diff --git a/storage/innobase/include/sync0arr.h b/storage/innobase/include/sync0arr.h index 5f1280f5e28..6e931346238 100644 --- a/storage/innobase/include/sync0arr.h +++ b/storage/innobase/include/sync0arr.h @@ -115,8 +115,11 @@ Prints warnings of long semaphore waits to stderr. @return TRUE if fatal semaphore wait threshold was exceeded */ UNIV_INTERN ibool -sync_array_print_long_waits(void); -/*=============================*/ +sync_array_print_long_waits( +/*========================*/ + os_thread_id_t* waiter, /*!< out: longest waiting thread */ + const void** sema) /*!< out: longest-waited-for semaphore */ + __attribute__((nonnull)); /********************************************************************//** Validates the integrity of the wait array. Checks that the number of reserved cells equals the count variable. */ diff --git a/storage/innobase/srv/srv0srv.c b/storage/innobase/srv/srv0srv.c index 99af0b23a04..3af7a86a164 100644 --- a/storage/innobase/srv/srv0srv.c +++ b/storage/innobase/srv/srv0srv.c @@ -2367,6 +2367,12 @@ srv_error_monitor_thread( ib_uint64_t old_lsn; ib_uint64_t new_lsn; ib_int64_t sig_count; + /* longest waiting thread for a semaphore */ + os_thread_id_t waiter = os_thread_get_curr_id(); + os_thread_id_t old_waiter = waiter; + /* the semaphore that is being waited for */ + const void* sema = NULL; + const void* old_sema = NULL; old_lsn = srv_start_lsn; @@ -2420,7 +2426,8 @@ loop: sync_arr_wake_threads_if_sema_free(); - if (sync_array_print_long_waits()) { + if (sync_array_print_long_waits(&waiter, &sema) + && sema == old_sema && os_thread_eq(waiter, old_waiter)) { fatal_cnt++; if (fatal_cnt > 10) { @@ -2435,6 +2442,8 @@ loop: } } else { fatal_cnt = 0; + old_waiter = waiter; + old_sema = sema; } /* Flush stderr so that a database user gets the output diff --git a/storage/innobase/sync/sync0arr.c b/storage/innobase/sync/sync0arr.c index 0d1581b41b4..30caddccced 100644 --- a/storage/innobase/sync/sync0arr.c +++ b/storage/innobase/sync/sync0arr.c @@ -915,8 +915,10 @@ Prints warnings of long semaphore waits to stderr. @return TRUE if fatal semaphore wait threshold was exceeded */ UNIV_INTERN ibool -sync_array_print_long_waits(void) -/*=============================*/ +sync_array_print_long_waits( +/*========================*/ + os_thread_id_t* waiter, /*!< out: longest waiting thread */ + const void** sema) /*!< out: longest-waited-for semaphore */ { sync_cell_t* cell; ibool old_val; @@ -924,6 +926,7 @@ sync_array_print_long_waits(void) ulint i; ulint fatal_timeout = srv_fatal_semaphore_wait_threshold; ibool fatal = FALSE; + double longest_diff = 0; #ifdef UNIV_DEBUG_VALGRIND /* Increase the timeouts if running under valgrind because it executes @@ -939,22 +942,36 @@ sync_array_print_long_waits(void) for (i = 0; i < sync_primary_wait_array->n_cells; i++) { + double diff; + void* wait_object; + cell = sync_array_get_nth_cell(sync_primary_wait_array, i); - if (cell->wait_object != NULL && cell->waiting - && difftime(time(NULL), cell->reservation_time) - > SYNC_ARRAY_TIMEOUT) { + wait_object = cell->wait_object; + + if (wait_object == NULL || !cell->waiting) { + + continue; + } + + diff = difftime(time(NULL), cell->reservation_time); + + if (diff > SYNC_ARRAY_TIMEOUT) { fputs("InnoDB: Warning: a long semaphore wait:\n", stderr); sync_array_cell_print(stderr, cell); noticed = TRUE; } - if (cell->wait_object != NULL && cell->waiting - && difftime(time(NULL), cell->reservation_time) - > fatal_timeout) { + if (diff > fatal_timeout) { fatal = TRUE; } + + if (diff > longest_diff) { + longest_diff = diff; + *sema = wait_object; + *waiter = cell->thread; + } } if (noticed) {