1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "base/trace_event/trace_event_impl.h"
6
7 #include <fcntl.h>
8 #include <stddef.h>
9 #include <stdint.h>
10
11 #include "base/format_macros.h"
12 #include "base/logging.h"
13 #include "base/posix/eintr_wrapper.h"
14 #include "base/strings/stringprintf.h"
15 #include "base/synchronization/waitable_event.h"
16 #include "base/trace_event/trace_event.h"
17
18 namespace base {
19 namespace trace_event {
20
21 namespace {
22
23 int g_atrace_fd = -1;
24 const char kATraceMarkerFile[] = "/sys/kernel/debug/tracing/trace_marker";
25
WriteToATrace(int fd,const char * buffer,size_t size)26 void WriteToATrace(int fd, const char* buffer, size_t size) {
27 size_t total_written = 0;
28 while (total_written < size) {
29 ssize_t written = HANDLE_EINTR(write(
30 fd, buffer + total_written, size - total_written));
31 if (written <= 0)
32 break;
33 total_written += written;
34 }
35 if (total_written < size) {
36 PLOG(WARNING) << "Failed to write buffer '" << std::string(buffer, size)
37 << "' to " << kATraceMarkerFile;
38 }
39 }
40
WriteEvent(char phase,const char * category_group,const char * name,unsigned long long id,const char ** arg_names,const unsigned char * arg_types,const TraceEvent::TraceValue * arg_values,const std::unique_ptr<ConvertableToTraceFormat> * convertable_values,unsigned int flags)41 void WriteEvent(
42 char phase,
43 const char* category_group,
44 const char* name,
45 unsigned long long id,
46 const char** arg_names,
47 const unsigned char* arg_types,
48 const TraceEvent::TraceValue* arg_values,
49 const std::unique_ptr<ConvertableToTraceFormat>* convertable_values,
50 unsigned int flags) {
51 std::string out = StringPrintf("%c|%d|%s", phase, getpid(), name);
52 if (flags & TRACE_EVENT_FLAG_HAS_ID)
53 StringAppendF(&out, "-%" PRIx64, static_cast<uint64_t>(id));
54 out += '|';
55
56 for (int i = 0; i < kTraceMaxNumArgs && arg_names[i];
57 ++i) {
58 if (i)
59 out += ';';
60 out += arg_names[i];
61 out += '=';
62 std::string::size_type value_start = out.length();
63 if (arg_types[i] == TRACE_VALUE_TYPE_CONVERTABLE)
64 convertable_values[i]->AppendAsTraceFormat(&out);
65 else
66 TraceEvent::AppendValueAsJSON(arg_types[i], arg_values[i], &out);
67
68 // Remove the quotes which may confuse the atrace script.
69 ReplaceSubstringsAfterOffset(&out, value_start, "\\\"", "'");
70 ReplaceSubstringsAfterOffset(&out, value_start, "\"", "");
71 // Replace chars used for separators with similar chars in the value.
72 std::replace(out.begin() + value_start, out.end(), ';', ',');
73 std::replace(out.begin() + value_start, out.end(), '|', '!');
74 }
75
76 out += '|';
77 out += category_group;
78 WriteToATrace(g_atrace_fd, out.c_str(), out.size());
79 }
80
NoOpOutputCallback(WaitableEvent * complete_event,const scoped_refptr<RefCountedString> &,bool has_more_events)81 void NoOpOutputCallback(WaitableEvent* complete_event,
82 const scoped_refptr<RefCountedString>&,
83 bool has_more_events) {
84 if (!has_more_events)
85 complete_event->Signal();
86 }
87
EndChromeTracing(TraceLog * trace_log,WaitableEvent * complete_event)88 void EndChromeTracing(TraceLog* trace_log,
89 WaitableEvent* complete_event) {
90 trace_log->SetDisabled();
91 // Delete the buffered trace events as they have been sent to atrace.
92 trace_log->Flush(Bind(&NoOpOutputCallback, complete_event));
93 }
94
95 } // namespace
96
97 // These functions support Android systrace.py when 'webview' category is
98 // traced. With the new adb_profile_chrome, we may have two phases:
99 // - before WebView is ready for combined tracing, we can use adb_profile_chrome
100 // to trace android categories other than 'webview' and chromium categories.
101 // In this way we can avoid the conflict between StartATrace/StopATrace and
102 // the intents.
103 // - TODO(wangxianzhu): after WebView is ready for combined tracing, remove
104 // StartATrace, StopATrace and SendToATrace, and perhaps send Java traces
105 // directly to atrace in trace_event_binding.cc.
