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mdbx: cleanup freelist_save().

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Change-Id: I552e6d7edac61e66b8954f6b58485d6b07194ab5
This commit is contained in:
Leo Yuriev 2017-07-23 16:25:25 +03:00
parent 1babb0a4f7
commit 4fa4129add
1 changed files with 47 additions and 46 deletions
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91
src/mdbx.c
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@ -2896,25 +2896,24 @@ static int mdbx_freelist_save(MDBX_txn *txn) {
* Page numbers cannot disappear from txn->mt_free_pages[]. */ * Page numbers cannot disappear from txn->mt_free_pages[]. */
MDBX_cursor mc; MDBX_cursor mc;
MDBX_env *env = txn->mt_env; MDBX_env *env = txn->mt_env;
int rc, maxfree_1pg = env->me_maxfree_1pg, more = 1; int rc, more = 1;
txnid_t cleanup_reclaimed_id = 0, head_id = 0; txnid_t cleanup_reclaimed_id = 0, head_id = 0;
pgno_t befree_count = 0, *mop; pgno_t befree_count = 0;
ssize_t head_room = 0, total_room = 0, mop_len, clean_limit; ssize_t head_room = 0, total_room = 0;
unsigned cleanup_reclaimed_pos = 0, refill_reclaimed_pos = 0; unsigned cleanup_reclaimed_pos = 0, refill_reclaimed_pos = 0;
const bool lifo = (env->me_flags & MDBX_LIFORECLAIM) != 0; const bool lifo = (env->me_flags & MDBX_LIFORECLAIM) != 0;
mdbx_cursor_init(&mc, txn, FREE_DBI, NULL); mdbx_cursor_init(&mc, txn, FREE_DBI, NULL);
/* MDBX_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */ /* MDBX_RESERVE cancels meminit in ovpage malloc (when no WRITEMAP) */
clean_limit = (env->me_flags & (MDBX_NOMEMINIT | MDBX_WRITEMAP)) const ssize_t clean_limit = (env->me_flags & (MDBX_NOMEMINIT | MDBX_WRITEMAP))
? SSIZE_MAX ? SSIZE_MAX
: maxfree_1pg; : env->me_maxfree_1pg;
again_on_freelist_change: again_on_freelist_change:
for (;;) { while (1) {
/* Come back here after each Put() in case freelist changed */ /* Come back here after each Put() in case freelist changed */
MDBX_val key, data; MDBX_val key, data;
ssize_t j;
if (!lifo) { if (!lifo) {
/* If using records from freeDB which we have not yet deleted, /* If using records from freeDB which we have not yet deleted,
@ -3009,19 +3008,19 @@ again_on_freelist_change:
continue; continue;
} }
mop = env->me_reclaimed_pglist; const ssize_t rpl_len =
mop_len = (mop ? mop[0] : 0) + txn->mt_loose_count; (env->me_reclaimed_pglist ? env->me_reclaimed_pglist[0] : 0) +
txn->mt_loose_count;
if (mop_len && refill_reclaimed_pos == 0) if (rpl_len && refill_reclaimed_pos == 0)
refill_reclaimed_pos = 1; refill_reclaimed_pos = 1;
/* Reserve records for me_reclaimed_pglist[]. Split it if multi-page, /* Reserve records for me_reclaimed_pglist[]. Split it if multi-page,
* to avoid searching freeDB for a page range. Use keys in * to avoid searching freeDB for a page range. Use keys in
* range [1,me_last_reclaimed]: Smaller than txnid of oldest reader. */ * range [1,me_last_reclaimed]: Smaller than txnid of oldest reader. */
if (total_room >= mop_len) { if (total_room >= rpl_len) {
if (total_room == mop_len || --more < 0) if (total_room == rpl_len || --more < 0)
break; break;
} else if (head_room >= maxfree_1pg && head_id > 1) { } else if (head_room >= env->me_maxfree_1pg && head_id > 1) {
/* Keep current record (overflow page), add a new one */ /* Keep current record (overflow page), add a new one */
head_id--; head_id--;
refill_reclaimed_pos++; refill_reclaimed_pos++;
@ -3068,12 +3067,12 @@ again_on_freelist_change:
