> |
| ** |
| ** Licensed under the Apache License, Version 2.0 (the "License"); |
| ** you may not use this file except in compliance with the License. |
| ** You may obtain a copy of the License at |
| ** |
| ** http://www.apache.org/licenses/LICENSE-2.0 |
| ** |
| ** Unless required by applicable law or agreed to in writing, software |
| ** distributed under the License is distributed on an "AS IS" BASIS, |
| ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| ** See the License for the specific language governing permissions and |
| ** limitations under the License. |
| */ |
| |
| #define TRACE_TAG FDEVENT |
| |
| #include "sysdeps.h" |
| #include "fdevent.h" |
| |
| #include <fcntl.h> |
| #include <stdint.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| |
| #include <atomic> |
| #include <deque> |
| #include <functional> |
| #include <list> |
| #include <mutex> |
| #include <unordered_map> |
| #include <vector> |
| |
| #include <android-base/logging.h> |
| #include <android-base/stringprintf.h> |
| #include <android-base/thread_annotations.h> |
| #include <android-base/threads.h> |
| |
| #include "adb_io.h" |
| #include "adb_trace.h" |
| #include "adb_unique_fd.h" |
| #include "adb_utils.h" |
| |
| #define FDE_EVENTMASK 0x00ff |
| #define FDE_STATEMASK 0xff00 |
| |
| #define FDE_ACTIVE 0x0100 |
| #define FDE_PENDING 0x0200 |
| #define FDE_CREATED 0x0400 |
| |
| struct PollNode { |
| fdevent* fde; |
| adb_pollfd pollfd; |
| |
| explicit PollNode(fdevent* fde) : fde(fde) { |
| memset(&pollfd, 0, sizeof(pollfd)); |
| pollfd.fd = fde->fd.get(); |
| |
| #if defined(__linux__) |
| // Always enable POLLRDHUP, so the host server can take action when some clients disconnect. |
| // Then we can avoid leaving many sockets in CLOSE_WAIT state. See http://b/23314034. |
| pollfd.events = POLLRDHUP; |
| #endif |
| } |
| }; |
| |
| // 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; |
| |
| 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()>>(); |
| |
| void check_main_thread() { |
| if (main_thread_valid) { |
| CHECK_EQ(main_thread_id, android::base::GetThreadId()); |
| } |
| } |
| |
| void set_main_thread() { |
| main_thread_valid = true; |
| main_thread_id = android::base::GetThreadId(); |
| } |
| |
| 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 %d %s)", fde->fd.get(), state.c_str()); |
| } |
| |
| void fdevent_install(fdevent* fde, int fd, fd_func func, void* arg) { |
| check_main_thread(); |
| CHECK_GE(fd, 0); |
| memset(fde, 0, sizeof(fdevent)); |
| } |
| |
| fdevent* fdevent_create(int fd, fd_func func, void* arg) { |
| check_main_thread(); |
| CHECK_GE(fd, 0); |
| |
| fdevent* fde = new fdevent(); |
| fde->state = FDE_ACTIVE; |
| fde->fd.reset(fd); |
| fde->func = func; |
| fde->arg = arg; |
| if (!set_file_block_mode(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; |
| } |
| auto pair = g_poll_node_map.emplace(fde->fd.get(), PollNode(fde)); |
| CHECK(pair.second) << "install existing fd " << fd; |
| |
| fde->state |= FDE_CREATED; |
| return fde; |
| } |
| |
| void fdevent_destroy(fdevent* fde) { |
| check_main_thread(); |
| if (fde == 0) return; |
| if (!(fde->state & FDE_CREATED)) { |
| LOG(FATAL) << "destroying fde not created by fdevent_create(): " << dump_fde(fde); |
| } |
| |
| if (fde->state & FDE_ACTIVE) { |
| g_poll_node_map.erase(fde->fd.get()); |
| if (fde->state & FDE_PENDING) { |
| g_pending_list.remove(fde); |
| } |
| fde->fd.reset(); |
| fde->state = 0; |
| fde->events = 0; |
| } |
| |
| delete fde; |
| } |
| |
| 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()); |
| PollNode& node = it->second; |
| if (events & FDE_READ) { |
| node.pollfd.events |= POLLIN; |
| } else { |
| node.pollfd.events &= ~POLLIN; |
| } |
| |
| if (events & FDE_WRITE) { |
| node.pollfd.events |= POLLOUT; |
| } else { |
| 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); |
| fde->state &= ~FDE_PENDING; |
| } |
| } |
| } |
| |
| void fdevent_add(fdevent* fde, unsigned events) { |
| check_main_thread(); |
| fdevent_set(fde, (fde->state & FDE_EVENTMASK) | events); |
| } |
| |
| void fdevent_del(fdevent* fde, unsigned events) { |
| check_main_thread(); |
| fdevent_set(fde, (fde->state & FDE_EVENTMASK) & ~events); |
| } |
| |
| static std::string dump_pollfds(const std::vector<adb_pollfd>& pollfds) { |
