Hi hackers,
Some discrepancies between wait_event_names.txt and predefined LWLocks tranches
have been observed, see: a493e741d32 ,08b9b9e043b and c3623703f36.
To prevent new discrepancies from occurring, this patch series aims to $SUBJECT
(as 5b1b9bce844 did for predefined LWLocks).
The patch series contains:
0001 - Extracts the predefined LWLocks tranches from lwlock.c and puts them
in a new file (namely lwlocktranchelist.h). This way, we can include this file
in lwlock.c using the same macro pattern as we do for lwlocklist.h.
This gives us the chance to cross-check with wait_event_names.txt in
generate-lwlocknames.pl in the same way as 5b1b9bce844 did.
It's much simpler and makes more sense than having generate-lwlocknames.pl
parsing lwlock.c.
0002 - While doing changes in generate-lwlocknames.pl, I noticed that
$continue is not used (Oversight in commit da952b415f4), so let's remove it.
0003 - Cross-check lists of predefined tranches
Same idea as 5b1b9bce844 i.e if the lists (in wait_event_names.txt and
lwlocktranchelist.h) do not match exactly, building will fail.
I wonder if once these get in, we could also generate "BuiltinTrancheIds" (in
lwlock.h) from lwlocktranchelist.h with generate-lwlocknames.pl.
Regards,
--
Bertrand Drouvot
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com
>From 830e9dce82d42eddbd7281f4267bb771162dbd47 Mon Sep 17 00:00:00 2001
From: Bertrand Drouvot <bertranddrouvot...@gmail.com>
Date: Fri, 18 Jul 2025 10:03:18 +0000
Subject: [PATCH v1 1/3] Create lwlocktranchelist.h
This commit extracts the predefined LWLocks tranches from lwlock.c and puts them
in a new file (namely lwlocktranchelist.h).
This way, we can include this file in lwlock.c using the same macro pattern
as we do for lwlocklist.h.
This gives us the chance to cross-check with wait_event_names.txt in
generate-lwlocknames.pl in a following commit.
---
src/backend/storage/lmgr/lwlock.c | 47 ++--------------
src/include/storage/lwlocktranchelist.h | 72 +++++++++++++++++++++++++
src/tools/pginclude/headerscheck | 1 +
3 files changed, 78 insertions(+), 42 deletions(-)
create mode 100644 src/include/storage/lwlocktranchelist.h
diff --git a/src/backend/storage/lmgr/lwlock.c b/src/backend/storage/lmgr/lwlock.c
index 2d43bf2cc13..9c6285ea4cb 100644
--- a/src/backend/storage/lmgr/lwlock.c
+++ b/src/backend/storage/lmgr/lwlock.c
@@ -124,7 +124,7 @@ StaticAssertDecl((LW_VAL_EXCLUSIVE & LW_FLAG_MASK) == 0,
*
* 2. There are some predefined tranches for built-in groups of locks.
* These are listed in enum BuiltinTrancheIds in lwlock.h, and their names
- * appear in BuiltinTrancheNames[] below.
+ * appear in lwlocktranchelist.h.
*
* 3. Extensions can create new tranches, via either RequestNamedLWLockTranche
* or LWLockRegisterTranche. The names of these that are known in the current
@@ -137,47 +137,10 @@ static const char *const BuiltinTrancheNames[] = {
#define PG_LWLOCK(id, lockname) [id] = CppAsString(lockname),
#include "storage/lwlocklist.h"
#undef PG_LWLOCK
- [LWTRANCHE_XACT_BUFFER] = "XactBuffer",
- [LWTRANCHE_COMMITTS_BUFFER] = "CommitTsBuffer",
- [LWTRANCHE_SUBTRANS_BUFFER] = "SubtransBuffer",
- [LWTRANCHE_MULTIXACTOFFSET_BUFFER] = "MultiXactOffsetBuffer",
- [LWTRANCHE_MULTIXACTMEMBER_BUFFER] = "MultiXactMemberBuffer",
