/*************************************************************************** * * File: queue.c * * INTEL Corporation Proprietary Information * Copyright (c) 1996 Intel Corporation. * * This listing is supplied under the terms of a license agreement * with INTEL Corporation and may not be used, copied, nor disclosed * except in accordance with the terms of that agreement. * *************************************************************************** * * $Workfile: queue.c $ * $Revision: 1.8 $ * $Modtime: 13 Dec 1996 11:48:16 $ * $Log: S:\sturgeon\src\h245ws\vcs\queue.c_v $ * * Rev 1.8 13 Dec 1996 12:13:12 SBELL1 * moved ifdef _cplusplus to after includes * * Rev 1.7 May 28 1996 10:39:00 plantz * Change QFree to not free objects on the queue; instead it insists that * the queue be empty. * * Rev 1.6 21 May 1996 16:21:36 EHOWARDX * Added DeleteCriticalSection to QFree(). * * Rev 1.5 Apr 24 1996 16:18:58 plantz * Removed include winsock2.h and incommon.h * * Rev 1.3.1.0 Apr 24 1996 16:16:42 plantz * Removed include winsock2.h and callcont.h * * Rev 1.3 01 Apr 1996 14:53:28 EHOWARDX * Changed pQUEUE to PQUEUE. * * Rev 1.1 09 Mar 1996 21:12:34 EHOWARDX * Fixes as result of testing. * * Rev 1.0 08 Mar 1996 20:22:38 unknown * Initial revision. * ***************************************************************************/ #ifndef STRICT #define STRICT #endif // not defined STRICT #pragma warning ( disable : 4115 4201 4214 4514 ) #undef _WIN32_WINNT // override bogus platform definition in our common build environment #include "precomp.h" #include "queue.h" #include "linkapi.h" #include "h245ws.h" #if defined(__cplusplus) extern "C" { #endif // (__cplusplus) /*-*------------------------------------------------------------------------- Function Name: QCreate Syntax: PQUEUE QCreate(void); Parameters: None. Summary: Allocates and initializes a new queue. Returns: NULL - Allocation of memory for new queue failed. Otherwise - Address of new queue created. -------------------------------------------------------------------------*-*/ PQUEUE QCreate(void) { register PQUEUE pQueue; /* pointer to the new queue */ /* Allocate a new queue */ pQueue = (PQUEUE)MemAlloc(sizeof(QUEUE)); if (pQueue != NULL) { /* Initialize the new queue */ pQueue->nHead = pQueue->nTail = Q_NULL; InitializeCriticalSection(&pQueue->CriticalSection); } return pQueue; } /* QCreate */ /*-*------------------------------------------------------------------------- Function Name: QFree Syntax: void QFree(PQUEUE pQueue); Parameters: pQueue -pointer to the queue to free Summary: Deallocates a queue that was allocated by QCreate. -------------------------------------------------------------------------*-*/ void QFree(PQUEUE pQueue) { /* The queue must be empty before it is freed. */ HWSASSERT(pQueue->nHead == Q_NULL); /* Free the queue. */ DeleteCriticalSection(&pQueue->CriticalSection); MemFree(pQueue); } /* QFree */ /* * NAME * QRemove - remove object from head of queue * * ARGUMENTS * pQueue Pointer to queue * * RETURN VALUE * Pointer to object dequeued or NULL of queue empty */ /*-*------------------------------------------------------------------------- Function Name: QRemove Syntax: LPVOID QRemove(PQUEUE pQueue); Parameters: pQueue - Pointer to queue. Summary: Removes and returns object from head of queue. Returns: NULL - Queue was empty. Otherwise - Address of object dequeued. -------------------------------------------------------------------------*-*/ LPVOID QRemove(PQUEUE pQueue) { register