From ed7cc8f460e91931d082af7785b8c228457b813e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Emel=20=C5=9Eim=C5=9Fek?= <emelhasdal@gmail.com>
Date: Mon, 6 Mar 2023 13:59:45 +0300
Subject: [PATCH] Remove unused lock functions (#6747)

Code cleanup. This change removes two unused functions seemingly left
over after a previous refactoring of shard move code.
---
 src/backend/distributed/utils/resource_lock.c | 39 -------------------
 src/include/distributed/resource_lock.h       |  5 +--
 2 files changed, 1 insertion(+), 43 deletions(-)

diff --git a/src/backend/distributed/utils/resource_lock.c b/src/backend/distributed/utils/resource_lock.c
index cc4cb0d88..7b8edf758 100644
--- a/src/backend/distributed/utils/resource_lock.c
+++ b/src/backend/distributed/utils/resource_lock.c
@@ -503,45 +503,6 @@ SetLocktagForShardDistributionMetadata(int64 shardId, LOCKTAG *tag)
 }
 
 
-/*
- * LockPlacementCleanup takes an exclusive lock to ensure that only one process
- * can cleanup placements at the same time.
- */
-void
-LockPlacementCleanup(void)
-{
-	LOCKTAG tag;
-	const bool sessionLock = false;
-	const bool dontWait = false;
-
-	/* Moves acquire lock with a constant operation id CITUS_SHARD_MOVE.
-	 * This will change as we add support for parallel moves.
-	 */
-	SET_LOCKTAG_CITUS_OPERATION(tag, CITUS_SHARD_MOVE);
-	(void) LockAcquire(&tag, ExclusiveLock, sessionLock, dontWait);
-}
-
-
-/*
- * TryLockPlacementCleanup takes an exclusive lock to ensure that only one
- * process can cleanup placements at the same time.
- */
-bool
-TryLockPlacementCleanup(void)
-{
-	LOCKTAG tag;
-	const bool sessionLock = false;
-	const bool dontWait = true;
-
-	/* Moves acquire lock with a constant operation id CITUS_SHARD_MOVE.
-	 * This will change as we add support for parallel moves.
-	 */
-	SET_LOCKTAG_CITUS_OPERATION(tag, CITUS_SHARD_MOVE);
-	bool lockAcquired = LockAcquire(&tag, ExclusiveLock, sessionLock, dontWait);
-	return lockAcquired;
-}
-
-
 /*
  * LockReferencedReferenceShardDistributionMetadata acquires shard distribution
  * metadata locks with the given lock mode on the reference tables which has a
diff --git a/src/include/distributed/resource_lock.h b/src/include/distributed/resource_lock.h
index 9e143e467..9efa1b767 100644
--- a/src/include/distributed/resource_lock.h
+++ b/src/include/distributed/resource_lock.h
@@ -53,8 +53,7 @@ typedef enum CitusOperations
 	CITUS_NONBLOCKING_SPLIT = 1,
 	CITUS_CREATE_DISTRIBUTED_TABLE_CONCURRENTLY = 2,
 	CITUS_CREATE_COLOCATION_DEFAULT = 3,
-	CITUS_SHARD_MOVE = 4,
-	CITUS_BACKGROUND_TASK_MONITOR = 5
+	CITUS_BACKGROUND_TASK_MONITOR = 4
 } CitusOperations;
 
 /* reuse advisory lock, but with different, unused field 4 (4)*/
@@ -165,8 +164,6 @@ enum DistLockConfigs
 
 /* Lock shard/relation metadata for safe modifications */
 extern void LockShardDistributionMetadata(int64 shardId, LOCKMODE lockMode);
-extern void LockPlacementCleanup(void);
-extern bool TryLockPlacementCleanup(void);
 extern void EnsureShardOwner(uint64 shardId, bool missingOk);
 extern void LockShardListMetadataOnWorkers(LOCKMODE lockmode, List *shardIntervalList);
 extern void BlockWritesToShardList(List *shardList);