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/****************************************************************
* *
* Copyright 2009, 2014 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 "gtmio.h"
#include "lv_val.h"
#include "op.h"
#include "gdsroot.h"
#include "stringpool.h"
#include "stp_parms.h"
#include "gtm_facility.h"
#include "fileinfo.h"
#include "gdsbt.h"
#include "gdsfhead.h"
#include "alias.h"
#include <rtnhdr.h>
#include "stack_frame.h"
GBLREF symval *curr_symval;
GBLREF uint4 dollar_tlevel;
/* Delete all aliases and the data they point to.
*
* Two things need to happen:
* 1) Scan the hash table for aliased base variables and remove them.
* 2) Scan ALL subscripted vars for containers, delete the data they point to maintaining
* proper maintenance of reference counts and unmark the container making it a normal value.
*
* Since an alias with two references ceases being an alias if a reference is killed, we
* cannot just do a simple scan and delete references. We will leave "klingons" who used to
* be aliases but now are not. So we do this in a 3 step procedure:
* 1) Identify all overt aliases in the hash table.
* 2) For the entries that are not aliases but which contain alias containers, scan those
* arrays for containers, remove the container attribute and do the necessary refcnt
* cleanup. When all containers have been removed (including step 3), any remaining
* orphaned data will be recovered by the next LVGC.
* 3) Go through the list of HTEs recorded in step one and kill their hash table reference.
*/
void op_killaliasall(void)
{
ht_ent_mname *tabent, *tabent_top;
lv_val *lvp, *lvp_top, *lvrefp;
symval *symv;
int lowest_symvlvl;
ht_ent_mname **htearraycur = NULL, **htearray = NULL, **htearraytop;
SET_ACTIVE_LV(NULL, TRUE, actlv_op_killaliasall); /* If we get here, subscript set was successful.
* Clear active_lv to avoid later cleanup issues */
lowest_symvlvl = MAXPOSINT4;
/* First pass through hash table we record HTEs that have > 1 trefcnt. We will delete these in a later
* loop but don't want to delete any until all are found.
*/
for (tabent = curr_symval->h_symtab.base, tabent_top = curr_symval->h_symtab.top; tabent < tabent_top; tabent++)
{
if (HTENT_VALID_MNAME(tabent, lv_val, lvp) && lvp && (1 < lvp->stats.trefcnt))
{ /* Verify room in the table, expand if necessary */
assert(LV_IS_BASE_VAR(lvp));
ADD_TO_STPARRAY(tabent, htearray, htearraycur, htearraytop, ht_ent_mname);
/* Need to find the lowest level symval that is affected by this kill * so we can mark all necessary
* symvals as having had alias activity.
*/
lvp = (lv_val *)tabent->value;
symv = LV_GET_SYMVAL(lvp);
if (lowest_symvlvl > symv->symvlvl)
lowest_symvlvl = symv->symvlvl;
}
}
/* This next, less scenic trip through the hash table entries we scan any arrays we
* find for containers that must be dealt with. We couldn't deal with these until all
* the "blatant" aliases were identified.
*/
for (tabent = curr_symval->h_symtab.base, tabent_top = curr_symval->h_symtab.top; tabent < tabent_top; tabent++)
{
if (HTENT_VALID_MNAME(tabent, lv_val, lvp) && lvp && (1 == lvp->stats.trefcnt))
{ /* Var was not an alias but now need to check if var has any containers in it
* that likewise need to be processed (and de-container-ized).
*/
assert(LV_IS_BASE_VAR(lvp));
KILL_CNTNRS_IN_TREE(lvp); /* Note macro has LV_GET_CHILD() check in it */
}
}
/* Now we can go through the hash table entries we identified in the first step and delete them. */
for (htearraytop = htearraycur, htearraycur = htearray; htearraycur < htearraytop; ++htearraycur)
{
assert(htearraycur);
tabent = *htearraycur;
lvp = (lv_val *)tabent->value;
assert(lvp);
assert(LV_IS_BASE_VAR(lvp));
assert(0 < lvp->stats.trefcnt);
/* Clone var if necessary */
if (dollar_tlevel && (NULL != lvp->tp_var) && !lvp->tp_var->var_cloned)
TP_VAR_CLONE(lvp);
/* Decrement reference count and cleanup if necessary */
DECR_BASE_REF(tabent, lvp, TRUE);
}
/* Now mark all symvals from the earliest affected by our command to the current as having had alias activity */
MARK_ALIAS_ACTIVE(lowest_symvlvl);
}
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