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#ifndef SANDBOX_MAC_DISPATCH_SOURCE_MACH_H_
6#define SANDBOX_MAC_DISPATCH_SOURCE_MACH_H_
7
8#include <dispatch/dispatch.h>
9
10#include "base/basictypes.h"
11#include "sandbox/sandbox_export.h"
12
13namespace sandbox {
14
15// This class encapsulates a MACH_RECV dispatch source. When this object is
16// destroyed, the source will be cancelled and it will wait for the source
17// to stop executing work. The source can run on either a user-supplied queue,
18// or it can create its own for the source.
19class SANDBOX_EXPORT DispatchSourceMach {
20 public:
21  // Creates a new dispatch source for the |port| and schedules it on a new
22  // queue that will be created with |name|. When a Mach message is received,
23  // the |event_handler| will be called.
24  DispatchSourceMach(const char* name,
25                     mach_port_t port,
26                     void (^event_handler)());
27
28  // Creates a new dispatch source with the same semantics as above, but rather
29  // than creating a new queue, it schedules the source on |queue|.
30  DispatchSourceMach(dispatch_queue_t queue,
31                     mach_port_t port,
32                     void (^event_handler)());
33
34  // Cancels the source and waits for it to become fully cancelled before
35  // releasing the source.
36  ~DispatchSourceMach();
37
38  // Resumes the source. This must be called before any Mach messages will
39  // be received.
40  void Resume();
41
42 private:
43  // Cancels the source, after which this class will no longer receive Mach
44  // messages. Calling this more than once is a no-op.
45  void Cancel();
46
47  // The dispatch queue used to service the source_.
48  dispatch_queue_t queue_;
49
50  // A MACH_RECV dispatch source.
51  dispatch_source_t source_;
52
53  // Semaphore used to wait on the |source_|'s cancellation in the destructor.
54  dispatch_semaphore_t source_canceled_;
55
56  DISALLOW_COPY_AND_ASSIGN(DispatchSourceMach);
57};
58
59}  // namespace sandbox
60
61#endif  // SANDBOX_MAC_DISPATCH_SOURCE_MACH_H_
62