0003-Introduce-pending-flag-for-GUC-assign-hooks-20251013.patch
application/x-patch
Filename: 0003-Introduce-pending-flag-for-GUC-assign-hooks-20251013.patch
Type: application/x-patch
Part: 0
Patch
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API reference →
Format: format-patch
Series: patch 0003
Subject: Introduce pending flag for GUC assign hooks
| File | + | − |
|---|---|---|
| src/backend/access/transam/xlog.c | 1 | 1 |
| src/backend/commands/variable.c | 3 | 3 |
| src/backend/libpq/pqcomm.c | 4 | 4 |
| src/backend/tcop/postgres.c | 1 | 1 |
| src/backend/utils/misc/guc.c | 40 | 19 |
| src/backend/utils/misc/stack_depth.c | 1 | 1 |
| src/include/utils/guc.h | 1 | 1 |
| src/include/utils/guc_hooks.h | 10 | 10 |
From f616d9a4e88c9edabae143d6f402c3f54730cd0d Mon Sep 17 00:00:00 2001
From: Dmitrii Dolgov <9erthalion6@gmail.com>
Date: Sun, 6 Apr 2025 16:40:32 +0200
Subject: [PATCH 03/19] Introduce pending flag for GUC assign hooks
Currently an assing hook can perform some preprocessing of a new value,
but it cannot change the behavior, which dictates that the new value
will be applied immediately after the hook. Certain GUC options (like
shared_buffers, coming in subsequent patches) may need coordinating work
between backends to change, meaning we cannot apply it right away.
Add a new flag "pending" for an assign hook to allow the hook indicate
exactly that. If the pending flag is set after the hook, the new value
will not be applied and it's handling becomes the hook's implementation
responsibility.
Note, that this also requires changes in the way how GUCs are getting
reported, but the patch does not cover that yet.
---
src/backend/access/transam/xlog.c | 2 +-
src/backend/commands/variable.c | 6 +--
src/backend/libpq/pqcomm.c | 8 ++--
src/backend/tcop/postgres.c | 2 +-
src/backend/utils/misc/guc.c | 59 +++++++++++++++++++---------
src/backend/utils/misc/stack_depth.c | 2 +-
src/include/utils/guc.h | 2 +-
src/include/utils/guc_hooks.h | 20 +++++-----
8 files changed, 61 insertions(+), 40 deletions(-)
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index eceab341255..cc48b253bc8 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -2197,7 +2197,7 @@ CalculateCheckpointSegments(void)
}
void
-assign_max_wal_size(int newval, void *extra)
+assign_max_wal_size(int newval, void *extra, bool *pending)
{
max_wal_size_mb = newval;
CalculateCheckpointSegments();
diff --git a/src/backend/commands/variable.c b/src/backend/commands/variable.c
index 608f10d9412..e40dae2ddf2 100644
--- a/src/backend/commands/variable.c
+++ b/src/backend/commands/variable.c
@@ -1143,7 +1143,7 @@ check_cluster_name(char **newval, void **extra, GucSource source)
* GUC assign_hook for maintenance_io_concurrency
*/
void
-assign_maintenance_io_concurrency(int newval, void *extra)
+assign_maintenance_io_concurrency(int newval, void *extra, bool *pending)
{
/*
* Reconfigure recovery prefetching, because a setting it depends on
@@ -1161,12 +1161,12 @@ assign_maintenance_io_concurrency(int newval, void *extra)
* they may be assigned in either order.