| std::string result; |
| for (const auto& pollfd : pollfds) { |
| std::string op; |
| if (pollfd.events & POLLIN) { |
| op += "R"; |
| } |
| if (pollfd.events & POLLOUT) { |
| op += "W"; |
| } |
| android::base::StringAppendF(&result, " %d(%s)", pollfd.fd, op.c_str()); |
| } |
| return result; |
| } |
| |
| static void fdevent_process() { |
| std::vector<adb_pollfd> pollfds; |
| for (const auto& pair : g_poll_node_map) { |
| pollfds.push_back(pair.second.pollfd); |
| } |
| CHECK_GT(pollfds.size(), 0u); |
| D("poll(), pollfds = %s", dump_pollfds(pollfds).c_str()); |
| int ret = adb_poll(&pollfds[0], pollfds.size(), -1); |
| if (ret == -1) { |
| PLOG(ERROR) << "poll(), ret = " << ret; |
| return; |
| } |
| for (const auto& pollfd : pollfds) { |
| if (pollfd.revents != 0) { |
| D("for fd %d, revents = %x", pollfd.fd, pollfd.revents); |
| } |
| unsigned events = 0; |
| if (pollfd.revents & POLLIN) { |
| events |= FDE_READ; |
| } |
| if (pollfd.revents & POLLOUT) { |
| events |= FDE_WRITE; |
| } |
| if (pollfd.revents & (POLLERR | POLLHUP | POLLNVAL)) { |
| // We fake a read, as the rest of the code assumes that errors will |
| // be detected at that point. |
| events |= FDE_READ | FDE_ERROR; |
| } |
| #if defined(__linux__) |
| if (pollfd.revents & POLLRDHUP) { |
| events |= FDE_READ | FDE_ERROR; |
| } |
| #endif |
| if (events != 0) { |
| auto it = g_poll_node_map.find(pollfd.fd); |
| CHECK(it != g_poll_node_map.end()); |
| fdevent* fde = it->second.fde; |
| CHECK_EQ(fde->fd.get(), pollfd.fd); |
| fde->events |= events; |
| D("%s got events %x", dump_fde(fde).c_str(), events); |
| fde->state |= FDE_PENDING; |
| g_pending_list.push_back(fde); |
| } |
| } |
| } |
| |
| static void fdevent_call_fdfunc(fdevent* fde) { |
| unsigned events = fde->events; |
| fde->events = 0; |
| CHECK(fde->state & FDE_PENDING); |
| fde->state &= (~FDE_PENDING); |
| D("fdevent_call_fdfunc %s", dump_fde(fde).c_str()); |
| fde->func(fde->fd.get(), events, fde->arg); |
| } |
| |
| static void fdevent_run_flush() EXCLUDES(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()) { |
| break; |
| } |
| fn = run_queue.front(); |
| run_queue.pop_front(); |
| } |
| fn(); |
| } |
| } |
| |
| static void fdevent_run_func(int fd, unsigned ev, void* /* userdata */) { |
| CHECK_GE(fd, 0); |
| CHECK(ev & FDE_READ); |
| |
| char buf[1024]; |
| |
| // Empty the fd. |
| if (adb_read(fd, buf, sizeof(buf)) == -1) { |
| PLOG(FATAL) << "failed to empty run queue notify fd"; |
| } |
| |
| // Mark that we need to flush, and then run it at the end of fdevent_loop. |
| run_needs_flush = true; |
| } |
| |
| static void fdevent_run_setup() { |
| { |
| std::lock_guard<std::mutex> lock(run_queue_mutex); |
| CHECK(run_queue_notify_fd.get() == -1); |
| int s[2]; |
| if (adb_socketpair(s) != 0) { |
| PLOG(FATAL) << "failed to create run queue notify socketpair"; |
| } |
| |
| if (!set_file_block_mode(s[0], false) || !set_file_block_mode(s[1], false)) { |
| 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); |
| CHECK(fde != nullptr); |
| fdevent_add(fde, FDE_READ); |
| } |
| |
| fdevent_run_flush(); |
| } |
| |
| 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)); |
| |
| // 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); |
| |
| // It's possible that we get EAGAIN here, if lots of notifications came in while handling. |
| if (rc == 0) { |
| PLOG(FATAL) << "run queue notify fd was closed?"; |
| } else if (rc == -1 && errno != EAGAIN) { |
| PLOG(FATAL) << "failed to write to run queue notify fd"; |
| } |
| } |
| } |
| |
| void fdevent_loop() { |
| set_main_thread(); |
| fdevent_run_setup(); |
| |
| while (true) { |
| if (terminate_loop) { |
| return; |
| } |
| |
| D("--- --- waiting for events"); |
| |
| fdevent_process(); |
| |
| while (!g_pending_list.empty()) { |
| fdevent* fde = g_pending_list.front(); |
| g_pending_list.pop_front(); |
| fdevent_call_fdfunc(fde); |
| } |
| |
| if (run_needs_flush) { |
| fdevent_run_flush(); |
| run_needs_flush = false; |
| } |
| } |
| } |
| |
| void fdevent_terminate_loop() { |
| terminate_loop = true; |
| } |
| |
| size_t fdevent_installed_count() { |
| return g_poll_node_map.size(); |
| } |
| |
| 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; |
| } |