Mac: Create a pid->task_t mapping in the browser process.

Since nothing writes to this map in the browser atm, this does not have any visible effect.

BUG=13156,25454
TEST=unittest

Review URL: http://codereview.chromium.org/501138

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@35092 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 141 insertions, 3 deletions

diff --git a/chrome/browser/mach_broker_mac.cc b/chrome/browser/mach_broker_mac.cc
new file mode 100644
index 0000000..59f7728
--- /dev/null
+++ b/chrome/browser/mach_broker_mac.cc
@@ -0,0 +1,35 @@
+// Copyright (c) 2009 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/mach_broker_mac.h"
+
+#include "base/logging.h"
+
+// Returns the global MachBroker.
+MachBroker* MachBroker::instance() {
+  return Singleton<MachBroker>::get();
+}
+
+// Adds mach info for a given pid.
+void MachBroker::RegisterPid(
+    base::ProcessHandle pid, const MachInfo& mach_info) {
+  AutoLock lock(lock_);
+  DCHECK_EQ(0u, mach_map_.count(pid));
+  mach_map_[pid] = mach_info;
+}
+
+// Removes all mappings belonging to |pid| from the broker.
+void MachBroker::Invalidate(base::ProcessHandle pid) {
+  AutoLock lock(lock_);
+  mach_map_.erase(pid);
+}
+
+// Returns the mach task belonging to |pid|.
+mach_port_t MachBroker::TaskForPid(base::ProcessHandle pid) const {
+  AutoLock lock(lock_);
+  MachBroker::MachMap::const_iterator it = mach_map_.find(pid);
+  if (it == mach_map_.end())
+    return MACH_PORT_NULL;
+  return it->second.mach_task_;
+}
diff --git a/chrome/browser/mach_broker_mac.h b/chrome/browser/mach_broker_mac.h
new file mode 100644
index 0000000..67f4fec
--- /dev/null
+++ b/chrome/browser/mach_broker_mac.h
@@ -0,0 +1,73 @@
+// Copyright (c) 2009 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.
+
+#ifndef CHROME_BROWSER_MACH_BROKER_H_
+#define CHROME_BROWSER_MACH_BROKER_H_
+
+#include <map>
+
+#include <mach/mach.h>
+
+#include "base/lock.h"
+#include "base/process.h"
+#include "base/process_util.h"
+#include "base/singleton.h"
+
+// On OS X, the mach_port_t of a process is required to collect metrics about
+// the process. Running |task_for_pid()| is only allowed for privileged code.
+// However, a process has port rights to all its subprocesses, so let the
+// browser's child processes send their Mach port to the browser over IPC.
+// This way, the brower can at least collect metrics of its child processes,
+// which is what it's most interested in anyway.
+//
+// Mach ports can only be sent over Mach IPC, not over the |socketpair()| that
+// the regular IPC system uses. Hence, the child processes open a Mach
+// connection shortly after launching and ipc their mach data to the browser
+// process. This data is kept in a global |MachBroker| object.
+//
+// Since this data arrives over a separate channel, it is not available
+// immediately after a child process has been started.
+class MachBroker : public base::ProcessMetrics::PortProvider {
+ public:
+  // Returns the global MachBroker.
+  static MachBroker* instance();
+
+  struct MachInfo {
+    MachInfo() : mach_task_(MACH_PORT_NULL) {}
+
+    MachInfo& SetTask(mach_port_t task) {
+      mach_task_ = task;
+      return *this;
+    }
+
+    mach_port_t mach_task_;
+  };
+
+  // Adds mach info for a given pid.
+  void RegisterPid(base::ProcessHandle pid, const MachInfo& mach_info);
+
+  // Removes all mappings belonging to |pid| from the broker.
+  void Invalidate(base::ProcessHandle pid);
+
+  // Implement |ProcessMetrics::PortProvider|.
+  virtual mach_port_t TaskForPid(base::ProcessHandle process) const;
+
+ private:
+  // Private constructor.
+  MachBroker() {}
+  friend struct DefaultSingletonTraits<MachBroker>;
+  friend class MachBrokerTest;
+
+  // Stores mach info for every process in the broker.
+  typedef std::map<base::ProcessHandle, MachInfo> MachMap;
+  MachMap mach_map_;
+
+  // Mutex that guards |mach_map_|.
+  mutable Lock lock_;
+
+  DISALLOW_COPY_AND_ASSIGN(MachBroker);
+};
+
+#endif  // CHROME_BROWSER_MACH_BROKER_H_
+
diff --git a/chrome/browser/mach_broker_mac_unittest.cc b/chrome/browser/mach_broker_mac_unittest.cc
new file mode 100644
index 0000000..56cc2ae2
--- /dev/null
+++ b/chrome/browser/mach_broker_mac_unittest.cc
@@ -0,0 +1,24 @@
+// Copyright (c) 2009 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/mach_broker_mac.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+class MachBrokerTest : public testing::Test {
+ public:
+  MachBroker broker_;
+};
+
+TEST_F(MachBrokerTest, Setter) {
+  broker_.RegisterPid(1u, MachBroker::MachInfo().SetTask(2u));
+  EXPECT_EQ(2u, broker_.TaskForPid(1));
+  EXPECT_EQ(0u, broker_.TaskForPid(2));
+}
+
+TEST_F(MachBrokerTest, Invalidate) {
+  broker_.RegisterPid(1u, MachBroker::MachInfo().SetTask(2));
+  broker_.Invalidate(1u);
+  EXPECT_EQ(0u, broker_.TaskForPid(1));
+}
diff --git a/chrome/browser/task_manager.cc b/chrome/browser/task_manager.cc
index edd7b37..0667f94 100644
--- a/chrome/browser/task_manager.cc
+++ b/chrome/browser/task_manager.cc
@@ -29,6 +29,10 @@
 #include "net/url_request/url_request.h"
 #include "net/url_request/url_request_job.h"
 
