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fis-gtm/sr_port/tp_hist.c

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/****************************************************************
* *
* Copyright 2001, 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_string.h"
#include "gdsroot.h"
#include "gdskill.h"
#include "gdsblk.h"
#include "gtm_facility.h"
#include "fileinfo.h"
#include "gdsbt.h"
#include "gdsfhead.h"
#include "gdscc.h"
#include "filestruct.h"
#include "copy.h"
#include "jnl.h"
#include "buddy_list.h" /* needed for tp.h */
#include "longcpy.h"
#include "hashtab_int4.h" /* needed for tp.h and cws_insert.h */
#include "tp.h"
#include "longset.h" /* needed for cws_insert.h */
#include "hashtab.h" /* needed for cws_insert.h */
#include "cws_insert.h"
#include "memcoherency.h"
#include "wbox_test_init.h"
#define MMBLK_OFFSET(BLK) \
(cs_addrs->db_addrs[0] + (cs_addrs->hdr->start_vbn - 1) * DISK_BLOCK_SIZE + (off_t)(cs_addrs->hdr->blk_size * (BLK)))
#define REPOSITION_PTR(ptr, type, delta, begin, end) \
{ \
assert((sm_uc_ptr_t)(ptr) >= (sm_uc_ptr_t)(begin)); \
assert((sm_uc_ptr_t)(ptr) <= (sm_uc_ptr_t)(end)); \
(ptr) = (type *)((sm_uc_ptr_t)(ptr) + delta); \
}
#define REPOSITION_PTR_IF_NOT_NULL(ptr, type, delta, begin, end) \
{ \
if (ptr) \
REPOSITION_PTR(ptr, type, delta, begin, end); \
}
#define REPOSITION_GVNH_HIST(GVNH, CSA, DELTA, SI) \
{ \
srch_blk_status *t1; \
\
if (GVNH->gd_csa == CSA) \
{ /* reposition pointers only if global corresponds to current database file */ \
for (t1 = GVNH->hist.h; t1->blk_num; t1++) \
REPOSITION_PTR_IF_NOT_NULL(t1->first_tp_srch_status, struct srch_blk_status_struct, \
DELTA, SI->first_tp_hist, SI->last_tp_hist); \
} else \
assert((GVNH != gv_target) && (GVNH != cs_addrs->dir_tree)); \
}
GBLREF gv_namehead *gv_target, *gvt_tp_list;
GBLREF sgm_info *sgm_info_ptr;
GBLREF gd_region *gv_cur_region;
GBLREF sgmnt_addrs *cs_addrs;
GBLREF trans_num local_tn; /* transaction number for THIS PROCESS */
GBLREF int4 n_pvtmods, n_blkmods;
GBLREF unsigned int t_tries;
GBLREF uint4 t_err;
GBLREF int4 tprestart_syslog_delta;
GBLREF boolean_t is_updproc;
GBLREF boolean_t mupip_jnl_recover;
GBLREF boolean_t gvdupsetnoop; /* if TRUE, duplicate SETs update journal but not database (except for curr_tn++) */
GBLREF uint4 process_id;
error_def(ERR_TRANS2BIG);
error_def(ERR_GVKILLFAIL);
error_def(ERR_GVPUTFAIL);
void gds_tp_hist_moved(sgm_info *si, srch_hist *hist1);
enum cdb_sc tp_hist(srch_hist *hist1)
{
int hist_index;
srch_hist *hist;
off_chain chain;
srch_blk_status *t1, *t2;
block_id blk;
srch_blk_status *local_hash_entry;
enum cdb_sc status = cdb_sc_normal;
boolean_t is_mm, store_history;
sgm_info *si;
ht_ent_int4 *tabent, *lookup_tabent;
cw_set_element *cse;
cache_rec_ptr_t cr;
# ifdef DEBUG
boolean_t wc_blocked;
boolean_t ready2signal_gvundef_lcl;
# endif
gv_namehead *gvt; /* store local copy of global "gv_target" for faster access */
DCL_THREADGBL_ACCESS;
SETUP_THREADGBL_ACCESS;
DEBUG_ONLY(
/* Store global variable ready2signal_gvundef in a local variable and reset the global right away to ensure that
* the global value does not incorrectly get carried over to the next call of "t_end".
