fis-gtm/sr_port/op_setalsctin2als.c

112 lines
4.7 KiB
C

/****************************************************************
* *
* Copyright 2009, 2011 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 "gtm_stdio.h"
#include "gtm_string.h"
#include "rtnhdr.h"
#include "stack_frame.h"
#include "op.h"
#include "lv_val.h"
#include "gdsroot.h"
#include "gtm_facility.h"
#include "fileinfo.h"
#include "gdsbt.h"
#include "gdsfhead.h"
#include "alias.h"
#include "min_max.h"
GBLREF stack_frame *frame_pointer;
GBLREF symval *curr_symval;
GBLREF uint4 dollar_tlevel;
GBLREF lv_val *active_lv;
/* Operation - The destination variable becomes a new alias of the data pointed to by the source container variable:
*
* 1) Index into the variable name table to get the variable name for the new alias (destination).
* 2) Create the hash for the variable and look up in hash table (adding if not yet created).
* 3) See if hash entry has a value pointer. If yes and same as source var, we are done (NOOP).
* 4) Set hash entry to point to new lv_val.
* 5) Whichever symval of source container or the alias it pointed to has the largest address, that symval is the
* earliest symval affected by this alias action. Mark all interveening symvals (end points included) as having
* had alias activity via MARK_ALIAS_ACTIVE macro. This is so we can properly handle issues in an exlusive NEW
* situation involving multiple symvals and potential aliasing between them.
*/
void op_setalsctin2als(lv_val *srclv, int destindx)
{
ht_ent_mname *tabent;
mname_entry *varname;
lv_val *srclvc, *dstlv, *src_baselv;
int4 srcsymvlvl;
boolean_t added;
error_def(ERR_ALIASEXPECTED);
assert(srclv);
assert(!LV_IS_BASE_VAR(srclv)); /* Verify subscripted var */
if (!(srclv->v.mvtype & MV_ALIASCONT))
rts_error(VARLSTCNT(1) ERR_ALIASEXPECTED);
srclvc = (lv_val *)srclv->v.str.addr;
assert(srclvc);
assert(LV_IS_BASE_VAR(srclvc)); /* Verify base var */
assert(srclvc->stats.trefcnt >= srclvc->stats.crefcnt);
assert(1 <= srclvc->stats.crefcnt); /* Verify we have an existing container reference */
src_baselv = LV_GET_BASE_VAR(srclv);
srcsymvlvl = LV_SYMVAL(src_baselv)->symvlvl; /* lv_val may go away below so record symlvl */
varname = &(((mname_entry *)frame_pointer->vartab_ptr)[destindx]);
DEBUG_ONLY(added = FALSE);
/* Find hash table entry */
if (NULL == (tabent = (ht_ent_mname *)frame_pointer->l_symtab[destindx])) /* note tabent assignment */
{ /* No fast path to hash table entry -- look it up the hard(er) way */
varname = &(((mname_entry *)frame_pointer->vartab_ptr)[destindx]);
added = add_hashtab_mname_symval(&curr_symval->h_symtab, varname, NULL, &tabent);
}
assert(tabent);
assert(tabent || added);
dstlv = (lv_val *)tabent->value;
if (NULL == dstlv && curr_symval->tp_save_all)
{ /* dstlv does not exist yet we need to be able to save a previous "novalue" lvval in case a TPRESTART
needs to restore the value. Create a var so its undefined status can be saved.
*/
lv_newname(tabent, curr_symval);
dstlv = (lv_val *)tabent->value;
assert(dstlv);
}
/* Note dstlv could still be NULL if this is the first assignment to the target and the var is not being TPSAVed */
assert(dstlv != srclv); /* Since source is container, this is an impossible situation */
INCR_TREFCNT(srclvc); /* Increment before dstlv processing to prevent removal of last reference to srclvc */
if (dstlv)
{
assert(LV_IS_BASE_VAR(dstlv)); /* Verify base var */
if (dollar_tlevel && (NULL != dstlv->tp_var) && !dstlv->tp_var->var_cloned)
TP_VAR_CLONE(dstlv);
assert(0 < dstlv->stats.trefcnt);
assert(0 < (dstlv->stats.trefcnt - dstlv->stats.crefcnt)); /* Make sure there is one non-container reference */
DECR_TREFCNT(dstlv);
assert(dstlv->stats.trefcnt >= dstlv->stats.crefcnt);
if (0 == dstlv->stats.trefcnt)
{ /* Non alias -- make room for an alias to live here instead */
lv_kill(dstlv, DOTPSAVE_TRUE, DO_SUBTREE_TRUE);
LV_FREESLOT(dstlv);
} /* Else alias pointer in the hash table is just replaced below */
}
frame_pointer->l_symtab[destindx] = tabent;
DBGRFCT((stderr, "op_setalsct2als: hte 0x"lvaddr" being reset from 0x"lvaddr" to 0x"lvaddr"\n",
tabent, tabent->value, srclvc));
tabent->value = (void *)srclvc;
/* These symvals have had alias activity */
MARK_ALIAS_ACTIVE(MIN(srcsymvlvl, LV_SYMVAL(srclvc)->symvlvl));
active_lv = (lv_val *)NULL; /* if we get here, subscript set was successful. clear active_lv to avoid later
cleanup problems */
}