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// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "content/browser/browser_shutdown_profile_dumper.h"
#include "base/command_line.h"
#include "base/files/file_path.h"
#include "base/files/file_util.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/single_thread_task_runner.h"
#include "base/synchronization/waitable_event.h"
#include "base/threading/thread.h"
#include "base/threading/thread_restrictions.h"
#include "base/trace_event/trace_event.h"
#include "base/trace_event/trace_event_impl.h"
#include "components/tracing/tracing_switches.h"
namespace content {
BrowserShutdownProfileDumper::BrowserShutdownProfileDumper(
const base::FilePath& dump_file_name)
: dump_file_name_(dump_file_name),
blocks_(0),
dump_file_(NULL) {
}
BrowserShutdownProfileDumper::~BrowserShutdownProfileDumper() {
WriteTracesToDisc();
}
static float GetTraceBufferPercentFull() {
base::trace_event::TraceLogStatus status =
base::trace_event::TraceLog::GetInstance()->GetStatus();
return 100 * static_cast<float>(static_cast<double>(status.event_count) /
status.event_capacity);
}
void BrowserShutdownProfileDumper::WriteTracesToDisc() {
// Note: I have seen a usage of 0.000xx% when dumping - which fits easily.
// Since the tracer stops when the trace buffer is filled, we'd rather save
// what we have than nothing since we might see from the amount of events
// that caused the problem.
DVLOG(1) << "Flushing shutdown traces to disc. The buffer is "
<< GetTraceBufferPercentFull() << "% full.";
DCHECK(!dump_file_);
dump_file_ = base::OpenFile(dump_file_name_, "w+");
if (!IsFileValid()) {
LOG(ERROR) << "Failed to open performance trace file: "
<< dump_file_name_.value();
return;
}
WriteString("{\"traceEvents\":");
WriteString("[");
// TraceLog::Flush() requires the calling thread to have a message loop.
// As the message loop of the current thread may have quit, start another
// thread for flushing the trace.
base::WaitableEvent flush_complete_event(false, false);
base::Thread flush_thread("browser_shutdown_trace_event_flush");
flush_thread.Start();
flush_thread.task_runner()->PostTask(
FROM_HERE, base::Bind(&BrowserShutdownProfileDumper::EndTraceAndFlush,
base::Unretained(this),
base::Unretained(&flush_complete_event)));
bool original_wait_allowed = base::ThreadRestrictions::SetWaitAllowed(true);
flush_complete_event.Wait();
base::ThreadRestrictions::SetWaitAllowed(original_wait_allowed);
}
void BrowserShutdownProfileDumper::EndTraceAndFlush(
base::WaitableEvent* flush_complete_event) {
base::trace_event::TraceLog::GetInstance()->SetDisabled();
base::trace_event::TraceLog::GetInstance()->Flush(
base::Bind(&BrowserShutdownProfileDumper::WriteTraceDataCollected,
base::Unretained(this),
base::Unretained(flush_complete_event)));
}
// static
base::FilePath BrowserShutdownProfileDumper::GetShutdownProfileFileName() {
const base::CommandLine& command_line =
*base::CommandLine::ForCurrentProcess();
base::FilePath trace_file =
command_line.GetSwitchValuePath(switches::kTraceShutdownFile);
if (!trace_file.empty())
return trace_file;
// Default to saving the startup trace into the current dir.
return base::FilePath().AppendASCII("chrometrace.log");
}
void BrowserShutdownProfileDumper::WriteTraceDataCollected(
base::WaitableEvent* flush_complete_event,
const scoped_refptr<base::RefCountedString>& events_str,
bool has_more_events) {
if (!IsFileValid()) {
flush_complete_event->Signal();
return;
}
if (blocks_) {
// Blocks are not comma separated. Beginning with the second block we
// start therefore to add one in front of the previous block.
WriteString(",");
}
++blocks_;
WriteString(events_str->data());
if (!has_more_events) {
WriteString("]");
WriteString("}");
CloseFile();
flush_complete_event->Signal();
}
}
bool BrowserShutdownProfileDumper::IsFileValid() {
return dump_file_ && (ferror(dump_file_) == 0);
}
void BrowserShutdownProfileDumper::WriteString(const std::string& string) {
WriteChars(string.data(), string.size());
}
void BrowserShutdownProfileDumper::WriteChars(const char* chars, size_t size) {
if (!IsFileValid())
return;
size_t written = fwrite(chars, 1, size, dump_file_);
if (written != size) {
LOG(ERROR) << "Error " << ferror(dump_file_)
<< " in fwrite() to trace file '" << dump_file_name_.value()
<< "'";
CloseFile();
}
}
void BrowserShutdownProfileDumper::CloseFile() {
if (!dump_file_)
return;
base::CloseFile(dump_file_);
dump_file_ = NULL;
}
} // namespace content
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