1 /*
2 * Copyright (C) 2017 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 #include "chre/platform/shared/platform_log.h"
18
19 #include <cstdarg>
20 #include <cstdio>
21 #include <iostream>
22
23 namespace chre {
24
logLooper()25 void PlatformLogBase::logLooper() {
26 while (1) {
27 std::unique_ptr<char> logMessage;
28
29 {
30 std::unique_lock<std::mutex> lock(mMutex);
31 mConditionVariable.wait(lock, [this]{
32 return (!mLogQueue.empty() || mStopLogger);
33 });
34
35 if (!mLogQueue.empty()) {
36 // Move the log message to avoid holding a lock for longer than
37 // required.
38 logMessage = std::move(mLogQueue.front());
39 mLogQueue.pop();
40 } else if (mStopLogger) {
41 // The stop logger is checked in an else-if to allow the main log queue
42 // to drain when the logger is stopping.
43 break;
44 }
45 }
46
47 // If we get here, there must be a log message to output. This is outside of
48 // the context of the lock which means that the logging thread will only be
49 // blocked for the minimum amount of time.
50 std::cerr << logMessage.get() << std::endl;
51 }
52 }
53
PlatformLog()54 PlatformLog::PlatformLog() {
55 mLoggerThread = std::thread(&PlatformLog::logLooper, this);
56 }
57
~PlatformLog()58 PlatformLog::~PlatformLog() {
59 {
60 std::unique_lock<std::mutex> lock(mMutex);
61 mStopLogger = true;
62 mConditionVariable.notify_one();
63 }
64
65 mLoggerThread.join();
66 }
67
log(const char * formatStr,...)68 void PlatformLog::log(const char *formatStr, ...) {
69 char *formattedStr;
70 va_list argList;
71 va_start(argList, formatStr);
72 int result = vasprintf(&formattedStr, formatStr, argList);
73 va_end(argList);
74
75 if (result >= 0) {
76 // Wrap the formatted string into a unique_ptr so that it will be free'd
77 // once it has been logged.
78 std::unique_ptr<char> log(formattedStr);
79
80 std::unique_lock<std::mutex> lock(mMutex);
81 mLogQueue.push(std::move(log));
82 mConditionVariable.notify_one();
83 } else {
84 std::cerr << "Failed to allocate log message" << std::endl;
85 abort();
86 }
87 }
88
89 } // namespace chre
90