Bluetooth: Add a timeout in async_fd_watcher

am: 7d42dcad6e

Change-Id: I0086b5ca130b11b296d3fe839c1e099ed4044425

bluetooth/1.0/default/Android.bp

@@ -38,7 +38,9 @@ cc_library_shared {
 cc_test_host {
     name: "bluetooth-vendor-interface-unit-tests",
     srcs: [
+        "async_fd_watcher.cc",
         "bluetooth_address.cc",
+        "test/async_fd_watcher_unittest.cc",
         "test/bluetooth_address_test.cc",
         "test/properties.cc",
     ],

bluetooth/1.0/default/async_fd_watcher.cc

@@ -50,6 +50,20 @@ int AsyncFdWatcher::WatchFdForNonBlockingReads(
   return 0;
 }
 
+int AsyncFdWatcher::ConfigureTimeout(
+    const std::chrono::milliseconds timeout,
+    const TimeoutCallback& on_timeout_callback) {
+  // Add timeout and callback
+  {
+    std::unique_lock<std::mutex> guard(timeout_mutex_);
+    timeout_cb_ = on_timeout_callback;
+    timeout_ms_ = timeout;
+  }
+
+  notifyThread();
+  return 0;
+}
+
 void AsyncFdWatcher::StopWatchingFileDescriptor() { stopThread(); }
 
 AsyncFdWatcher::~AsyncFdWatcher() {}
@@ -86,6 +100,11 @@ int AsyncFdWatcher::stopThread() {
     read_fd_ = -1;
   }
 
+  {
+    std::unique_lock<std::mutex> guard(timeout_mutex_);
+    timeout_cb_ = nullptr;
+  }
+
   return 0;
 }
 
@@ -104,21 +123,37 @@ void AsyncFdWatcher::ThreadRoutine() {
     FD_SET(notification_listen_fd_, &read_fds);
     FD_SET(read_fd_, &read_fds);
 
-    // Wait until there is data available to read on some FD
-    int nfds = std::max(notification_listen_fd_, read_fd_);
-    int retval = select(nfds + 1, &read_fds, NULL, NULL, NULL);
-    if (retval <= 0) continue;  // there was some error or a timeout
+    struct timeval timeout;
+    struct timeval* timeout_ptr = NULL;
+    if (timeout_ms_ > std::chrono::milliseconds(0)) {
+      timeout.tv_sec = timeout_ms_.count() / 1000;
+      timeout.tv_usec = (timeout_ms_.count() % 1000) * 1000;
+      timeout_ptr = &timeout;
+    }
 
-    // Read data from the notification FD
+    // Wait until there is data available to read on some FD.
+    int nfds = std::max(notification_listen_fd_, read_fd_);
+    int retval = select(nfds + 1, &read_fds, NULL, NULL, timeout_ptr);
+
+    // There was some error.
+    if (retval < 0) continue;
+
+    // Timeout.
+    if (retval == 0) {
+      std::unique_lock<std::mutex> guard(timeout_mutex_);
+      if (timeout_ms_ > std::chrono::milliseconds(0) && timeout_cb_)
+        timeout_cb_();
+      continue;
+    }
+
+    // Read data from the notification FD.
     if (FD_ISSET(notification_listen_fd_, &read_fds)) {
       char buffer[] = {0};
       TEMP_FAILURE_RETRY(read(notification_listen_fd_, buffer, 1));
+      continue;
     }
 
-    // Make sure we're still running
-    if (!running_) break;
-
-    // Invoke the data ready callback if appropriate
+    // Invoke the data ready callback if appropriate.
     if (FD_ISSET(read_fd_, &read_fds)) {
       std::unique_lock<std::mutex> guard(internal_mutex_);
       if (cb_) cb_(read_fd_);

bluetooth/1.0/default/async_fd_watcher.h

@@ -26,6 +26,7 @@ namespace V1_0 {
 namespace implementation {
 
 using ReadCallback = std::function<void(int)>;
+using TimeoutCallback = std::function<void(void)>;
 
 class AsyncFdWatcher {
  public:
@@ -34,6 +35,8 @@ class AsyncFdWatcher {
 
   int WatchFdForNonBlockingReads(int file_descriptor,
                                  const ReadCallback& on_read_fd_ready_callback);
+  int ConfigureTimeout(const std::chrono::milliseconds timeout,
+                       const TimeoutCallback& on_timeout_callback);
   void StopWatchingFileDescriptor();
 
  private:
@@ -48,11 +51,14 @@ class AsyncFdWatcher {
   std::atomic_bool running_{false};
   std::thread thread_;
   std::mutex internal_mutex_;
+  std::mutex timeout_mutex_;
 
   int read_fd_;
   int notification_listen_fd_;
   int notification_write_fd_;
   ReadCallback cb_;
+  TimeoutCallback timeout_cb_;
+  std::chrono::milliseconds timeout_ms_;
 };
 
