src/Git/SharedMutex.cpp

   1 /**
   2 * SharedMutex.cpp
   3 * @Author   Tu Yongce <yongce (at) 126 (dot) com>
   4 * @Created  2008-11-17
   5 * @Modified 2008-11-17
   6 * @Version  0.1
   7 */
   8 #include "StdAfx.h"
   9 #include "SharedMutex.h"
  10
  11
  12 SharedMutex::SharedMutex(): m_sharedNum(0), m_exclusiveNum(0), m_lockType(LOCK_NONE), m_mutex(0), m_sharedEvent(0),m_exclusiveEvent(0)
  13 {
  14
  15 }
  16
  17 SharedMutex::~SharedMutex()
  18 {
  19
  20 }
  21
  22 void SharedMutex::Release()
  23 {
  24         if (m_mutex)
  25         {
  26                 ::CloseHandle(m_mutex);
  27                 m_mutex = NULL;
  28         }
  29         if (m_sharedEvent)
  30         {
  31                 ::CloseHandle(m_sharedEvent);
  32                 m_sharedEvent = NULL;
  33         }
  34         if (m_exclusiveEvent)
  35         {
  36                 ::CloseHandle(m_exclusiveEvent);
  37                 m_exclusiveEvent = NULL;
  38         }
  39 }
  40 void SharedMutex::Init()
  41 {
  42         m_sharedNum = m_exclusiveNum = 0;
  43         m_lockType = LOCK_NONE;
  44
  45         // ´´½¨ÓÃÓÚ±£»¤ÄÚ²¿Êý¾ÝµÄ»¥³âÁ¿
  46     m_mutex = ::CreateMutex(NULL, FALSE, NULL);
  47     // ´´½¨ÓÃÓÚÍ¬²½¹²Ïí·ÃÎÊÏß³ÌµÄÊÂ¼þ£¨ÊÖ¶¯ÊÂ¼þ£©
  48     m_sharedEvent = ::CreateEvent(NULL, TRUE, FALSE, NULL);
  49     // ´´½¨ÓÃÓÚÍ¬²½¶ÀÕ¼·ÃÎÊÏß³ÌµÄÊÂ¼þ£¨×Ô¶¯ÊÂ¼þ£©
  50     m_exclusiveEvent = ::CreateEvent(NULL, FALSE, FALSE, NULL);
  51 }
  52
  53 // »ñÈ¡¹²Ïí·ÃÎÊÈ¨
  54 bool SharedMutex::AcquireShared(DWORD waitTime)
  55 {
  56     ::WaitForSingleObject(m_mutex, INFINITE);
  57     ++m_sharedNum;
  58     if (m_lockType == LOCK_EXCLUSIVE) {
  59         DWORD retCode = ::SignalObjectAndWait(m_mutex, m_sharedEvent, waitTime, FALSE);
  60         if (retCode == WAIT_OBJECT_0) {
  61             return true;
  62         } else {
  63             if (retCode == WAIT_TIMEOUT)
  64                 ::SetLastError(WAIT_TIMEOUT);
  65             return false;
  66         }
  67     }
  68     m_lockType = LOCK_SHARED;
  69     ::ReleaseMutex(m_mutex);
  70     return true;
  71 }
  72
  73 // ÊÍ·Å¹²Ïí·ÃÎÊÈ¨
  74 void SharedMutex::ReleaseShared()
  75 {
  76     //assert(m_lockType == LOCK_SHARED);
  77     ::WaitForSingleObject(m_mutex, INFINITE);
  78     --m_sharedNum;
  79     if (m_sharedNum == 0) {
  80         if (m_exclusiveNum > 0) {
  81             // »½ÐÑÒ»¸ö¶ÀÕ¼·ÃÎÊÏß³Ì
  82             m_lockType = LOCK_EXCLUSIVE;
  83             ::SetEvent(m_exclusiveEvent);
  84         } else {
  85             // Ã»ÓÐµÈ´ýÏß³Ì
  86             m_lockType = LOCK_NONE;
  87         }
  88     }
  89     ::ReleaseMutex(m_mutex);
  90 }
  91
  92 // »ñÈ¡¶ÀÕ¼·ÃÎÊÈ¨
  93 bool SharedMutex::AcquireExclusive(DWORD waitTime)
  94 {
  95
  96     ::WaitForSingleObject(m_mutex, INFINITE);
  97     ++m_exclusiveNum;
  98     if (m_lockType != LOCK_NONE) {
  99         DWORD retCode = ::SignalObjectAndWait(m_mutex, m_exclusiveEvent, waitTime, FALSE);
 100         if (retCode == WAIT_OBJECT_0) {
 101             return true;
 102         } else {
 103             if (retCode == WAIT_TIMEOUT)
 104                 ::SetLastError(WAIT_TIMEOUT);
 105             return false;
 106         }
 107     }
 108     m_lockType = LOCK_EXCLUSIVE;
 109     ::ReleaseMutex(m_mutex);
 110     return true;
 111 }
 112
 113 // ÊÍ·Å¶ÀÕ¼·ÃÎÊÈ¨
 114 void SharedMutex::ReleaseExclusive()
 115 {
 116 //    assert(m_lockType == LOCK_EXCLUSIVE);
 117     ::WaitForSingleObject(m_mutex, INFINITE);
 118     --m_exclusiveNum;
 119     // ¶ÀÕ¼·ÃÎÊÏß³ÌÓÅÏÈ
 120     if (m_exclusiveNum > 0) {
 121         // »½ÐÑÒ»¸ö¶ÀÕ¼·ÃÎÊÏß³Ì
 122         ::SetEvent(m_exclusiveEvent);
 123     } else if (m_sharedNum > 0) {
 124         // »½ÐÑµ±Ç°ËùÓÐ¹²Ïí·ÃÎÊÏß³Ì
 125         m_lockType = LOCK_SHARED;
 126         ::PulseEvent(m_sharedEvent);
 127     } else {
 128         // Ã»ÓÐµÈ´ýÏß³Ì
 129         m_lockType = LOCK_NONE;
 130     }
 131     ::ReleaseMutex(m_mutex);
 132 }