On 2024-Feb-23, Heikki Linnakangas wrote:
> On 12/02/2024 19:01, Tristan Partin wrote:
> > On Wed Jan 24, 2024 at 8:09 AM CST, Alvaro Herrera wrote:
> > > IMO it would be less ugly to have the origin file lwlocknames.txt be
> > > not a text file but a .h with a macro that can be defined by
> > > interested parties so that they can extract what they want from the
> > > file, like PG_CMDTAG or PG_KEYWORD. Using Perl for this seems dirty...
> >
> > I really like this idea, and would definitely be more inclined to see
> > a solution like this.
>
> +1 to that idea from me too. Seems pretty straightforward.
OK, here's a patch that does it. I have not touched Meson yet.
I'm pretty disappointed of not being able to remove
generate-lwlocknames.pl (it now generates the .h, no longer the .c
file), but I can't find a way to do the equivalent #defines in CPP ...
it'd require invoking the C preprocessor twice. Maybe an intermediate
.h file would solve the problem, but I have no idea how would that work
with Meson. I guess I'll do it in Make and let somebody suggest a Meson
way.
--
Álvaro Herrera PostgreSQL Developer — https://www.EnterpriseDB.com/
"El hombre nunca sabe de lo que es capaz hasta que lo intenta" (C. Dickens)
>From c70ae4eff6ec8e8965207d6e0d6d8fcdcd91cf16 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvhe...@alvh.no-ip.org>
Date: Fri, 1 Mar 2024 13:03:10 +0100
Subject: [PATCH] Rework lwlocknames.txt to become lwlocklist.h
This saves some code and some space in BuiltinTrancheNames, as foreseen
in commit 74a730631065.
---
src/backend/Makefile | 4 +-
src/backend/storage/lmgr/.gitignore | 1 -
src/backend/storage/lmgr/Makefile | 9 +-
.../storage/lmgr/generate-lwlocknames.pl | 52 ++++++------
src/backend/storage/lmgr/lwlock.c | 15 ++--
src/backend/storage/lmgr/lwlocknames.txt | 60 --------------
.../utils/activity/wait_event_names.txt | 8 +-
src/include/storage/lwlocklist.h | 82 +++++++++++++++++++
8 files changed, 124 insertions(+), 107 deletions(-)
delete mode 100644 src/backend/storage/lmgr/lwlocknames.txt
create mode 100644 src/include/storage/lwlocklist.h
diff --git a/src/backend/Makefile b/src/backend/Makefile
index d66e2a4b9f..34bb6393c4 100644
--- a/src/backend/Makefile
+++ b/src/backend/Makefile
@@ -110,8 +110,8 @@ $(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 storage/lmgr/lwlocknames.txt utils/activity/wait_event_names.txt
- $(MAKE) -C storage/lmgr lwlocknames.h lwlocknames.c
+storage/lmgr/lwlocknames.h: storage/lmgr/generate-lwlocknames.pl $(top_srcdir)/src/include/storage/lwlocklist.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
$(MAKE) -C utils/activity wait_event_types.h pgstat_wait_event.c wait_event_funcs_data.c
diff --git a/src/backend/storage/lmgr/.gitignore b/src/backend/storage/lmgr/.gitignore
index dab4c3f580..8e5b734f15 100644
--- a/src/backend/storage/lmgr/.gitignore
+++ b/src/backend/storage/lmgr/.gitignore
@@ -1,3 +1,2 @@
-/lwlocknames.c
/lwlocknames.h
/s_lock_test
diff --git a/src/backend/storage/lmgr/Makefile b/src/backend/storage/lmgr/Makefile
index 1aef423384..9d7dbe5abd 100644
--- a/src/backend/storage/lmgr/Makefile
+++ b/src/backend/storage/lmgr/Makefile
@@ -18,7 +18,6 @@ OBJS = \
lmgr.o \
lock.o \
lwlock.o \
- lwlocknames.o \
predicate.o \
proc.o \
s_lock.o \
@@ -35,11 +34,7 @@ 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
-# see notes in src/backend/parser/Makefile