 

bluetooth/1.0/default/test/async_fd_watcher_unittest.cc

@@ -0,0 +1,295 @@
+//
+// Copyright 2017 The Android Open Source Project
+//
+// 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.
+//
+
+#include "async_fd_watcher.h"
+#include <gtest/gtest.h>
+#include <cstdint>
+#include <cstring>
+#include <vector>
+
+#include <netdb.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <utils/Log.h>
+
+namespace android {
+namespace hardware {
+namespace bluetooth {
+namespace V1_0 {
+namespace implementation {
+
+class AsyncFdWatcherSocketTest : public ::testing::Test {
+ public:
+  static const uint16_t kPort = 6111;
+  static const size_t kBufferSize = 16;
+
+  bool CheckBufferEquals() {
+    return strcmp(server_buffer_, client_buffer_) == 0;
+  }
+
+ protected:
+  int StartServer() {
+    ALOGD("%s", __func__);
+    struct sockaddr_in serv_addr;
+    int fd = socket(AF_INET, SOCK_STREAM, 0);
+    EXPECT_FALSE(fd < 0);
+
+    memset(&serv_addr, 0, sizeof(serv_addr));
+    serv_addr.sin_family = AF_INET;
+    serv_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+    serv_addr.sin_port = htons(kPort);
+    int reuse_flag = 1;
+    EXPECT_FALSE(setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &reuse_flag,
+                            sizeof(reuse_flag)) < 0);
+    EXPECT_FALSE(bind(fd, (sockaddr*)&serv_addr, sizeof(serv_addr)) <
+                 0);
+
+    ALOGD("%s before listen", __func__);
+    listen(fd, 1);
+    return fd;
+  }
+
+  int AcceptConnection(int fd) {
+    ALOGD("%s", __func__);
+    struct sockaddr_in cli_addr;
+    memset(&cli_addr, 0, sizeof(cli_addr));
+    socklen_t clilen = sizeof(cli_addr);
+
+    int connection_fd = accept(fd, (struct sockaddr*)&cli_addr, &clilen);
+    EXPECT_FALSE(connection_fd < 0);
+
+    return connection_fd;
+  }
+
+  void ReadIncomingMessage(int fd) {
+    ALOGD("%s", __func__);
+    int n = TEMP_FAILURE_RETRY(read(fd, server_buffer_, kBufferSize - 1));
+    EXPECT_FALSE(n < 0);
+
+    if (n == 0)  // got EOF
+      ALOGD("%s: EOF", __func__);
+    else
+      ALOGD("%s: Got something", __func__);
+      n = write(fd, "1", 1);
+  }
+
+  void SetUp() override {
+    ALOGD("%s", __func__);
+    memset(server_buffer_, 0, kBufferSize);
+    memset(client_buffer_, 0, kBufferSize);
+  }
+
+  void ConfigureServer() {
+    socket_fd_ = StartServer();
+
+    conn_watcher_.WatchFdForNonBlockingReads(socket_fd_, [this](int fd) {
+      int connection_fd = AcceptConnection(fd);
+      ALOGD("%s: Conn_watcher fd = %d", __func__, fd);
+
+      conn_watcher_.ConfigureTimeout(std::chrono::seconds(0), [this]() { bool connection_timeout_cleared = false; ASSERT_TRUE(connection_timeout_cleared); });
+
+      ALOGD("%s: 3", __func__);
+      async_fd_watcher_.WatchFdForNonBlockingReads(
+          connection_fd, [this](int fd) { ReadIncomingMessage(fd); });
+
+      // Time out if it takes longer than a second.
+      SetTimeout(std::chrono::seconds(1));
+    });
+    conn_watcher_.ConfigureTimeout(std::chrono::seconds(1), [this]() { bool connection_timeout = true; ASSERT_FALSE(connection_timeout); });
+  }
+
+  void CleanUpServer() {
+    async_fd_watcher_.StopWatchingFileDescriptor();
+    conn_watcher_.StopWatchingFileDescriptor();
+    close(socket_fd_);
+  }
+
+  void TearDown() override {
+    ALOGD("%s 3", __func__);
+    EXPECT_TRUE(CheckBufferEquals());
+  }
+
+  void OnTimeout() {
+    ALOGD("%s", __func__);
+    timed_out_ = true;
+  }
+
+  void ClearTimeout() {
+    ALOGD("%s", __func__);
+    timed_out_ = false;
+  }
+
+  bool TimedOut() {
+    ALOGD("%s %d", __func__, timed_out_? 1 : 0);
+    return timed_out_;
+  }
+
+  void SetTimeout(std::chrono::milliseconds timeout_ms) {
+    ALOGD("%s", __func__);
+    async_fd_watcher_.ConfigureTimeout(timeout_ms, [this]() { OnTimeout(); });
+    ClearTimeout();
+  }
+
+  int ConnectClient() {
+    ALOGD("%s", __func__);
+    int socket_cli_fd = socket(AF_INET, SOCK_STREAM, 0);
+    EXPECT_FALSE(socket_cli_fd < 0);
+