- [LWTRANCHE_NOTIFY_BUFFER] = "NotifyBuffer",
- [LWTRANCHE_SERIAL_BUFFER] = "SerialBuffer",
- [LWTRANCHE_WAL_INSERT] = "WALInsert",
- [LWTRANCHE_BUFFER_CONTENT] = "BufferContent",
- [LWTRANCHE_REPLICATION_ORIGIN_STATE] = "ReplicationOriginState",
- [LWTRANCHE_REPLICATION_SLOT_IO] = "ReplicationSlotIO",
- [LWTRANCHE_LOCK_FASTPATH] = "LockFastPath",
- [LWTRANCHE_BUFFER_MAPPING] = "BufferMapping",
- [LWTRANCHE_LOCK_MANAGER] = "LockManager",
- [LWTRANCHE_PREDICATE_LOCK_MANAGER] = "PredicateLockManager",
- [LWTRANCHE_PARALLEL_HASH_JOIN] = "ParallelHashJoin",
- [LWTRANCHE_PARALLEL_BTREE_SCAN] = "ParallelBtreeScan",
- [LWTRANCHE_PARALLEL_QUERY_DSA] = "ParallelQueryDSA",
- [LWTRANCHE_PER_SESSION_DSA] = "PerSessionDSA",
- [LWTRANCHE_PER_SESSION_RECORD_TYPE] = "PerSessionRecordType",
- [LWTRANCHE_PER_SESSION_RECORD_TYPMOD] = "PerSessionRecordTypmod",
- [LWTRANCHE_SHARED_TUPLESTORE] = "SharedTupleStore",
- [LWTRANCHE_SHARED_TIDBITMAP] = "SharedTidBitmap",
- [LWTRANCHE_PARALLEL_APPEND] = "ParallelAppend",
- [LWTRANCHE_PER_XACT_PREDICATE_LIST] = "PerXactPredicateList",
- [LWTRANCHE_PGSTATS_DSA] = "PgStatsDSA",
- [LWTRANCHE_PGSTATS_HASH] = "PgStatsHash",
- [LWTRANCHE_PGSTATS_DATA] = "PgStatsData",
- [LWTRANCHE_LAUNCHER_DSA] = "LogicalRepLauncherDSA",
- [LWTRANCHE_LAUNCHER_HASH] = "LogicalRepLauncherHash",
- [LWTRANCHE_DSM_REGISTRY_DSA] = "DSMRegistryDSA",
- [LWTRANCHE_DSM_REGISTRY_HASH] = "DSMRegistryHash",
- [LWTRANCHE_COMMITTS_SLRU] = "CommitTsSLRU",
- [LWTRANCHE_MULTIXACTOFFSET_SLRU] = "MultiXactOffsetSLRU",
- [LWTRANCHE_MULTIXACTMEMBER_SLRU] = "MultiXactMemberSLRU",
- [LWTRANCHE_NOTIFY_SLRU] = "NotifySLRU",
- [LWTRANCHE_SERIAL_SLRU] = "SerialSLRU",
- [LWTRANCHE_SUBTRANS_SLRU] = "SubtransSLRU",
- [LWTRANCHE_XACT_SLRU] = "XactSLRU",
- [LWTRANCHE_PARALLEL_VACUUM_DSA] = "ParallelVacuumDSA",
- [LWTRANCHE_AIO_URING_COMPLETION] = "AioUringCompletion",
+
+#define PG_BUILTIN_LWTRANCHE(id, name) [id] = name,
+#include "storage/lwlocktranchelist.h"
+#undef PG_BUILTIN_LWTRANCHE
};
StaticAssertDecl(lengthof(BuiltinTrancheNames) ==
diff --git a/src/include/storage/lwlocktranchelist.h b/src/include/storage/lwlocktranchelist.h
new file mode 100644
index 00000000000..5f45f5f8d0b
--- /dev/null
+++ b/src/include/storage/lwlocktranchelist.h
@@ -0,0 +1,72 @@
+/*-------------------------------------------------------------------------
+ *
+ * lwlocktranchelist.h
+ *
+ * The predefined built-in LWLock tranche list is kept in its own source
+ * file for use by automatic tools. The exact representation of a tranche
+ * is determined by the PG_BUILTIN_LWTRANCHE macro, which is not defined in
+ * this file; it can be defined by the caller for special purposes.
+ *
+ * Also, generate-lwlocknames.pl processes this file for validation against
+ * wait_event_names.txt.
+ *
+ * Portions Copyright (c) 1996-2025, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/include/storage/lwlocktranchelist.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/*
+ * Predefined tranches for built-in groups of locks.
+ *
+ * If you add a tranche, do not forget to update the section WaitEventLWLock of
+ * wait_event_names.txt.
+ *
+ * Note that the tranche names here should match exactly what appears
+ * in wait_event_names.txt.