*/
ready2signal_gvundef_lcl = TREF(ready2signal_gvundef);
TREF(ready2signal_gvundef) = FALSE;
)
is_mm = (dba_mm == cs_addrs->hdr->acc_meth);
assert((NULL != sgm_info_ptr) && (cs_addrs->sgm_info_ptr == sgm_info_ptr));
si = sgm_info_ptr;
gvt = gv_target;
store_history = (!gvt->noisolation || ERR_GVKILLFAIL == t_err || ERR_GVPUTFAIL == t_err);
assert(hist1 != &gvt->hist);
/* Ideally, store_history should be computed separately for blk_targets of gv_target->hist and hist1,
* i.e. within the outer for loop below. But this is not needed since if t_err is ERR_GVPUTFAIL,
* store_history is TRUE both for gv_target->hist and hist1 (which is cs_addrs->dir_tree if non-NULL)
* (in the latter case, TRUE because cs_addrs->dir_tree always has NOISOLATION turned off) and if not,
* we should have the same blk_target for both the histories and hence the same value for
* !blk_target->noisolation and hence the same value for store_history. We assert this is the case below.
*/
assert(ERR_GVPUTFAIL == t_err && (NULL == hist1 || hist1 == &cs_addrs->dir_tree->hist && !cs_addrs->dir_tree->noisolation)
|| !hist1 || hist1->h[0].blk_target == gvt);
/* We are going to reference fields from shared memory including cr->in_tend and t1->buffaddr->tn in that order (as part
* of the TP_IS_CDB_SC_BLKMOD macro below). To ensure we read an uptodate value of cr->in_tend, we do a read memory
* barrier here. Note that to avoid out-of-order reads, the read memory barrier needs to be done AFTER the reference
* that sets t1->tn (in a caller function usually gvcst_search.c) and the reference that accesses t1->buffaddr->tn
* (in this function below as part of the TP_IS_CDB_SC_BLKMOD macro). Therefore it is ok to do this at the start of
* this function. If cr->in_tend changes concurrently AFTER we do the read memory barrier and we dont see the change
* in the cr->in_tend reference below, then, as long as the values we see pass the cdb_sc_blkmod check, it is ok to
* consider this transaction as good because whatever change happened concurrently occurred only after we reached this
* part of the code which means that while the caller functions gvcst_put.c,gvcst_search.c etc. were traversing the
* tree and accessing the buffers, they were guaranteed to have seen a consistent state of the database.
*/
SHM_READ_MEMORY_BARRIER;
for (hist = &gvt->hist; hist != NULL && cdb_sc_normal == status; hist = (hist == &gvt->hist) ? hist1 : NULL)
{ /* this loop execute once or twice: 1st for gv_target and then for hist1, if any */
if (tprestart_syslog_delta)
n_blkmods = n_pvtmods = 0;
for (t1 = hist->h; HIST_TERMINATOR != (blk = t1->blk_num); t1++)
{
if (si->start_tn > t1->tn)
si->start_tn = t1->tn;
/* Since this validation is done out of crit, it is crucial to perform the blkmod check
* ahead of the cycle check. There is a subtle chance that, if we do the check the other
* way round, the block may pass the cycle check (although it still has been modified)
* and just before the blkmod check, the buffer gets reused for another block whose block
* transaction number is less than the history's tn. The same care should be taken in
* all the other out-of-crit places which are (as of 1/15/2000)
* t_qread, gvcst_search, gvcst_put --- nars.
*
* Note that the correctness of this out-of-crit-validation mechanism also relies on the
* fact that the block-transaction-number is modified before the contents of the block
* in gvcst_blk_build and other places in bg_update and mm_update. This is needed because
* our decision here is based on looking at the transaction number in the block-header
* rather than the BT table (done in tp_tend and t_end). If the block-tn got updated
* after the block contents get modified, then we may incorrectly decide (looking at the
* tn) that the block hasn't changed when actually its contents have.
*/
chain = *(off_chain *)&blk;
if (!chain.flag)
{ /* We need to ensure the shared copy hasn't changed since the beginning of the
* transaction since not checking that can cause at least false UNDEFs.
* e.g. Say earlier in this TP transaction we had gone down
* a level-1 root-block 4 (say) to reach leaf-level block 10 (say) to get at a
* particular key (^x). Let reorg have swapped the contents of block 10 with the
* block 20. Before the start of this particular mini-action in TP, block 4 would
* lead to block 20 (for the same key ^x). If block 20 happens to be in the cw_set
* of this region for this transaction, we would be using that instead of the shared
* memory copy. Now, the private copy of block 20 would not contain the key ^x. But
* we shouldn't incorrectly conclude that ^x is not present in the database. For this
* we should check whether the shared memory copy of block 20 is still not changed.
