Extract locking behaviour from ProcessSingleton.

chrome/browser/process_singleton_lock.cc

Index: chrome/browser/process_singleton_lock.cc
diff --git a/chrome/browser/process_singleton_lock.cc b/chrome/browser/process_singleton_lock.cc
new file mode 100644
index 0000000000000000000000000000000000000000..69636b76f8b3cbf1457b43c25a0bdbeed09605a1
--- /dev/null
+++ b/chrome/browser/process_singleton_lock.cc
@@ -0,0 +1,54 @@
+// Copyright (c) 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 "chrome/browser/process_singleton_lock.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+
+ProcessSingletonLock::ProcessSingletonLock(
+    const ProcessSingleton::NotificationCallback& original_callback)
+    : locked_(true),
+      original_callback_(original_callback) {}
+
+ProcessSingletonLock::~ProcessSingletonLock() {}
+
+ProcessSingleton::NotificationCallback
+ProcessSingletonLock::AsNotificationCallback() {

[gab, 2013/03/27 18:03:26]

nit: indent 4 spaces

[erikwright (departed), 2013/03/28 03:16:34]

I believe the current incarnation to be correct per style guide.

[grt (UTC plus 2), 2013/04/04 15:17:18]

@gab's right: 4-space indent here; see
https://groups.google.com/a/chromium.org/d/msg/chromium-dev/3SrDWEOwGIg/FdfIp...

+  return base::Bind(&ProcessSingletonLock::NotificationCallbackImpl,
+                    base::Unretained(this));
+}
+
+void ProcessSingletonLock::Unlock() {
+  DCHECK(CalledOnValidThread());
+  locked_ = false;
+
+  // Replay the command lines of the messages which were received while the
+  // ProcessSingleton was locked. Only replay each message once.
+  std::set<DelayedStartupMessage> replayed_messages;
+  for (std::vector<DelayedStartupMessage>::const_iterator it =
+           saved_startup_messages_.begin();
+       it != saved_startup_messages_.end(); ++it) {
+    if (replayed_messages.find(*it) !=
+        replayed_messages.end())

[gab, 2013/03/27 18:03:26]

nit: indent 4 more spaces.

[erikwright (departed), 2013/03/28 03:16:34]

n/a.

+      continue;
+    original_callback_.Run(CommandLine(it->first), it->second);
+    replayed_messages.insert(*it);
+  }
+  saved_startup_messages_.clear();
+}
+
+bool ProcessSingletonLock::NotificationCallbackImpl(
+    const CommandLine& command_line,
+    const base::FilePath& current_directory) {
+  if (locked_) {
+    // If locked, it means we are not ready to process this message because
+    // we are probably in a first run critical phase.
+    saved_startup_messages_.push_back(
+        std::make_pair(command_line.argv(), current_directory));
+    return true;
+  } else {
+    return original_callback_.Run(command_line, current_directory);
+  }
+}