1 // Copyright 2013 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 "content/browser/browser_shutdown_profile_dumper.h"
6
7 #include "base/base_switches.h"
8 #include "base/command_line.h"
9 #include "base/debug/trace_event.h"
10 #include "base/debug/trace_event_impl.h"
11 #include "base/files/file_path.h"
12 #include "base/files/file_util.h"
13 #include "base/logging.h"
14 #include "base/synchronization/waitable_event.h"
15 #include "base/threading/thread.h"
16 #include "base/threading/thread_restrictions.h"
17 #include "content/public/common/content_switches.h"
18
19 namespace content {
20
BrowserShutdownProfileDumper(const base::FilePath & dump_file_name)21 BrowserShutdownProfileDumper::BrowserShutdownProfileDumper(
22 const base::FilePath& dump_file_name)
23 : dump_file_name_(dump_file_name),
24 blocks_(0),
25 dump_file_(NULL) {
26 }
27
~BrowserShutdownProfileDumper()28 BrowserShutdownProfileDumper::~BrowserShutdownProfileDumper() {
29 WriteTracesToDisc();
30 }
31
WriteTracesToDisc()32 void BrowserShutdownProfileDumper::WriteTracesToDisc() {
33 // Note: I have seen a usage of 0.000xx% when dumping - which fits easily.
34 // Since the tracer stops when the trace buffer is filled, we'd rather save
35 // what we have than nothing since we might see from the amount of events
36 // that caused the problem.
37 DVLOG(1) << "Flushing shutdown traces to disc. The buffer is %" <<
38 base::debug::TraceLog::GetInstance()->GetBufferPercentFull() <<
39 " full.";
40 DCHECK(!dump_file_);
41 dump_file_ = base::OpenFile(dump_file_name_, "w+");
42 if (!IsFileValid()) {
43 LOG(ERROR) << "Failed to open performance trace file: "
44 << dump_file_name_.value();
45 return;
46 }
47 WriteString("{\"traceEvents\":");
48 WriteString("[");
49
50 // TraceLog::Flush() requires the calling thread to have a message loop.
51 // As the message loop of the current thread may have quit, start another
52 // thread for flushing the trace.
53 base::WaitableEvent flush_complete_event(false, false);
54 base::Thread flush_thread("browser_shutdown_trace_event_flush");
55 flush_thread.Start();
56 flush_thread.message_loop()->PostTask(
57 FROM_HERE,
58 base::Bind(&BrowserShutdownProfileDumper::EndTraceAndFlush,
59 base::Unretained(this),
60 base::Unretained(&flush_complete_event)));
61
62 bool original_wait_allowed = base::ThreadRestrictions::SetWaitAllowed(true);
63 flush_complete_event.Wait();
64 base::ThreadRestrictions::SetWaitAllowed(original_wait_allowed);
65 }
66
EndTraceAndFlush(base::WaitableEvent * flush_complete_event)67 void BrowserShutdownProfileDumper::EndTraceAndFlush(
68 base::WaitableEvent* flush_complete_event) {
69 base::debug::TraceLog::GetInstance()->SetDisabled();
70 base::debug::TraceLog::GetInstance()->Flush(
71 base::Bind(&BrowserShutdownProfileDumper::WriteTraceDataCollected,
72 base::Unretained(this),
73 base::Unretained(flush_complete_event)));
74 }
75
76 // static
GetShutdownProfileFileName()77 base::FilePath BrowserShutdownProfileDumper::GetShutdownProfileFileName() {
78 const base::CommandLine& command_line =
79 *base::CommandLine::ForCurrentProcess();
80 base::FilePath trace_file =
81 command_line.GetSwitchValuePath(switches::kTraceShutdownFile);
82
83 if (!trace_file.empty())
84 return trace_file;
85
86 // Default to saving the startup trace into the current dir.
87 return base::FilePath().AppendASCII("chrometrace.log");
88 }
89
WriteTraceDataCollected(base::WaitableEvent * flush_complete_event,const scoped_refptr<base::RefCountedString> & events_str,bool has_more_events)90 void BrowserShutdownProfileDumper::WriteTraceDataCollected(
91 base::WaitableEvent* flush_complete_event,
92 const scoped_refptr<base::RefCountedString>& events_str,
93 bool has_more_events) {
94 if (!IsFileValid()) {
95 flush_complete_event->Signal();
96 return;
97 }
98 if (blocks_) {
99 // Blocks are not comma separated. Beginning with the second block we
100 // start therefore to add one in front of the previous block.
101 WriteString(",");
102 }
103 ++blocks_;
104 WriteString(events_str->data());
105
106 if (!has_more_events) {
107 WriteString("]");
108 WriteString("}");
109 CloseFile();
110 flush_complete_event->Signal();
111 }
112 }
113
IsFileValid()114 bool BrowserShutdownProfileDumper::IsFileValid() {
115 return dump_file_ && (ferror(dump_file_) == 0);
116 }
117
WriteString(const std::string & string)118 void BrowserShutdownProfileDumper::WriteString(const std::string& string) {
119 WriteChars(string.data(), string.size());
120 }
121
WriteChars(const char * chars,size_t size)122 void BrowserShutdownProfileDumper::WriteChars(const char* chars, size_t size) {
123 if (!IsFileValid())
124 return;
125
126 size_t written = fwrite(chars, 1, size, dump_file_);
127 if (written != size) {
128 LOG(ERROR) << "Error " << ferror(dump_file_)
129 << " in fwrite() to trace file '" << dump_file_name_.value()
130 << "'";
131 CloseFile();
132 }
133 }
134
CloseFile()135 void BrowserShutdownProfileDumper::CloseFile() {
136 if (!dump_file_)
137 return;
138 base::CloseFile(dump_file_);
139 dump_file_ = NULL;
140 }
141
142 } // namespace content
143