diff options
Diffstat (limited to 'storage/innobase/trx/trx0i_s.c')
| -rw-r--r-- | storage/innobase/trx/trx0i_s.c | 34 |
1 files changed, 10 insertions, 24 deletions
diff --git a/storage/innobase/trx/trx0i_s.c b/storage/innobase/trx/trx0i_s.c index c18b747da6d..aa0a9c797f2 100644 --- a/storage/innobase/trx/trx0i_s.c +++ b/storage/innobase/trx/trx0i_s.c @@ -155,10 +155,6 @@ struct trx_i_s_cache_struct { ullint last_read; /*!< last time the cache was read; measured in microseconds since epoch */ - mutex_t last_read_mutex;/*!< mutex protecting the - last_read member - it is updated - inside a shared lock of the - rw_lock member */ i_s_table_cache_t innodb_trx; /*!< innodb_trx table */ i_s_table_cache_t innodb_locks; /*!< innodb_locks table */ i_s_table_cache_t innodb_lock_waits;/*!< innodb_lock_waits table */ @@ -1225,13 +1221,6 @@ can_cache_be_updated( { ullint now; - /* Here we read cache->last_read without acquiring its mutex - because last_read is only updated when a shared rw lock on the - whole cache is being held (see trx_i_s_cache_end_read()) and - we are currently holding an exclusive rw lock on the cache. - So it is not possible for last_read to be updated while we are - reading it. */ - #ifdef UNIV_SYNC_DEBUG ut_a(rw_lock_own(&cache->rw_lock, RW_LOCK_EX)); #endif @@ -1329,6 +1318,12 @@ trx_i_s_possibly_fetch_data_into_cache( /*===================================*/ trx_i_s_cache_t* cache) /*!< in/out: cache */ { + ullint now; + +#ifdef UNIV_SYNC_DEBUG + ut_a(rw_lock_own(&cache->rw_lock, RW_LOCK_EX)); +#endif + if (!can_cache_be_updated(cache)) { return(1); @@ -1341,6 +1336,10 @@ trx_i_s_possibly_fetch_data_into_cache( mutex_exit(&kernel_mutex); + /* update cache last read time */ + now = ut_time_us(NULL); + cache->last_read = now; + return(0); } @@ -1371,8 +1370,6 @@ trx_i_s_cache_init( release kernel_mutex release trx_i_s_cache_t::rw_lock acquire trx_i_s_cache_t::rw_lock, S - acquire trx_i_s_cache_t::last_read_mutex - release trx_i_s_cache_t::last_read_mutex release trx_i_s_cache_t::rw_lock */ rw_lock_create(trx_i_s_cache_lock_key, &cache->rw_lock, @@ -1380,9 +1377,6 @@ trx_i_s_cache_init( cache->last_read = 0; - mutex_create(cache_last_read_mutex_key, - &cache->last_read_mutex, SYNC_TRX_I_S_LAST_READ); - table_cache_init(&cache->innodb_trx, sizeof(i_s_trx_row_t)); table_cache_init(&cache->innodb_locks, sizeof(i_s_locks_row_t)); table_cache_init(&cache->innodb_lock_waits, @@ -1433,18 +1427,10 @@ trx_i_s_cache_end_read( /*===================*/ trx_i_s_cache_t* cache) /*!< in: cache */ { - ullint now; - #ifdef UNIV_SYNC_DEBUG ut_a(rw_lock_own(&cache->rw_lock, RW_LOCK_SHARED)); #endif - /* update cache last read time */ - now = ut_time_us(NULL); - mutex_enter(&cache->last_read_mutex); - cache->last_read = now; - mutex_exit(&cache->last_read_mutex); - rw_lock_s_unlock(&cache->rw_lock); } |