106
StartATrace()107 void TraceLog::StartATrace() {
108 if (g_atrace_fd != -1)
109 return;
110
111 g_atrace_fd = HANDLE_EINTR(open(kATraceMarkerFile, O_WRONLY));
112 if (g_atrace_fd == -1) {
113 PLOG(WARNING) << "Couldn't open " << kATraceMarkerFile;
114 return;
115 }
116 TraceConfig trace_config;
117 trace_config.SetTraceRecordMode(RECORD_CONTINUOUSLY);
118 SetEnabled(trace_config, TraceLog::RECORDING_MODE);
119 }
120
StopATrace()121 void TraceLog::StopATrace() {
122 if (g_atrace_fd == -1)
123 return;
124
125 close(g_atrace_fd);
126 g_atrace_fd = -1;
127
128 // TraceLog::Flush() requires the current thread to have a message loop, but
129 // this thread called from Java may not have one, so flush in another thread.
130 Thread end_chrome_tracing_thread("end_chrome_tracing");
131 WaitableEvent complete_event(WaitableEvent::ResetPolicy::AUTOMATIC,
132 WaitableEvent::InitialState::NOT_SIGNALED);
133 end_chrome_tracing_thread.Start();
134 end_chrome_tracing_thread.task_runner()->PostTask(
135 FROM_HERE, base::Bind(&EndChromeTracing, Unretained(this),
136 Unretained(&complete_event)));
137 complete_event.Wait();
138 }
139
SendToATrace()140 void TraceEvent::SendToATrace() {
141 if (g_atrace_fd == -1)
142 return;
143
144 const char* category_group =
145 TraceLog::GetCategoryGroupName(category_group_enabled_);
146
147 switch (phase_) {
148 case TRACE_EVENT_PHASE_BEGIN:
149 WriteEvent('B', category_group, name_, id_,
150 arg_names_, arg_types_, arg_values_, convertable_values_,
151 flags_);
152 break;
153
154 case TRACE_EVENT_PHASE_COMPLETE:
155 WriteEvent(duration_.ToInternalValue() == -1 ? 'B' : 'E',
156 category_group, name_, id_,
157 arg_names_, arg_types_, arg_values_, convertable_values_,
158 flags_);
159 break;
160
161 case TRACE_EVENT_PHASE_END:
162 // Though a single 'E' is enough, here append pid, name and
163 // category_group etc. So that unpaired events can be found easily.
164 WriteEvent('E', category_group, name_, id_,
165 arg_names_, arg_types_, arg_values_, convertable_values_,
166 flags_);
167 break;
168
169 case TRACE_EVENT_PHASE_INSTANT:
170 // Simulate an instance event with a pair of begin/end events.
171 WriteEvent('B', category_group, name_, id_,
172 arg_names_, arg_types_, arg_values_, convertable_values_,
173 flags_);
174 WriteToATrace(g_atrace_fd, "E", 1);
175 break;
176
177 case TRACE_EVENT_PHASE_COUNTER:
178 for (int i = 0; i < kTraceMaxNumArgs && arg_names_[i]; ++i) {
179 DCHECK(arg_types_[i] == TRACE_VALUE_TYPE_INT);
180 std::string out = base::StringPrintf(
181 "C|%d|%s-%s", getpid(), name_, arg_names_[i]);
182 if (flags_ & TRACE_EVENT_FLAG_HAS_ID)
183 StringAppendF(&out, "-%" PRIx64, static_cast<uint64_t>(id_));
184 StringAppendF(&out, "|%d|%s",
185 static_cast<int>(arg_values_[i].as_int), category_group);
186 WriteToATrace(g_atrace_fd, out.c_str(), out.size());
187 }
188 break;
189
190 default:
191 // Do nothing.
192 break;
193 }
194 }
195
AddClockSyncMetadataEvent()196 void TraceLog::AddClockSyncMetadataEvent() {
197 int atrace_fd = HANDLE_EINTR(open(kATraceMarkerFile, O_WRONLY | O_APPEND));
198 if (atrace_fd == -1) {
199 PLOG(WARNING) << "Couldn't open " << kATraceMarkerFile;
200 return;
201 }
202
203 // Android's kernel trace system has a trace_marker feature: this is a file on
204 // debugfs that takes the written data and pushes it onto the trace
205 // buffer. So, to establish clock sync, we write our monotonic clock into that
206 // trace buffer.
207 double now_in_seconds = (TimeTicks::Now() - TimeTicks()).InSecondsF();
208 std::string marker = StringPrintf(
209 "trace_event_clock_sync: parent_ts=%f\n", now_in_seconds);
210 WriteToATrace(atrace_fd, marker.c_str(), marker.size());
211 close(atrace_fd);
212 }
213
214 } // namespace trace_event
215 } // namespace base
216