chromeos/dbus/blocking_method_caller.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chromeos/dbus/blocking_method_caller.h"
   6
   7 #include "base/bind.h"
   8 #include "base/callback_helpers.h"
   9 #include "base/location.h"
  10 #include "base/task_runner.h"
  11 #include "base/threading/thread_restrictions.h"
  12 #include "dbus/bus.h"
  13 #include "dbus/object_proxy.h"
  14
  15 namespace chromeos {
  16
  17 namespace {
  18
  19 // This function is a part of CallMethodAndBlock implementation.
  20 void CallMethodAndBlockInternal(
  21     scoped_ptr<dbus::Response>* response,
  22     base::ScopedClosureRunner* signaler,
  23     dbus::ObjectProxy* proxy,
  24     dbus::MethodCall* method_call) {
  25   *response = proxy->CallMethodAndBlock(
  26       method_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT);
  27 }
  28
  29 }  // namespace
  30
  31 BlockingMethodCaller::BlockingMethodCaller(dbus::Bus* bus,
  32                                            dbus::ObjectProxy* proxy)
  33     : bus_(bus),
  34       proxy_(proxy),
  35       on_blocking_method_call_(false /* manual_reset */,
  36                                false /* initially_signaled */) {
  37 }
  38
  39 BlockingMethodCaller::~BlockingMethodCaller() {
  40 }
  41
  42 scoped_ptr<dbus::Response> BlockingMethodCaller::CallMethodAndBlock(
  43     dbus::MethodCall* method_call) {
  44   // on_blocking_method_call_->Signal() will be called when |signaler| is
  45   // destroyed.
  46   base::Closure signal_task(
  47       base::Bind(&base::WaitableEvent::Signal,
  48                  base::Unretained(&on_blocking_method_call_)));
  49   base::ScopedClosureRunner* signaler =
  50       new base::ScopedClosureRunner(signal_task);
  51
  52   scoped_ptr<dbus::Response> response;
  53   bus_->GetDBusTaskRunner()->PostTask(
  54       FROM_HERE,
  55       base::Bind(&CallMethodAndBlockInternal,
  56                  &response,
  57                  base::Owned(signaler),
  58                  base::Unretained(proxy_),
  59                  method_call));
  60   // http://crbug.com/125360
  61   base::ThreadRestrictions::ScopedAllowWait allow_wait;
  62   on_blocking_method_call_.Wait();
  63   return response.Pass();
  64 }
  65
  66 }  // namespace chromeos