NdbCondition.c
上传用户:romrleung
上传日期:2022-05-23
资源大小:18897k
文件大小:4k
- /* Copyright (C) 2003 MySQL AB
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
- #include <ndb_global.h>
- #include "NdbCondition.h"
- #include <NdbMutex.h>
- struct NdbCondition
- {
- long nWaiters;
- NdbMutex* pNdbMutexWaitersLock;
- HANDLE hSemaphore;
- HANDLE hEventWaitersDone;
- int bWasBroadcast;
- };
- struct NdbCondition*
- NdbCondition_Create(void)
- {
- int result = 0;
- struct NdbCondition* pNdbCondition = (struct NdbCondition*)malloc(sizeof(struct NdbCondition));
- if(!pNdbCondition)
- return 0;
-
- pNdbCondition->nWaiters = 0;
- pNdbCondition->bWasBroadcast = 0;
- if(!(pNdbCondition->hSemaphore = CreateSemaphore(0, 0, MAXLONG, 0)))
- result = -1;
- else if(!(pNdbCondition->pNdbMutexWaitersLock = NdbMutex_Create()))
- result = -1;
- else if(!(pNdbCondition->hEventWaitersDone = CreateEvent(0, 0, 0, 0)))
- result = -1;
- assert(!result);
- return pNdbCondition;
- }
- int
- NdbCondition_Wait(struct NdbCondition* p_cond,
- NdbMutex* p_mutex)
- {
- int result;
- int bLastWaiter;
- if(!p_cond || !p_mutex)
- return 1;
-
- NdbMutex_Lock(p_cond->pNdbMutexWaitersLock);
- p_cond->nWaiters++;
- NdbMutex_Unlock(p_cond->pNdbMutexWaitersLock);
-
- if(NdbMutex_Unlock(p_mutex))
- return -1;
- result = WaitForSingleObject (p_cond->hSemaphore, INFINITE);
- NdbMutex_Lock(p_cond->pNdbMutexWaitersLock);
- p_cond->nWaiters--;
- bLastWaiter = (p_cond->bWasBroadcast && p_cond->nWaiters==0);
- NdbMutex_Unlock(p_cond->pNdbMutexWaitersLock);
-
- if(result==WAIT_OBJECT_0 && bLastWaiter)
- SetEvent(p_cond->hEventWaitersDone);
-
- NdbMutex_Lock(p_mutex);
- return result;
- }
- int
- NdbCondition_WaitTimeout(struct NdbCondition* p_cond,
- NdbMutex* p_mutex,
- int msecs)
- {
- int result;
- int bLastWaiter;
- if (!p_cond || !p_mutex)
- return 1;
-
- NdbMutex_Lock(p_cond->pNdbMutexWaitersLock);
- p_cond->nWaiters++;
- NdbMutex_Unlock(p_cond->pNdbMutexWaitersLock);
- if(msecs<0)
- msecs = 0;
- if(NdbMutex_Unlock(p_mutex))
- return -1;
- result = WaitForSingleObject(p_cond->hSemaphore, msecs);
- NdbMutex_Lock(p_cond->pNdbMutexWaitersLock);
- p_cond->nWaiters--;
- bLastWaiter = (p_cond->bWasBroadcast && p_cond->nWaiters==0);
- NdbMutex_Unlock(p_cond->pNdbMutexWaitersLock);
- if(result!=WAIT_OBJECT_0)
- result = -1;
- if(bLastWaiter)
- SetEvent(p_cond->hEventWaitersDone);
- NdbMutex_Lock(p_mutex);
- return result;
- }
- int
- NdbCondition_Signal(struct NdbCondition* p_cond)
- {
- int bHaveWaiters;
- if(!p_cond)
- return 1;
-
- NdbMutex_Lock(p_cond->pNdbMutexWaitersLock);
- bHaveWaiters = (p_cond->nWaiters > 0);
- NdbMutex_Unlock(p_cond->pNdbMutexWaitersLock);
-
- if(bHaveWaiters)
- return (ReleaseSemaphore(p_cond->hSemaphore, 1, 0) ? 0 : -1);
- else
- return 0;
- }
- int NdbCondition_Broadcast(struct NdbCondition* p_cond)
- {
- int bHaveWaiters;
- int result = 0;
- if(!p_cond)
- return 1;
-
- NdbMutex_Lock(p_cond->pNdbMutexWaitersLock);
- bHaveWaiters = 0;
- if(p_cond->nWaiters > 0)
- {
- p_cond->bWasBroadcast = !0;
- bHaveWaiters = 1;
- }
- NdbMutex_Unlock(p_cond->pNdbMutexWaitersLock);
- if(bHaveWaiters)
- {
- if(!ReleaseSemaphore(p_cond->hSemaphore, p_cond->nWaiters, 0))
- result = -1;
- else if(WaitForSingleObject (p_cond->hEventWaitersDone, INFINITE) != WAIT_OBJECT_0)
- result = -1;
- p_cond->bWasBroadcast = 0;
- }
- return result;
- }
- int NdbCondition_Destroy(struct NdbCondition* p_cond)
- {
- int result;
- if(!p_cond)
- return 1;
-
- CloseHandle(p_cond->hEventWaitersDone);
- NdbMutex_Destroy(p_cond->pNdbMutexWaitersLock);
- result = (CloseHandle(p_cond->hSemaphore) ? 0 : -1);
- free(p_cond);
- return 0;
- }