Start with async and HCI
Bug: 205758693
Test: unit tests
Change-Id: I16a8be44bce5f2d233582ab6db17c30d068fa9c0
diff --git a/bluetooth/async/Android.bp b/bluetooth/async/Android.bp
new file mode 100644
index 0000000..bd7d7b8
--- /dev/null
+++ b/bluetooth/async/Android.bp
@@ -0,0 +1,41 @@
+package {
+ default_applicable_licenses: ["hardware_interfaces_license"],
+}
+
+cc_library_static {
+ name: "android.hardware.bluetooth.async",
+ vendor_available: true,
+ host_supported: true,
+ srcs: [
+ "async_fd_watcher.cc",
+ ],
+ export_include_dirs: ["."],
+ shared_libs: [
+ "liblog",
+ ],
+ cflags: [
+ "-Wall",
+ "-Werror",
+ ],
+}
+
+cc_test {
+ name: "bluetooth-vendor-interface-async-test",
+ host_supported: true,
+ srcs: [
+ "test/async_fd_watcher_unittest.cc",
+ ],
+ shared_libs: [
+ "liblog",
+ "libutils",
+ ],
+ static_libs: [
+ "android.hardware.bluetooth.async",
+ "libgmock",
+ ],
+ cflags: [
+ "-Wall",
+ "-Werror",
+ ],
+ test_suites: ["general-tests"],
+}
diff --git a/bluetooth/async/async_fd_watcher.cc b/bluetooth/async/async_fd_watcher.cc
new file mode 100644
index 0000000..fb634ff
--- /dev/null
+++ b/bluetooth/async/async_fd_watcher.cc
@@ -0,0 +1,176 @@
+/*
+ * Copyright 2022 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 <string.h>
+
+#include <algorithm>
+#include <atomic>
+#include <condition_variable>
+#include <map>
+#include <mutex>
+#include <thread>
+#include <vector>
+
+#include "fcntl.h"
+#include "log/log.h"
+#include "sys/select.h"
+#include "unistd.h"
+
+static const int INVALID_FD = -1;
+
+namespace android::hardware::bluetooth::async {
+
+int AsyncFdWatcher::WatchFdForNonBlockingReads(
+ int file_descriptor, const ReadCallback& on_read_fd_ready_callback) {
+ // Add file descriptor and callback
+ {
+ std::unique_lock<std::mutex> guard(internal_mutex_);
+ watched_fds_[file_descriptor] = on_read_fd_ready_callback;
+ }
+
+ // Start the thread if not started yet
+ return tryStartThread();
+}
+
+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::StopWatchingFileDescriptors() { stopThread(); }
+
+AsyncFdWatcher::~AsyncFdWatcher() {}
+
+// Make sure to call this with at least one file descriptor ready to be
+// watched upon or the thread routine will return immediately
+int AsyncFdWatcher::tryStartThread() {
+ if (std::atomic_exchange(&running_, true)) return 0;
+
+ // Set up the communication channel
+ int pipe_fds[2];
+ if (pipe2(pipe_fds, O_NONBLOCK)) return -1;
+
+ notification_listen_fd_ = pipe_fds[0];
+ notification_write_fd_ = pipe_fds[1];
+
+ thread_ = std::thread([this]() { ThreadRoutine(); });
+ if (!thread_.joinable()) return -1;
+
+ return 0;
+}
+
+int AsyncFdWatcher::stopThread() {
+ if (!std::atomic_exchange(&running_, false)) return 0;
+
+ notifyThread();
+ if (std::this_thread::get_id() != thread_.get_id()) {
+ thread_.join();
+ }
+
+ {
+ std::unique_lock<std::mutex> guard(internal_mutex_);
+ watched_fds_.clear();
+ }
+
+ {
+ std::unique_lock<std::mutex> guard(timeout_mutex_);
+ timeout_cb_ = nullptr;
+ }
+
+ close(notification_listen_fd_);
+ close(notification_write_fd_);
+
+ return 0;
+}
+
+int AsyncFdWatcher::notifyThread() {
+ uint8_t buffer[] = {0};
+ if (TEMP_FAILURE_RETRY(write(notification_write_fd_, &buffer, 1)) < 0) {
+ return -1;
+ }
+ return 0;
+}
+
+void AsyncFdWatcher::ThreadRoutine() {
+ while (running_) {
+ fd_set read_fds;
+ FD_ZERO(&read_fds);
+ FD_SET(notification_listen_fd_, &read_fds);
+ int max_read_fd = INVALID_FD;
+ for (auto& it : watched_fds_) {
+ FD_SET(it.first, &read_fds);
+ max_read_fd = std::max(max_read_fd, it.first);
+ }
+
+ 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;
+ }
+
+ // Wait until there is data available to read on some FD.
