1 // Copyright 2009 Google Inc. All Rights Reserved.
2
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6
7 // http://www.apache.org/licenses/LICENSE-2.0
8
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "logger.h"
16
17 #include <pthread.h>
18 #include <stdarg.h>
19 #include <stdio.h>
20 #include <time.h>
21 #include <unistd.h>
22
23 #include <string>
24 #include <vector>
25
26 // This file must work with autoconf on its public version,
27 // so these includes are correct.
28 #include "sattypes.h"
29
30
GlobalLogger()31 Logger *Logger::GlobalLogger() {
32 static Logger logger;
33 return &logger;
34 }
35
VLogF(int priority,const char * format,va_list args)36 void Logger::VLogF(int priority, const char *format, va_list args) {
37 if (priority > verbosity_) {
38 return;
39 }
40 char buffer[4096];
41 size_t length = 0;
42 if (log_timestamps_) {
43 time_t raw_time;
44 time(&raw_time);
45 struct tm time_struct;
46 localtime_r(&raw_time, &time_struct);
47 length = strftime(buffer, sizeof(buffer), "%Y/%m/%d-%H:%M:%S(%Z) ",
48 &time_struct);
49 LOGGER_ASSERT(length); // Catch if the buffer is set too small.
50 }
51 length += vsnprintf(buffer + length, sizeof(buffer) - length, format, args);
52 if (length >= sizeof(buffer)) {
53 length = sizeof(buffer);
54 buffer[sizeof(buffer) - 1] = '\n';
55 }
56 QueueLogLine(new string(buffer, length));
57 }
58
StartThread()59 void Logger::StartThread() {
60 LOGGER_ASSERT(!thread_running_);
61 thread_running_ = true;
62 LOGGER_ASSERT(0 == pthread_create(&thread_, NULL, &StartRoutine, this));
63 }
64
StopThread()65 void Logger::StopThread() {
66 // Allow this to be called before the thread has started.
67 if (!thread_running_) {
68 return;
69 }
70 thread_running_ = false;
71 int retval = pthread_mutex_lock(&queued_lines_mutex_);
72 LOGGER_ASSERT(0 == retval);
73 bool need_cond_signal = queued_lines_.empty();
74 queued_lines_.push_back(NULL);
75 retval = pthread_mutex_unlock(&queued_lines_mutex_);
76 LOGGER_ASSERT(0 == retval);
77 if (need_cond_signal) {
78 retval = pthread_cond_signal(&queued_lines_cond_);
79 LOGGER_ASSERT(0 == retval);
80 }
81 retval = pthread_join(thread_, NULL);
82 LOGGER_ASSERT(0 == retval);
83 }
84
Logger()85 Logger::Logger()
86 : verbosity_(20),
87 log_fd_(-1),
88 thread_running_(false),
89 log_timestamps_(true) {
90 LOGGER_ASSERT(0 == pthread_mutex_init(&queued_lines_mutex_, NULL));
91 LOGGER_ASSERT(0 == pthread_cond_init(&queued_lines_cond_, NULL));
92 LOGGER_ASSERT(0 == pthread_cond_init(&full_queue_cond_, NULL));
93 }
94
~Logger()95 Logger::~Logger() {
96 LOGGER_ASSERT(0 == pthread_mutex_destroy(&queued_lines_mutex_));
97 LOGGER_ASSERT(0 == pthread_cond_destroy(&queued_lines_cond_));
98 LOGGER_ASSERT(0 == pthread_cond_destroy(&full_queue_cond_));
99 }
100
QueueLogLine(string * line)101 void Logger::QueueLogLine(string *line) {
102 LOGGER_ASSERT(line != NULL);
103 LOGGER_ASSERT(0 == pthread_mutex_lock(&queued_lines_mutex_));
104 if (thread_running_) {
105 if (queued_lines_.size() >= kMaxQueueSize) {
106 LOGGER_ASSERT(0 == pthread_cond_wait(&full_queue_cond_,
107 &queued_lines_mutex_));
108 }
109 if (queued_lines_.empty()) {
110 LOGGER_ASSERT(0 == pthread_cond_signal(&queued_lines_cond_));
111 }
112 queued_lines_.push_back(line);
113 } else {
114 WriteAndDeleteLogLine(line);
115 }
116 LOGGER_ASSERT(0 == pthread_mutex_unlock(&queued_lines_mutex_));
117 }
118
WriteAndDeleteLogLine(string * line)119 void Logger::WriteAndDeleteLogLine(string *line) {
120 LOGGER_ASSERT(line != NULL);
121 ssize_t bytes_written;
122 if (log_fd_ >= 0) {
123 bytes_written = write(log_fd_, line->data(), line->size());
124 LOGGER_ASSERT(bytes_written == static_cast<ssize_t>(line->size()));
125 }
126 bytes_written = write(STDOUT_FILENO, line->data(), line->size());
127 LOGGER_ASSERT(bytes_written == static_cast<ssize_t>(line->size()));
128 delete line;
129 }
130
StartRoutine(void * ptr)131 void *Logger::StartRoutine(void *ptr) {
132 Logger *self = static_cast<Logger*>(ptr);
133 self->ThreadMain();
134 return NULL;
135 }
136
ThreadMain()137 void Logger::ThreadMain() {
138 vector<string*> local_queue;
139 LOGGER_ASSERT(0 == pthread_mutex_lock(&queued_lines_mutex_));
140
141 for (;;) {
142 if (queued_lines_.empty()) {
143 LOGGER_ASSERT(0 == pthread_cond_wait(&queued_lines_cond_,
144 &queued_lines_mutex_));
145 continue;
146 }
147
148 // We move the log lines into a local queue so we can release the lock
149 // while writing them to disk, preventing other threads from blocking on
150 // our writes.
151 local_queue.swap(queued_lines_);
152 if (local_queue.size() >= kMaxQueueSize) {
153 LOGGER_ASSERT(0 == pthread_cond_broadcast(&full_queue_cond_));
154 }
155
156 // Unlock while we process our local queue.
157 LOGGER_ASSERT(0 == pthread_mutex_unlock(&queued_lines_mutex_));
158 for (vector<string*>::const_iterator it = local_queue.begin();
159 it != local_queue.end(); ++it) {
160 if (*it == NULL) {
161 // NULL is guaranteed to be at the end.
162 return;
163 }
164 WriteAndDeleteLogLine(*it);
165 }
166 local_queue.clear();
167 // We must hold the lock at the start of each iteration of this for loop.
168 LOGGER_ASSERT(0 == pthread_mutex_lock(&queued_lines_mutex_));
169 }
170 }
171