00001 /* 00002 * critsec.h 00003 * 00004 * Critical section mutex class. 00005 * 00006 * Portable Windows Library 00007 * 00008 * Copyright (C) 2004 Post Increment 00009 * 00010 * The contents of this file are subject to the Mozilla Public License 00011 * Version 1.0 (the "License"); you may not use this file except in 00012 * compliance with the License. You may obtain a copy of the License at 00013 * http://www.mozilla.org/MPL/ 00014 * 00015 * Software distributed under the License is distributed on an "AS IS" 00016 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See 00017 * the License for the specific language governing rights and limitations 00018 * under the License. 00019 * 00020 * The Original Code is Portable Windows Library. 00021 * 00022 * The Initial Developer of the Original Code is Post Increment 00023 * 00024 * Contributor(s): ______________________________________. 00025 * 00026 * $Log: critsec.h,v $ 00027 * Revision 1.9 2004/05/16 23:31:07 csoutheren 00028 * Updated API documentation 00029 * 00030 * Revision 1.8 2004/05/12 04:36:13 csoutheren 00031 * Fixed problems with using sem_wait and friends on systems that do not 00032 * support atomic integers 00033 * 00034 * Revision 1.7 2004/04/21 11:22:56 csoutheren 00035 * Modified to work with gcc 3.4.0 00036 * 00037 * Revision 1.6 2004/04/14 06:58:00 csoutheren 00038 * Fixed PAtomicInteger and PSmartPointer to use real atomic operations 00039 * 00040 * Revision 1.5 2004/04/12 03:35:26 csoutheren 00041 * Fixed problems with non-recursuve mutexes and critical sections on 00042 * older compilers and libc 00043 * 00044 * Revision 1.4 2004/04/12 00:58:45 csoutheren 00045 * Fixed PAtomicInteger on Linux, and modified PMutex to use it 00046 * 00047 * Revision 1.3 2004/04/12 00:36:04 csoutheren 00048 * Added new class PAtomicInteger and added Windows implementation 00049 * 00050 * Revision 1.2 2004/04/11 03:20:41 csoutheren 00051 * Added Unix implementation of PCriticalSection 00052 * 00053 * Revision 1.1 2004/04/11 02:55:17 csoutheren 00054 * Added PCriticalSection for Windows 00055 * Added compile time option for PContainer to use critical sections to provide thread safety under some circumstances 00056 * 00057 */ 00058 00059 #ifndef _PCRITICALSECTION 00060 #define _PCRITICALSECTION 00061 00062 #if P_HAS_ATOMIC_INT 00063 #if P_NEEDS_GNU_CXX_NAMESPACE 00064 #define EXCHANGE_AND_ADD(v,i) __gnu_cxx::__exchange_and_add(v,i) 00065 #else 00066 #define EXCHANGE_AND_ADD(v,i) __exchange_and_add(v,i) 00067 #endif 00068 #endif 00069 00076 class PCriticalSection : public PObject 00077 { 00078 PCLASSINFO(PCriticalSection, PObject); 00079 00080 public: 00085 PINLINE PCriticalSection(); 00086 00089 PINLINE ~PCriticalSection(); 00091 00096 PINLINE void Enter(); 00097 00100 PINLINE void Leave(); 00101 00103 00104 private: 00105 PCriticalSection & operator=(const PCriticalSection &) { return *this; } 00106 00107 // Include platform dependent part of class 00108 #ifdef _WIN32 00109 #include "msos/ptlib/critsec.h" 00110 #else 00111 #include "unix/ptlib/critsec.h" 00112 #endif 00113 }; 00114 00115 00116 class PEnterAndLeave { 00117 public: 00122 inline PEnterAndLeave( 00123 PCriticalSection & _critSec, 00124 BOOL enter = TRUE 00125 ) 00126 : critSec(_critSec) 00127 { if (enter) critSec.Enter(); } 00128 00133 inline ~PEnterAndLeave() 00134 { critSec.Leave(); } 00135 00136 protected: 00137 PCriticalSection & critSec; 00138 }; 00139 00140 00149 class PAtomicInteger 00150 { 00151 #if defined(_WIN32) || defined(DOC_PLUS_PLUS) 00152 public: 00155 inline PAtomicInteger(long v = 0) 00156 : value(v) { } 00157 00165 BOOL IsZero() const { return value == 0; } 00166 00172 inline long operator++() { return InterlockedIncrement(&value); } 00173 00179 inline long operator--() { return InterlockedDecrement(&value); } 00180 00184 inline operator long () const { return value; } 00185 00189 inline void SetValue(long v) { value = v; } 00190 protected: 00191 long value; 00192 #elif P_HAS_ATOMIC_INT 00193 public: 00194 inline PAtomicInteger(int v = 0) 00195 : value(v) { } 00196 BOOL IsZero() const { return value == 0; } 00197 inline int operator++() { return EXCHANGE_AND_ADD(&value, 1) + 1; } 00198 inline int unsigned operator--() { return EXCHANGE_AND_ADD(&value, -1) - 1; } 00199 inline operator int () const { return value; } 00200 inline void SetValue(int v) { value = v; } 00201 protected: 00202 _Atomic_word value; 00203 #else 00204 protected: 00205 PCriticalSection critSec; 00206 public: 00207 inline PAtomicInteger(int v = 0) 00208 : value(v) { } 00209 BOOL IsZero() const { return value == 0; } 00210 inline int operator++() { PEnterAndLeave m(critSec); value++; return value;} 00211 inline int operator--() { PEnterAndLeave m(critSec); value--; return value;} 00212 inline operator int () const { return value; } 00213 inline void SetValue(int v) { value = v; } 00214 private: 00215 PAtomicInteger & operator=(const PAtomicInteger & ref) { value = (int)ref; return *this; } 00216 protected: 00217 int value; 00218 #endif 00219 }; 00220 00221 #endif 00222 00223 // End Of File ///////////////////////////////////////////////////////////////