TB9.2 Example Applications: examples/PIPS/opencmessagequeuelibraryex/engine/src/msgqinternals.c Source File

00001 
+00010 #include <stdlib.h>
+00011 #include "MsgQInternal.h"
+00012 
+00013 
+00014 /* Declaration and definition of Internal Functions and data structures */
+00015 MSGQ_INFO_PTR        MsgQInfo[MSGQ_TBL_SZ];
+00016 MSGQ_INFO_LIST_PTR   MsgQListHead = NULL;
+00017 
+00018 inline unsigned int HashIndex(ULONG qName);
+00019 
+00020 /*************** INTERNAL FUNCTIONS ******************************/
+00021 
+00022 /***************************************************************************
+00023 *  InstallMsqQTable (qName, qid, semId, sendState, numMsgs, err)
+00024 *  Function: This function installs a queue into the hash table
+00025 ****************************************************************************/
+00026 
+00027 int InstallMsqQTable(ULONG qName, int qId, int semId, int* err) {
+00028 
+00029         MSGQ_INFO_PTR pMsgQInfo = NULL;
+00030         unsigned int  index;
+00031 
+00032         if ((pMsgQInfo = MsgQTableLookup(qName)) == NULL) {
+00033                 pMsgQInfo = (MSGQ_INFO_PTR)malloc(sizeof(*pMsgQInfo));
+00034 
+00035                 if(pMsgQInfo != NULL) {
+00036                         index = HashIndex(qName);
+00037 
+00038                         pMsgQInfo->next  = MsgQInfo[index];
+00039                         MsgQInfo[index]   = pMsgQInfo;
+00040                         pMsgQInfo->qName = qName;
+00041                         pMsgQInfo->qId   = qId;
+00042                         pMsgQInfo->semId = semId;
+00043                         pMsgQInfo->sendState = MSG_Q_READY;
+00044                         pMsgQInfo->numMsgs   = 0;
+00045 
+00046                         *err = OK;
+00047                         return (OK);
+00048                 }
+00049                 else
+00050                         *err = KMsgQLibNoMemoryErr;
+00051         }
+00052         else
+00053                 *err = KMsgQLibQIdErr;
+00054 
+00055         return(ERROR);
+00056 
+00057 }
+00058 
+00059 
+00060 /******************************************************************************
+00061 *  HashIndex
+00062 *  Function: This function returns the hash index
+00063 *******************************************************************************/
+00064 
+00065 inline unsigned int HashIndex(ULONG qName) {
+00066         return(qName % MSGQ_TBL_SZ);
+00067 }
+00068 
+00069 
+00070 /************************************************************************
+00071 *  MsgQTableLookup (qName)
+00072 *  Function: This function finds the block pointer for each queue
+00073 *************************************************************************/
+00074 
+00075 MSGQ_INFO* MsgQTableLookup(ULONG qName) {
+00076         MSGQ_INFO_PTR pMsgQInfo = NULL;
+00077 
+00078         for (pMsgQInfo = MsgQInfo[HashIndex(qName)]; pMsgQInfo != NULL; pMsgQInfo = pMsgQInfo->next) {
+00079                 if (qName == pMsgQInfo->qName)
+00080                         return(pMsgQInfo);
+00081         }
+00082 
+00083         return(NULL);
+00084 }
+00085 
+00086 
+00087 /*************************************************************************
+00088 *  RemoveFromMsqQTable (qName, err)
+00089 *  Function: This function removes a queue from the hash table
+00090 **************************************************************************/
+00091 
+00092 
+00093 int RemoveFromMsqQTable(ULONG qName, int* err) {
+00094         unsigned int  index = 0;
+00095         MSGQ_INFO_PTR prev = NULL;
+00096         MSGQ_INFO_PTR pMsgQInfo = NULL;
+00097 
+00098         index = HashIndex(qName);
+00099         for (pMsgQInfo = MsgQInfo[index]; pMsgQInfo != NULL; pMsgQInfo = pMsgQInfo->next) {
+00100                 if (qName == pMsgQInfo->qName)
+00101                         break;
+00102                 prev = pMsgQInfo;
+00103         }
+00104 
+00105         if (pMsgQInfo != NULL) {
+00106                 if (prev == NULL)
+00107                         MsgQInfo[index] = pMsgQInfo->next;
+00108                 else
+00109                         prev->next = pMsgQInfo->next;
+00110 
+00111                 free((void*)pMsgQInfo);
+00112                 *err = OK;
+00113                 return (OK);
+00114         }
+00115         else
+00116                 *err = KMsgQLibQIdErr;
+00117 
+00118         return(ERROR);
+00119 }
+00120 
+00121 
+00122 /************************************************************************
+00123 *  AddToMsgQTable (qName)
+00124 *  Function: Adding a queue to list
+00125 *************************************************************************/
+00126 
+00127 void AddToMsgQTable(ULONG qName) {
+00128         MSGQ_INFO_LIST_PTR tempNext;
+00129 
+00130         if (MsgQListHead != NULL) {
+00131                 /* subsequent entries */
+00132                 tempNext = MsgQListHead->next;
+00133 
+00134                 if ((MsgQListHead->next = (MSGQ_INFO_LIST*)malloc(sizeof(MSGQ_INFO_LIST))) != NULL)             {
+00135                         MsgQListHead->next->next = tempNext;
+00136                         MsgQListHead->next->qName = qName;
+00137                 }
+00138                 else 
+00139                         MsgQListHead->next = tempNext;
+00140         }
+00141         else {
+00142                 if ((MsgQListHead = (MSGQ_INFO_LIST*)malloc(sizeof(MSGQ_INFO_LIST))) != NULL) {
+00143                         MsgQListHead->next = NULL;
+00144                         MsgQListHead->qName = qName;
+00145                 }
+00146         }
+00147 }
+00148 
+00149 /************************************************************************
+00150 *  DeleteFromMsgQTable (qName)
+00151 *  Function:  removing a queu entry from  list
+00152 *************************************************************************/
+00153 
+00154 void DeleteFromMsgQTable(ULONG qName) {
+00155         MSGQ_INFO_LIST_PTR prev = NULL;
+00156         MSGQ_INFO_LIST_PTR pMsgQInfo = NULL;
+00157 
+00158         for (pMsgQInfo = MsgQListHead; pMsgQInfo != NULL; pMsgQInfo = pMsgQInfo->next) {
+00159                 if (qName == pMsgQInfo->qName)
+00160                         break;
+00161                 prev = pMsgQInfo;
+00162         }
+00163 
+00164         if (pMsgQInfo != NULL) {
+00165                 /* Check whether prev pointer is null or not. If it is Null, update Head pointer */
+00166                 if( prev == NULL )
+00167                         MsgQListHead = MsgQListHead->next ;
+00168 
+00169                 /* Else update the linked list by removing present node and updating prev next pointer */
+00170                 else
+00171                         prev->next = pMsgQInfo->next;
+00172 
+00173                 /* Now free up the memory used by the present node */
+00174                 free((void*) pMsgQInfo);
+00175         }
+00176 }
+