hcq/MaxScale
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Added write and read lock to DCB to protect concurrent threads fro executing EPOLLIN and EPOLLOUT events on same descriptor, respectively. Added consistency checks and trace logging.

Browse Source
This commit is contained in:
vraatikka
2013-08-28 23:09:37 +03:00
parent f2f119f692
commit ae9fce8591
3 changed files with 94 additions and 21 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
server/core/poll.c
View File

@ -201,7 +201,8 @@ poll_waitevents(void *arg)
{
DCB *dcb = (DCB *)events[i].data.ptr;
__uint32_t ev = events[i].events;
CHK_DCB(dcb);
skygw_log_write(
LOGFILE_TRACE,
"%lu [poll_waitevents] event %d",
@ -218,11 +219,24 @@ poll_waitevents(void *arg)
continue;
}
if (dcb->state == DCB_STATE_DISCONNECTED ||
dcb->state == DCB_STATE_PROCESSING)
{
skygw_log_write(
LOGFILE_TRACE,
"%lu [poll_waitevents] dcb state is "
"%s",
pthread_self(),
STRDCBSTATE(dcb->state));
continue;
}
if (ev & EPOLLERR)
{
atomic_add(&pollStats.n_error, 1);
dcb->func.error(dcb);
if (DCB_ISZOMBIE(dcb)) {
continue;
}
@ -238,16 +252,32 @@ poll_waitevents(void *arg)
}
if (ev & EPOLLOUT)
{
simple_mutex_lock(&dcb->dcb_write_lock, true);
ss_info_dassert(!dcb->dcb_write_active,
"Write already active");
dcb->dcb_write_active = TRUE;
skygw_log_write(LOGFILE_TRACE,
"%lu [poll_waitevents] "
"Write in fd %d",
pthread_self(),
dcb->fd);
atomic_add(&pollStats.n_write, 1);
dcb->func.write_ready(dcb);
dcb->func.write_ready(dcb);
dcb->dcb_write_active = FALSE;
simple_mutex_unlock(
&dcb->dcb_write_lock);
}
if (ev & EPOLLIN)
{
simple_mutex_lock(&dcb->dcb_read_lock,
true);
ss_info_dassert(!dcb->dcb_read_active,
"Read already active");
dcb->dcb_read_active = TRUE;
if (dcb->state == DCB_STATE_LISTENING)
{
skygw_log_write(
@ -270,6 +300,9 @@ poll_waitevents(void *arg)
atomic_add(&pollStats.n_read, 1);
dcb->func.read(dcb);
}
dcb->dcb_read_active = FALSE;
simple_mutex_unlock(
&dcb->dcb_read_lock);
}
} /**< for */
no_op = FALSE;