1// Protocol Buffers - Google's data interchange format
2// Copyright 2008 Google Inc.  All rights reserved.
3// http://code.google.com/p/protobuf/
4//
5// Redistribution and use in source and binary forms, with or without
6// modification, are permitted provided that the following conditions are
7// met:
8//
9//     * Redistributions of source code must retain the above copyright
10// notice, this list of conditions and the following disclaimer.
11//     * Redistributions in binary form must reproduce the above
12// copyright notice, this list of conditions and the following disclaimer
13// in the documentation and/or other materials provided with the
14// distribution.
15//     * Neither the name of Google Inc. nor the names of its
16// contributors may be used to endorse or promote products derived from
17// this software without specific prior written permission.
18//
19// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30
31// Author: kenton@google.com (Kenton Varda)
32//
33// emulates google3/base/once.h
34//
35// This header is intended to be included only by internal .cc files and
36// generated .pb.cc files.  Users should not use this directly.
37
38#ifdef _WIN32
39#include <windows.h>
40#endif
41
42#include <google/protobuf/stubs/once.h>
43
44namespace google {
45namespace protobuf {
46
47#ifdef _WIN32
48
49struct ProtobufOnceInternal {
50  ProtobufOnceInternal() {
51    InitializeCriticalSection(&critical_section);
52  }
53  ~ProtobufOnceInternal() {
54    DeleteCriticalSection(&critical_section);
55  }
56  CRITICAL_SECTION critical_section;
57};
58
59ProtobufOnceType::~ProtobufOnceType()
60{
61  delete internal_;
62  internal_ = NULL;
63}
64
65ProtobufOnceType::ProtobufOnceType() {
66  // internal_ may be non-NULL if Init() was already called.
67  if (internal_ == NULL) internal_ = new ProtobufOnceInternal;
68}
69
70void ProtobufOnceType::Init(void (*init_func)()) {
71  // internal_ may be NULL if we're still in dynamic initialization and the
72  // constructor has not been called yet.  As mentioned in once.h, we assume
73  // that the program is still single-threaded at this time, and therefore it
74  // should be safe to initialize internal_ like so.
75  if (internal_ == NULL) internal_ = new ProtobufOnceInternal;
76
77  EnterCriticalSection(&internal_->critical_section);
78  if (!initialized_) {
79    init_func();
80    initialized_ = true;
81  }
82  LeaveCriticalSection(&internal_->critical_section);
83}
84
85#endif
86
87}  // namespace protobuf
88}  // namespace google
89