*/
assert(is_mm || t1->cr || t1->first_tp_srch_status);
ASSERT_IS_WITHIN_TP_HIST_ARRAY_BOUNDS(t1->first_tp_srch_status, si);
t2 = t1->first_tp_srch_status ? t1->first_tp_srch_status : t1;
cr = t2->cr;
/* Assert that cr->in_tend is never equal to our process_id since at this point we should
* never have locked a buffer for phase2 commit. The only exception is if the previous
* transaction by this process had a commit-time error and secshr_db_clnup finished the
* transaction and had set csd->wc_blocked to TRUE. It is possible in that case no process
* has yet done a cache-recovery by the time we come to tp_hist as part of the next transaction
* in which case cr->in_tend could still be pointing to our process_id. Note that
* csd->wc_blocked could be changing concurrently so need to note it down in a local variable
* BEFORE checking the value of cr->in_tend.
*/
DEBUG_ONLY(wc_blocked = cs_addrs->hdr->wc_blocked;)
assert((NULL == cr) || (process_id != cr->in_tend) || wc_blocked);
if (TP_IS_CDB_SC_BLKMOD(cr, t2))
{
cse = t1->cse;
/* Check if the cse already has a recompute list (i.e. NOISOLATION turned ON)
* If so no need to restart the transaction even though the block changed.
* We will detect this change in tp_tend and recompute the update array anyways.
*/
if ((NULL == cse) || !cse->recompute_list_head || cse->write_type)
{
assert((CDB_STAGNATE > t_tries)
|| (gtm_white_box_test_case_enabled
&& (WBTEST_TP_HIST_CDB_SC_BLKMOD == gtm_white_box_test_case_number)));
if (tprestart_syslog_delta)
{
n_blkmods++;
if (t2->cse || t1->cse)
n_pvtmods++;
if (1 != n_blkmods)
continue;
}
TP_TRACE_HIST_MOD(t2->blk_num, t2->blk_target, tp_blkmod_tp_hist,
cs_addrs->hdr, t2->tn, ((blk_hdr_ptr_t)t2->buffaddr)->tn, t2->level);
status = cdb_sc_blkmod;
BREAK_IN_PRO__CONTINUE_IN_DBG;
} else
{ /* In case of VMS, it is possible we (gvcst_search) could have been looking at
* a newly formed twin buffer while setting the first_rec portion of the clue.
* It is possible that the twin buffer was obtained by a db_csh_getn and that
* it does not yet contain the records of the block we were interested in. This
* means we could have been looking at a completely different block (the one that
* was previously sitting in that global buffer) while constructing the first_rec
* portion of the gv_target's clue which means first_rec is no longer reliable.
* Hence reset it in this case to be safe. Note that tp_hist need not detect
* all cases of blkmods accurately since this check is done outside of crit. Any
* cases that are not detected here will get caught by tp_tend (which will invoke
* "recompute_upd_array" function) so a similar reset of the first_rec needs to
* happen there too.
*
* In Unix, there is no twinning so we dont have that issue. But it is possible
* that if gvcst_search is reading from a buffer that is being modified
* concurrently, it could pick up the first half of first_rec from the pre-update
* copy of the block and the second half of first_rec from the post-update copy of
* the block. Depending on the actual byte sequences, it is possible that this
* mixed first_rec is LESSER than the correct value. This could therefore cause
* DBKEYORD integ errors in case this is used for the next transaction. It is
* therefore necessary to invalidate the first_rec in this case (C9J07-003162).
*/
if (gvt->clue.end)
GVT_CLUE_INVALIDATE_FIRST_REC(gvt);
# ifdef DEBUG
/* Assert that this is a leaf level block of a global with NOISOLATION
* and that this is a SET operation (not a GET or KILL). The only exception
* we know of to this is that the global corresponding to the incoming history
* (t1) could have NOISOLATION turned OFF but yet contain a block which is
* already part of the first_tp_hist structure (t2) for a different global that
* has NOISOLATION turned ON. This is possible if MUPIP REORG swapped the block
* AFTER the tp_hist was done for the NOISOLATION-ON-global but BEFORE the
* tp_hist (the current one) for the NOISOLATION-OFF-global. This is definitely
* a restartable situation that will be detected in tp_tend. Even though
* we know t1->blk_target != t2->blk_target in this case, we choose to defer
* the restart because we suspect this case is very infrequent that it is better
* to avoid the performance hit of a check in this frequently used code.
