Cross-check lists of built-in LWLock tranches.

lwlock.c, lwlock.h, and wait_event_names.txt each contain a list of
built-in LWLock tranches.  It is easy to miss one or the other when
adding or removing tranches, and discrepancies have adverse effects
(e.g., breaking JOINs between pg_stat_activity and pg_wait_events).
This commit moves the lists of built-in tranches in lwlock.{c,h} to
lwlocklist.h and adds a cross-check to the script that generates
lwlocknames.h.  If the lists do not match exactly, building will
fail.

Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/aHpOgwuFQfcFMZ/B%40ip-10-97-1-34.eu-west-3.compute.internal

src/include/storage/lwlock.h

@@ -176,51 +176,23 @@ extern void LWLockInitialize(LWLock *lock, int tranche_id);
  * Every tranche ID less than NUM_INDIVIDUAL_LWLOCKS is reserved; also,
  * we reserve additional tranche IDs for builtin tranches not included in
  * the set of individual LWLocks.  A call to LWLockNewTrancheId will never
- * return a value less than LWTRANCHE_FIRST_USER_DEFINED.
+ * return a value less than LWTRANCHE_FIRST_USER_DEFINED.  The actual list of
+ * built-in tranches is kept in lwlocklist.h.
  */
 typedef enum BuiltinTrancheIds
 {
-	LWTRANCHE_XACT_BUFFER = NUM_INDIVIDUAL_LWLOCKS,
-	LWTRANCHE_COMMITTS_BUFFER,
-	LWTRANCHE_SUBTRANS_BUFFER,
-	LWTRANCHE_MULTIXACTOFFSET_BUFFER,
-	LWTRANCHE_MULTIXACTMEMBER_BUFFER,
-	LWTRANCHE_NOTIFY_BUFFER,
-	LWTRANCHE_SERIAL_BUFFER,
-	LWTRANCHE_WAL_INSERT,
-	LWTRANCHE_BUFFER_CONTENT,
-	LWTRANCHE_REPLICATION_ORIGIN_STATE,
-	LWTRANCHE_REPLICATION_SLOT_IO,
-	LWTRANCHE_LOCK_FASTPATH,
-	LWTRANCHE_BUFFER_MAPPING,
-	LWTRANCHE_LOCK_MANAGER,
-	LWTRANCHE_PREDICATE_LOCK_MANAGER,
-	LWTRANCHE_PARALLEL_HASH_JOIN,
-	LWTRANCHE_PARALLEL_BTREE_SCAN,
-	LWTRANCHE_PARALLEL_QUERY_DSA,
-	LWTRANCHE_PER_SESSION_DSA,
-	LWTRANCHE_PER_SESSION_RECORD_TYPE,
-	LWTRANCHE_PER_SESSION_RECORD_TYPMOD,
-	LWTRANCHE_SHARED_TUPLESTORE,
-	LWTRANCHE_SHARED_TIDBITMAP,
-	LWTRANCHE_PARALLEL_APPEND,
-	LWTRANCHE_PER_XACT_PREDICATE_LIST,
-	LWTRANCHE_PGSTATS_DSA,
-	LWTRANCHE_PGSTATS_HASH,
-	LWTRANCHE_PGSTATS_DATA,
-	LWTRANCHE_LAUNCHER_DSA,
-	LWTRANCHE_LAUNCHER_HASH,
-	LWTRANCHE_DSM_REGISTRY_DSA,
-	LWTRANCHE_DSM_REGISTRY_HASH,
-	LWTRANCHE_COMMITTS_SLRU,
-	LWTRANCHE_MULTIXACTMEMBER_SLRU,
-	LWTRANCHE_MULTIXACTOFFSET_SLRU,
-	LWTRANCHE_NOTIFY_SLRU,
-	LWTRANCHE_SERIAL_SLRU,
-	LWTRANCHE_SUBTRANS_SLRU,
-	LWTRANCHE_XACT_SLRU,
-	LWTRANCHE_PARALLEL_VACUUM_DSA,
-	LWTRANCHE_AIO_URING_COMPLETION,
+	/*
+	 * LWTRANCHE_INVALID is an unused value that only exists to initialize the
+	 * rest of the tranches to appropriate values.
+	 */
+	LWTRANCHE_INVALID = NUM_INDIVIDUAL_LWLOCKS - 1,
+
+#define PG_LWLOCK(id, name)
+#define PG_LWLOCKTRANCHE(id, name) LWTRANCHE_##id,
+#include "storage/lwlocklist.h"
+#undef PG_LWLOCK
+#undef PG_LWLOCKTRANCHE
+
 	LWTRANCHE_FIRST_USER_DEFINED,
 }			BuiltinTrancheIds;
 

