00001 00002 /****************************************************************************** 00003 Module: SWMRG.h 00004 Notices: Copyright (c) 2000 Jeffrey Richter 00005 ******************************************************************************/ 00006 00007 00008 #pragma once 00009 00010 00012 00018 class CSWMRG { 00019 public: 00020 CSWMRG(); // Constructor 00021 ~CSWMRG(); // Destructor 00022 00023 VOID WaitToRead(); // Call this to gain shared read access 00024 VOID WaitToWrite(); // Call this to gain exclusive write access 00025 VOID Done(); // Call this when done accessing the resource 00026 00027 private: 00028 CRITICAL_SECTION m_cs; // Permits exclusive access to other members 00029 HANDLE m_hsemReaders; // Readers wait on this if a writer has access 00030 HANDLE m_hsemWriters; // Writers wait on this if a reader has access 00031 int m_nWaitingReaders; // Number of readers waiting for access 00032 int m_nWaitingWriters; // Number of writers waiting for access 00033 int m_nActive; // Number of threads currently with access 00034 // (0=no threads, >0=# of readers, -1=1 writer) 00035 }; 00036 00037
1.2.13.1 written by Dimitri van Heesch,
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