void
rw_lock_create_func(
/*================*/
rw_lock_t* lock, /* in: pointer to memory */
char* cfile_name, /* in: file name where created */
ulint cline) /* in: file line where created */
{
/* If this is the very first time a synchronization
object is created, then the following call initializes
the sync system. */
mutex_create(rw_lock_get_mutex(lock));
mutex_set_level(rw_lock_get_mutex(lock), SYNC_NO_ORDER_CHECK);
lock->mutex.cfile_name = cfile_name;
lock->mutex.cline = cline;
rw_lock_set_waiters(lock, 0);
rw_lock_set_writer(lock, RW_LOCK_NOT_LOCKED);
lock->writer_count = 0;
rw_lock_set_reader_count(lock, 0);
lock->writer_is_wait_ex = FALSE;
UT_LIST_INIT(lock->debug_list);
lock->magic_n = RW_LOCK_MAGIC_N;
lock->level = SYNC_LEVEL_NONE;
lock->cfile_name = cfile_name;
lock->cline = cline;
lock->last_s_file_name = "not yet reserved";
lock->last_x_file_name = "not yet reserved";
lock->last_s_line = 0;
lock->last_x_line = 0;
mutex_enter(&rw_lock_list_mutex);
UT_LIST_ADD_FIRST(list, rw_lock_list, lock);
mutex_exit(&rw_lock_list_mutex);
}
/**********************************************************************
Low-level function for acquiring an exclusive lock. */
UNIV_INLINE
ulint
rw_lock_x_lock_low(
/*===============*/
/* out: RW_LOCK_NOT_LOCKED if did
not succeed, RW_LOCK_EX if success,
RW_LOCK_WAIT_EX, if got wait reservation */
rw_lock_t* lock, /* in: pointer to rw-lock */
ulint pass, /* in: pass value; != 0, if the lock will
be passed to another thread to unlock */
const char* file_name,/* in: file name where lock requested */
ulint line) /* in: line where requested */
{
ut_ad(mutex_own(rw_lock_get_mutex(lock)));
if (rw_lock_get_writer(lock) == RW_LOCK_NOT_LOCKED) {
if (rw_lock_get_reader_count(lock) == 0) {
rw_lock_set_writer(lock, RW_LOCK_EX);
lock->writer_thread = os_thread_get_curr_id();
lock->writer_count++;
lock->pass = pass;
#ifdef UNIV_SYNC_DEBUG
rw_lock_add_debug_info(lock, pass, RW_LOCK_EX,
file_name, line);
#endif
lock->last_x_file_name = file_name;
lock->last_x_line = (unsigned int) line;
/* Locking succeeded, we may return */
return(RW_LOCK_EX);
} else {
/* There are readers, we have to wait */
rw_lock_set_writer(lock, RW_LOCK_WAIT_EX);
lock->writer_thread = os_thread_get_curr_id();
lock->pass = pass;
lock->writer_is_wait_ex = TRUE;
#ifdef UNIV_SYNC_DEBUG
rw_lock_add_debug_info(lock, pass, RW_LOCK_WAIT_EX,
file_name, line);
#endif
return(RW_LOCK_WAIT_EX);
}
} else if ((rw_lock_get_writer(lock) == RW_LOCK_WAIT_EX)
&& os_thread_eq(lock->writer_thread,
os_thread_get_curr_id())) {
if (rw_lock_get_reader_count(lock) == 0) {
rw_lock_set_writer(lock, RW_LOCK_EX);
lock->writer_count++;
lock->pass = pass;
lock->writer_is_wait_ex = FALSE;
#ifdef UNIV_SYNC_DEBUG
rw_lock_remove_debug_info(lock, pass, RW_LOCK_WAIT_EX);
rw_lock_add_debug_info(lock, pass, RW_LOCK_EX,
file_name, line);
#endif
lock->last_x_file_name = file_name;
lock->last_x_line = (unsigned int) line;
/* Locking succeeded, we may return */
return(RW_LOCK_EX);
}
return(RW_LOCK_WAIT_EX);
} else if ((rw_lock_get_writer(lock) == RW_LOCK_EX)
&& os_thread_eq(lock->writer_thread,
os_thread_get_curr_id())
&& (lock->pass == 0)
&& (pass == 0)) {
lock->writer_count++;
#ifdef UNIV_SYNC_DEBUG
rw_lock_add_debug_info(lock, pass, RW_LOCK_EX, file_name,
line);
#endif
lock->last_x_file_name = file_name;
lock->last_x_line = (unsigned int) line;
/* Locking succeeded, we may return */
return(RW_LOCK_EX);
}
/* Locking did not succeed */
return(RW_LOCK_NOT_LOCKED);
}
void
rw_lock_create_func(
/*================*/
rw_lock_t* lock, /* in: pointer to memory */
#ifdef UNIV_DEBUG
# ifdef UNIV_SYNC_DEBUG
ulint level, /* in: level */
# endif /* UNIV_SYNC_DEBUG */
const char* cmutex_name, /* in: mutex name */
#endif /* UNIV_DEBUG */
const char* cfile_name, /* in: file name where created */
ulint cline) /* in: file line where created */
{
/* If this is the very first time a synchronization object is
created, then the following call initializes the sync system. */
mutex_create(rw_lock_get_mutex(lock), SYNC_NO_ORDER_CHECK);
lock->mutex.cfile_name = cfile_name;
lock->mutex.cline = cline;
#if defined UNIV_DEBUG && !defined UNIV_HOTBACKUP
lock->mutex.cmutex_name = cmutex_name;
lock->mutex.mutex_type = 1;
#endif /* UNIV_DEBUG && !UNIV_HOTBACKUP */
rw_lock_set_waiters(lock, 0);
rw_lock_set_writer(lock, RW_LOCK_NOT_LOCKED);
lock->writer_count = 0;
rw_lock_set_reader_count(lock, 0);
lock->writer_is_wait_ex = FALSE;
#ifdef UNIV_SYNC_DEBUG
UT_LIST_INIT(lock->debug_list);
lock->level = level;
#endif /* UNIV_SYNC_DEBUG */
lock->magic_n = RW_LOCK_MAGIC_N;
lock->cfile_name = cfile_name;
lock->cline = (unsigned int) cline;
lock->last_s_file_name = "not yet reserved";
lock->last_x_file_name = "not yet reserved";
lock->last_s_line = 0;
lock->last_x_line = 0;
lock->event = os_event_create(NULL);
#ifdef __WIN__
lock->wait_ex_event = os_event_create(NULL);
#endif
mutex_enter(&rw_lock_list_mutex);
if (UT_LIST_GET_LEN(rw_lock_list) > 0) {
ut_a(UT_LIST_GET_FIRST(rw_lock_list)->magic_n
== RW_LOCK_MAGIC_N);
}
UT_LIST_ADD_FIRST(list, rw_lock_list, lock);
mutex_exit(&rw_lock_list_mutex);
}
