/* 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, uint4 onln_rlbk_action)
{
int spins, maxspins, retries, max_retries;
unix_db_info *udi;
sgmnt_addrs *repl_csa;
boolean_t cycle_mismatch;
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);
if (jnlpool.repl_inst_filehdr->file_corrupt && !jgbl.onlnrlbk)
{
/* Journal pool indicates an abnormally terminated online rollback. Cannot continue until
* the rollback command is re-run to bring the journal pool/file and instance file to a
* consistent state.
*/
/* No need to release the latch before rts_error (mupip_exit_handler will do it for us) */
rts_error(VARLSTCNT(8) ERR_REPLREQROLLBACK, 2, LEN_AND_STR(udi->fn),
ERR_TEXT, 2, LEN_AND_LIT("file_corrupt field in instance file header is set to"
" TRUE"));
}
cycle_mismatch = (repl_csa->onln_rlbk_cycle != jnlpool.jnlpool_ctl->onln_rlbk_cycle);
assert((ASSERT_NO_ONLINE_ROLLBACK != onln_rlbk_action) || !cycle_mismatch);
if ((HANDLE_CONCUR_ONLINE_ROLLBACK == onln_rlbk_action) && cycle_mismatch)
{
assert(is_src_server);
SYNC_ONLN_RLBK_CYCLES;
gtmsource_onln_rlbk_clnup(); /* side-effect : sets gtmsource_state */
rel_gtmsource_srv_latch(latch);
}
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);
assert(jnlpool.gtmsource_local && jnlpool.gtmsource_local->gtmsource_pid);
rts_error(VARLSTCNT(5) ERR_SRVLCKWT2LNG, 2, max_timeout_in_secs, jnlpool.gtmsource_local->gtmsource_pid);
return FALSE; /* to keep the compiler happy */
}
/* Note about usage of this function : Create dummy gd_region, gd_segment, file_control,
* unix_db_info, sgmnt_addrs, and allocate mutex_struct (and NUM_CRIT_ENTRY * mutex_que_entry),
* mutex_spin_parms_struct, and node_local in shared memory. Initialize the fields as in
* jnlpool_init(). Pass the address of the dummy region as argument to this function.
*/
boolean_t grab_lock(gd_region *reg, boolean_t is_blocking_wait, uint4 onln_rlbk_action)
{
unix_db_info *udi;
sgmnt_addrs *csa;
enum cdb_sc status;
mutex_spin_parms_ptr_t mutex_spin_parms;
char scndry_msg[OUT_BUFF_SIZE];
# ifdef DEBUG
DCL_THREADGBL_ACCESS;
SETUP_THREADGBL_ACCESS;
# endif
udi = FILE_INFO(reg);
csa = &udi->s_addrs;
assert(!csa->hold_onto_crit);
assert(!csa->now_crit);
if (!csa->now_crit)
{
assert(0 == crit_count);
crit_count++; /* prevent interrupts */
DEBUG_ONLY(locknl = csa->nl); /* for DEBUG_ONLY LOCK_HIST macro */
mutex_spin_parms = (mutex_spin_parms_ptr_t)((sm_uc_ptr_t)csa->critical + JNLPOOL_CRIT_SPACE);
/* This assumes that mutex_spin_parms_t is located immediately after the crit structures */
/* As of 10/07/98, crashcnt field in mutex_struct is not changed by any function for the dummy region */
if (is_blocking_wait)
status = mutex_lockw(reg, mutex_spin_parms, 0);
else
status = mutex_lockwim(reg, mutex_spin_parms, 0);
DEBUG_ONLY(locknl = NULL); /* restore "locknl" to default value */
if (status != cdb_sc_normal)
{
crit_count = 0;
switch(status)
{
case cdb_sc_critreset: /* As of 10/07/98, this return value is not possible */
rts_error_csa(CSA_ARG(NULL) VARLSTCNT(4) ERR_CRITRESET, 2, REG_LEN_STR(reg));
case cdb_sc_dbccerr:
rts_error_csa(CSA_ARG(NULL) VARLSTCNT(4) ERR_DBCCERR, 2, REG_LEN_STR(reg));
case cdb_sc_nolock:
return FALSE;
default:
assertpro(FALSE && status);
}
return FALSE;
}
/* There is only one case we know of when csa->nl->in_crit can be non-zero and that is when a process holding
* crit gets kill -9ed and another process ends up invoking "secshr_db_clnup" which in turn clears the
* crit semaphore (making it available for waiters) but does not also clear csa->nl->in_crit since it does not
* hold crit at that point. But in that case, the pid reported in csa->nl->in_crit should be dead. Check that.
