/*
* Release semaphores at shutdown or shmem reinitialization
*
* (called as an on_shmem_exit callback, hence funny argument list)
*/
static void
ReleaseSemaphores(int status, Datum arg)
{
int i;
for (i = 0; i < numSemaSets; i++)
IpcSemaphoreKill(mySemaSets[i]);
free(mySemaSets);
}
/*
* ProcFreeAllSemaphores -
* on exiting the postmaster, we free up all the semaphores allocated
* to the lmgrs of the backends.
*/
void
ProcFreeAllSemaphores()
{
int i;
int32 *freeSemMap = ProcGlobal->freeSemMap;
for(i=0; i < MAX_PROC_SEMS/PROC_NSEMS_PER_SET; i++) {
if (freeSemMap[i]!=0)
IpcSemaphoreKill(ProcGlobal->currKey + i);
}
}
/*
* ProcFreeSem -
* free up our semaphore in the semaphore set. If we're the last one
* in the set, also remove the semaphore set.
*/
static void
ProcFreeSem(IpcSemaphoreKey semKey, int semNum)
{
int mask;
int i;
int32 *freeSemMap = ProcGlobal->freeSemMap;
i = semKey - ProcGlobal->currKey;
mask = ~(1 << semNum);
freeSemMap[i] &= mask;
if (freeSemMap[i]==0)
IpcSemaphoreKill(semKey);
}
/*
* CreateSpinlocks -- Create a sysV semaphore array for
* the spinlocks
*
*/
bool
CreateSpinlocks(IPCKey key)
{
int status;
IpcSemaphoreId semid;
semid = IpcSemaphoreCreate(key, MAX_SPINS, IPCProtection,
IpcSemaphoreDefaultStartValue, 1, &status);
if (status == IpcSemIdExist) {
IpcSemaphoreKill(key);
elog(NOTICE,"Destroying old spinlock semaphore");
semid = IpcSemaphoreCreate(key, MAX_SPINS, IPCProtection,
IpcSemaphoreDefaultStartValue, 1, &status);
}
if (semid >= 0) {
SpinLockId = semid;
return(TRUE);
}
/* cannot create spinlocks */
elog(FATAL,"CreateSpinlocks: cannot create spin locks");
return(FALSE);
}
