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cleaned up locking - this is an old code written w/o consideration of SMP

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thread safe locking issues
This commit is contained in:
Jeff Hill
2006-11-28 18:54:03 +00:00
parent 1707e28d2e
commit ecb43bedd9
2 changed files with 42 additions and 96 deletions
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133
src/db/dbEvent.c
View File

@@ -90,10 +90,7 @@ struct event_user {
epicsMutexId lock;
epicsEventId ppendsem; /* Wait while empty */
epicsEventId pflush_sem; /* wait for flush */
OVRFFUNC *overflow_sub; /* called when overflow detect */
void *overflow_arg; /* parameter to above */
EXTRALABORFUNC *extralabor_sub;/* off load to event task */
void *extralabor_arg;/* parameter to above */
@@ -194,12 +191,6 @@ int epicsShareAPI dbel ( const char *pname, unsigned level )
if ( level > 0 ) {
printf ( "%4.4s", pdbFldDes->name );
/* they should never see this one */
if ( pevent->ev_que->evUser->queovr ) {
printf ( " !! event discard count=%d !!",
pevent->ev_que->evUser->queovr );
}
printf ( " { " );
if ( pevent->select & DBE_VALUE ) printf( "VALUE " );
if ( pevent->select & DBE_LOG ) printf( "LOG " );
@@ -565,36 +556,22 @@ void epicsShareAPI db_cancel_event (dbEventSubscription es)
return;
}
/*
* DB_ADD_OVERFLOW_EVENT()
*
* Specify a routine to be executed for event que overflow condition
*/
int epicsShareAPI db_add_overflow_event (
dbEventCtx ctx, OVRFFUNC *overflow_sub, void *overflow_arg)
{
struct event_user *evUser = (struct event_user *) ctx;
evUser->overflow_sub = overflow_sub;
evUser->overflow_arg = overflow_arg;
return DB_EVENT_OK;
}
/*
* DB_FLUSH_EXTRA_LABOR_EVENT()
*
* waits for extra labor in progress to finish
*/
int epicsShareAPI db_flush_extra_labor_event (dbEventCtx ctx)
void epicsShareAPI db_flush_extra_labor_event (dbEventCtx ctx)
{
struct event_user *evUser = (struct event_user *) ctx;
while(evUser->extraLaborBusy){
epicsMutexMustLock ( evUser->lock );
while ( evUser->extraLaborBusy ) {
epicsMutexUnlock ( evUser->lock );
epicsThreadSleep(1.0);
epicsMutexMustLock ( evUser->lock );
}
return DB_EVENT_OK;
epicsMutexUnlock ( evUser->lock );
}
/*
@@ -625,19 +602,18 @@ int epicsShareAPI db_post_extra_labor (dbEventCtx ctx)
struct event_user *evUser = (struct event_user *) ctx;
int doit;
epicsMutexMustLock ( evUser->lock );
if ( ! evUser->extra_labor ) {
epicsMutexMustLock ( evUser->lock );
if ( ! evUser->extra_labor ) {
evUser->extra_labor = TRUE;
doit = TRUE;
}
else {
doit = FALSE;
}
epicsMutexUnlock ( evUser->lock );
if ( doit ) {
epicsEventSignal(evUser->ppendsem);
}
evUser->extra_labor = TRUE;
doit = TRUE;
}
else {
doit = FALSE;
}
epicsMutexUnlock ( evUser->lock );
if ( doit ) {
epicsEventSignal(evUser->ppendsem);
}
return DB_EVENT_OK;
@@ -700,11 +676,11 @@ LOCAL void db_post_single_event_private (struct evSubscrip *event)
firstEventFlag = 0;
}
/*
* otherwise if the current entry is available then
* fill it in and advance the ring buffer
* Otherwise, the current entry must be available.
* Fill it in and advance the ring buffer.
*/
else if ( ev_que->evque[ev_que->putix] == EVENTQEMPTY ) {
else {
assert ( ev_que->evque[ev_que->putix] == EVENTQEMPTY );
pLog = &ev_que->valque[ev_que->putix];
ev_que->evque[ev_que->putix] = event;
if (event->npend>0u) {
@@ -723,14 +699,6 @@ LOCAL void db_post_single_event_private (struct evSubscrip *event)
}
ev_que->putix = RNGINC ( ev_que->putix );
}
else {
/*
* this should never occur if this is bug free
*/
ev_que->evUser->queovr++;
pLog = NULL;
firstEventFlag = 0;
}
if (pLog && event->valque) {
struct dbCommon *precord = event->paddr->precord;
@@ -948,50 +916,31 @@ LOCAL void event_task (void *pParm)
* check to see if the caller has offloaded
* labor to this task
*/
epicsMutexMustLock ( evUser->lock );
evUser->extraLaborBusy = TRUE;
if(evUser->extra_labor && evUser->extralabor_sub){
epicsMutexMustLock ( evUser->lock );
if(evUser->extra_labor && evUser->extralabor_sub){
evUser->extra_labor = FALSE;
pExtraLaborSub = evUser->extralabor_sub;
pExtraLaborArg = evUser->extralabor_arg;
}
else {
pExtraLaborSub = NULL;
pExtraLaborArg = NULL;
}
if ( evUser->extra_labor && evUser->extralabor_sub ) {
evUser->extra_labor = FALSE;
pExtraLaborSub = evUser->extralabor_sub;
pExtraLaborArg = evUser->extralabor_arg;
}
else {
pExtraLaborSub = NULL;
pExtraLaborArg = NULL;
}
if ( pExtraLaborSub ) {
epicsMutexUnlock ( evUser->lock );
if(pExtraLaborSub){
(*pExtraLaborSub)(pExtraLaborArg);
}
(*pExtraLaborSub)(pExtraLaborArg);
epicsMutexMustLock ( evUser->lock );
}
evUser->extraLaborBusy = FALSE;
if(evUser->extra_labor && evUser->extralabor_sub){
evUser->extra_labor = FALSE;
(*evUser->extralabor_sub)(evUser->extralabor_arg);
}
epicsMutexUnlock ( evUser->lock );
for ( ev_que = &evUser->firstque; ev_que;
ev_que = ev_que->nextque ) {
event_read (ev_que);
}
/*
* The following do not introduce event latency since they
* are not between notification and posting events.
*/
if(evUser->queovr){
if(evUser->overflow_sub)
(*evUser->overflow_sub)(
evUser->overflow_arg,
evUser->queovr);
else
errlogPrintf("Events lost, discard count was %d\n",
evUser->queovr);
evUser->queovr = 0;
}
}while(!evUser->pendexit);
} while( ! evUser->pendexit );
epicsMutexDestroy(evUser->firstque.writelock);
@@ -1027,14 +976,14 @@ int epicsShareAPI db_start_events (
{
struct event_user *evUser = (struct event_user *) ctx;
epicsMutexMustLock (evUser->firstque.writelock);
epicsMutexMustLock ( evUser->lock );
/*
* only one ca_pend_event thread may be
* started for each evUser
*/
if (evUser->taskid) {
epicsMutexUnlock (evUser->firstque.writelock);
epicsMutexUnlock ( evUser->lock );
return DB_EVENT_OK;
}
@@ -1048,10 +997,10 @@ int epicsShareAPI db_start_events (
taskname, osiPriority, epicsThreadGetStackSize(epicsThreadStackMedium),
event_task, (void *)evUser);
if (!evUser->taskid) {
epicsMutexUnlock (evUser->firstque.writelock);
epicsMutexUnlock ( evUser->lock );
return DB_EVENT_ERROR;
}
epicsMutexUnlock (evUser->firstque.writelock);
epicsMutexUnlock ( evUser->lock );
return DB_EVENT_OK;
}

