00001 /******************************************************************************* 00002 * Copyright (C) 2004 Vintela, Inc. All rights reserved. 00003 * Copyright (C) 2005 Novell, Inc. All rights reserved. 00004 * 00005 * Redistribution and use in source and binary forms, with or without 00006 * modification, are permitted provided that the following conditions are met: 00007 * 00008 * - Redistributions of source code must retain the above copyright notice, 00009 * this list of conditions and the following disclaimer. 00010 * 00011 * - Redistributions in binary form must reproduce the above copyright notice, 00012 * this list of conditions and the following disclaimer in the documentation 00013 * and/or other materials provided with the distribution. 00014 * 00015 * - Neither the name of Vintela, Inc., Novell, Inc., nor the names of its 00016 * contributors may be used to endorse or promote products derived from this 00017 * software without specific prior written permission. 00018 * 00019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' 00020 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 00021 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 00022 * ARE DISCLAIMED. IN NO EVENT SHALL Vintela, Inc., Novell, Inc., OR THE 00023 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 00024 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 00025 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 00026 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 00027 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 00028 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 00029 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00030 *******************************************************************************/ 00031 00036 #include "blocxx/BLOCXX_config.h" 00037 #include "blocxx/ThreadOnce.hpp" 00038 #include "blocxx/Assertion.hpp" 00039 00040 #if defined(BLOCXX_WIN32) 00041 00042 #include <stdio.h> 00043 00044 namespace BLOCXX_NAMESPACE 00045 { 00046 00047 void callOnce(OnceFlag& flag, void (*func)()) 00048 { 00049 // this is the double-checked locking pattern, but with a bit more strength than normally implemented :-) 00050 if (InterlockedCompareExchange(&flag, 1, 1) == 0) 00051 { 00052 wchar_t mutexName[MAX_PATH]; 00053 _snwprintf(mutexName, MAX_PATH, L"%X-%p-587ccea9-c95a-4e81-ac51-ab0ddc6cef63", GetCurrentProcessId(), &flag); 00054 mutexName[MAX_PATH - 1] = 0; 00055 00056 HANDLE mutex = CreateMutexW(NULL, FALSE, mutexName); 00057 BLOCXX_ASSERT(mutex != NULL); 00058 00059 int res = 0; 00060 res = WaitForSingleObject(mutex, INFINITE); 00061 BLOCXX_ASSERT(res == WAIT_OBJECT_0); 00062 00063 if (InterlockedCompareExchange(&flag, 1, 1) == 0) 00064 { 00065 try 00066 { 00067 func(); 00068 } 00069 catch (...) 00070 { 00071 res = ReleaseMutex(mutex); 00072 BLOCXX_ASSERT(res); 00073 res = CloseHandle(mutex); 00074 BLOCXX_ASSERT(res); 00075 throw; 00076 } 00077 InterlockedExchange(&flag, 1); 00078 } 00079 00080 res = ReleaseMutex(mutex); 00081 BLOCXX_ASSERT(res); 00082 res = CloseHandle(mutex); 00083 BLOCXX_ASSERT(res); 00084 } 00085 } 00086 00087 00088 } // end namespace BLOCXX_NAMESPACE 00089 00090 #endif 00091 00092