Add multi_process_lock to chrome/common

base/shared_mutex_mac.cc

Index: base/shared_mutex_mac.cc
diff --git a/base/shared_mutex_mac.cc b/base/shared_mutex_mac.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d6a1a93d1783d51bc2b1a9b6f968d48375eb29e9
--- /dev/null
+++ b/base/shared_mutex_mac.cc
@@ -0,0 +1,32 @@
+// 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 "base/shared_mutex.h"
+#include "base/mac/scoped_cftyperef.h"

[Mark Mentovai, 2010/11/09 17:43:14]

Blank line before.

[dmac, 2010/11/11 21:47:59]

Done.

+#include "base/sys_string_conversions.h"
+
+namespace base {
+
+SharedMutex::SharedMutex(const std::string& name) : port_(NULL), name_(name) {
+}

[Mark Mentovai, 2010/11/09 17:43:14]

Blank line before, and }  // namespace base.

[dmac, 2010/11/11 21:47:59]

Sorry... what do you mean? A couple of us read your comment and couldn't parse
it ;-)

+
+bool SharedMutex::TryLock() {
+  CFStringRef cf_name(base::SysUTF8ToCFStringRef(name_));
+  base::mac::ScopedCFTypeRef<CFStringRef> scoped_cf_name(cf_name);
+  port_ = CFMessagePortCreateLocal(NULL,

[Mark Mentovai, 2010/11/09 17:43:14]

I’d have just thrown all of these on the same line.

[dmac, 2010/11/11 21:47:59]

Done.

+                                   cf_name,
+                                   NULL,
+                                   NULL,
+                                   NULL);
+  return port_ != NULL;
+}
+
+void SharedMutex::Unlock() {
+  if (port_) {

[Mark Mentovai, 2010/11/09 17:43:14]

port_ could have just been a ScopedCFTypeRef.

[dmac, 2010/11/11 21:47:59]

Done.

+    CFRelease(port_);
+    port_ = NULL;
+  }
+}
+
+}  // namespace base