MDEV-21336 Memory leaks related to innodb_debug_sync

This essentially reverts commit b393e2cb0c079b30563dcc87a62002c9c778643c.

The leak might have been fixed, but because the
DEBUG_SYNC instrumentation for InnoDB purge threads was reverted
in 10.5 commit 5e62b6a5e06eb02cbde1e34e95e26f42d87fce02
as part of introducing a thread pool, it is easiest to revert
the entire change.

1 files changed, 0 insertions, 21 deletions

diff --git a/storage/innobase/row/row0purge.cc b/storage/innobase/row/row0purge.cc
index 5f2a854ba92..f4fd617f154 100644
--- a/storage/innobase/row/row0purge.cc
+++ b/storage/innobase/row/row0purge.cc
@@ -46,7 +46,6 @@ Created 3/14/1997 Heikki Tuuri
 #include "handler.h"
 #include "ha_innodb.h"
 #include "fil0fil.h"
-#include "debug_sync.h"
 
 /*************************************************************************
 IMPORTANT NOTE: Any operation that generates redo MUST check that there
@@ -1209,26 +1208,6 @@ row_purge_step(
 
 	node->start();
 
-#ifdef UNIV_DEBUG
-	srv_slot_t *slot = thr->thread_slot;
-	ut_ad(slot);
-
-	rw_lock_x_lock(&slot->debug_sync_lock);
-	while (UT_LIST_GET_LEN(slot->debug_sync)) {
-		srv_slot_t::debug_sync_t *sync =
-					UT_LIST_GET_FIRST(slot->debug_sync);
-		const char* sync_str = reinterpret_cast<char*>(&sync[1]);
-		bool result = debug_sync_set_action(current_thd,
-						    sync_str,
-						    strlen(sync_str));
-		ut_a(!result);
-
-		UT_LIST_REMOVE(slot->debug_sync, sync);
-		ut_free(sync);
-	}
-	rw_lock_x_unlock(&slot->debug_sync_lock);
-#endif
-
 	if (!(node->undo_recs == NULL || ib_vector_is_empty(node->undo_recs))) {
 		trx_purge_rec_t*purge_rec;