Correction. Perhaps not assert in all cases but the second locker always detects the failure (lock != 1) in pbeBEginTrans returns error and the caller (PBE) aborts the transaction attempt.
/AndersBj -----Original Message----- From: Anders Björnerstedt [mailto:[email protected]] Sent: den 12 augusti 2015 17:25 To: Zoran Milinkovic; Neelakanta Reddy; [email protected] Cc: [email protected] Subject: Re: [devel] [PATCH 1 of 1] imm:Decrement sqliteTransLock when BEGIN EXCLUSIVE TRANSACTION fails [#1426] If this happens then the second locker should exit assert. /AndersBj -----Original Message----- From: Zoran Milinkovic Sent: den 12 augusti 2015 14:51 To: Neelakanta Reddy; Anders Björnerstedt; [email protected] Cc: [email protected] Subject: RE: [PATCH 1 of 1] imm:Decrement sqliteTransLock when BEGIN EXCLUSIVE TRANSACTION fails [#1426] Hi Neelakanta, What will happen if there is a context-switch between thread1 and thread2 just after "while(sqliteTransLock) {" when sqliteTransLock == 0 ? Then both thread1 and thread2 will pass 'while' loop and both threads will increase sqliteTransLock. The likelihood that this happen is very very low, but I think that this case should also be covered. Best regards, Zoran -----Original Message----- From: Neelakanta Reddy [mailto:[email protected]] Sent: Wednesday, August 12, 2015 8:48 AM To: Zoran Milinkovic; Anders Björnerstedt; [email protected] Cc: [email protected] Subject: Re: [PATCH 1 of 1] imm:Decrement sqliteTransLock when BEGIN EXCLUSIVE TRANSACTION fails [#1426] Hi zoran, In the few line above there is check to verify sqliteTransLock in " while(sqliteTransLock) {" . Multiple threads are present only for 2PBE case. In the 2PBE case if a thread1 is waiting for lock and got the lock released, then sqliteTransLock will be incremented. If in this time a context-switch happens then the thread2 will be spinning in sqliteTransLock. Decrementing of sqliteTransLock may not be required. /Neel. On Tuesday 11 August 2015 06:34 PM, Zoran Milinkovic wrote: > Hi Neelakanta, > > Shouldn't sqliteTransLock be also decremented few lines above in " > if(sqliteTransLock != 1) {" statement ? > > Thanks, > Zoran > > -----Original Message----- > From: [email protected] [mailto:[email protected]] > Sent: Thursday, July 30, 2015 3:47 PM > To: Anders Björnerstedt; Zoran Milinkovic; [email protected] > Cc: [email protected] > Subject: [PATCH 1 of 1] imm:Decrement sqliteTransLock when BEGIN > EXCLUSIVE TRANSACTION fails [#1426] > > osaf/libs/common/immsv/immpbe_dump.cc | 1 + > 1 files changed, 1 insertions(+), 0 deletions(-) > > > There is a chance that NFS/shared-storage may re-attach after few > seconds, and transaction is not yet started, so decrement the > sqliteTransLock in pbeBeginTrans which releases the lock > > diff --git a/osaf/libs/common/immsv/immpbe_dump.cc > b/osaf/libs/common/immsv/immpbe_dump.cc > --- a/osaf/libs/common/immsv/immpbe_dump.cc > +++ b/osaf/libs/common/immsv/immpbe_dump.cc > @@ -2909,6 +2909,7 @@ SaAisErrorT pbeBeginTrans(void* db_handl > LOG_ER("SQL statement ('BEGIN EXCLUSIVE TRANSACTION') failed > because:\n %s", > execErr); > sqlite3_free(execErr); > + --sqliteTransLock; > return SA_AIS_ERR_FAILED_OPERATION; > } > return SA_AIS_OK; ------------------------------------------------------------------------------ _______________________________________________ Opensaf-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/opensaf-devel ------------------------------------------------------------------------------ _______________________________________________ Opensaf-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/opensaf-devel
