Fix possible lockup in pgbench with -R.

tglsfdc · tglsfdc · commit 46c193213adb · 2019-07-26T15:17:03.000-04:00
pgbench would sometimes get stuck waiting forever after its last client thread terminated, due to failing to check for there being nothing more to wait for. Bug introduced during refactoring in v10 (I didn't bother to try to assign blame to a specific commit). It's already repaired in HEAD/v12 thanks to commit 3bac77c, but v10 and v11 need this fix. Fabien Coelho, per report from Tomas Vondra; reviewed by Yoshikazu Imai Discussion: https://postgr.es/m/cc5d76c1-6144-bbed-ad1b-961d13d88f3b@2ndquadrant.com
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
@@ -4515,6 +4515,10 @@ threadRun(void *arg)
 			}
 		}
 
+		/* under throttling we may have finished the last client above */
+		if (remains == 0)
+			break;
+
 		/* also wake up to print the next progress report on time */
 		if (progress && min_usec > 0 && thread->tid == 0)
 		{

Original file line number	Diff line number	Diff line change
`@@ -4515,6 +4515,10 @@ threadRun(void *arg)`
`4515`	`4515`	`}`
`4516`	`4516`	`}`
`4517`	`4517`
	`4518`	`+ /* under throttling we may have finished the last client above */`
	`4519`	`+ if (remains == 0)`
	`4520`	`+ break;`
	`4521`	`+`
`4518`	`4522`	`/* also wake up to print the next progress report on time */`
`4519`	`4523`	`if (progress && min_usec > 0 && thread->tid == 0)`
`4520`	`4524`	`{`