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dbLock: fix initialization of self links

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initPVLinks() doesn't correctly handle case where a record links
to itself.  This results it being added twice to lockRecordList,
which corrupts the list count, and the lockset ref. counter.

The error appears in dbLockCleanupRecords() when not all
locksets are free'd.
This commit is contained in:
Michael Davidsaver
2015-07-09 17:07:49 -04:00
parent ff4c88ed05
commit 8f3fcc2787
1 changed files with 18 additions and 30 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/ioc/db/dbLock.c
+18 -30
View File
@@ -526,6 +526,11 @@ static int initPVLinks(void* junk, DBENTRY* pdbentry)
dbCommon *prec = pdbentry->precnode->precord;
lockSet *A=prec->lset->plockSet;
if(!A) {
A = prec->lset->plockSet = makeSet();
ellAdd(&A->lockRecordList, &prec->lset->node);
}
/* for each link originating from this record */
for(i=0; i<rtype->no_links; i++) {
DBADDR *paddr;
@@ -544,51 +549,31 @@ static int initPVLinks(void* junk, DBENTRY* pdbentry)
paddr = (DBADDR*)plink->value.pv_link.pvt;
B = paddr->precord->lset->plockSet;
if(A==B) {
/* these records are already in the same lockset */
} else if(B) {
assert(A!=B);
dbLockSetMerge(NULL, prec, paddr->precord);
assert(prec->lset->plockSet==paddr->precord->lset->plockSet);
/* Initial population of lockSets happens here. */
if(!A && !B) { /* neither side has a lockSet */
A = prec->lset->plockSet = paddr->precord->lset->plockSet = makeSet();
dbLockIncRef(A); /* ref for psecond */
ellAdd(&A->lockRecordList, &prec->lset->node);
ellAdd(&A->lockRecordList, &paddr->precord->lset->node);
} else if(!B) { /* fast merge paddr->precord into A */
} else {
/* fast merge paddr->precord into A */
paddr->precord->lset->plockSet = A;
dbLockIncRef(A);
ellAdd(&A->lockRecordList, &paddr->precord->lset->node);
} else if(!A) { /* fast merge prec into B */
A = prec->lset->plockSet = B;
dbLockIncRef(B);
ellAdd(&B->lockRecordList, &prec->lset->node);
}
}
return 0;
}
static int initSingleSets(void* junk, DBENTRY* pdbentry)
{
dbCommon *prec = pdbentry->precnode->precord;
lockSet *ls;
if(!prec->lset->plockSet) {
ls = prec->lset->plockSet = makeSet();
ellAdd(&ls->lockRecordList, &prec->lset->node);
}
return 0;
}
void dbLockInitRecords(dbBase *pdbbase)
{
epicsThreadOnce(&dbLockOnceInit, &dbLockOnce, NULL);
/* create all lockRecords */
forEachRecord(NULL, pdbbase, &createLockRecord);
/* create lockSets for pairs of records with DB_LINKs */
/* create lockSets */
forEachRecord(NULL, pdbbase, &initPVLinks);
/* create lockSets for all records with no DB_LINKs */
forEachRecord(NULL, pdbbase, &initSingleSets);
}
static int freeLockRecord(void* junk, DBENTRY* pdbentry)
@@ -598,6 +583,7 @@ static int freeLockRecord(void* junk, DBENTRY* pdbentry)
lockSet *ls = lr->plockSet;
prec->lset = NULL;
lr->precord = NULL;
assert(ls->refcount>0);
assert(ellCount(&ls->lockRecordList)>0);
@@ -639,6 +625,8 @@ void dbLockCleanupRecords(dbBase *pdbbase)
/* Caller must lock both pfirst and psecond.
* Assumes that pfirst has been modified
* to link to psecond.
*
* Note: locker may be NULL (during iocInit)
*/
void dbLockSetMerge(dbLocker *locker, dbCommon *pfirst, dbCommon *psecond)
{
@@ -660,7 +648,7 @@ void dbLockSetMerge(dbLocker *locker, dbCommon *pfirst, dbCommon *psecond)
cantProceed(NULL);
}
#endif
if(A->ownerlocker!=locker || B->ownerlocker!=locker) {
if(locker && (A->ownerlocker!=locker || B->ownerlocker!=locker)) {
errlogPrintf("dbLockSetMerge(%p,\"%s\",\"%s\") locker ownership violation %p %p (%p)\n",
locker, pfirst->name, psecond->name,
A->ownerlocker, B->ownerlocker, locker);