mirror of https://github.com/sipwise/kamailio.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
95 lines
2.6 KiB
95 lines
2.6 KiB
/*
|
|
* $Id$
|
|
*
|
|
* Copyright (C) 2006 iptelorg GmbH
|
|
*
|
|
* This file is part of ser, a free SIP server.
|
|
*
|
|
* ser is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version
|
|
*
|
|
* For a license to use the ser software under conditions
|
|
* other than those described here, or to purchase support for this
|
|
* software, please contact iptel.org by e-mail at the following addresses:
|
|
* info@iptel.org
|
|
*
|
|
* ser is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*
|
|
*/
|
|
|
|
#include "../../sched_yield.h"
|
|
#include "im_locks.h"
|
|
|
|
/* reader lock for ipmatch cache */
|
|
void reader_lock_imhash(void)
|
|
{
|
|
|
|
/* prefer writers: suggest readers not to claim a reader ref_count if
|
|
a writer is interested in writing; the reader goes spinning, not too
|
|
bad, writes are rare (Jiri) */
|
|
while (IM_HASH->writer_demand) sched_yield();
|
|
|
|
/* it may be that reader tried to read at the same time when writer
|
|
decided to write -- make sure reader doesn't enter */
|
|
while (1) {
|
|
lock_get(&(IM_HASH->read_lock));
|
|
if (IM_HASH->reader_count >= 0) {
|
|
IM_HASH->reader_count++;
|
|
lock_release(&(IM_HASH->read_lock));
|
|
break;
|
|
}
|
|
/* reader_count < 0 ... writer is active; retry */
|
|
lock_release(&(IM_HASH->read_lock));
|
|
sched_yield();
|
|
}
|
|
|
|
}
|
|
|
|
/* reader release for ipmatch cache */
|
|
void reader_release_imhash(void)
|
|
{
|
|
lock_get(&(IM_HASH->read_lock));
|
|
IM_HASH->reader_count--;
|
|
lock_release(&(IM_HASH->read_lock));
|
|
}
|
|
|
|
/* set writer demand on ipmatch cache */
|
|
void set_wd_imhash(void)
|
|
{
|
|
|
|
/* tell the readers to wait for a bit, while the new table becomes active */
|
|
IM_HASH->writer_demand = 1; /* write_lock is already set */
|
|
|
|
/* wait for the readers (Jiri) */
|
|
while(1) {
|
|
lock_get(&(IM_HASH->read_lock));
|
|
if (IM_HASH->reader_count == 0) {
|
|
IM_HASH->reader_count--;
|
|
lock_release(&(IM_HASH->read_lock));
|
|
break;
|
|
}
|
|
lock_release(&(IM_HASH->read_lock));
|
|
/* processes still reading, retry ! */
|
|
sched_yield();
|
|
}
|
|
}
|
|
|
|
/* delete writer demand on ipmatch cache */
|
|
void del_wd_imhash(void) {
|
|
|
|
lock_get(&(IM_HASH->read_lock));
|
|
IM_HASH->reader_count++;
|
|
lock_release(&(IM_HASH->read_lock));
|
|
IM_HASH->writer_demand = 0;
|
|
|
|
}
|