src/include/storage/lwlocklist.h

@@ -2,9 +2,10 @@
  *
  * 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
+ * The list of predefined LWLocks and built-in LWLock tranches is kept in
+ * its own source file for use by automatic tools.  The exact
+ * representation of a keyword is determined by the PG_LWLOCK and
+ * PG_LWLOCKTRANCHE macros, which are not defined in this file; they can be
  * defined by the caller for special purposes.
  *
  * Also, generate-lwlocknames.pl processes this file to create lwlocknames.h.
@@ -84,3 +85,53 @@ PG_LWLOCK(50, DSMRegistry)
 PG_LWLOCK(51, InjectionPoint)
 PG_LWLOCK(52, SerialControl)
 PG_LWLOCK(53, AioWorkerSubmissionQueue)
+
+/*
+ * There also exist several built-in LWLock tranches.  As with the predefined
+ * LWLocks, be sure to update the WaitEventLWLock section of
+ * src/backend/utils/activity/wait_event_names.txt when modifying this list.
+ *
+ * Note that the IDs here (the first value) don't include the LWTRANCHE_
+ * prefix.  It's added elsewhere.
+ */
+PG_LWLOCKTRANCHE(XACT_BUFFER, XactBuffer)
+PG_LWLOCKTRANCHE(COMMITTS_BUFFER, CommitTsBuffer)
+PG_LWLOCKTRANCHE(SUBTRANS_BUFFER, SubtransBuffer)
+PG_LWLOCKTRANCHE(MULTIXACTOFFSET_BUFFER, MultiXactOffsetBuffer)
+PG_LWLOCKTRANCHE(MULTIXACTMEMBER_BUFFER, MultiXactMemberBuffer)
+PG_LWLOCKTRANCHE(NOTIFY_BUFFER, NotifyBuffer)
+PG_LWLOCKTRANCHE(SERIAL_BUFFER, SerialBuffer)
+PG_LWLOCKTRANCHE(WAL_INSERT, WALInsert)
+PG_LWLOCKTRANCHE(BUFFER_CONTENT, BufferContent)
+PG_LWLOCKTRANCHE(REPLICATION_ORIGIN_STATE, ReplicationOriginState)
+PG_LWLOCKTRANCHE(REPLICATION_SLOT_IO, ReplicationSlotIO)
+PG_LWLOCKTRANCHE(LOCK_FASTPATH, LockFastPath)
+PG_LWLOCKTRANCHE(BUFFER_MAPPING, BufferMapping)
+PG_LWLOCKTRANCHE(LOCK_MANAGER, LockManager)
+PG_LWLOCKTRANCHE(PREDICATE_LOCK_MANAGER, PredicateLockManager)
+PG_LWLOCKTRANCHE(PARALLEL_HASH_JOIN, ParallelHashJoin)
+PG_LWLOCKTRANCHE(PARALLEL_BTREE_SCAN, ParallelBtreeScan)
+PG_LWLOCKTRANCHE(PARALLEL_QUERY_DSA, ParallelQueryDSA)
+PG_LWLOCKTRANCHE(PER_SESSION_DSA, PerSessionDSA)
+PG_LWLOCKTRANCHE(PER_SESSION_RECORD_TYPE, PerSessionRecordType)
+PG_LWLOCKTRANCHE(PER_SESSION_RECORD_TYPMOD, PerSessionRecordTypmod)
+PG_LWLOCKTRANCHE(SHARED_TUPLESTORE, SharedTupleStore)
+PG_LWLOCKTRANCHE(SHARED_TIDBITMAP, SharedTidBitmap)
+PG_LWLOCKTRANCHE(PARALLEL_APPEND, ParallelAppend)
+PG_LWLOCKTRANCHE(PER_XACT_PREDICATE_LIST, PerXactPredicateList)
+PG_LWLOCKTRANCHE(PGSTATS_DSA, PgStatsDSA)
+PG_LWLOCKTRANCHE(PGSTATS_HASH, PgStatsHash)
+PG_LWLOCKTRANCHE(PGSTATS_DATA, PgStatsData)
+PG_LWLOCKTRANCHE(LAUNCHER_DSA, LogicalRepLauncherDSA)
+PG_LWLOCKTRANCHE(LAUNCHER_HASH, LogicalRepLauncherHash)
+PG_LWLOCKTRANCHE(DSM_REGISTRY_DSA, DSMRegistryDSA)
+PG_LWLOCKTRANCHE(DSM_REGISTRY_HASH, DSMRegistryHash)
+PG_LWLOCKTRANCHE(COMMITTS_SLRU, CommitTsSLRU)
+PG_LWLOCKTRANCHE(MULTIXACTOFFSET_SLRU, MultiXactOffsetSLRU)
+PG_LWLOCKTRANCHE(MULTIXACTMEMBER_SLRU, MultiXactMemberSLRU)
+PG_LWLOCKTRANCHE(NOTIFY_SLRU, NotifySLRU)
+PG_LWLOCKTRANCHE(SERIAL_SLRU, SerialSLRU)
+PG_LWLOCKTRANCHE(SUBTRANS_SLRU, SubtransSLRU)
+PG_LWLOCKTRANCHE(XACT_SLRU, XactSLRU)
+PG_LWLOCKTRANCHE(PARALLEL_VACUUM_DSA, ParallelVacuumDSA)
+PG_LWLOCKTRANCHE(AIO_URING_COMPLETION, AioUringCompletion)