1//
2// detail/impl/win_static_mutex.ipp
3// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4//
5// Copyright (c) 2003-2016 Christopher M. Kohlhoff (chris at kohlhoff dot com)
6//
7// Distributed under the Boost Software License, Version 1.0. (See accompanying
8// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
9//
10
11#ifndef ASIO_DETAIL_IMPL_WIN_STATIC_MUTEX_IPP
12#define ASIO_DETAIL_IMPL_WIN_STATIC_MUTEX_IPP
13
14#if defined(_MSC_VER) && (_MSC_VER >= 1200)
15# pragma once
16#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
17
18#include "asio/detail/config.hpp"
19
20#if defined(ASIO_WINDOWS)
21
22#include <cstdio>
23#include "asio/detail/throw_error.hpp"
24#include "asio/detail/win_static_mutex.hpp"
25#include "asio/error.hpp"
26
27#include "asio/detail/push_options.hpp"
28
29namespace asio {
30namespace detail {
31
32void win_static_mutex::init()
33{
34  int error = do_init();
35  asio::error_code ec(error,
36      asio::error::get_system_category());
37  asio::detail::throw_error(ec, "static_mutex");
38}
39
40int win_static_mutex::do_init()
41{
42  using namespace std; // For sprintf.
43  wchar_t mutex_name[128];
44#if defined(ASIO_HAS_SECURE_RTL)
45  swprintf_s(
46#else // defined(ASIO_HAS_SECURE_RTL)
47  _snwprintf(
48#endif // defined(ASIO_HAS_SECURE_RTL)
49      mutex_name, 128, L"asio-58CCDC44-6264-4842-90C2-F3C545CB8AA7-%u-%p",
50      static_cast<unsigned int>(::GetCurrentProcessId()), this);
51
52#if defined(ASIO_WINDOWS_APP)
53  HANDLE mutex = ::CreateMutexExW(0, mutex_name, CREATE_MUTEX_INITIAL_OWNER, 0);
54#else // defined(ASIO_WINDOWS_APP)
55  HANDLE mutex = ::CreateMutexW(0, TRUE, mutex_name);
56#endif // defined(ASIO_WINDOWS_APP)
57  DWORD last_error = ::GetLastError();
58  if (mutex == 0)
59    return ::GetLastError();
60
61  if (last_error == ERROR_ALREADY_EXISTS)
62  {
63#if defined(ASIO_WINDOWS_APP)
64    ::WaitForSingleObjectEx(mutex, INFINITE, false);
65#else // defined(ASIO_WINDOWS_APP)
66    ::WaitForSingleObject(mutex, INFINITE);
67#endif // defined(ASIO_WINDOWS_APP)
68  }
69
70  if (initialised_)
71  {
72    ::ReleaseMutex(mutex);
73    ::CloseHandle(mutex);
74    return 0;
75  }
76
77#if defined(__MINGW32__)
78  // Not sure if MinGW supports structured exception handling, so for now
79  // we'll just call the Windows API and hope.
80# if defined(UNDER_CE)
81  ::InitializeCriticalSection(&crit_section_);
82# else
83  if (!::InitializeCriticalSectionAndSpinCount(&crit_section_, 0x80000000))
84  {
85    last_error = ::GetLastError();
86    ::ReleaseMutex(mutex);
87    ::CloseHandle(mutex);
88    return last_error;
89  }
90# endif
91#else
92  __try
93  {
94# if defined(UNDER_CE)
95    ::InitializeCriticalSection(&crit_section_);
96# elif defined(ASIO_WINDOWS_APP)
97    ::InitializeCriticalSectionEx(&crit_section_, 0x80000000, 0);
98# else
99    if (!::InitializeCriticalSectionAndSpinCount(&crit_section_, 0x80000000))
100    {
101      last_error = ::GetLastError();
102      ::ReleaseMutex(mutex);
103      ::CloseHandle(mutex);
104      return last_error;
105    }
106# endif
107  }
108  __except(GetExceptionCode() == STATUS_NO_MEMORY
109      ? EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH)
110  {
111    ::ReleaseMutex(mutex);
112    ::CloseHandle(mutex);
113    return ERROR_OUTOFMEMORY;
114  }
115#endif
116
117  initialised_ = true;
118  ::ReleaseMutex(mutex);
119  ::CloseHandle(mutex);
120  return 0;
121}
122
123} // namespace detail
124} // namespace asio
125
126#include "asio/detail/pop_options.hpp"
127
128#endif // defined(ASIO_WINDOWS)
129
130#endif // ASIO_DETAIL_IMPL_WIN_STATIC_MUTEX_IPP
131