From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 12 Feb 2016 22:12:23 +0000 (-0500)
Subject: Revert "isolationtester: don't repeat the is-it-waiting query when retrying a step."
X-Git-Tag: REL9_6_BETA1~701
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=dca369320f6023b55feb49f281d394181fc57903;p=postgresql

Revert "isolationtester: don't repeat the is-it-waiting query when retrying a step."

This mostly reverts commit 9c9782f066e0ce5424b8706df2cce147cb78170f.
I left in the parts that rearranged removal of completed waiting steps;
but the idea of not rechecking a step's blocked-ness isn't working.
---

diff --git a/src/test/isolation/isolationtester.c b/src/test/isolation/isolationtester.c
index da5ac9ee6c..0a9d25ce9c 100644
--- a/src/test/isolation/isolationtester.c
+++ b/src/test/isolation/isolationtester.c
@@ -699,8 +699,7 @@ run_permutation(TestSpec *testspec, int nsteps, Step **steps)
  * have executed additional steps in the permutation.
  *
  * When calling this function on behalf of a given step for a second or later
- * time, pass the STEP_RETRY flag.  In this case we don't need to recheck
- * whether it's waiting for a lock.
+ * time, pass the STEP_RETRY flag.  This only affects the messages printed.
  *
  * If the query returns an error, the message is saved in step->errormsg.
  * Caller should call report_error_message shortly after this, to have it
@@ -748,14 +747,6 @@ try_complete_step(Step *step, int flags)
 			{
 				int			ntuples;
 
-				/*
-				 * If this is a retry, assume without checking that the step
-				 * is still blocked.  This rule saves a lot of PREP_WAITING
-				 * queries and avoids any possible flappiness in the answer.
-				 */
-				if (flags & STEP_RETRY)
-					return true;
-
 				res = PQexecPrepared(conns[0], PREP_WAITING, 1,
 									 &backend_pids[step->session + 1],
 									 NULL, NULL, 0);
@@ -770,8 +761,9 @@ try_complete_step(Step *step, int flags)
 
 				if (ntuples >= 1)		/* waiting to acquire a lock */
 				{
-					printf("step %s: %s <waiting ...>\n",
-						   step->name, step->sql);
+					if (!(flags & STEP_RETRY))
+						printf("step %s: %s <waiting ...>\n",
+							   step->name, step->sql);
 					return true;
 				}
 				/* else, not waiting */