[Mac] Add a perf test that counts the number of Mach ports in the browser.

BUG=105513
TEST=This is one.


Review URL: http://codereview.chromium.org/9193024

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@119541 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 48 insertions, 2 deletions

diff --git a/base/mach_ipc_mac.h b/base/mach_ipc_mac.h
index 7d39101..d0898a3 100644
--- a/base/mach_ipc_mac.h
+++ b/base/mach_ipc_mac.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -309,6 +309,19 @@ class BASE_EXPORT MachPortSender {
   DISALLOW_COPY_AND_ASSIGN(MachPortSender);
 };
 
+//==============================================================================
+// Static utility functions.
+
+namespace mac {
+
+// Returns the number of Mach ports to which the given task has a right.
+// Note that unless the calling task has send rights to the passed task port,
+// this will fail unless the calling task is running as root.
+kern_return_t BASE_EXPORT GetNumberOfMachPorts(mach_port_t task_port,
+                                               int* port_count);
+
+}  // namespace mac
+
 }  // namespace base
 
 #endif // BASE_MACH_IPC_MAC_H_
diff --git a/base/mach_ipc_mac.mm b/base/mach_ipc_mac.mm
index b6dedd2..3d45dd7 100644
--- a/base/mach_ipc_mac.mm
+++ b/base/mach_ipc_mac.mm
@@ -1,10 +1,11 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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/mach_ipc_mac.h"
 
 #import <Foundation/Foundation.h>
+#include <mach/vm_map.h>
 
 #include <stdio.h>
 #include "base/logging.h"
@@ -322,4 +323,36 @@ kern_return_t MachPortSender::SendMessage(MachSendMessage &message,
   return result;
 }
 
+//==============================================================================
+
+namespace mac {
+
+kern_return_t GetNumberOfMachPorts(mach_port_t task_port, int* num_ports) {
+  mach_port_name_array_t names;
+  mach_msg_type_number_t names_count;
+  mach_port_type_array_t types;
+  mach_msg_type_number_t types_count;
+
+  // A friendlier interface would allow NULL buffers to only get the counts.
+  kern_return_t kr = mach_port_names(task_port, &names, &names_count,
+                                     &types, &types_count);
+  if (kr != KERN_SUCCESS)
+    return kr;
+
+  // The documentation states this is an invariant.
+  DCHECK_EQ(names_count, types_count);
+  *num_ports = names_count;
+
+  kr = vm_deallocate(mach_task_self(),
+      reinterpret_cast<vm_address_t>(names),
+      names_count * sizeof(mach_port_name_array_t));
+  kr = vm_deallocate(mach_task_self(),
+      reinterpret_cast<vm_address_t>(types),
+      types_count * sizeof(mach_port_type_array_t));
+
+  return kr;
+}
+
+}  // namespace mac
+
 }  // namespace base