*/
assert((0 == csa->nl->in_crit) || (FALSE == is_proc_alive(csa->nl->in_crit, 0)));
csa->nl->in_crit = process_id;
CRIT_TRACE(crit_ops_gw); /* see gdsbt.h for comment on placement */
crit_count = 0;
if (jnlpool.repl_inst_filehdr->file_corrupt && !jgbl.onlnrlbk)
{ /* Journal pool indicates an abnormally terminated online rollback. Cannot continue until the rollback
* command is re-run to bring the journal pool/file and instance file to a consistent state.
*/
SNPRINTF(scndry_msg, OUT_BUFF_SIZE, "Instance file header has file_corrupt field set to TRUE");
/* No need to do rel_lock before rts_error (mupip_exit_handler will do it for us) - BYPASSOK rts_error */
rts_error_csa(CSA_ARG(NULL) VARLSTCNT(8) ERR_REPLREQROLLBACK, 2, LEN_AND_STR(udi->fn),
ERR_TEXT, 2, LEN_AND_STR(scndry_msg));
}
/* If ASSERT_NO_ONLINE_ROLLBACK, then no concurrent online rollbacks can happen at this point. So, the jnlpool
* should be in in sync. There are two exceptions. If this is GT.CM GNP Server and the last client disconnected, the
* server invokes gtcmd_rundown which in-turn invokes gds_rundown thereby running down all active databases at this
* point but leaves the journal pool up and running. Now, if an online rollback is attempted, it increments the
* onln_rlbk_cycle in the journal pool, but csa->onln_rlbk_cycle is not synced yet. So, the grab_crit done in t_end
* will NOT detect a concurrent online rollback and it doesn't need to because the rollback happened AFTER the
* rundown. Assert that this is the only case we know of for the cycles to be out-of-sync. In PRO
* jnlpool_ctl->onln_rlbk_cycle is used only by the replication servers (which GT.CM is not) and so even if it
* continues with an out-of-sync csa->onln_rlbk_cycle, t_end logic does the right thing. The other exception is if
* GT.M initialized journal pool while opening database (belonging to a different instance) in gvcst_init (for
* anticipatory freeze) followed by an online rollback which increments the jnlpool_ctl->onln_rlbk_cycle but leaves
* the repl_csa->onln_rlbk_cycle out-of-sync. At this point, if a replicated database is open for the first time,
* we'll reach t_end to commit the update but will end up failing the below assert due to the out-of-sync
* onln_rlbk_cycle. So, assert accordingly. Note : even though the cycles are out-of-sync they are not an issue for
* GT.M because it always relies on the onln_rlbk_cycle from csa->nl and not from repl_csa. But, we don't remove the
* assert as it is valuable for replication servers (Source, Receiver and Update Process).
*/
assert((ASSERT_NO_ONLINE_ROLLBACK != onln_rlbk_action)
|| (csa->onln_rlbk_cycle == jnlpool.jnlpool_ctl->onln_rlbk_cycle) || IS_GTCM_GNP_SERVER_IMAGE
|| (jnlpool_init_needed && INST_FREEZE_ON_ERROR_POLICY));
if ((HANDLE_CONCUR_ONLINE_ROLLBACK == onln_rlbk_action)
&& (csa->onln_rlbk_cycle != jnlpool.jnlpool_ctl->onln_rlbk_cycle))
{
assert(is_src_server);
SYNC_ONLN_RLBK_CYCLES;
gtmsource_onln_rlbk_clnup(); /* side-effect : sets gtmsource_state */
rel_lock(reg); /* caller knows to disconnect and re-establish the connection */
}
}
return TRUE;
}
