From fb4c5d2798730f60b102d775f22fb53c26a6445d Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Fri, 21 Jan 2011 21:49:19 -0500
Subject: [PATCH] Code cleanup for assign_XactIsoLevel.
The new coding avoids a spurious debug message when a transaction
that has changed the isolation level has been rolled back. It also
allows the property to be freely changed to the current value within
a subtransaction.
Kevin Grittner, with one small change by me.
---
src/backend/commands/variable.c | 30 +++++++++++++++---------------
src/backend/utils/misc/guc.c | 2 +-
src/include/utils/guc.h | 1 +
3 files changed, 17 insertions(+), 16 deletions(-)
diff --git a/src/backend/commands/variable.c b/src/backend/commands/variable.c
index 848685f2e8a..1e9bdc3f218 100644
--- a/src/backend/commands/variable.c
+++ b/src/backend/commands/variable.c
@@ -546,27 +546,27 @@ show_log_timezone(void)
/*
* SET TRANSACTION ISOLATION LEVEL
*/
-
const char *
assign_XactIsoLevel(const char *value, bool doit, GucSource source)
{
- if (FirstSnapshotSet)
+ /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
+ if (source != PGC_S_OVERRIDE)
{
- ereport(GUC_complaint_elevel(source),
- (errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
- errmsg("SET TRANSACTION ISOLATION LEVEL must be called before any query")));
- /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
- if (source != PGC_S_OVERRIDE)
+ if (FirstSnapshotSet)
+ {
+ ereport(GUC_complaint_elevel(source),
+ (errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
+ errmsg("SET TRANSACTION ISOLATION LEVEL must be called before any query")));
return NULL;
- }
- else if (IsSubTransaction())
- {
- ereport(GUC_complaint_elevel(source),
- (errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
- errmsg("SET TRANSACTION ISOLATION LEVEL must not be called in a subtransaction")));
- /* source == PGC_S_OVERRIDE means do it anyway, eg at xact abort */
- if (source != PGC_S_OVERRIDE)
+ }
+ /* We ignore a subtransaction setting it to the existing value. */
+ if (IsSubTransaction() && strcmp(value, XactIsoLevel_string) != 0)
+ {
+ ereport(GUC_complaint_elevel(source),
+ (errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
+ errmsg("SET TRANSACTION ISOLATION LEVEL must not be called in a subtransaction")));
return NULL;
+ }
}
if (strcmp(value, "serializable") == 0)
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index e4dea31e793..ffff6015596 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -425,7 +425,6 @@ static int server_version_num;
static char *timezone_string;
static char *log_timezone_string;
static char *timezone_abbreviations_string;
-static char *XactIsoLevel_string;
static char *custom_variable_classes;
static int max_function_args;
static int max_index_keys;
@@ -440,6 +439,7 @@ static int effective_io_concurrency;
/* should be static, but commands/variable.c needs to get at these */
char *role_string;
char *session_authorization_string;
+char *XactIsoLevel_string;
/*
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index 91ad65e721f..c07f263ea07 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -201,6 +201,7 @@ extern char *ConfigFileName;
extern char *HbaFileName;
extern char *IdentFileName;
extern char *external_pid_file;
+extern char *XactIsoLevel_string;
extern char *application_name;
--
GitLab