diff options
Diffstat (limited to 'innobase/row/row0sel.c')
| -rw-r--r-- | innobase/row/row0sel.c | 35 |
1 files changed, 18 insertions, 17 deletions
diff --git a/innobase/row/row0sel.c b/innobase/row/row0sel.c index 4bc81ad8a8e..40994c9962c 100644 --- a/innobase/row/row0sel.c +++ b/innobase/row/row0sel.c @@ -2602,6 +2602,24 @@ row_search_for_mysql( printf("N tables locked %lu\n", trx->mysql_n_tables_locked); */ /*-------------------------------------------------------------*/ + /* PHASE 0: Release a possible s-latch we are holding on the + adaptive hash index latch if there is someone waiting behind */ + + if (trx->has_search_latch + && btr_search_latch.writer != RW_LOCK_NOT_LOCKED) { + + /* There is an x-latch request on the adaptive hash index: + release the s-latch to reduce starvation and wait for + BTR_SEA_TIMEOUT rounds before trying to keep it again over + calls from MySQL */ + + rw_lock_s_unlock(&btr_search_latch); + trx->has_search_latch = FALSE; + + trx->search_latch_timeout = BTR_SEA_TIMEOUT; + } + + /*-------------------------------------------------------------*/ /* PHASE 1: Try to pop the row from the prefetch cache */ if (direction == 0) { @@ -2736,23 +2754,7 @@ row_search_for_mysql( NOT prepared to inserts interleaved with the SELECT, and if we try that, we can deadlock on the adaptive hash index semaphore! */ - - if (btr_search_latch.writer != RW_LOCK_NOT_LOCKED) { - /* There is an x-latch request: release - a possible s-latch to reduce starvation - and wait for BTR_SEA_TIMEOUT rounds before - trying to keep it again over calls from - MySQL */ - - if (trx->has_search_latch) { - rw_lock_s_unlock(&btr_search_latch); - trx->has_search_latch = FALSE; - } - trx->search_latch_timeout = BTR_SEA_TIMEOUT; - - goto no_shortcut; - } #ifndef UNIV_SEARCH_DEBUG if (!trx->has_search_latch) { rw_lock_s_lock(&btr_search_latch); @@ -2810,7 +2812,6 @@ row_search_for_mysql( } } -no_shortcut: /*-------------------------------------------------------------*/ /* PHASE 3: Open or restore index cursor position */ |