5
src/db/dbEvent.h
View File

@@ -46,7 +46,6 @@ epicsShareFunc int epicsShareAPI db_post_events (
typedef void * dbEventCtx;
typedef void OVRFFUNC (void *overflow_arg, unsigned count);
typedef void EXTRALABORFUNC (void *extralabor_arg);
epicsShareFunc dbEventCtx epicsShareAPI db_init_events (void);
epicsShareFunc int epicsShareAPI db_start_events (
@@ -55,11 +54,9 @@ epicsShareFunc int epicsShareAPI db_start_events (
epicsShareFunc void epicsShareAPI db_close_events (dbEventCtx ctx);
epicsShareFunc void epicsShareAPI db_event_flow_ctrl_mode_on (dbEventCtx ctx);
epicsShareFunc void epicsShareAPI db_event_flow_ctrl_mode_off (dbEventCtx ctx);
epicsShareFunc int epicsShareAPI db_add_overflow_event (
dbEventCtx ctx, OVRFFUNC *overflow_sub, void *overflow_arg);
epicsShareFunc int epicsShareAPI db_add_extra_labor_event (
dbEventCtx ctx, EXTRALABORFUNC *func, void *arg);
epicsShareFunc int epicsShareAPI db_flush_extra_labor_event (dbEventCtx);
epicsShareFunc void epicsShareAPI db_flush_extra_labor_event (dbEventCtx);
epicsShareFunc int epicsShareAPI db_post_extra_labor (dbEventCtx ctx);
epicsShareFunc void epicsShareAPI db_event_change_priority ( dbEventCtx ctx, unsigned epicsPriority );