00001 // 00002 // Mutex_WIN32.cpp 00003 // 00004 // $Id: //poco/1.3/Foundation/src/Mutex_WIN32.cpp#3 $ 00005 // 00006 // Library: Foundation 00007 // Package: Threading 00008 // Module: Mutex 00009 // 00010 // Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH. 00011 // and Contributors. 00012 // 00013 // Permission is hereby granted, free of charge, to any person or organization 00014 // obtaining a copy of the software and accompanying documentation covered by 00015 // this license (the "Software") to use, reproduce, display, distribute, 00016 // execute, and transmit the Software, and to prepare derivative works of the 00017 // Software, and to permit third-parties to whom the Software is furnished to 00018 // do so, all subject to the following: 00019 // 00020 // The copyright notices in the Software and this entire statement, including 00021 // the above license grant, this restriction and the following disclaimer, 00022 // must be included in all copies of the Software, in whole or in part, and 00023 // all derivative works of the Software, unless such copies or derivative 00024 // works are solely in the form of machine-executable object code generated by 00025 // a source language processor. 00026 // 00027 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 00028 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 00029 // FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT 00030 // SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE 00031 // FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE, 00032 // ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 00033 // DEALINGS IN THE SOFTWARE. 00034 // 00035 00036 00037 #include "Poco/Mutex_WIN32.h" 00038 #include "Poco/Timestamp.h" 00039 00040 00041 namespace Poco { 00042 00043 00044 MutexImpl::MutexImpl() 00045 { 00046 // the fct has a boolean return value under WInnNt/2000/XP but not on Win98 00047 // the return only checks if the input address of &_cs was valid, so it is safe to omit it 00048 InitializeCriticalSectionAndSpinCount(&_cs, 4000); 00049 } 00050 00051 00052 MutexImpl::~MutexImpl() 00053 { 00054 DeleteCriticalSection(&_cs); 00055 } 00056 00057 00058 bool MutexImpl::tryLockImpl(long milliseconds) 00059 { 00060 const int sleepMillis = 5; 00061 Timestamp now; 00062 Timestamp::TimeDiff diff(Timestamp::TimeDiff(milliseconds)*1000); 00063 do 00064 { 00065 try 00066 { 00067 if (TryEnterCriticalSection(&_cs) == TRUE) 00068 return true; 00069 } 00070 catch (...) 00071 { 00072 throw SystemException("cannot lock mutex"); 00073 } 00074 Sleep(sleepMillis); 00075 } 00076 while (!now.isElapsed(diff)); 00077 return false; 00078 } 00079 00080 00081 } // namespace Poco