*/
assert((ERR_GVPUTFAIL == t_err) && (0 == t1->level)
&& (t1->blk_target->noisolation || t2->blk_target->noisolation));
if (t1->blk_target != t2->blk_target)
TREF(donot_commit) |= DONOTCOMMIT_TPHIST_BLKTARGET_MISMATCH;
# endif
}
}
/* Although t1->first_tp_srch_status (i.e. t2) is used for doing blkmod check,
* we need to use BOTH t1 and t1->first_tp_srch_status to do the cdb_sc_lostcr check.
*
* Need to use t1 for the cdb_sc_lostcr check
* -------------------------------------------
* We allow for recycled crs within a transaction but not within a mini-action (one that
* ends up calling tp_hist e.g. SET/KILL/GET etc.). An example of how recycled crs within
* a mini-action are possible is the M-kill. It does gvcst_search twice one for the left
* path and one for the right path that identifies the subtree of blocks to be killed.
* It is possible that the same block gets included in both the paths but with different
* state of the "cr" implying a block recycle within the KILL and hence the need for a restart.
*
* Need to also use t1->first_tp_srch_status (i.e. t2) for the cdb_sc_lostcr check
* --------------------------------------------------------------------------------
* tp_tend does not validate those blocks that have already been built privately
* (i.e. cse->new_buff is non-NULL). Instead it relies on tp_hist (called for every mini-action)
* to have done the validation right after the block was built. Hence we need to validate
* t1->first_tp_srch_status (right now) against the current state of the cache to ensure whatever
* shared memory buffer we used to privately build the block has not been recycled since.
*/
if ((t1 != t2) && t1->cr)
{
assert((sm_long_t)GDS_REL2ABS(t1->cr->buffaddr) == (sm_long_t)t1->buffaddr);
if (t1->cycle != t1->cr->cycle)
{
assert(CDB_STAGNATE > t_tries);
status = cdb_sc_lostcr;
break;
}
t1->cr->refer = TRUE;
}
if (cr)
{
assert((sm_long_t)GDS_REL2ABS(cr->buffaddr) == (sm_long_t)t2->buffaddr);
if (t2->cycle != cr->cycle)
{
assert(CDB_STAGNATE > t_tries);
status = cdb_sc_lostcr;
break;
}
cr->refer = TRUE;
}
}
/* Note that blocks created within the transaction (chain.flag != 0) are NOT counted
* in the read-set of this transaction. They are still counted against the write-set.
* si->num_of_blks is the count of the read-set (the si->blks_in_use has the actual block numbers)
* while si->cw_set_depth is the count of the write-set (si->first_cw_set has the block numbers).
* We have a limit on the maximum number of buffers that a TP transaction can have both in
* its read-set (64K buffers) and write-set (1/2 the number of global buffers). The former
* limit check is done here. The latter is done in tp_cw_list.c.
*
* Since created blocks are not added into the hashtable, we expect the "first_tp_srch_status"
* members of those block's srch_blk_status to be NULL. That is asserted below.
*
* For an existing block, we copy its search history into si->last_tp_hist.
* For a created block, we dont since it doesn't need to be validated at commit.
*/
assert(!chain.flag || !t1->first_tp_srch_status);
if (store_history && !chain.flag)
{
assert(si->cw_set_depth || !t1->cse);
local_hash_entry = t1->first_tp_srch_status;
DEBUG_ONLY(lookup_tabent = lookup_hashtab_int4(si->blks_in_use, (uint4 *)&blk));
ASSERT_IS_WITHIN_TP_HIST_ARRAY_BOUNDS(local_hash_entry, si);
if ((NULL == local_hash_entry) && add_hashtab_int4(si->blks_in_use, (uint4 *)&blk,
(void *)(si->last_tp_hist), &tabent))
{ /* not a duplicate block */
assert(NULL == lookup_tabent);
if (++si->num_of_blks > si->tp_hist_size)
{ /* catch the case where MUPIP recover or update process gets into this situation */
assert(!mupip_jnl_recover && !is_updproc);
delete_hashtab_int4(si->blks_in_use,(uint4 *)&blk);
si->num_of_blks--;
assert(si->num_of_blks == si->tp_hist_size);
rts_error(VARLSTCNT(4) ERR_TRANS2BIG, 2, REG_LEN_STR(gv_cur_region));
}
/* Either history has a clue or not.