+ */
+
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_XACT_BUFFER, "XactBuffer")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_COMMITTS_BUFFER, "CommitTsBuffer")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_SUBTRANS_BUFFER, "SubtransBuffer")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_MULTIXACTOFFSET_BUFFER, "MultiXactOffsetBuffer")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_MULTIXACTMEMBER_BUFFER, "MultiXactMemberBuffer")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_NOTIFY_BUFFER, "NotifyBuffer")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_SERIAL_BUFFER, "SerialBuffer")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_WAL_INSERT, "WALInsert")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_BUFFER_CONTENT, "BufferContent")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_REPLICATION_ORIGIN_STATE, "ReplicationOriginState")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_REPLICATION_SLOT_IO, "ReplicationSlotIO")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_LOCK_FASTPATH, "LockFastPath")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_BUFFER_MAPPING, "BufferMapping")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_LOCK_MANAGER, "LockManager")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_PREDICATE_LOCK_MANAGER, "PredicateLockManager")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_PARALLEL_HASH_JOIN, "ParallelHashJoin")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_PARALLEL_BTREE_SCAN, "ParallelBtreeScan")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_PARALLEL_QUERY_DSA, "ParallelQueryDSA")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_PER_SESSION_DSA, "PerSessionDSA")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_PER_SESSION_RECORD_TYPE, "PerSessionRecordType")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_PER_SESSION_RECORD_TYPMOD, "PerSessionRecordTypmod")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_SHARED_TUPLESTORE, "SharedTupleStore")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_SHARED_TIDBITMAP, "SharedTidBitmap")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_PARALLEL_APPEND, "ParallelAppend")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_PER_XACT_PREDICATE_LIST, "PerXactPredicateList")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_PGSTATS_DSA, "PgStatsDSA")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_PGSTATS_HASH, "PgStatsHash")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_PGSTATS_DATA, "PgStatsData")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_LAUNCHER_DSA, "LogicalRepLauncherDSA")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_LAUNCHER_HASH, "LogicalRepLauncherHash")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_DSM_REGISTRY_DSA, "DSMRegistryDSA")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_DSM_REGISTRY_HASH, "DSMRegistryHash")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_COMMITTS_SLRU, "CommitTsSLRU")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_MULTIXACTOFFSET_SLRU, "MultiXactOffsetSLRU")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_MULTIXACTMEMBER_SLRU, "MultiXactMemberSLRU")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_NOTIFY_SLRU, "NotifySLRU")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_SERIAL_SLRU, "SerialSLRU")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_SUBTRANS_SLRU, "SubtransSLRU")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_XACT_SLRU, "XactSLRU")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_PARALLEL_VACUUM_DSA, "ParallelVacuumDSA")
+PG_BUILTIN_LWTRANCHE(LWTRANCHE_AIO_URING_COMPLETION, "AioUringCompletion")
diff --git a/src/tools/pginclude/headerscheck b/src/tools/pginclude/headerscheck
index 9e86d049362..4dc5bfab995 100755
--- a/src/tools/pginclude/headerscheck
+++ b/src/tools/pginclude/headerscheck
@@ -132,6 +132,7 @@ do
test "$f" = src/interfaces/ecpg/preproc/ecpg_kwlist.h && continue
test "$f" = src/include/regex/regerrs.h && continue
test "$f" = src/include/storage/lwlocklist.h && continue
+ test "$f" = src/include/storage/lwlocktranchelist.h && continue
test "$f" = src/include/tcop/cmdtaglist.h && continue
test "$f" = src/pl/plpgsql/src/plerrcodes.h && continue
test "$f" = src/pl/plpython/spiexceptions.h && continue
--
2.34.1
>From 8cf82eb171eccf3144c5ca0050659c412b4b5069 Mon Sep 17 00:00:00 2001
From: Bertrand Drouvot <bertranddrouvot...@gmail.com>
Date: Fri, 18 Jul 2025 11:04:43 +0000
Subject: [PATCH v1 2/3] Remove unused variable in generate-lwlocknames.pl
$continue is not used, so let's remove it.
Oversight in commit da952b415f4.
