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         ::CloseHandle(m_mutex);
  25     ::CloseHandle(m_sharedEvent);
  26     ::CloseHandle(m_exclusiveEvent);
  27 }
  28 void SharedMutex::Init()
  29 {
  30         m_sharedNum = m_exclusiveNum = 0;
  31         m_lockType = LOCK_NONE;
  32
  33         // ´´½¨ÓÃÓÚ±£»¤ÄÚ²¿Êý¾ÝµÄ»¥³âÁ¿
  34     m_mutex = ::CreateMutex(NULL, FALSE, NULL);
  35     // ´´½¨ÓÃÓÚÍ¬²½¹²Ïí·ÃÎÊÏß³ÌµÄÊÂ¼þ£¨ÊÖ¶¯ÊÂ¼þ£©
  36     m_sharedEvent = ::CreateEvent(NULL, TRUE, FALSE, NULL);
  37     // ´´½¨ÓÃÓÚÍ¬²½¶ÀÕ¼·ÃÎÊÏß³ÌµÄÊÂ¼þ£¨×Ô¶¯ÊÂ¼þ£©
  38     m_exclusiveEvent = ::CreateEvent(NULL, FALSE, FALSE, NULL);
  39 }
  40
  41 // »ñÈ¡¹²Ïí·ÃÎÊÈ¨
  42 bool SharedMutex::AcquireShared(DWORD waitTime)
  43 {
  44     ::WaitForSingleObject(m_mutex, INFINITE);
  45     ++m_sharedNum;
  46     if (m_lockType == LOCK_EXCLUSIVE) {
  47         DWORD retCode = ::SignalObjectAndWait(m_mutex, m_sharedEvent, waitTime, FALSE);
  48         if (retCode == WAIT_OBJECT_0) {
  49             return true;
  50         } else {
  51             if (retCode == WAIT_TIMEOUT)
  52                 ::SetLastError(WAIT_TIMEOUT);
  53             return false;
  54         }
  55     }
  56     m_lockType = LOCK_SHARED;
  57     ::ReleaseMutex(m_mutex);
  58     return true;
  59 }
  60
  61 // ÊÍ·Å¹²Ïí·ÃÎÊÈ¨
  62 void SharedMutex::ReleaseShared()
  63 {
  64     //assert(m_lockType == LOCK_SHARED);
  65     ::WaitForSingleObject(m_mutex, INFINITE);
  66     --m_sharedNum;
  67     if (m_sharedNum == 0) {
  68         if (m_exclusiveNum > 0) {
  69             // »½ÐÑÒ»¸ö¶ÀÕ¼·ÃÎÊÏß³Ì
  70             m_lockType = LOCK_EXCLUSIVE;
  71             ::SetEvent(m_exclusiveEvent);
  72         } else {
  73             // Ã»ÓÐµÈ´ýÏß³Ì
  74             m_lockType = LOCK_NONE;
  75         }
  76     }
  77     ::ReleaseMutex(m_mutex);
  78 }
  79
  80 // »ñÈ¡¶ÀÕ¼·ÃÎÊÈ¨
  81 bool SharedMutex::AcquireExclusive(DWORD waitTime)
  82 {
  83
  84     ::WaitForSingleObject(m_mutex, INFINITE);
  85     ++m_exclusiveNum;
  86     if (m_lockType != LOCK_NONE) {
  87         DWORD retCode = ::SignalObjectAndWait(m_mutex, m_exclusiveEvent, waitTime, FALSE);
  88         if (retCode == WAIT_OBJECT_0) {
  89             return true;
  90         } else {
  91             if (retCode == WAIT_TIMEOUT)
  92                 ::SetLastError(WAIT_TIMEOUT);
  93             return false;
  94         }
  95     }
  96     m_lockType = LOCK_EXCLUSIVE;
  97     ::ReleaseMutex(m_mutex);
  98     return true;
  99 }
 100
 101 // ÊÍ·Å¶ÀÕ¼·ÃÎÊÈ¨
 102 void SharedMutex::ReleaseExclusive()
 103 {
 104 //    assert(m_lockType == LOCK_EXCLUSIVE);
 105     ::WaitForSingleObject(m_mutex, INFINITE);
 106     --m_exclusiveNum;
 107     // ¶ÀÕ¼·ÃÎÊÏß³ÌÓÅÏÈ
 108     if (m_exclusiveNum > 0) {
 109         // »½ÐÑÒ»¸ö¶ÀÕ¼·ÃÎÊÏß³Ì
 110         ::SetEvent(m_exclusiveEvent);
 111     } else if (m_sharedNum > 0) {
 112         // »½ÐÑµ±Ç°ËùÓÐ¹²Ïí·ÃÎÊÏß³Ì
 113         m_lockType = LOCK_SHARED;
 114         ::PulseEvent(m_sharedEvent);
 115     } else {
 116         // Ã»ÓÐµÈ´ýÏß³Ì
 117         m_lockType = LOCK_NONE;
 118     }
 119     ::ReleaseMutex(m_mutex);
 120 }