fis-gtm/sr_port/t_begin.c

97 lines
3.8 KiB
C

/****************************************************************
* *
* Copyright 2001, 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 "gdsroot.h"
#include "gdskill.h"
#include "gtm_facility.h"
#include "fileinfo.h"
#include "gdsbt.h"
#include "gdsfhead.h"
#include "gdsblk.h"
#include "gdscc.h"
#include "filestruct.h"
#include "jnl.h"
#include "buddy_list.h" /* needed for tp.h */
#include "hashtab_int4.h" /* needed for tp.h */
#include "tp.h"
#include "t_begin.h"
#include "have_crit.h"
GBLREF short crash_count;
GBLREF trans_num start_tn;
GBLREF cw_set_element cw_set[];
GBLREF unsigned char cw_set_depth, cw_map_depth;
GBLREF unsigned int t_tries;
GBLREF uint4 t_err;
GBLREF uint4 update_trans;
GBLREF gv_namehead *gv_target;
GBLREF sgmnt_addrs *cs_addrs;
GBLREF uint4 dollar_tlevel;
GBLREF jnl_format_buffer *non_tp_jfb_ptr;
GBLREF jnl_gbls_t jgbl;
GBLREF volatile int4 fast_lock_count;
GBLREF sgm_info *first_sgm_info;
void t_begin(uint4 err, uint4 upd_trans) /* err --> error code for current gvcst_routine */
{
srch_blk_status *s;
trans_num histtn;
DCL_THREADGBL_ACCESS;
SETUP_THREADGBL_ACCESS;
assert(!dollar_tlevel); /* if in TP, the T_BEGIN_xxx_NONTP_OR_TP macro should have been used and we will not be here */
/* any changes to the initialization in the two lines below might need a similar change in T_BEGIN_xxx_NONTP_OR_TP macros */
assert(INTRPT_OK_TO_INTERRUPT == intrpt_ok_state);
update_trans = upd_trans;
t_err = err;
/* If we use a clue then we must consider the oldest tn in the search history to be the start tn for this transaction */
/* start_tn manipulation for TP taken care of in tp_hist */
if (cs_addrs->critical)
crash_count = cs_addrs->critical->crashcnt;
start_tn = cs_addrs->ti->curr_tn;
/* Note: If gv_target was NULL before the start of a transaction and the only operations done inside the transaction
* are trigger deletions causing bitmap free operations, we can reach here with gv_target being NULL.
*/
if ((NULL != gv_target) && gv_target->clue.end)
{ /* Since we have a clue, determine if the clue history has lesser transaction numbers and if so use that
* as the start tn. Note that we need to take the MIN of all history level tns (see comment in tp_tend.c
* in valid_thru processing logic for why).
*/
for (s = &gv_target->hist.h[0]; s->blk_num; s++)
{
histtn = s->tn;
if (start_tn > histtn)
start_tn = histtn;
}
}
cw_set_depth = 0;
cw_map_depth = 0;
/* since this is mainline code and we know fast_lock_count should be 0 at this point reset it just in case it is not.
* having fast_lock_count non-zero will defer the database flushing logic and other critical parts of the system.
* hence this periodic reset at the beginning of each transaction.
*/
assert(0 == fast_lock_count);
fast_lock_count = 0;
t_tries = 0;
if (non_tp_jfb_ptr)
non_tp_jfb_ptr->record_size = 0; /* re-initialize it to 0 since TOTAL_NONTPJNL_REC_SIZE macro uses it */
assert(!TREF(donot_commit));
assert(!cs_addrs->now_crit || cs_addrs->hold_onto_crit); /* shouldn't hold crit at begin of transaction unless asked to */
/* Begin of a fresh transaction. This is analogous to tp_set_sgm done for TP transactions. However, unlike tp_set_sgm,
* we do not sync trigger cycles here. The reasoning is that trigger load events are in-frequent in the field and since
* Non-TP restarts are not as heavy-weight as TP restart, we chose to avoid unconditional memory references here and instead
* take the hit of infrequent restarts due to concurrent trigger loads
*/
}