diff options
Diffstat (limited to 'storage/innobase/sync/sync0rw.cc')
| -rw-r--r-- | storage/innobase/sync/sync0rw.cc | 44 |
1 files changed, 18 insertions, 26 deletions
diff --git a/storage/innobase/sync/sync0rw.cc b/storage/innobase/sync/sync0rw.cc index 2795fc902fc..983507fab0d 100644 --- a/storage/innobase/sync/sync0rw.cc +++ b/storage/innobase/sync/sync0rw.cc @@ -2,7 +2,7 @@ Copyright (c) 1995, 2016, Oracle and/or its affiliates. All Rights Reserved. Copyright (c) 2008, Google Inc. -Copyright (c) 2017, 2019, MariaDB Corporation. +Copyright (c) 2017, 2020, MariaDB Corporation. Portions of this file contain modifications contributed and copyrighted by Google, Inc. Those modifications are gratefully acknowledged and are described @@ -202,11 +202,8 @@ rw_lock_create_func( new(lock) rw_lock_t(); #endif /* UNIV_DEBUG */ - /* If this is the very first time a synchronization object is - created, then the following call initializes the sync system. */ - - lock->lock_word.store(X_LOCK_DECR, std::memory_order_relaxed); - lock->waiters.store(0, std::memory_order_relaxed); + lock->lock_word = X_LOCK_DECR; + lock->waiters = 0; lock->sx_recursive = 0; lock->writer_thread= 0; @@ -252,7 +249,7 @@ rw_lock_free_func( rw_lock_t* lock) /*!< in/out: rw-lock */ { ut_ad(rw_lock_validate(lock)); - ut_a(lock->lock_word.load(std::memory_order_relaxed) == X_LOCK_DECR); + ut_a(lock->lock_word == X_LOCK_DECR); mutex_enter(&rw_lock_list_mutex); @@ -294,7 +291,7 @@ lock_loop: /* Spin waiting for the writer field to become free */ HMT_low(); while (i < srv_n_spin_wait_rounds && - lock->lock_word.load(std::memory_order_relaxed) <= 0) { + lock->lock_word <= 0) { ut_delay(srv_spin_wait_delay); i++; } @@ -412,10 +409,10 @@ rw_lock_x_lock_wait_func( sync_array_t* sync_arr; int64_t count_os_wait = 0; - ut_ad(lock->lock_word.load(std::memory_order_relaxed) <= threshold); + ut_ad(lock->lock_word <= threshold); HMT_low(); - while (lock->lock_word.load(std::memory_order_relaxed) < threshold) { + while (lock->lock_word < threshold) { ut_delay(srv_spin_wait_delay); if (i < srv_n_spin_wait_rounds) { @@ -434,8 +431,7 @@ rw_lock_x_lock_wait_func( i = 0; /* Check lock_word to ensure wake-up isn't missed.*/ - if (lock->lock_word.load(std::memory_order_relaxed) < threshold) { - + if (lock->lock_word < threshold) { ++count_os_wait; /* Add debug info as it is needed to detect possible @@ -524,17 +520,15 @@ rw_lock_x_lock_low( file_name, line); } else { - auto lock_word = lock->lock_word.load(std::memory_order_relaxed); + int32_t lock_word = lock->lock_word; /* At least one X lock by this thread already exists. Add another. */ if (lock_word == 0 || lock_word == -X_LOCK_HALF_DECR) { - lock->lock_word.fetch_sub(X_LOCK_DECR, - std::memory_order_relaxed); + lock->lock_word -= X_LOCK_DECR; } else { ut_ad(lock_word <= -X_LOCK_DECR); - lock->lock_word.fetch_sub(1, - std::memory_order_relaxed); + lock->lock_word--; } } @@ -677,7 +671,7 @@ lock_loop: /* Spin waiting for the lock_word to become free */ HMT_low(); while (i < srv_n_spin_wait_rounds - && lock->lock_word.load(std::memory_order_relaxed) <= X_LOCK_HALF_DECR) { + && lock->lock_word <= X_LOCK_HALF_DECR) { ut_delay(srv_spin_wait_delay); i++; } @@ -778,7 +772,7 @@ lock_loop: /* Spin waiting for the lock_word to become free */ while (i < srv_n_spin_wait_rounds - && lock->lock_word.load(std::memory_order_relaxed) <= X_LOCK_HALF_DECR) { + && lock->lock_word <= X_LOCK_HALF_DECR) { ut_delay(srv_spin_wait_delay); i++; } @@ -841,13 +835,11 @@ rw_lock_validate( /*=============*/ const rw_lock_t* lock) /*!< in: rw-lock */ { - int32_t lock_word; - ut_ad(lock); - lock_word = lock->lock_word.load(std::memory_order_relaxed); + int32_t lock_word = lock->lock_word; - ut_ad(lock->waiters.load(std::memory_order_relaxed) < 2); + ut_ad(lock->waiters < 2); ut_ad(lock_word > -(2 * X_LOCK_DECR)); ut_ad(lock_word <= X_LOCK_DECR); @@ -910,7 +902,7 @@ rw_lock_add_debug_info( rw_lock_debug_mutex_exit(); if (pass == 0 && lock_type != RW_LOCK_X_WAIT) { - auto lock_word = lock->lock_word.load(std::memory_order_relaxed); + int32_t lock_word = lock->lock_word; /* Recursive x while holding SX (lock_type == RW_LOCK_X && lock_word == -X_LOCK_HALF_DECR) @@ -1096,11 +1088,11 @@ rw_lock_list_print_info( count++; - if (lock->lock_word.load(std::memory_order_relaxed) != X_LOCK_DECR) { + if (lock->lock_word != X_LOCK_DECR) { fprintf(file, "RW-LOCK: %p ", (void*) lock); - if (int32_t waiters= lock->waiters.load(std::memory_order_relaxed)) { + if (int32_t waiters= lock->waiters) { fprintf(file, " (%d waiters)\n", waiters); } else { putc('\n', file); |