LPVOID pObject; /* pointer to the object to remove */ EnterCriticalSection(&pQueue->CriticalSection); if (pQueue->nHead == Q_NULL) { /* If the queue is empty, we will return NULL */ pObject = NULL; } else { /* Get the pointer, NULL it in the apObjects array. */ pObject = pQueue->apObjects[pQueue->nHead]; pQueue->apObjects[pQueue->nHead] = NULL; /* Check to see if we've just emptied the queue; if so, set */ /* the nHead and nTail indices to Q_NULL. If not, set the nHead */ /* index to the right value. */ if (pQueue->nHead == pQueue->nTail) { pQueue->nHead = pQueue->nTail = Q_NULL; } else { pQueue->nHead = (pQueue->nHead + 1) % MAX_QUEUE_SIZE; } } LeaveCriticalSection(&pQueue->CriticalSection); return pObject; } /* QRemove */ /*-*------------------------------------------------------------------------- Function Name: QInsert Syntax: BOOL QInsert(PQUEUE pQueue, LPVOID pObject); Parameters: pQueue - Pointer to queue to insert object into. pObject - Pointer to object to insert into queue. Summary: Inserts an object at tail of queue. Returns: TRUE - Object successfully added to queue. FALSE - Queue full; object could not be added. -------------------------------------------------------------------------*-*/ BOOL QInsert(PQUEUE pQueue, LPVOID pObject) { register int iTemp; EnterCriticalSection(&pQueue->CriticalSection); /* If the queue is full, set the return value to FALSE and do */ /* nothing; if not, update the indices appropriately and set the */ /* return value to TRUE. */ if (pQueue->nHead == Q_NULL) { /* Queue is empty */ pQueue->apObjects[0] = pObject; pQueue->nHead = pQueue->nTail = 0; iTemp = TRUE; } else { iTemp = (pQueue->nTail + 1) % MAX_QUEUE_SIZE; if (iTemp == pQueue->nHead) { /* Queue is full */ iTemp = FALSE; } else { pQueue->apObjects[iTemp] = pObject; pQueue->nTail = iTemp; iTemp = TRUE; } } LeaveCriticalSection(&pQueue->CriticalSection); return (BOOL) iTemp; } /*-*------------------------------------------------------------------------- Function Name: QInsertAtHead Syntax: BOOL QInsertAtHead(PQUEUE pQueue, LPVOID pObject); Parameters: pQueue - Pointer to queue to insert object into. pObject - Pointer to object to insert into queue. Summary: Inserts an object at head of queue. Returns: TRUE - Object successfully added to queue. FALSE - Queue full; object could not be added. -------------------------------------------------------------------------*-*/ BOOL QInsertAtHead(PQUEUE pQueue, LPVOID pObject) { register int iTemp; EnterCriticalSection(&pQueue->CriticalSection); if (pQueue->nHead == Q_NULL) { /* Queue is empty */ pQueue->apObjects[0] = pObject; pQueue->nHead = pQueue->nTail = 0; iTemp = TRUE; } else { iTemp = (pQueue->nHead + (MAX_QUEUE_SIZE - 1)) % MAX_QUEUE_SIZE; if (iTemp == pQueue->nTail) { /* Queue is full */ iTemp = FALSE; } else { pQueue->apObjects[iTemp] = pObject; pQueue->nHead = iTemp; iTemp = TRUE; } } LeaveCriticalSection(&pQueue->CriticalSection); return (BOOL) iTemp; } /* QInsertAtHead */ /*-*------------------------------------------------------------------------- Function Name: IsQEmpty Syntax: BOOL IsQEmpty(PQUEUE pQueue); Parameters: pQueue - Pointer to queue to check. Summary: Checks if a queue is empty. Returns: TRUE - Queue is empty. FALSE - Queue contains at least one object. -------------------------------------------------------------------------*-*/ BOOL IsQEmpty(PQUEUE pQueue) { return (pQueue->nHead == Q_NULL ? TRUE : FALSE); } /* IsQEmpty */ #if defined(__cplusplus) } #endif // (__cplusplus)