* If yes, then it could have been constructed in an earlier
* local_tn or the current local_tn.
* If an earlier local_tn, then the logic in gvcst_search would
* have nullified first_tp_srch_status members.
* If the current local_tn, then this block should have been
* added in the hashtable already and we shouldn't be
* in this part of the code.
* If no, then we t_qread all the blocks in the search path. The
* blocks may have been read already in this local_tn or not.
* If already read in this local_tn, then this block should have
* been added in the hashtable already and we shouldn't be
* in this part of the code.
* If not already read in this local_tn, then t_qread of this block
* should have returned a NULL for first_tp_srch_status.
* In either case, the first_tp_srch_status member should be NULL.
*/
assert(NULL == t1->first_tp_srch_status);
/* If history array is full, allocate more */
if (si->last_tp_hist - si->first_tp_hist == si->cur_tp_hist_size)
gds_tp_hist_moved(si, hist1);
memcpy(si->last_tp_hist, t1, SIZEOF(srch_blk_status));
t1->first_tp_srch_status = si->last_tp_hist;
si->last_tp_hist++;
/* Ensure that we are doing an M-kill if for a non-isolated global we end up
* adding to the history a leaf-level block which has no corresponding cse.
* To be more specific we are doing an M-kill that freed up the data block from
* the B-tree, but that checking involves more coding.
* The only exception to this is if we are in an M-set and the set was a duplicate
* set. Since we do not have that information (gvcst_put the caller has it),
* we do a less stringent check and ensure the optimization ("gvdupsetnoop"
* global variable) is turned on at the very least.
*/
assert(!t1->blk_target->noisolation || t1->level || t1->cse
|| ((ERR_GVKILLFAIL == t_err)
|| ((ERR_GVPUTFAIL == t_err) && gvdupsetnoop)));
} else
{ /* While it is almost always true that local_hash_entry is non-NULL here, there
* is a very rare case when it can be NULL. That is when two histories are passed
* each containing the same block. In that case, when the loop is executed
* for the first history, the block would have been added into the hashtable.
* During the second history's loop, the first_tp_srch_status member in
* the srch_blk_status for the second history will be NULL although the
* block is already in the hashtable. But that can be only because of a
* call from gvcst_kill() or one of the $order,$data,$query routines. Among
* these, gvcst_kill() is the only one that can create a condition which
* will require us to update the "cse" field in the first_tp_hist array
* (i.e. the block may have a null "cse" field in the first_tp_hist array
* when it would have been modified as part of the kill in which case we
* need to modify the first_tp_hist array appropriately). In that
* rare case (i.e. local_hash_entry is NULL), we don't need to change
* anything in the first_tp_hist array anyway since we would have updated
* it during the previous for-loop for the first history. Hence the check
* for if (local_hash_entry) below.
*/
/* Ensure that "first_tp_srch_status" reflects what is in the hash-table.
* The only exception is when two histories are passed (explained above)
*/
assert(local_hash_entry && lookup_tabent && (local_hash_entry == lookup_tabent->value)
|| !local_hash_entry && (hist == hist1));
/* Ensure we don't miss updating "cse" */
assert((NULL != local_hash_entry) || ((srch_blk_status *)(tabent->value))->cse|| !t1->cse);
assert(!local_hash_entry || !local_hash_entry->cse || !t1->cse
|| (t1->cse == local_hash_entry->cse)
|| (t1->cse->low_tlevel == local_hash_entry->cse));
if (local_hash_entry && t1->cse)
{
assert(is_mm || local_hash_entry->cse
|| ((t1->first_tp_srch_status == local_hash_entry)
&& (t1->cycle == local_hash_entry->cycle)
&& (t1->cr == local_hash_entry->cr)
&& (t1->buffaddr == local_hash_entry->buffaddr)));
local_hash_entry->cse = t1->cse;
}
}
}
t1->cse = NULL;
}
# ifdef DEBUG
/* Now that this history has been successfully validated, check that the current history transaction
* numbers can never be older than their corresponding first_tp_srch_status values.
*/
if (cdb_sc_normal == status)
{
for (t1 = hist->h; HIST_TERMINATOR != (blk = t1->blk_num); t1++)
{
t2 = t1->first_tp_srch_status ? t1->first_tp_srch_status : t1;
assert(t2->tn <= t1->tn);
/* Take this time to also check that gv_targets match between t1 and t2.
* If they dont, the restart should be detected in tp_tend.
