From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Tue, 17 Mar 2020 01:36:53 +0000 (-0400)
Subject: Remove useless pfree()s at the ends of various ValuePerCall SRFs.
X-Git-Url: http://git.postgresql.org/gitweb/-?a=commitdiff_plain;h=41b45576d532ab6ef4a968f78b5b06d700ebf61f;p=users%2Fc2main%2Fpostgres.git

Remove useless pfree()s at the ends of various ValuePerCall SRFs.

We don't need to manually clean up allocations in a SRF's
multi_call_memory_ctx, because the SRF_RETURN_DONE infrastructure
takes care of that (and also ensures that it will happen even if the
function never gets a final call, which simple manual cleanup cannot
do).

Hence, the code removed by this patch is a waste of code and cycles.
Worse, it gives the impression that cleaning up manually is a thing,
which can lead to more serious errors such as those fixed in
commits 085b6b667 and b4570d33a.  So we should get rid of it.

These are not quite actual bugs though, so I couldn't muster the
enthusiasm to back-patch.  Fix in HEAD only.

Justin Pryzby

Discussion: https://postgr.es/m/20200308173103.GC1357@telsasoft.com
---

diff --git a/contrib/pageinspect/btreefuncs.c b/contrib/pageinspect/btreefuncs.c
index e6a2fc1e15..e7a323044b 100644
--- a/contrib/pageinspect/btreefuncs.c
+++ b/contrib/pageinspect/btreefuncs.c
@@ -502,12 +502,8 @@ bt_page_items(PG_FUNCTION_ARGS)
 		uargs->offset++;
 		SRF_RETURN_NEXT(fctx, result);
 	}
-	else
-	{
-		pfree(uargs->page);
-		pfree(uargs);
-		SRF_RETURN_DONE(fctx);
-	}
+
+	SRF_RETURN_DONE(fctx);
 }
 
 /*-------------------------------------------------------
@@ -590,11 +586,8 @@ bt_page_items_bytea(PG_FUNCTION_ARGS)
 		uargs->offset++;
 		SRF_RETURN_NEXT(fctx, result);
 	}
-	else
-	{
-		pfree(uargs);
-		SRF_RETURN_DONE(fctx);
-	}
+
+	SRF_RETURN_DONE(fctx);
 }
 
 /* Number of output arguments (columns) for bt_metap() */
diff --git a/contrib/pageinspect/ginfuncs.c b/contrib/pageinspect/ginfuncs.c
index 7e2cafab74..711473579a 100644
--- a/contrib/pageinspect/ginfuncs.c
+++ b/contrib/pageinspect/ginfuncs.c
@@ -260,6 +260,6 @@ gin_leafpage_items(PG_FUNCTION_ARGS)
 
 		SRF_RETURN_NEXT(fctx, result);
 	}
-	else
-		SRF_RETURN_DONE(fctx);
+
+	SRF_RETURN_DONE(fctx);
 }
diff --git a/contrib/pageinspect/hashfuncs.c b/contrib/pageinspect/hashfuncs.c
index 984ac33186..3b2f0339cf 100644
--- a/contrib/pageinspect/hashfuncs.c
+++ b/contrib/pageinspect/hashfuncs.c
@@ -374,11 +374,8 @@ hash_page_items(PG_FUNCTION_ARGS)
 
 		SRF_RETURN_NEXT(fctx, result);
 	}
-	else
-	{
-		pfree(uargs);
-		SRF_RETURN_DONE(fctx);
-	}
+
+	SRF_RETURN_DONE(fctx);
 }
 
 /* ------------------------------------------------
diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c
index 50e98caaeb..fdd0394ffa 100644
--- a/src/backend/access/transam/multixact.c
+++ b/src/backend/access/transam/multixact.c
@@ -3388,9 +3388,5 @@ pg_get_multixact_members(PG_FUNCTION_ARGS)
 		SRF_RETURN_NEXT(funccxt, HeapTupleGetDatum(tuple));
 	}
 
-	if (multi->nmembers > 0)
-		pfree(multi->members);
-	pfree(multi);
-
 	SRF_RETURN_DONE(funccxt);
 }
diff --git a/src/backend/tsearch/wparser.c b/src/backend/tsearch/wparser.c
index 88005c0519..9c1fc7b101 100644
--- a/src/backend/tsearch/wparser.c
+++ b/src/backend/tsearch/wparser.c
@@ -104,9 +104,6 @@ tt_process_call(FuncCallContext *funcctx)
 		st->cur++;
 		return result;
 	}
-	if (st->list)
-		pfree(st->list);
-	pfree(st);
 	return (Datum) 0;
 }
 
@@ -245,12 +242,6 @@ prs_process_call(FuncCallContext *funcctx)
 		st->cur++;
 		return result;
 	}
-	else
-	{
-		if (st->list)
-			pfree(st->list);
-		pfree(st);
-	}
 	return (Datum) 0;
 }
 
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index f92861d8d2..4b5007e0d6 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -535,7 +535,6 @@ jsonb_object_keys(PG_FUNCTION_ARGS)
 {
 	FuncCallContext *funcctx;
 	OkeysState *state;
-	int			i;
 
 	if (SRF_IS_FIRSTCALL())
 	{
@@ -598,12 +597,6 @@ jsonb_object_keys(PG_FUNCTION_ARGS)
 		SRF_RETURN_NEXT(funcctx, CStringGetTextDatum(nxt));
 	}
 
-	/* cleanup to reduce or eliminate memory leaks */
-	for (i = 0; i < state->result_count; i++)
-		pfree(state->result[i]);
-	pfree(state->result);
-	pfree(state);
-
 	SRF_RETURN_DONE(funcctx);
 }
 
@@ -706,7 +699,6 @@ json_object_keys(PG_FUNCTION_ARGS)
 {
 	FuncCallContext *funcctx;
 	OkeysState *state;
-	int			i;
 
 	if (SRF_IS_FIRSTCALL())
 	{
@@ -755,12 +747,6 @@ json_object_keys(PG_FUNCTION_ARGS)
 		SRF_RETURN_NEXT(funcctx, CStringGetTextDatum(nxt));
 	}
 
-	/* cleanup to reduce or eliminate memory leaks */
-	for (i = 0; i < state->result_count; i++)
-		pfree(state->result[i]);
-	pfree(state->result);
-	pfree(state);
-
 	SRF_RETURN_DONE(funcctx);
 }
 
diff --git a/src/backend/utils/adt/tsvector_op.c b/src/backend/utils/adt/tsvector_op.c
index 108dd998c7..24525879b7 100644
--- a/src/backend/utils/adt/tsvector_op.c
+++ b/src/backend/utils/adt/tsvector_op.c
@@ -706,7 +706,6 @@ tsvector_unnest(PG_FUNCTION_ARGS)
 	}
 	else
 	{
-		pfree(tsin);
 		SRF_RETURN_DONE(funcctx);
 	}
 }