1 /*
2 * Copyright (C) 2021 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #define LOG_TAG "AAudioCommandQueue"
18 //#define LOG_NDEBUG 0
19
20 #include <chrono>
21
22 #include <utils/Log.h>
23
24 #include "AAudioCommandQueue.h"
25
26 namespace aaudio {
27
sendCommand(const std::shared_ptr<AAudioCommand> & command)28 aaudio_result_t AAudioCommandQueue::sendCommand(const std::shared_ptr<AAudioCommand>& command) {
29 {
30 std::scoped_lock<std::mutex> _l(mLock);
31 if (!mRunning) {
32 ALOGE("Tried to send command while it was not running");
33 return AAUDIO_ERROR_INVALID_STATE;
34 }
35 mCommands.push(command);
36 mWaitWorkCond.notify_one();
37 }
38
39 std::unique_lock _cl(command->lock);
40 android::base::ScopedLockAssertion lockAssertion(command->lock);
41 ALOGV("Sending command %d, wait for reply(%d) with timeout %jd",
42 command->operationCode, command->isWaitingForReply, command->timeoutNanoseconds);
43 // `mWaitForReply` is first initialized when the command is constructed. It will be flipped
44 // when the command is completed.
45 auto timeoutExpire = std::chrono::steady_clock::now()
46 + std::chrono::nanoseconds(command->timeoutNanoseconds);
47 while (command->isWaitingForReply) {
48 if (command->conditionVariable.wait_until(_cl, timeoutExpire)
49 == std::cv_status::timeout) {
50 ALOGD("Command %d time out", command->operationCode);
51 command->result = AAUDIO_ERROR_TIMEOUT;
52 command->isWaitingForReply = false;
53 }
54 }
55 ALOGV("Command %d sent with result as %d", command->operationCode, command->result);
56 return command->result;
57 }
58
waitForCommand(int64_t timeoutNanos)59 std::shared_ptr<AAudioCommand> AAudioCommandQueue::waitForCommand(int64_t timeoutNanos) {
60 std::shared_ptr<AAudioCommand> command;
61 {
62 std::unique_lock _l(mLock);
63 android::base::ScopedLockAssertion lockAssertion(mLock);
64 if (timeoutNanos >= 0) {
65 mWaitWorkCond.wait_for(_l, std::chrono::nanoseconds(timeoutNanos), [this]() {
66 android::base::ScopedLockAssertion lockAssertion(mLock);
67 return !mRunning || !mCommands.empty();
68 });
69 } else {
70 mWaitWorkCond.wait(_l, [this]() {
71 android::base::ScopedLockAssertion lockAssertion(mLock);
72 return !mRunning || !mCommands.empty();
73 });
74 }
75 if (!mCommands.empty() && mRunning) {
76 command = mCommands.front();
77 mCommands.pop();
78 }
79 }
80 return command;
81 }
82
startWaiting()83 void AAudioCommandQueue::startWaiting() {
84 std::scoped_lock<std::mutex> _l(mLock);
85 mRunning = true;
86 }
87
stopWaiting()88 void AAudioCommandQueue::stopWaiting() {
89 std::scoped_lock<std::mutex> _l(mLock);
90 mRunning = false;
91 // Clear all commands in the queue as the command thread is stopped.
92 while (!mCommands.empty()) {
93 auto command = mCommands.front();
94 mCommands.pop();
95 std::scoped_lock<std::mutex> _cl(command->lock);
96 // If the command is waiting for result, returns AAUDIO_ERROR_INVALID_STATE
97 // as there is no thread waiting for the command.
98 if (command->isWaitingForReply) {
99 command->result = AAUDIO_ERROR_INVALID_STATE;
100 command->isWaitingForReply = false;
101 command->conditionVariable.notify_one();
102 }
103 }
104 mWaitWorkCond.notify_one();
105 }
106
107 } // namespace aaudio