+    struct sockaddr_in serv_addr;
+    memset((void*)&serv_addr, 0, sizeof(serv_addr));
+    serv_addr.sin_family = AF_INET;
+    serv_addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+    serv_addr.sin_port = htons(kPort);
+
+    int result =
+        connect(socket_cli_fd, (struct sockaddr*)&serv_addr, sizeof(serv_addr));
+    EXPECT_FALSE(result < 0);
+
+    return socket_cli_fd;
+  }
+
+  void WriteFromClient(int socket_cli_fd) {
+    ALOGD("%s", __func__);
+    strcpy(client_buffer_, "1");
+    int n = write(socket_cli_fd, client_buffer_, strlen(client_buffer_));
+    EXPECT_TRUE(n > 0);
+  }
+
+  void AwaitServerResponse(int socket_cli_fd) {
+    ALOGD("%s", __func__);
+    int n = read(socket_cli_fd, client_buffer_, 1);
+    ALOGD("%s done", __func__);
+    EXPECT_TRUE(n > 0);
+  }
+
+ private:
+  AsyncFdWatcher async_fd_watcher_;
+  AsyncFdWatcher conn_watcher_;
+  int socket_fd_;
+  char server_buffer_[kBufferSize];
+  char client_buffer_[kBufferSize];
+  bool timed_out_;
+};
+
+// Use a single AsyncFdWatcher to signal a connection to the server socket.
+TEST_F(AsyncFdWatcherSocketTest, Connect) {
+  int socket_fd = StartServer();
+
+  AsyncFdWatcher conn_watcher;
+  conn_watcher.WatchFdForNonBlockingReads(socket_fd, [this](int fd) {
+    int connection_fd = AcceptConnection(fd);
+    close(connection_fd);
+  });
+
+  // Fail if the client doesn't connect within 1 second.
+  conn_watcher.ConfigureTimeout(std::chrono::seconds(1), [this]() {
+     bool connection_timeout = true;
+     ASSERT_FALSE(connection_timeout);
+  });
+
+  ConnectClient();
+  conn_watcher.StopWatchingFileDescriptor();
+  close(socket_fd);
+}
+
+// Use a single AsyncFdWatcher to signal a connection to the server socket.
+TEST_F(AsyncFdWatcherSocketTest, TimedOutConnect) {
+  int socket_fd = StartServer();
+  bool timed_out = false;
+  bool* timeout_ptr = &timed_out;
+
+  AsyncFdWatcher conn_watcher;
+  conn_watcher.WatchFdForNonBlockingReads(socket_fd, [this](int fd) {
+    int connection_fd = AcceptConnection(fd);
+    close(connection_fd);
+  });
+
+  // Set the timeout flag after 100ms.
+  conn_watcher.ConfigureTimeout(std::chrono::milliseconds(100), [this, timeout_ptr]() { *timeout_ptr = true; });
+  EXPECT_FALSE(timed_out);
+  sleep(1);
+  EXPECT_TRUE(timed_out);
+  conn_watcher.StopWatchingFileDescriptor();
+  close(socket_fd);
+}
+
+// Use two AsyncFdWatchers to set up a server socket.
+TEST_F(AsyncFdWatcherSocketTest, ClientServer) {
+  ConfigureServer();
+  int socket_cli_fd = ConnectClient();
+
+  WriteFromClient(socket_cli_fd);
+
+  AwaitServerResponse(socket_cli_fd);
+
+  close(socket_cli_fd);
+  CleanUpServer();
+}
+
+// Use two AsyncFdWatchers to set up a server socket, which times out.
+TEST_F(AsyncFdWatcherSocketTest, TimeOutTest) {
+  ConfigureServer();
+  int socket_cli_fd = ConnectClient();
+
+  while (!TimedOut()) sleep(1);
+
+  close(socket_cli_fd);
+  CleanUpServer();
+}
+
+// Use two AsyncFdWatchers to set up a server socket, which times out.
+TEST_F(AsyncFdWatcherSocketTest, RepeatedTimeOutTest) {
+  ConfigureServer();
+  int socket_cli_fd = ConnectClient();
+  ClearTimeout();
+
+  // Time out when there are no writes.
+  EXPECT_FALSE(TimedOut());
+  sleep(2);
+  EXPECT_TRUE(TimedOut());
+  ClearTimeout();
+
+  // Don't time out when there is a write.
+  WriteFromClient(socket_cli_fd);
+  AwaitServerResponse(socket_cli_fd);
+  EXPECT_FALSE(TimedOut());
+  ClearTimeout();
+
+  // Time out when the write is late.
+  sleep(2);
+  WriteFromClient(socket_cli_fd);
+  AwaitServerResponse(socket_cli_fd);
+  EXPECT_TRUE(TimedOut());
+  ClearTimeout();
+
+  // Time out when there is a pause after a write.
+  WriteFromClient(socket_cli_fd);
+  sleep(2);
+  AwaitServerResponse(socket_cli_fd);
+  EXPECT_TRUE(TimedOut());
+  ClearTimeout();
+
+  close(socket_cli_fd);
+  CleanUpServer();
+}
+
+} // namespace implementation
+} // namespace V1_0
+} // namespace bluetooth
+} // namespace hardware
+} // namespace android