-lwlocknames.c: lwlocknames.h
- touch $@
-
-lwlocknames.h: $(top_srcdir)/src/backend/storage/lmgr/lwlocknames.txt $(top_srcdir)/src/backend/utils/activity/wait_event_names.txt generate-lwlocknames.pl
+lwlocknames.h: $(top_srcdir)/src/include/storage/lwlocklist.h $(top_srcdir)/src/backend/utils/activity/wait_event_names.txt generate-lwlocknames.pl
$(PERL) $(srcdir)/generate-lwlocknames.pl $^
check: s_lock_test
@@ -47,4 +42,4 @@ check: s_lock_test
clean:
rm -f s_lock_test
- rm -f lwlocknames.h lwlocknames.c
+ rm -f lwlocknames.h
diff --git a/src/backend/storage/lmgr/generate-lwlocknames.pl b/src/backend/storage/lmgr/generate-lwlocknames.pl
index 7b93ecf6c1..f46634a180 100644
--- a/src/backend/storage/lmgr/generate-lwlocknames.pl
+++ b/src/backend/storage/lmgr/generate-lwlocknames.pl
@@ -1,6 +1,6 @@
#!/usr/bin/perl
#
-# Generate lwlocknames.h and lwlocknames.c from lwlocknames.txt
+# Generate lwlocknames.h from lwlocklist.h
# Copyright (c) 2000-2024, PostgreSQL Global Development Group
use strict;
@@ -14,26 +14,22 @@ my $continue = "\n";
GetOptions('outdir:s' => \$output_path);
-open my $lwlocknames, '<', $ARGV[0] or die;
+open my $lwlocklist, '<', $ARGV[0] or die;
open my $wait_event_names, '<', $ARGV[1] or die;
# Include PID in suffix in case parallel make runs this multiple times.
my $htmp = "$output_path/lwlocknames.h.tmp$$";
-my $ctmp = "$output_path/lwlocknames.c.tmp$$";
open my $h, '>', $htmp or die "Could not open $htmp: $!";
-open my $c, '>', $ctmp or die "Could not open $ctmp: $!";
my $autogen =
- "/* autogenerated from src/backend/storage/lmgr/lwlocknames.txt, do not edit */\n";
+ "/* autogenerated from src/backend/storage/lmgr/lwlocklist.h, do not edit */\n";
print $h $autogen;
print $h "/* there is deliberately not an #ifndef LWLOCKNAMES_H here */\n\n";
-print $c $autogen, "\n";
-print $c "const char *const IndividualLWLockNames[] = {";
#
# First, record the predefined LWLocks listed in wait_event_names.txt. We'll
-# cross-check those with the ones in lwlocknames.txt.
+# cross-check those with the ones in lwlocklist.h.
#
my @wait_event_lwlocks;
my $record_lwlocks = 0;
@@ -64,17 +60,30 @@ while (<$wait_event_names>)
push(@wait_event_lwlocks, $waiteventname . "Lock");
}
+my $in_comment = 0;
my $i = 0;
-while (<$lwlocknames>)
+while (<$lwlocklist>)
{
chomp;
- # Skip comments
- next if /^#/;
+ # Skip uniline C comments and empty lines
+ next if m{^\s*/\*.*\*/$};
next if /^\s*$/;
- die "unable to parse lwlocknames.txt"
- unless /^(\w+)\s+(\d+)$/;
+ # skip multiline C comments
+ if ($in_comment == 1)
+ {
+ $in_comment = 0 if m{\*/};
+ next;
+ }
+ elsif (m{^\s*/\*})
+ {
+ $in_comment = 1;
+ next;
+ }
+
+ die "unable to parse lwlocklist.h line \"$_\""
+ unless /^PG_LWLOCK\((\w+),\s+(\d+)\)$/;
(my $lockname, my $lockidx) = ($1, $2);
@@ -82,25 +91,23 @@ while (<$lwlocknames>)
$trimmedlockname =~ s/Lock$//;
die "lock names must end with 'Lock'" if $trimmedlockname eq $lockname;
- die "lwlocknames.txt not in order" if $lockidx < $lastlockidx;
- die "lwlocknames.txt has duplicates" if $lockidx == $lastlockidx;
+ die "lwlocklist.h not in order" if $lockidx < $lastlockidx;
+ die "lwlocklist.h has duplicates" if $lockidx == $lastlockidx;
- die "$lockname defined in lwlocknames.txt but missing from "
+ die "$lockname defined in lwlocklist.h but missing from "
. "wait_event_names.txt"
if $i >= scalar @wait_event_lwlocks;