* Set the flag donot_commit to catch the case this does not restart.
*/
if (t2->blk_target != t1->blk_target)
TREF(donot_commit) |= DONOTCOMMIT_TPHIST_BLKTARGET_MISMATCH;
}
}
# endif
}
/* If validation has succeeded, assert that if gtm_gvundef_fatal is non-zero, then we better not signal a GVUNDEF */
assert((cdb_sc_normal != status) || !TREF(gtm_gvundef_fatal) || !ready2signal_gvundef_lcl);
ADD_TO_GVT_TP_LIST(gvt); /* updates gvt->read_local_tn & adds gvt to gvt_tp_list : both only if needed */
CWS_RESET;
return status;
}
void gds_tp_hist_moved(sgm_info *si, srch_hist *hist1)
{
gv_namehead *gvnh;
ht_ent_int4 *tabent, *topent;
sm_long_t delta;
srch_blk_status *new_first_tp_hist, *t1;
tlevel_info *tli;
srch_blk_status *srch_stat;
sgmnt_addrs *csa;
assert(si->cur_tp_hist_size < si->tp_hist_size);
si->cur_tp_hist_size <<= 1;
new_first_tp_hist = (srch_blk_status *)malloc(SIZEOF(srch_blk_status) * si->cur_tp_hist_size);
longcpy((uchar_ptr_t)new_first_tp_hist, (uchar_ptr_t)si->first_tp_hist,
(sm_uc_ptr_t)si->last_tp_hist - (sm_uc_ptr_t)si->first_tp_hist);
delta = (sm_long_t)((sm_uc_ptr_t)new_first_tp_hist - (sm_uc_ptr_t)si->first_tp_hist);
for (tabent = si->blks_in_use->base, topent = si->blks_in_use->top; tabent < topent; tabent++)
{
if (HTENT_VALID_INT4(tabent, srch_blk_status, srch_stat))
{
REPOSITION_PTR(srch_stat, srch_blk_status, delta, si->first_tp_hist, si->last_tp_hist);
tabent->value = (void *)srch_stat;
}
}
for (tli = si->tlvl_info_head; tli; tli = tli->next_tlevel_info)
REPOSITION_PTR_IF_NOT_NULL(tli->tlvl_tp_hist_info, srch_blk_status, delta, si->first_tp_hist, si->last_tp_hist);
csa = si->tp_csa;
/* Adjust histories of gvtargets used in this TP transaction. Note that it is possible "gv_target" or "cs_addrs->dir_tree"
* might not yet be part of this list even though they will be at the end of the current invocation of tp_hist.
* In this case too gv_target's pointers need to be repositioned.
*/
for (gvnh = gvt_tp_list; NULL != gvnh; gvnh = gvnh->next_tp_gvnh)
{
assert(gvnh->read_local_tn == local_tn);
REPOSITION_GVNH_HIST(gvnh, csa, delta, si);
}
if (local_tn != gv_target->read_local_tn) /* Note: gv_target could be "cs_addrs->dir_tree" at this point in some cases */
REPOSITION_GVNH_HIST(gv_target, csa, delta, si);
/* cs_addrs->dir_tree (directory tree) history does not need any special repositioning. That is because either
* (a) It is the same as gv_target in which case we would have done the repositioning in the previous statement OR
* (b) It is different from gv_target in which case there are two subcases.
* (1) It was accessed in this TP transaction. If so it would have been in gvt_tp_list and repositioning
* would have already happened above.
* (2) It was NOT accessed in this TP transaction. If so it will not have any "first_tp_srch_status" fields
* that need repositioning either. Any non-zero "first_tp_srch_status" values are left over from
* previous transactions and could coincidentally match our current tp_hist range so we can not
* even add any asserts to validate this reasoning.
*/
assert(NULL == hist1 || hist1 != &gv_target->hist); /* ensure that gv_target isn't doubly repositioned */
if ((NULL != hist1) && (hist1 != &cs_addrs->dir_tree->hist)) /* ensure we don't reposition directory tree again */
{
for (t1 = hist1->h; t1->blk_num; t1++)
REPOSITION_PTR_IF_NOT_NULL(t1->first_tp_srch_status, struct srch_blk_status_struct,
delta, si->first_tp_hist, si->last_tp_hist);
}
free(si->first_tp_hist);
si->first_tp_hist = new_first_tp_hist;
si->last_tp_hist = (srch_blk_status *)((sm_uc_ptr_t)si->last_tp_hist + delta);
}
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