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Added VALGRIND_YIELD to be able to abort from busy loops

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Valgrind is single threaded and only changes threads as part of
system calls or waits.

I found some busy loops where the server assumes that some other
thread will change the state, which will not happen with valgrind.

Added VALGRIND_YIELD to the loops, which calls pthread_yield() if
HAVE_VALGRIND is defined.

Added pthread_yield() to the loops in table_cache.

We should consider changing some of the VALGRIND_YIELD calls to call
pthread_yield() as busy loop without any sleep() is usually a bad
thing.

Reviewer: svojtovich@gmail.com
This commit is contained in:
Monty 2025-01-20 19:30:19 +02:00
parent d9c3b775b8
commit aae9b50a53
4 changed files with 11 additions and 0 deletions
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4
include/my_valgrind.h
View File

@ -42,6 +42,7 @@
# else
# define MSAN_STAT_WORKAROUND(st) ((void) 0)
# endif
# define VALGRIND_YIELD
#elif defined(HAVE_VALGRIND_MEMCHECK_H) && defined(HAVE_valgrind)
# include <valgrind/memcheck.h>
# define HAVE_MEM_CHECK
@ -55,6 +56,7 @@
# define MEM_SET_VBITS(a,b,len) VALGRIND_SET_VBITS(a,b,len)
# define REDZONE_SIZE 8
# define MSAN_STAT_WORKAROUND(st) ((void) 0)
# define VALGRIND_YIELD pthread_yield()
#elif defined(__SANITIZE_ADDRESS__) && (!defined(_MSC_VER) || defined (__clang__))
# include <sanitizer/asan_interface.h>
/* How to do manual poisoning:
@ -70,6 +72,7 @@ https://github.com/google/sanitizers/wiki/AddressSanitizerManualPoisoning */
# define MEM_SET_VBITS(a,b,len) ((void) 0)
# define MSAN_STAT_WORKAROUND(st) ((void) 0)
# define REDZONE_SIZE 8
# define VALGRIND_YIELD
#else
# define MEM_UNDEFINED(a,len) ((void) 0)
# define MEM_MAKE_ADDRESSABLE(a,len) ((void) 0)
@ -81,6 +84,7 @@ https://github.com/google/sanitizers/wiki/AddressSanitizerManualPoisoning */
# define MEM_SET_VBITS(a,b,len) ((void) 0)
# define REDZONE_SIZE 0
# define MSAN_STAT_WORKAROUND(st) ((void) 0)
# define VALGRIND_YIELD
#endif /* __has_feature(memory_sanitizer) */
#ifdef TRASH_FREED_MEMORY

2
sql/sql_base.cc
View File

@ -4721,6 +4721,7 @@ restart:
goto error;
error= FALSE;
pthread_yield();
goto restart;
}
goto error;
@ -4786,6 +4787,7 @@ restart:
error= FALSE;
sroutine_to_open= &thd->lex->sroutines_list.first;
pthread_yield();
goto restart;
}
/*

1
sql/table_cache.cc
View File

@ -901,6 +901,7 @@ retry:
{
mysql_mutex_unlock(&element->LOCK_table_share);
lf_hash_search_unpin(thd->tdc_hash_pins);
VALGRIND_YIELD;
goto retry;
}
lf_hash_search_unpin(thd->tdc_hash_pins);

4
storage/innobase/trx/trx0purge.cc
View File

@ -1189,7 +1189,10 @@ dict_table_t *purge_sys_t::close_and_reopen(table_id_t id, THD *thd,
dict_table_t *table= trx_purge_table_open(id, mdl_context, mdl);
if (table == reinterpret_cast<dict_table_t*>(-1))
{
VALGRIND_YIELD;
goto retry;
}
for (que_thr_t *thr= UT_LIST_GET_FIRST(purge_sys.query->thrs); thr;
thr= UT_LIST_GET_NEXT(thrs, thr))
@ -1205,6 +1208,7 @@ dict_table_t *purge_sys_t::close_and_reopen(table_id_t id, THD *thd,
{
if (table)
dict_table_close(table, thd, *mdl);
VALGRIND_YIELD;
goto retry;
}
}