1berry/MariaDB-server
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

False alarm about incorrect mutex taking removed.

Browse Source 
storage/maria/ma_loghandler.c:
  Number of the buffer now passed to buffer initialization function to assign buffer number and break false alarm "chain" by switching off deadlock detection for one buffer.
This commit is contained in:
unknown 2008-12-08 11:22:49 +02:00
parent 45521d9710
commit e1ee25e4fb
1 changed files with 20 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
storage/maria/ma_loghandler.c
View File

@ -1404,18 +1404,21 @@ LSN translog_get_file_max_lsn_stored(uint32 file)
SYNOPSIS
translog_buffer_init()
buffer The buffer to initialize
num Number of this buffer
RETURN
0 OK
1 Error
*/
static my_bool translog_buffer_init(struct st_translog_buffer *buffer)
static my_bool translog_buffer_init(struct st_translog_buffer *buffer, int num)
{
DBUG_ENTER("translog_buffer_init");
buffer->prev_last_lsn= buffer->last_lsn= LSN_IMPOSSIBLE;
DBUG_PRINT("info", ("last_lsn and prev_last_lsn set to 0 buffer: 0x%lx",
(ulong) buffer));
buffer->buffer_no= (uint8) num;
/* This Buffer File */
buffer->file= NULL;
buffer->overlay= 0;
@ -1430,10 +1433,23 @@ static my_bool translog_buffer_init(struct st_translog_buffer *buffer)
buffer->copy_to_buffer_in_progress= 0;
/* list of waiting buffer ready threads */
buffer->waiting_flush= 0;
/* lock for the buffer. Current buffer also lock the handler */
/*
Buffers locked by fallowing mutex. As far as buffers create logical
circle (after last buffer goes first) it trigger false alarm of deadlock
detect system, so we remove check of deadlock for this buffers. In deed
all mutex locks concentrated around current buffer except flushing
thread (but it is only one thread). One thread can't take more then
2 buffer locks at once. So deadlock is impossible here.
To prevent false alarm of dead lock detection we switch dead lock
detection for one buffer in the middle of the buffers chain. Excluding
only one of eight buffers from deadlock detection hardly can hide other
possible problems which include this mutexes.
*/
if (my_pthread_mutex_init(&buffer->mutex, MY_MUTEX_INIT_FAST,
"translog_buffer->mutex",
MYF_NO_DEADLOCK_DETECTION) ||
(num == TRANSLOG_BUFFERS_NO - 2 ?
MYF_NO_DEADLOCK_DETECTION : 0)) ||
pthread_cond_init(&buffer->prev_sent_to_disk_cond, 0))
DBUG_RETURN(1);
buffer->is_closing_buffer= 0;
@ -3555,9 +3571,8 @@ my_bool translog_init_with_table(const char *directory,
/* Buffers for log writing */
for (i= 0; i < TRANSLOG_BUFFERS_NO; i++)
{
if (translog_buffer_init(log_descriptor.buffers + i))
if (translog_buffer_init(log_descriptor.buffers + i, i))
goto err;
log_descriptor.buffers[i].buffer_no= (uint8) i;
DBUG_PRINT("info", ("translog_buffer buffer #%u: 0x%lx",
i, (ulong) log_descriptor.buffers + i));
}