Added command line switches and UI (controlled via a build option)

chrome/common/profiling.cc

+// Copyright (c) 2010 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 "chrome/common/profiling.h"
+
+#include "base/at_exit.h"
+#include "base/command_line.h"
+#include "base/debug/profiler.h"
+#include "base/message_loop.h"
+#include "base/string_util.h"
+#include "chrome/common/chrome_switches.h"
+
+namespace {
+std::string GetProfileName() {
+  const std::string default_profile_name("chrome-profile-{pid}");

[jamesr, 2011/02/01 01:21:45]

nit: this should be static and some sort of kThingy

[DaveMoore, 2011/02/01 19:21:55]

Done.

+  static std::string profile_name;
+
+  if (profile_name.empty()) {
+    const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+    if (command_line.HasSwitch(switches::kProfilingFile))
+      profile_name = command_line.GetSwitchValueASCII(switches::kProfilingFile);
+    else
+      profile_name = default_profile_name;
+    std::string process_type =
+        command_line.GetSwitchValueASCII(switches::kProcessType);
+    std::string type = process_type.empty() ?
+        std::string("browser") : std::string(process_type);
+    ReplaceSubstringsAfterOffset(&profile_name, 0, "{type}", type.c_str());
+  }
+  return profile_name;
+}
+
+void FlushProfilingData(MessageLoop* loop) {
+  if (Profiling::BeingProfiled()) {

[Evan Martin, 2011/02/01 02:45:59]

Can do an early-exit here to reduce indentation

[DaveMoore, 2011/02/01 19:21:55]

Done.

+    base::debug::FlushProfiling();
+    const int kProfilingFlushSeconds = 10;

[jamesr, 2011/02/01 01:21:45]

nit: static

[Evan Martin, 2011/02/01 02:45:59]

Just my opinion, but I don't think that's required here.

[DaveMoore, 2011/02/01 19:21:55]

Done.

+    static int flush_seconds = 0;
+    if (!flush_seconds) {

[Evan Martin, 2011/02/01 02:45:59]

Is it possible for this to race between multiple threads?  This feels like it
should maybe be state for the current object.  Or it should just be grabbed in
Profiling::Start and stashed into a file-static int.

[DaveMoore, 2011/02/01 19:21:55]

This should only be called from the main thread. I don't know how safe the
underlying stuff is (obviously there is safety in the lower level functions but
I'm not sure about the top level entry points).
I've added a comment to the .h file.
On 2011/02/01 02:45:59, Evan Martin wrote:

+      const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+      std::string profiling_flush =
+          command_line.GetSwitchValueASCII(switches::kProfilingFlush);
+      if (!profiling_flush.empty()) {
+        flush_seconds = atoi(profiling_flush.c_str());
+        DCHECK(flush_seconds > 0);
+      } else {
+        flush_seconds = kProfilingFlushSeconds;
+      }
+    }
+    loop->PostDelayedTask(FROM_HERE,
+        NewRunnableFunction(FlushProfilingData, loop),
+        flush_seconds * 1000);
+  }
+}
+
+} // namespace
+
+// static
+void Profiling::StartAtStart() {
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+  std::string process_type =
+      command_line.GetSwitchValueASCII(switches::kProcessType);
+
+  if (command_line.HasSwitch(switches::kProfilingAtStart)) {
+    std::string process_type_to_start =
+        command_line.GetSwitchValueASCII(switches::kProfilingAtStart);
+    if (process_type == process_type_to_start)
+      Start();
+  }
+}
+
+// static
+void Profiling::Start() {
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+  bool flush = command_line.HasSwitch(switches::kProfilingFlush);
+  base::debug::StartProfiling(GetProfileName());
+
+  // Schedule profile data flushing for single process because it doesn't
+  // get written out correctly on exit.
+  if (flush && MessageLoop::current())
+    FlushProfilingData(MessageLoop::current());
+}
+
+// static
+void Profiling::Stop() {
+  base::debug::StopProfiling();
+}
+
+// static
+bool Profiling::BeingProfiled() {
+  return base::debug::BeingProfiled();
+}
+
+// static
+void Profiling::Toggle() {
+  if (BeingProfiled())
+    Stop();
+  else
+    Start();
+}
+
+// static
+void Profiling::MainMessageLoopStarted() {
+  if (BeingProfiled()) {
+    const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+    bool flush = command_line.HasSwitch(switches::kProfilingFlush);
+    if (flush)
+      FlushProfilingData(MessageLoop::current());
+  }
+}