---
src/backend/storage/lmgr/generate-lwlocknames.pl | 3 ---
1 file changed, 3 deletions(-)
diff --git a/src/backend/storage/lmgr/generate-lwlocknames.pl b/src/backend/storage/lmgr/generate-lwlocknames.pl
index 4441b7cba0c..c7a6720440d 100644
--- a/src/backend/storage/lmgr/generate-lwlocknames.pl
+++ b/src/backend/storage/lmgr/generate-lwlocknames.pl
@@ -10,7 +10,6 @@ use Getopt::Long;
my $output_path = '.';
my $lastlockidx = -1;
-my $continue = "\n";
GetOptions('outdir:s' => \$output_path);
@@ -102,10 +101,8 @@ while (<$lwlocklist>)
while ($lastlockidx < $lockidx - 1)
{
++$lastlockidx;
- $continue = ",\n";
}
$lastlockidx = $lockidx;
- $continue = ",\n";
# Add a "Lock" suffix to each lock name, as the C code depends on that
printf $h "#define %-32s (&MainLWLockArray[$lockidx].lock)\n",
--
2.34.1
>From a24e6af77e27589c9eaa5ceda017490c80bebad8 Mon Sep 17 00:00:00 2001
From: Bertrand Drouvot <bertranddrouvot...@gmail.com>
Date: Fri, 18 Jul 2025 11:19:19 +0000
Subject: [PATCH v1 3/3] Cross-check lists of predefined tranches.
Both builtin_lwlocktranchelist.h and wait_event_names.txt contain a list of all
the predefined tranches. It is easy to miss one or the other (see a493e741d32
,08b9b9e043b and c3623703f36).
This commit adds a cross-check of these lists to the script that already does
the same cross-check for lwlocklist.h.
If the lists do not match exactly, building will fail (same as in 5b1b9bce844).
---
src/backend/Makefile | 2 +-
src/backend/storage/lmgr/Makefile | 2 +-
.../storage/lmgr/generate-lwlocknames.pl | 77 +++++++++++++++++--
src/include/storage/meson.build | 1 +
4 files changed, 74 insertions(+), 8 deletions(-)
diff --git a/src/backend/Makefile b/src/backend/Makefile
index 7344c8c7f5c..cda1bbe2b35 100644
--- a/src/backend/Makefile
+++ b/src/backend/Makefile
@@ -111,7 +111,7 @@ $(top_builddir)/src/port/libpgport_srv.a: | submake-libpgport
parser/gram.h: parser/gram.y
$(MAKE) -C parser gram.h
-storage/lmgr/lwlocknames.h: storage/lmgr/generate-lwlocknames.pl ../include/storage/lwlocklist.h utils/activity/wait_event_names.txt
+storage/lmgr/lwlocknames.h: storage/lmgr/generate-lwlocknames.pl ../include/storage/lwlocklist.h ../include/storage/lwlocktranchelist.h utils/activity/wait_event_names.txt
$(MAKE) -C storage/lmgr lwlocknames.h
utils/activity/wait_event_types.h: utils/activity/generate-wait_event_types.pl utils/activity/wait_event_names.txt
diff --git a/src/backend/storage/lmgr/Makefile b/src/backend/storage/lmgr/Makefile
index 6cbaf23b855..523804889ae 100644
--- a/src/backend/storage/lmgr/Makefile
+++ b/src/backend/storage/lmgr/Makefile
@@ -33,7 +33,7 @@ s_lock_test: s_lock.c $(top_builddir)/src/common/libpgcommon.a $(top_builddir)/s
$(TASPATH) -L $(top_builddir)/src/common -lpgcommon \
-L $(top_builddir)/src/port -lpgport -lm -o s_lock_test
-lwlocknames.h: ../../../include/storage/lwlocklist.h ../../utils/activity/wait_event_names.txt generate-lwlocknames.pl
+lwlocknames.h: ../../../include/storage/lwlocklist.h ../../../include/storage/lwlocktranchelist.h ../../utils/activity/wait_event_names.txt generate-lwlocknames.pl
$(PERL) $(srcdir)/generate-lwlocknames.pl $^
check: s_lock_test
diff --git a/src/backend/storage/lmgr/generate-lwlocknames.pl b/src/backend/storage/lmgr/generate-lwlocknames.pl
index c7a6720440d..4732c17f03d 100644
--- a/src/backend/storage/lmgr/generate-lwlocknames.pl
+++ b/src/backend/storage/lmgr/generate-lwlocknames.pl
@@ -14,7 +14,8 @@ my $lastlockidx = -1;
GetOptions('outdir:s' => \$output_path);
open my $lwlocklist, '<', $ARGV[0] or die;
-open my $wait_event_names, '<', $ARGV[1] or die;
+open my $builtin_lwtranche_list, '<', $ARGV[1] or die;
+open my $wait_event_names, '<', $ARGV[2] or die;
# Include PID in suffix in case parallel make runs this multiple times.
my $htmp = "$output_path/lwlocknames.h.tmp$$";
@@ -27,18 +28,25 @@ print $h "/* there is deliberately not an #ifndef LWLOCKNAMES_H here */\n\n";
#
-# First, record the predefined LWLocks listed in wait_event_names.txt. We'll
-# cross-check those with the ones in lwlocklist.h.