+#if defined(OS_MACOSX)
+#include "chrome/browser/mach_broker_mac.h"
+#endif
+
 namespace {
 
 // The delay between updates of the information (in ms).
@@ -536,9 +540,8 @@ void TaskManagerModel::AddResource(TaskManager::Resource* resource) {
 #if !defined(OS_MACOSX)
         base::ProcessMetrics::CreateProcessMetrics(process);
 #else
-        // TODO(thakis): Write a port provider that knows the task ports of
-        // child processes.
-        base::ProcessMetrics::CreateProcessMetrics(process, NULL);
+        base::ProcessMetrics::CreateProcessMetrics(process,
+                                                   MachBroker::instance());
 #endif
 
     metrics_map_[process] = pm;
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index fe0328a..fe69765 100755
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -1098,6 +1098,8 @@
         'browser/login_prompt_mac.h',
         'browser/login_prompt_mac.mm',
         'browser/login_prompt_win.cc',
+        'browser/mach_broker_mac.cc',
+        'browser/mach_broker_mac.h',
         'browser/memory_details.cc',
         'browser/memory_details_linux.cc',
         'browser/memory_details_mac.cc',
diff --git a/chrome/chrome_tests.gypi b/chrome/chrome_tests.gypi
index 9c3cb9f..4f510d6 100755
--- a/chrome/chrome_tests.gypi
+++ b/chrome/chrome_tests.gypi
@@ -724,6 +724,7 @@
         'browser/keychain_mock_mac.h',
         'browser/login_prompt_unittest.cc',
         'browser/meta_table_helper_unittest.cc',
+        'browser/mach_broker_mac_unittest.cc',
         'browser/metrics/metrics_log_unittest.cc',
         'browser/metrics/metrics_response_unittest.cc',
         'browser/metrics/metrics_service_unittest.cc',