+ int nfds = std::max(notification_listen_fd_, max_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) {
+ // Allow the timeout callback to modify the timeout.
+ TimeoutCallback saved_cb;
+ {
+ std::unique_lock<std::mutex> guard(timeout_mutex_);
+ if (timeout_ms_ > std::chrono::milliseconds(0)) saved_cb = timeout_cb_;
+ }
+ if (saved_cb != nullptr) saved_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;
+ }
+
+ // Invoke the data ready callbacks if appropriate.
+ {
+ // Hold the mutex to make sure that the callbacks are still valid.
+ std::unique_lock<std::mutex> guard(internal_mutex_);
+ for (auto& it : watched_fds_) {
+ if (FD_ISSET(it.first, &read_fds)) {
+ it.second(it.first);
+ }
+ }
+ }
+ }
+}
+
+} // namespace android::hardware::bluetooth::async
diff --git a/bluetooth/async/async_fd_watcher.h b/bluetooth/async/async_fd_watcher.h
new file mode 100644
index 0000000..b50a7a0
--- /dev/null
+++ b/bluetooth/async/async_fd_watcher.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2022 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.
+ */
+
+#pragma once
+
+#include <map>
+#include <mutex>
+#include <thread>
+
+namespace android::hardware::bluetooth::async {
+
+using ReadCallback = std::function<void(int)>;
+using TimeoutCallback = std::function<void(void)>;
+
+class AsyncFdWatcher {
+ public:
+ AsyncFdWatcher() = default;
+ ~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 StopWatchingFileDescriptors();
+
+ private:
+ AsyncFdWatcher(const AsyncFdWatcher&) = delete;
+ AsyncFdWatcher& operator=(const AsyncFdWatcher&) = delete;
+
+ int tryStartThread();
+ int stopThread();
+ int notifyThread();
+ void ThreadRoutine();
+
+ std::atomic_bool running_{false};
+ std::thread thread_;
+ std::mutex internal_mutex_;
+ std::mutex timeout_mutex_;
+
+ std::map<int, ReadCallback> watched_fds_;
+ int notification_listen_fd_;
+ int notification_write_fd_;
+ TimeoutCallback timeout_cb_;
+ std::chrono::milliseconds timeout_ms_;
+};
+
+} // namespace android::hardware::bluetooth::async
diff --git a/bluetooth/async/test/async_fd_watcher_unittest.cc b/bluetooth/async/test/async_fd_watcher_unittest.cc
new file mode 100644
index 0000000..6d75f10
--- /dev/null
+++ b/bluetooth/async/test/async_fd_watcher_unittest.cc
@@ -0,0 +1,377 @@
+/*
+ * Copyright 2022 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.
+ */
+
+#define LOG_TAG "async_fd_watcher_unittest"
+
+#include "async_fd_watcher.h"
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+#include <log/log.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <cstdint>
+#include <cstring>
+#include <vector>
+
+namespace android::hardware::bluetooth::async_test {
+
+using android::hardware::bluetooth::async::AsyncFdWatcher;
+
+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), []() {
+ 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), []() {
+ bool connection_timeout = true;
+ ASSERT_FALSE(connection_timeout);
+ });
+ }
+
+ void CleanUpServer() {
+ async_fd_watcher_.StopWatchingFileDescriptors();
+ conn_watcher_.StopWatchingFileDescriptors();
+ 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), []() {
+ bool connection_timeout = true;
+ ASSERT_FALSE(connection_timeout);
+ });
+
+ int socket_cli_fd = ConnectClient();
+ conn_watcher.StopWatchingFileDescriptors();
+ close(socket_fd);
+ close(socket_cli_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),
+ [timeout_ptr]() { *timeout_ptr = true; });
+ EXPECT_FALSE(timed_out);
+ sleep(1);
+ EXPECT_TRUE(timed_out);
+ conn_watcher.StopWatchingFileDescriptors();
+ close(socket_fd);
+}
+
+// Modify the timeout in a timeout callback.
