postgres.git / summary / log / commit / refs

commit    e5b7451ea36d52815085cc2d9f2434c35b837978
Author:   Robert Haas <rhaas@postgresql.org>
Date:     Thu Jan 05 18:12:16 2017 +0000
First released in: 10.0, 9.6.2

    Fix possible leak of semaphore count.
    
    Commit 4aec49899e5782247e134f94ce1c6ee926f88e1c reorganized the order
    of operations here so that we no longer increment the number of "extra
    waits" before locking the semaphore, but it did not change the
    starting value of extraWaits from 0 to -1 to compensate.  In the worst
    case, this could leak a semaphore count, but that seems to be unlikely
    in practice.
    
    Discussion: http://postgr.es/m/CAA4eK1JyVqXiMba+-a589Rk0pyHsyKkGxeumVKjU6Y74hdrVLQ@mail.gmail.com
    
    Amit Kapila, per an off-list report by Dilip Kumar.  Reviewed by me.


 src/backend/storage/ipc/procarray.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 83b0c71f528..3f47b984eef 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -484,7 +484,6 @@ ProcArrayGroupClearXid(PGPROC *proc, TransactionId latestXid)
 	volatile PROC_HDR *procglobal = ProcGlobal;
 	uint32		nextidx;
 	uint32		wakeidx;
-	int			extraWaits = -1;
 
 	/* We should definitely have an XID to clear. */
 	Assert(TransactionIdIsValid(allPgXact[proc->pgprocno].xid));
@@ -511,6 +510,8 @@ ProcArrayGroupClearXid(PGPROC *proc, TransactionId latestXid)
 	 */
 	if (nextidx != INVALID_PGPROCNO)
 	{
+		int			extraWaits = 0;
+
 		/* Sleep until the leader clears our XID. */
 		for (;;)
 		{


[parent: 933b46644c78]