die "lists of predefined LWLocks do not match (first mismatch at "
. "$wait_event_lwlocks[$i] in wait_event_names.txt and $lockname in "
- . "lwlocknames.txt)"
+ . "lwlocklist.h)"
if $wait_event_lwlocks[$i] ne $lockname;
$i++;
while ($lastlockidx < $lockidx - 1)
{
++$lastlockidx;
- printf $c "%s \"<unassigned:%d>\"", $continue, $lastlockidx;
$continue = ",\n";
}
- printf $c "%s \"%s\"", $continue, $trimmedlockname;
$lastlockidx = $lockidx;
$continue = ",\n";
@@ -109,18 +116,15 @@ while (<$lwlocknames>)
die
"$wait_event_lwlocks[$i] defined in wait_event_names.txt but missing from "
- . "lwlocknames.txt"
+ . "lwlocklist.h"
if $i < scalar @wait_event_lwlocks;
-printf $c "\n};\n";
print $h "\n";
printf $h "#define NUM_INDIVIDUAL_LWLOCKS %s\n", $lastlockidx + 1;
close $h;
-close $c;
rename($htmp, "$output_path/lwlocknames.h")
|| die "rename: $htmp to $output_path/lwlocknames.h: $!";
-rename($ctmp, "$output_path/lwlocknames.c") || die "rename: $ctmp: $!";
-close $lwlocknames;
+close $lwlocklist;
diff --git a/src/backend/storage/lmgr/lwlock.c b/src/backend/storage/lmgr/lwlock.c
index d405c61b21..1112389af5 100644
--- a/src/backend/storage/lmgr/lwlock.c
+++ b/src/backend/storage/lmgr/lwlock.c
@@ -115,8 +115,8 @@ StaticAssertDecl(LW_VAL_EXCLUSIVE > (uint32) MAX_BACKENDS,
* There are three sorts of LWLock "tranches":
*
* 1. The individually-named locks defined in lwlocknames.h each have their
- * own tranche. The names of these tranches appear in IndividualLWLockNames[]
- * in lwlocknames.c.
+ * own tranche. We absorb the names of these tranches from there into
+ * BuiltinTrancheNames here.
*
* 2. There are some predefined tranches for built-in groups of locks.
* These are listed in enum BuiltinTrancheIds in lwlock.h, and their names
@@ -129,9 +129,10 @@ StaticAssertDecl(LW_VAL_EXCLUSIVE > (uint32) MAX_BACKENDS,
* All these names are user-visible as wait event names, so choose with care
* ... and do not forget to update the documentation's list of wait events.
*/
-extern const char *const IndividualLWLockNames[]; /* in lwlocknames.c */
-
static const char *const BuiltinTrancheNames[] = {
+#define PG_LWLOCK(lockname, id) [id] = CppAsString(lockname),
+#include "storage/lwlocknames.h"
+#undef PG_LWLOCK
[LWTRANCHE_XACT_BUFFER] = "XactBuffer",
[LWTRANCHE_COMMITTS_BUFFER] = "CommitTsBuffer",
[LWTRANCHE_SUBTRANS_BUFFER] = "SubtransBuffer",
@@ -745,11 +746,7 @@ LWLockReportWaitEnd(void)
static const char *
GetLWTrancheName(uint16 trancheId)
{
- /* Individual LWLock? */
- if (trancheId < NUM_INDIVIDUAL_LWLOCKS)
- return IndividualLWLockNames[trancheId];
-
- /* Built-in tranche? */
+ /* Built-in tranche or individual LWLock? */
if (trancheId < LWTRANCHE_FIRST_USER_DEFINED)
return BuiltinTrancheNames[trancheId];
diff --git a/src/backend/storage/lmgr/lwlocknames.txt b/src/backend/storage/lmgr/lwlocknames.txt
deleted file mode 100644
index 284d168f77..0000000000
--- a/src/backend/storage/lmgr/lwlocknames.txt
+++ /dev/null
@@ -1,60 +0,0 @@
-# Some commonly-used locks have predefined positions within MainLWLockArray;
-# these are defined here. If you add a lock, add it to the end to avoid
-# renumbering the existing locks; if you remove a lock, consider leaving a gap
-# in the numbering sequence for the benefit of DTrace and other external
-# debugging scripts. Also, do not forget to update the section
-# WaitEventLWLock of src/backend/utils/activity/wait_event_names.txt.