*/
void
-assign_io_max_combine_limit(int newval, void *extra)
+assign_io_max_combine_limit(int newval, void *extra, bool *pending)
{
io_combine_limit = Min(newval, io_combine_limit_guc);
}
void
-assign_io_combine_limit(int newval, void *extra)
+assign_io_combine_limit(int newval, void *extra, bool *pending)
{
io_combine_limit = Min(io_max_combine_limit, newval);
}
diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c
index 25f739a6a17..1726a7c0993 100644
--- a/src/backend/libpq/pqcomm.c
+++ b/src/backend/libpq/pqcomm.c
@@ -1951,7 +1951,7 @@ pq_settcpusertimeout(int timeout, Port *port)
* GUC assign_hook for tcp_keepalives_idle
*/
void
-assign_tcp_keepalives_idle(int newval, void *extra)
+assign_tcp_keepalives_idle(int newval, void *extra, bool *pending)
{
/*
* The kernel API provides no way to test a value without setting it; and
@@ -1984,7 +1984,7 @@ show_tcp_keepalives_idle(void)
* GUC assign_hook for tcp_keepalives_interval
*/
void
-assign_tcp_keepalives_interval(int newval, void *extra)
+assign_tcp_keepalives_interval(int newval, void *extra, bool *pending)
{
/* See comments in assign_tcp_keepalives_idle */
(void) pq_setkeepalivesinterval(newval, MyProcPort);
@@ -2007,7 +2007,7 @@ show_tcp_keepalives_interval(void)
* GUC assign_hook for tcp_keepalives_count
*/
void
-assign_tcp_keepalives_count(int newval, void *extra)
+assign_tcp_keepalives_count(int newval, void *extra, bool *pending)
{
/* See comments in assign_tcp_keepalives_idle */
(void) pq_setkeepalivescount(newval, MyProcPort);
@@ -2030,7 +2030,7 @@ show_tcp_keepalives_count(void)
* GUC assign_hook for tcp_user_timeout
*/
void
-assign_tcp_user_timeout(int newval, void *extra)
+assign_tcp_user_timeout(int newval, void *extra, bool *pending)
{
/* See comments in assign_tcp_keepalives_idle */
(void) pq_settcpusertimeout(newval, MyProcPort);
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 7dd75a490aa..193efeb9022 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3597,7 +3597,7 @@ check_log_stats(bool *newval, void **extra, GucSource source)
/* GUC assign hook for transaction_timeout */
void
-assign_transaction_timeout(int newval, void *extra)
+assign_transaction_timeout(int newval, void *extra, bool *pending)
{
if (IsTransactionState())
{
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 8794e26ef1d..c9361a0e423 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -1681,6 +1681,7 @@ InitializeOneGUCOption(struct config_generic *gconf)
struct config_int *conf = (struct config_int *) gconf;
int newval = conf->boot_val;
void *extra = NULL;
+ bool pending = false;
Assert(newval >= conf->min);
Assert(newval <= conf->max);
@@ -1689,9 +1690,13 @@ InitializeOneGUCOption(struct config_generic *gconf)
elog(FATAL, "failed to initialize %s to %d",
conf->gen.name, newval);
if (conf->assign_hook)
- conf->assign_hook(newval, extra);
- *conf->variable = conf->reset_val = newval;
- conf->gen.extra = conf->reset_extra = extra;
+ conf->assign_hook(newval, extra, &pending);
+
+ if (!pending)
+ {
+ *conf->variable = conf->reset_val = newval;
+ conf->gen.extra = conf->reset_extra = extra;
+ }
break;
}
case PGC_REAL:
@@ -2047,13 +2052,18 @@ ResetAllOptions(void)
case PGC_INT:
{
struct config_int *conf = (struct config_int *) gconf;
+ bool pending = false;
if (conf->assign_hook)
conf->assign_hook(conf->reset_val,
- conf->reset_extra);
- *conf->variable = conf->reset_val;
- set_extra_field(&conf->gen, &conf->gen.extra,
- conf->reset_extra);
+ conf->reset_extra,
+ &pending);
+ if (!pending)
+ {
+ *conf->variable = conf->reset_val;
+ set_extra_field(&conf->gen, &conf->gen.extra,
+ conf->reset_extra);
+ }
break;
}
case PGC_REAL:
@@ -2430,16 +2440,21 @@ AtEOXact_GUC(bool isCommit, int nestLevel)
struct config_int *conf = (struct config_int *) gconf;
int newval = newvalue.val.intval;
void *newextra = newvalue.extra;
+ bool pending = false;
if (*conf->variable != newval ||
conf->gen.extra != newextra)
{
if (conf->assign_hook)
- conf->assign_hook(newval, newextra);
- *conf->variable = newval;
- set_extra_field(&conf->gen, &conf->gen.extra,
- newextra);
- changed = true;
+ conf->assign_hook(newval, newextra, &pending);
+
+ if (!pending)
+ {
+ *conf->variable = newval;
+ set_extra_field(&conf->gen, &conf->gen.extra,
+ newextra);
+ changed = true;
+ }
}
break;
}
@@ -3856,18 +3871,24 @@ set_config_with_handle(const char *name, config_handle *handle,
if (changeVal)
{
+ bool pending = false;
+
/* Save old value to support transaction abort */
if (!makeDefault)
push_old_value(&conf->gen, action);
if (conf->assign_hook)
- conf->assign_hook(newval, newextra);
- *conf->variable = newval;
- set_extra_field(&conf->gen, &conf->gen.extra,
- newextra);
- set_guc_source(&conf->gen, source);
- conf->gen.scontext = context;
- conf->gen.srole = srole;
+ conf->assign_hook(newval, newextra, &pending);
+
+ if (!pending)