+TEST_F(AsyncFdWatcherSocketTest, TimedOutSchedulesTimeout) {
+ int socket_fd = StartServer();
+ bool timed_out = false;
+ bool timed_out2 = false;
+
+ AsyncFdWatcher conn_watcher;
+ conn_watcher.WatchFdForNonBlockingReads(socket_fd, [this](int fd) {
+ int connection_fd = AcceptConnection(fd);
+ close(connection_fd);
+ });
+
+ // Set a timeout flag in each callback.
+ conn_watcher.ConfigureTimeout(std::chrono::milliseconds(500),
+ [&conn_watcher, &timed_out, &timed_out2]() {
+ timed_out = true;
+ conn_watcher.ConfigureTimeout(
+ std::chrono::seconds(1),
+ [&timed_out2]() { timed_out2 = true; });
+ });
+ EXPECT_FALSE(timed_out);
+ EXPECT_FALSE(timed_out2);
+ sleep(1);
+ EXPECT_TRUE(timed_out);
+ EXPECT_FALSE(timed_out2);
+ sleep(1);
+ EXPECT_TRUE(timed_out);
+ EXPECT_TRUE(timed_out2);
+ conn_watcher.StopWatchingFileDescriptors();
+ close(socket_fd);
+}
+
+MATCHER_P(ReadAndMatchSingleChar, byte,
+ "Reads a byte from the file descriptor and matches the value against "
+ "byte") {
+ char inbuf[1] = {0};
+
+ int n = TEMP_FAILURE_RETRY(read(arg, inbuf, 1));
+
+ TEMP_FAILURE_RETRY(write(arg, inbuf, 1));
+ if (n != 1) {
+ return false;
+ }
+ return inbuf[0] == byte;
+};
+
+// Use a single AsyncFdWatcher to watch two file descriptors.
+TEST_F(AsyncFdWatcherSocketTest, WatchTwoFileDescriptors) {
+ int sockfd1[2];
+ int sockfd2[2];
+ socketpair(AF_LOCAL, SOCK_STREAM, 0, sockfd1);
+ socketpair(AF_LOCAL, SOCK_STREAM, 0, sockfd2);
+
+ testing::MockFunction<void(int)> cb1;
+ testing::MockFunction<void(int)> cb2;
+
+ AsyncFdWatcher watcher;
+ watcher.WatchFdForNonBlockingReads(sockfd1[0], cb1.AsStdFunction());
+
+ watcher.WatchFdForNonBlockingReads(sockfd2[0], cb2.AsStdFunction());
+
+ EXPECT_CALL(cb1, Call(ReadAndMatchSingleChar('1')));
+ char one_buf[1] = {'1'};
+ TEMP_FAILURE_RETRY(write(sockfd1[1], one_buf, sizeof(one_buf)));
+
+ EXPECT_CALL(cb2, Call(ReadAndMatchSingleChar('2')));
+ char two_buf[1] = {'2'};
+ TEMP_FAILURE_RETRY(write(sockfd2[1], two_buf, sizeof(two_buf)));
+
+ // Blocking read instead of a flush.
+ TEMP_FAILURE_RETRY(read(sockfd1[1], one_buf, sizeof(one_buf)));
+ TEMP_FAILURE_RETRY(read(sockfd2[1], two_buf, sizeof(two_buf)));
+
+ watcher.StopWatchingFileDescriptors();
+}
+
+// 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 android::hardware::bluetooth::async_test