Use aux process resource owner in walsender

AIO will need a resource owner to do IO. Right now we create a resowner
on-demand during basebackup, and we could do the same for AIO. But it seems
easier to just always create an aux process resowner.

Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Noah Misch <noah@leadboat.com>
Discussion: https://postgr.es/m/1f6b50a7-38ef-4d87-8246-786d39f46ab9@iki.fi

src/backend/backup/basebackup.c

@@ -250,8 +250,10 @@ perform_base_backup(basebackup_options *opt, bbsink *sink,
 	state.bytes_total_is_valid = false;
 
 	/* we're going to use a BufFile, so we need a ResourceOwner */
-	Assert(CurrentResourceOwner == NULL);
+	Assert(AuxProcessResourceOwner != NULL);
-	CurrentResourceOwner = ResourceOwnerCreate(NULL, "base backup");
+	Assert(CurrentResourceOwner == AuxProcessResourceOwner ||
+		   CurrentResourceOwner == NULL);
+	CurrentResourceOwner = AuxProcessResourceOwner;
 
 	backup_started_in_recovery = RecoveryInProgress();
 
@@ -672,7 +674,7 @@ perform_base_backup(basebackup_options *opt, bbsink *sink,
 	FreeBackupManifest(&manifest);
 
 	/* clean up the resource owner we created */
-	WalSndResourceCleanup(true);
+	ReleaseAuxProcessResources(true);
 
 	basebackup_progress_done();
 }

src/backend/replication/walsender.c

@@ -282,10 +282,8 @@ InitWalSender(void)
 	/* Create a per-walsender data structure in shared memory */
 	InitWalSenderSlot();
 
-	/*
+	/* need resource owner for e.g. basebackups */
-	 * We don't currently need any ResourceOwner in a walsender process, but
+	CreateAuxProcessResourceOwner();
-	 * if we did, we could call CreateAuxProcessResourceOwner here.
-	 */
 
 	/*
 	 * Let postmaster know that we're a WAL sender. Once we've declared us as
@@ -346,7 +344,7 @@ WalSndErrorCleanup(void)
 	 * without a transaction, we've got to clean that up now.
 	 */
 	if (!IsTransactionOrTransactionBlock())
-		WalSndResourceCleanup(false);
+		ReleaseAuxProcessResources(false);
 
 	if (got_STOPPING || got_SIGUSR2)
 		proc_exit(0);
@@ -355,34 +353,6 @@ WalSndErrorCleanup(void)
 	WalSndSetState(WALSNDSTATE_STARTUP);
 }
 
-/*
- * Clean up any ResourceOwner we created.
- */
-void
-WalSndResourceCleanup(bool isCommit)
-{
-	ResourceOwner resowner;
-
-	if (CurrentResourceOwner == NULL)
-		return;
-
-	/*
-	 * Deleting CurrentResourceOwner is not allowed, so we must save a pointer
-	 * in a local variable and clear it first.
-	 */
-	resowner = CurrentResourceOwner;
-	CurrentResourceOwner = NULL;
-
-	/* Now we can release resources and delete it. */
-	ResourceOwnerRelease(resowner,
-						 RESOURCE_RELEASE_BEFORE_LOCKS, isCommit, true);
-	ResourceOwnerRelease(resowner,
-						 RESOURCE_RELEASE_LOCKS, isCommit, true);
-	ResourceOwnerRelease(resowner,
-						 RESOURCE_RELEASE_AFTER_LOCKS, isCommit, true);
-	ResourceOwnerDelete(resowner);
-}
-
 /*
  * Handle a client's connection abort in an orderly manner.
  */
@@ -685,8 +655,10 @@ UploadManifest(void)
 	 * parsing the manifest will use the cryptohash stuff, which requires a
 	 * resource owner
 	 */
-	Assert(CurrentResourceOwner == NULL);
+	Assert(AuxProcessResourceOwner != NULL);
-	CurrentResourceOwner = ResourceOwnerCreate(NULL, "base backup");
+	Assert(CurrentResourceOwner == AuxProcessResourceOwner ||
+		   CurrentResourceOwner == NULL);
+	CurrentResourceOwner = AuxProcessResourceOwner;
 
 	/* Prepare to read manifest data into a temporary context. */
 	mcxt = AllocSetContextCreate(CurrentMemoryContext,
@@ -723,7 +695,7 @@ UploadManifest(void)
 	uploaded_manifest_mcxt = mcxt;
 
 	/* clean up the resource owner we created */
-	WalSndResourceCleanup(true);
+	ReleaseAuxProcessResources(true);
 }
 
 /*

src/include/replication/walsender.h

@@ -38,7 +38,6 @@ extern PGDLLIMPORT bool log_replication_commands;
 extern void InitWalSender(void);
 extern bool exec_replication_command(const char *cmd_string);
 extern void WalSndErrorCleanup(void);
-extern void WalSndResourceCleanup(bool isCommit);
 extern void PhysicalWakeupLogicalWalSnd(void);
 extern XLogRecPtr GetStandbyFlushRecPtr(TimeLineID *tli);
 extern void WalSndSignals(void);