fis-gtm/sr_unix/gtmsource_srv_latch.c

105 lines
3.3 KiB
C

/****************************************************************
* *
* Copyright 2012 Fidelity Information Services, Inc *
* *
* This source code contains the intellectual property *
* of its copyright holder(s), and is made available *
* under a license. If you do not know the terms of *
* the license, please stop and do not read further. *
* *
****************************************************************/
#include "mdef.h"
#include <errno.h>
#include "aswp.h"
#include "gtm_facility.h"
#include "fileinfo.h"
#include "gdsroot.h"
#include "gdsbt.h"
#include "gdsfhead.h"
#include "filestruct.h"
#include "copy.h"
#include "interlock.h"
#include "performcaslatchcheck.h"
#include "relqop.h"
#include "wcs_sleep.h"
#include "caller_id.h"
#include "rel_quant.h"
#include "sleep_cnt.h"
#include "gtmsource_srv_latch.h"
#include "repl_msg.h"
#include "gtmsource.h"
#include "repl_instance.h"
#include "have_crit.h"
GBLREF int4 process_id;
GBLREF int num_additional_processors;
GBLREF jnlpool_addrs jnlpool;
#ifdef DEBUG
GBLREF node_local_ptr_t locknl;
GBLREF gd_region *gv_cur_region;
#endif
/* Note we don't increment fast_lock_count as part of getting the latch and decrement it when releasing it because ROLLBACK
* can hold onto this latch for a long while and can do updates in this duration and we should NOT have a non-zero fast_lock_count
* as many places like t_begin/dsk_read have asserts to this effect. It is okay to NOT increment fast_lock_count as ROLLBACK
* anyways have logic to disable interrupts the moment it starts doing database updates.
*/
boolean_t grab_gtmsource_srv_latch(sm_global_latch_ptr_t latch, uint4 max_timeout_in_secs)
{
int spins, maxspins, retries, max_retries;
unix_db_info *udi;
sgmnt_addrs *repl_csa;
assert(!have_crit(CRIT_HAVE_ANY_REG));
udi = FILE_INFO(jnlpool.jnlpool_dummy_reg);
repl_csa = &udi->s_addrs;
maxspins = num_additional_processors ? MAX_LOCK_SPINS(LOCK_SPINS, num_additional_processors) : 1;
max_retries = max_timeout_in_secs * 4 * 1000; /* outer-loop : X minutes, 1 loop in 4 is sleep of 1 ms */
for (retries = max_retries - 1; 0 < retries; retries--)
{
for (spins = maxspins; 0 < spins; spins--)
{
assert(latch->u.parts.latch_pid != process_id); /* We better not hold it if trying to get it */
if (GET_SWAPLOCK(latch))
{
DEBUG_ONLY(locknl = repl_csa->nl); /* Use the journal pool to maintain lock history */
LOCK_HIST("OBTN", latch, process_id, retries);
DEBUG_ONLY(locknl = NULL);
return TRUE;
}
}
if (retries & 0x3)
{ /* On all but every 4th pass, do a simple rel_quant */
rel_quant();
} else
{
/* On every 4th pass, we bide for awhile */
wcs_sleep(LOCK_SLEEP);
if (RETRY_CASLATCH_CUTOFF == (retries % LOCK_TRIES))
performCASLatchCheck(latch, TRUE);
}
}
DUMP_LOCKHIST();
assert(FALSE);
return FALSE;
}
boolean_t rel_gtmsource_srv_latch(sm_global_latch_ptr_t latch)
{
sgmnt_addrs *repl_csa;
repl_csa = &FILE_INFO(jnlpool.jnlpool_dummy_reg)->s_addrs;
DEBUG_ONLY(locknl = repl_csa->nl);
LOCK_HIST("RLSE", latch, process_id, 0);
DEBUG_ONLY(locknl = NULL);
assert(process_id == latch->u.parts.latch_pid);
RELEASE_SWAPLOCK(latch);
return TRUE;
}
boolean_t gtmsource_srv_latch_held_by_us()
{
return (process_id == jnlpool.gtmsource_local->gtmsource_srv_latch.u.parts.latch_pid);
}