base/mac/dispatch_source_mach.cc

   1 // Copyright 2014 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 "base/mac/dispatch_source_mach.h"
   6
   7 namespace base {
   8
   9 DispatchSourceMach::DispatchSourceMach(const char* name,
  10                                        mach_port_t port,
  11                                        void (^event_handler)())
  12     // TODO(rsesek): Specify DISPATCH_QUEUE_SERIAL, in the 10.7 SDK. NULL
  13     // means the same thing but is not symbolically clear.
  14     : DispatchSourceMach(dispatch_queue_create(name, NULL),
  15                          port,
  16                          event_handler) {
  17   // Since the queue was created above in the delegated constructor, and it was
  18   // subsequently retained, release it here.
  19   dispatch_release(queue_);
  20 }
  21
  22 DispatchSourceMach::DispatchSourceMach(dispatch_queue_t queue,
  23                                        mach_port_t port,
  24                                        void (^event_handler)())
  25     : queue_(queue),
  26       source_(dispatch_source_create(DISPATCH_SOURCE_TYPE_MACH_RECV,
  27           port, 0, queue_)),
  28       source_canceled_(dispatch_semaphore_create(0)) {
  29   dispatch_retain(queue);
  30
  31   dispatch_source_set_event_handler(source_, event_handler);
  32   dispatch_source_set_cancel_handler(source_, ^{
  33       dispatch_semaphore_signal(source_canceled_);
  34   });
  35 }
  36
  37 DispatchSourceMach::~DispatchSourceMach() {
  38   Cancel();
  39 }
  40
  41 void DispatchSourceMach::Resume() {
  42   dispatch_resume(source_);
  43 }
  44
  45 void DispatchSourceMach::Cancel() {
  46   if (source_) {
  47     dispatch_source_cancel(source_);
  48     dispatch_release(source_);
  49     source_ = NULL;
  50
  51     dispatch_semaphore_wait(source_canceled_, DISPATCH_TIME_FOREVER);
  52     dispatch_release(source_canceled_);
  53     source_canceled_ = NULL;
  54   }
  55
  56   if (queue_) {
  57     dispatch_release(queue_);
  58     queue_ = NULL;
  59   }
  60 }
  61
  62 }  // namespace base