-
-# 0 is available; was formerly BufFreelistLock
-ShmemIndexLock 1
-OidGenLock 2
-XidGenLock 3
-ProcArrayLock 4
-SInvalReadLock 5
-SInvalWriteLock 6
-WALBufMappingLock 7
-WALWriteLock 8
-ControlFileLock 9
-# 10 was CheckpointLock
-# 11 was XactSLRULock
-# 12 was SubtransSLRULock
-MultiXactGenLock 13
-# 14 was MultiXactOffsetSLRULock
-# 15 was MultiXactMemberSLRULock
-RelCacheInitLock 16
-CheckpointerCommLock 17
-TwoPhaseStateLock 18
-TablespaceCreateLock 19
-BtreeVacuumLock 20
-AddinShmemInitLock 21
-AutovacuumLock 22
-AutovacuumScheduleLock 23
-SyncScanLock 24
-RelationMappingLock 25
-#26 was NotifySLRULock
-NotifyQueueLock 27
-SerializableXactHashLock 28
-SerializableFinishedListLock 29
-SerializablePredicateListLock 30
-# 31 was SerialSLRULock
-SyncRepLock 32
-BackgroundWorkerLock 33
-DynamicSharedMemoryControlLock 34
-AutoFileLock 35
-ReplicationSlotAllocationLock 36
-ReplicationSlotControlLock 37
-#38 was CommitTsSLRULock
-CommitTsLock 39
-ReplicationOriginLock 40
-MultiXactTruncationLock 41
-# 42 was OldSnapshotTimeMapLock
-LogicalRepWorkerLock 43
-XactTruncationLock 44
-# 45 was XactTruncationLock until removal of BackendRandomLock
-WrapLimitsVacuumLock 46
-NotifyQueueTailLock 47
-WaitEventExtensionLock 48
-WALSummarizerLock 49
-DSMRegistryLock 50
-InjectionPointLock 51
-SerialControlLock 52
diff --git a/src/backend/utils/activity/wait_event_names.txt b/src/backend/utils/activity/wait_event_names.txt
index ec2f31f82a..105ca977a5 100644
--- a/src/backend/utils/activity/wait_event_names.txt
+++ b/src/backend/utils/activity/wait_event_names.txt
@@ -279,9 +279,9 @@ Extension "Waiting in an extension."
# This class of wait events has its own set of C structure, so these are
# only used for the documentation.
#
-# NB: Predefined LWLocks (i.e., those declared in lwlocknames.txt) must be
+# NB: Predefined LWLocks (i.e., those declared in lwlocknames.h) must be
# listed in the top section of locks and must be listed in the same order as in
-# lwlocknames.txt.
+# lwlocknames.h.
#
Section: ClassName - WaitEventLWLock
@@ -332,9 +332,9 @@ SerialControl "Waiting to read or update shared <filename>pg_serial</filename> s
#
# END OF PREDEFINED LWLOCKS (DO NOT CHANGE THIS LINE)
#
-# Predefined LWLocks (i.e., those declared in lwlocknames.txt) must be listed
+# Predefined LWLocks (i.e., those declared in lwlocknames.h) must be listed
# in the section above and must be listed in the same order as in
-# lwlocknames.txt. Other LWLocks must be listed in the section below.
+# lwlocknames.h. Other LWLocks must be listed in the section below.
#
XactBuffer "Waiting for I/O on a transaction status SLRU buffer."
diff --git a/src/include/storage/lwlocklist.h b/src/include/storage/lwlocklist.h
new file mode 100644
index 0000000000..3396eed58e
--- /dev/null
+++ b/src/include/storage/lwlocklist.h
@@ -0,0 +1,82 @@
+/*-------------------------------------------------------------------------
+ *
+ * lwlocklist.h
+ *
+ * The predefined LWLock list is kept in its own source file for use by
+ * automatic tools. The exact representation of a keyword is determined by
+ * the PG_LWLOCK macro, which is not defined in this file; it can be
+ * defined by the caller for special purposes.