+# First, record the predefined LWLocks and built-in tranches listed in
+# wait_event_names.txt. We'll cross-check those with the ones in lwlocklist.h
+# and in lwlocktranchelist.h.
#
+my @wait_event_builtin_tranches;
my @wait_event_lwlocks;
my $record_lwlocks = 0;
+my $in_builtin_tranches = 0;
while (<$wait_event_names>)
{
chomp;
- # Check for end marker.
- last if /^# END OF PREDEFINED LWLOCKS/;
+ # Check for predefined end marker.
+ if (/^# END OF PREDEFINED LWLOCKS/)
+ {
+ $in_builtin_tranches = 1;
+ next;
+ }
# Skip comments and empty lines.
next if /^#/;
@@ -54,9 +62,20 @@ while (<$wait_event_names>)
# Go to the next line if we are not yet recording LWLocks.
next if not $record_lwlocks;
+ # Stop recording if we reach another section.
+ last if /^Section:/;
+
# Record the LWLock.
(my $waiteventname, my $waitevendocsentence) = split(/\t/, $_);
- push(@wait_event_lwlocks, $waiteventname);
+
+ if ($in_builtin_tranches)
+ {
+ push(@wait_event_builtin_tranches, $waiteventname);
+ }
+ else
+ {
+ push(@wait_event_lwlocks, $waiteventname);
+ }
}
my $in_comment = 0;
@@ -114,6 +133,52 @@ die
. "lwlocklist.h"
if $i < scalar @wait_event_lwlocks;
+$in_comment = 0;
+$i = 0;
+
+# Cross-check the built-in tranches in lwlocktranchelist.h with
+# wait_event_names.txt.
+while (<$builtin_lwtranche_list>)
+{
+ chomp;
+
+ # Skip single-line C comments and empty lines
+ next if m{^\s*/\*.*\*/$};
+ next if /^\s*$/;
+
+ # skip multiline C comments
+ if ($in_comment == 1)
+ {
+ $in_comment = 0 if m{\*/};
+ next;
+ }
+ elsif (m{^\s*/\*})
+ {
+ $in_comment = 1;
+ next;
+ }
+
+ die "unable to parse lwlocktranchelist.h line \"$_\""
+ unless /^PG_BUILTIN_LWTRANCHE\((\w+),\s*"([^"]+)"\)$/;
+
+ my ($tranche_id, $tranche_name) = ($1, $2);
+
+ die "$tranche_name defined in lwlocktranchelist.h but missing from "
+ . "wait_event_names.txt"
+ if $i >= scalar @wait_event_builtin_tranches;
+ die "lists of built-in tranches do not match (first mismatch at "
+ . "$wait_event_builtin_tranches[$i] in wait_event_names.txt and $tranche_name in "
+ . "lwlocktranchelist.h)"
+ if $wait_event_builtin_tranches[$i] ne $tranche_name;
+
+ $i++;
+}
+
+die
+ "$wait_event_builtin_tranches[$i] defined in wait_event_names.txt but missing from "
+ . "lwlocktranchelist.h"
+ if $i < scalar @wait_event_builtin_tranches;
+
print $h "\n";
printf $h "#define NUM_INDIVIDUAL_LWLOCKS %s\n", $lastlockidx + 1;
diff --git a/src/include/storage/meson.build b/src/include/storage/meson.build
index 1e0f5080727..c2d95befd1b 100644
--- a/src/include/storage/meson.build
+++ b/src/include/storage/meson.build
@@ -3,6 +3,7 @@
lwlocknames_h = custom_target('lwlocknames_h',
input: files(
'../../include/storage/lwlocklist.h',
+ '../../include/storage/lwlocktranchelist.h',
'../../backend/utils/activity/wait_event_names.txt'),
output: ['lwlocknames.h'],
command: [
--
2.34.1