+ {
+ *conf->variable = newval;
+ set_extra_field(&conf->gen, &conf->gen.extra,
+ newextra);
+ set_guc_source(&conf->gen, source);
+ conf->gen.scontext = context;
+ conf->gen.srole = srole;
+ }
}
if (makeDefault)
{
diff --git a/src/backend/utils/misc/stack_depth.c b/src/backend/utils/misc/stack_depth.c
index 8f7cf531fbc..ef59ae62008 100644
--- a/src/backend/utils/misc/stack_depth.c
+++ b/src/backend/utils/misc/stack_depth.c
@@ -156,7 +156,7 @@ check_max_stack_depth(int *newval, void **extra, GucSource source)
/* GUC assign hook for max_stack_depth */
void
-assign_max_stack_depth(int newval, void *extra)
+assign_max_stack_depth(int newval, void *extra, bool *pending)
{
ssize_t newval_bytes = newval * (ssize_t) 1024;
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index f21ec37da89..c3056cd2da8 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -187,7 +187,7 @@ typedef bool (*GucStringCheckHook) (char **newval, void **extra, GucSource sourc
typedef bool (*GucEnumCheckHook) (int *newval, void **extra, GucSource source);
typedef void (*GucBoolAssignHook) (bool newval, void *extra);
-typedef void (*GucIntAssignHook) (int newval, void *extra);
+typedef void (*GucIntAssignHook) (int newval, void *extra, bool *pending);
typedef void (*GucRealAssignHook) (double newval, void *extra);
typedef void (*GucStringAssignHook) (const char *newval, void *extra);
typedef void (*GucEnumAssignHook) (int newval, void *extra);
diff --git a/src/include/utils/guc_hooks.h b/src/include/utils/guc_hooks.h
index 82ac8646a8d..658c799419e 100644
--- a/src/include/utils/guc_hooks.h
+++ b/src/include/utils/guc_hooks.h
@@ -81,12 +81,12 @@ extern bool check_log_stats(bool *newval, void **extra, GucSource source);
extern bool check_log_timezone(char **newval, void **extra, GucSource source);
extern void assign_log_timezone(const char *newval, void *extra);
extern const char *show_log_timezone(void);
-extern void assign_maintenance_io_concurrency(int newval, void *extra);
-extern void assign_io_max_combine_limit(int newval, void *extra);
-extern void assign_io_combine_limit(int newval, void *extra);
-extern void assign_max_wal_size(int newval, void *extra);
+extern void assign_maintenance_io_concurrency(int newval, void *extra, bool *pending);
+extern void assign_io_max_combine_limit(int newval, void *extra, bool *pending);
+extern void assign_io_combine_limit(int newval, void *extra, bool *pending);
+extern void assign_max_wal_size(int newval, void *extra, bool *pending);
extern bool check_max_stack_depth(int *newval, void **extra, GucSource source);
-extern void assign_max_stack_depth(int newval, void *extra);
+extern void assign_max_stack_depth(int newval, void *extra, bool *pending);
extern bool check_multixact_member_buffers(int *newval, void **extra,
GucSource source);
extern bool check_multixact_offset_buffers(int *newval, void **extra,
@@ -141,13 +141,13 @@ extern void assign_synchronous_standby_names(const char *newval, void *extra);
extern void assign_synchronous_commit(int newval, void *extra);
extern void assign_syslog_facility(int newval, void *extra);
extern void assign_syslog_ident(const char *newval, void *extra);
-extern void assign_tcp_keepalives_count(int newval, void *extra);
+extern void assign_tcp_keepalives_count(int newval, void *extra, bool *pending);
extern const char *show_tcp_keepalives_count(void);
-extern void assign_tcp_keepalives_idle(int newval, void *extra);
+extern void assign_tcp_keepalives_idle(int newval, void *extra, bool *pending);
extern const char *show_tcp_keepalives_idle(void);
-extern void assign_tcp_keepalives_interval(int newval, void *extra);
+extern void assign_tcp_keepalives_interval(int newval, void *extra, bool *pending);
extern const char *show_tcp_keepalives_interval(void);
-extern void assign_tcp_user_timeout(int newval, void *extra);
+extern void assign_tcp_user_timeout(int newval, void *extra, bool *pending);
extern const char *show_tcp_user_timeout(void);
extern bool check_temp_buffers(int *newval, void **extra, GucSource source);
extern bool check_temp_tablespaces(char **newval, void **extra,
@@ -163,7 +163,7 @@ extern bool check_transaction_buffers(int *newval, void **extra, GucSource sourc
extern bool check_transaction_deferrable(bool *newval, void **extra, GucSource source);
extern bool check_transaction_isolation(int *newval, void **extra, GucSource source);
extern bool check_transaction_read_only(bool *newval, void **extra, GucSource source);
-extern void assign_transaction_timeout(int newval, void *extra);
+extern void assign_transaction_timeout(int newval, void *extra, bool *pending);
extern const char *show_unix_socket_permissions(void);
extern bool check_wal_buffers(int *newval, void **extra, GucSource source);
extern bool check_wal_consistency_checking(char **newval, void **extra,
--
2.34.1