/******************************************************************//**
Checks that the rw-lock has been initialized and that there are no
simultaneous shared and exclusive locks.
@return TRUE */
UNIV_INTERN
ibool
rw_lock_validate(
/*=============*/
rw_lock_t* lock) /*!< in: rw-lock */
{
ulint waiters;
lint lock_word;
ut_a(lock);
waiters = rw_lock_get_waiters(lock);
lock_word = lock->lock_word;
ut_ad(lock->magic_n == RW_LOCK_MAGIC_N);
ut_a(waiters == 0 || waiters == 1);
ut_a(lock_word > -X_LOCK_DECR ||(-lock_word) % X_LOCK_DECR == 0);
return(TRUE);
}
void
rw_lock_free(
/*=========*/
rw_lock_t* lock) /* in: rw-lock */
{
ut_ad(rw_lock_validate(lock));
ut_a(rw_lock_get_writer(lock) == RW_LOCK_NOT_LOCKED);
ut_a(rw_lock_get_waiters(lock) == 0);
ut_a(rw_lock_get_reader_count(lock) == 0);
lock->magic_n = 0;
mutex_free(rw_lock_get_mutex(lock));
mutex_enter(&rw_lock_list_mutex);
UT_LIST_REMOVE(list, rw_lock_list, lock);
mutex_exit(&rw_lock_list_mutex);
}
/***************************************************************//**
Prints debug info of an rw-lock. */
UNIV_INTERN
void
rw_lock_print(
/*==========*/
rw_lock_t* lock) /*!< in: rw-lock */
{
rw_lock_debug_t* info;
fprintf(stderr,
"-------------\n"
"RW-LATCH INFO\n"
"RW-LATCH: %p ", (void*) lock);
#ifndef INNODB_RW_LOCKS_USE_ATOMICS
/* We used to acquire lock->mutex here, but it would cause a
recursive call to sync_thread_add_level() if UNIV_SYNC_DEBUG
is defined. Since this function is only invoked from
sync_thread_levels_g(), let us choose the smaller evil:
performing dirty reads instead of causing bogus deadlocks or
assertion failures. */
#endif
if (lock->lock_word != X_LOCK_DECR) {
if (rw_lock_get_waiters(lock)) {
fputs(" Waiters for the lock exist\n", stderr);
} else {
putc('\n', stderr);
}
rw_lock_debug_mutex_enter();
info = UT_LIST_GET_FIRST(lock->debug_list);
while (info != NULL) {
rw_lock_debug_print(stderr, info);
info = UT_LIST_GET_NEXT(list, info);
}
rw_lock_debug_mutex_exit();
}
}