+ *
+ * Also, generate-lwlock-names.pl processes this file.
+ *
+ * Portions Copyright (c) 1996-2024, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * IDENTIFICATION
+ * src/include/storage/lwlocklist.h
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/*
+ * Some commonly-used locks have predefined positions within MainLWLockArray;
+ * these are defined here. If you add a lock, add it to the end to avoid
+ * renumbering the existing locks; if you remove a lock, consider leaving a gap
+ * in the numbering sequence for the benefit of DTrace and other external
+ * debugging scripts. Also, do not forget to update the section
+ * WaitEventLWLock of src/backend/utils/activity/wait_event_names.txt.
+ */
+
+/* 0 is available; was formerly BufFreelistLock */
+PG_LWLOCK(ShmemIndexLock, 1)
+PG_LWLOCK(OidGenLock, 2)
+PG_LWLOCK(XidGenLock, 3)
+PG_LWLOCK(ProcArrayLock, 4)
+PG_LWLOCK(SInvalReadLock, 5)
+PG_LWLOCK(SInvalWriteLock, 6)
+PG_LWLOCK(WALBufMappingLock, 7)
+PG_LWLOCK(WALWriteLock, 8)
+PG_LWLOCK(ControlFileLock, 9)
+/* 10 was CheckpointLock */
+/* 11 was XactSLRULock */
+/* 12 was SubtransSLRULock */
+PG_LWLOCK(MultiXactGenLock, 13)
+/* 14 was MultiXactOffsetSLRULock */
+/* 15 was MultiXactMemberSLRULock */
+PG_LWLOCK(RelCacheInitLock, 16)
+PG_LWLOCK(CheckpointerCommLock, 17)
+PG_LWLOCK(TwoPhaseStateLock, 18)
+PG_LWLOCK(TablespaceCreateLock, 19)
+PG_LWLOCK(BtreeVacuumLock, 20)
+PG_LWLOCK(AddinShmemInitLock, 21)
+PG_LWLOCK(AutovacuumLock, 22)
+PG_LWLOCK(AutovacuumScheduleLock, 23)
+PG_LWLOCK(SyncScanLock, 24)
+PG_LWLOCK(RelationMappingLock, 25)
+/* 26 was NotifySLRULock */
+PG_LWLOCK(NotifyQueueLock, 27)
+PG_LWLOCK(SerializableXactHashLock, 28)
+PG_LWLOCK(SerializableFinishedListLock, 29)
+PG_LWLOCK(SerializablePredicateListLock, 30)
+/* 31 was SerialSLRULock */
+PG_LWLOCK(SyncRepLock, 32)
+PG_LWLOCK(BackgroundWorkerLock, 33)
+PG_LWLOCK(DynamicSharedMemoryControlLock, 34)
+PG_LWLOCK(AutoFileLock, 35)
+PG_LWLOCK(ReplicationSlotAllocationLock, 36)
+PG_LWLOCK(ReplicationSlotControlLock, 37)
+/* 38 was CommitTsSLRULock */
+PG_LWLOCK(CommitTsLock, 39)
+PG_LWLOCK(ReplicationOriginLock, 40)
+PG_LWLOCK(MultiXactTruncationLock, 41)
+/* 42 was OldSnapshotTimeMapLock */
+PG_LWLOCK(LogicalRepWorkerLock, 43)
+PG_LWLOCK(XactTruncationLock, 44)
+/* 45 was XactTruncationLock until removal of BackendRandomLock */
+PG_LWLOCK(WrapLimitsVacuumLock, 46)
+PG_LWLOCK(NotifyQueueTailLock, 47)
+PG_LWLOCK(WaitEventExtensionLock, 48)
+PG_LWLOCK(WALSummarizerLock, 49)
+PG_LWLOCK(DSMRegistryLock, 50)
+PG_LWLOCK(InjectionPointLock, 51)
+PG_LWLOCK(SerialControlLock, 52)
--
2.39.2