/* (Re)write {key = head_id, IDL length = head_room} */ /* (Re)write {key = head_id, IDL length = head_room} */
total_room -= head_room; total_room -= head_room;
head_room = mop_len - total_room; head_room = rpl_len - total_room;
if (head_room > maxfree_1pg && head_id > 1) { if (head_room > env->me_maxfree_1pg && head_id > 1) {
/* Overflow multi-page for part of me_reclaimed_pglist */ /* Overflow multi-page for part of me_reclaimed_pglist */
head_room /= (head_id < INT16_MAX) ? (pgno_t)head_id head_room /= (head_id < INT16_MAX) ? (pgno_t)head_id
: INT16_MAX; /* amortize page sizes */ : INT16_MAX; /* amortize page sizes */
head_room += maxfree_1pg - head_room % (maxfree_1pg + 1); head_room += env->me_maxfree_1pg - head_room % (env->me_maxfree_1pg + 1);
} else if (head_room < 0) { } else if (head_room < 0) {
/* Rare case, not bothering to delete this record */ /* Rare case, not bothering to delete this record */
head_room = 0; head_room = 0;
@ -3088,10 +3087,10 @@ again_on_freelist_change:
/* IDL is initially empty, zero out at least the length */ /* IDL is initially empty, zero out at least the length */
pgno_t *pgs = (pgno_t *)data.iov_base; pgno_t *pgs = (pgno_t *)data.iov_base;
j = head_room > clean_limit ? head_room : 0; ssize_t i = head_room > clean_limit ? head_room : 0;
do { do {
pgs[j] = 0; pgs[i] = 0;
} while (--j >= 0); } while (--i >= 0);
total_room += head_room; total_room += head_room;
continue; continue;
} }
@ -3103,43 +3102,40 @@ again_on_freelist_change:
/* Return loose page numbers to me_reclaimed_pglist, though usually none are /* Return loose page numbers to me_reclaimed_pglist, though usually none are
* left at this point. The pages themselves remain in dirtylist. */ * left at this point. The pages themselves remain in dirtylist. */
if (txn->mt_loose_pages) { if (txn->mt_loose_pages) {
MDBX_page *mp = txn->mt_loose_pages;
unsigned count = txn->mt_loose_count;
MDBX_IDL loose;
/* Room for loose pages + temp IDL with same */ /* Room for loose pages + temp IDL with same */
if ((rc = mdbx_midl_need(&env->me_reclaimed_pglist, 2 * count + 1)) != 0) if ((rc = mdbx_midl_need(&env->me_reclaimed_pglist,
2 * txn->mt_loose_count + 1)) != 0)
goto bailout; goto bailout;
mop = env->me_reclaimed_pglist; MDBX_IDL loose = env->me_reclaimed_pglist +
loose = mop + MDBX_IDL_ALLOCLEN(mop) - count; MDBX_IDL_ALLOCLEN(env->me_reclaimed_pglist) -
for (count = 0; mp; mp = NEXT_LOOSE_PAGE(mp)) txn->mt_loose_count;
unsigned count = 0;
for (MDBX_page *mp = txn->mt_loose_pages; mp; mp = NEXT_LOOSE_PAGE(mp))
loose[++count] = mp->mp_pgno; loose[++count] = mp->mp_pgno;
loose[0] = count; loose[0] = count;
mdbx_midl_sort(loose); mdbx_midl_sort(loose);
mdbx_midl_xmerge(mop, loose); mdbx_midl_xmerge(env->me_reclaimed_pglist, loose);
txn->mt_loose_pages = NULL; txn->mt_loose_pages = NULL;
txn->mt_loose_count = 0; txn->mt_loose_count = 0;
mop_len = mop[0];
} }
/* Fill in the reserved me_reclaimed_pglist records */ /* Fill in the reserved me_reclaimed_pglist records */
rc = MDBX_SUCCESS; rc = MDBX_SUCCESS;
if (mop_len) { if (env->me_reclaimed_pglist && env->me_reclaimed_pglist[0]) {
MDBX_val key, data; MDBX_val key, data;
key.iov_len = data.iov_len = 0; /* avoid MSVC warning */ key.iov_len = data.iov_len = 0; /* avoid MSVC warning */
key.iov_base = data.iov_base = NULL; key.iov_base = data.iov_base = NULL;
mop += mop_len; size_t rpl_left = env->me_reclaimed_pglist[0];
pgno_t *rpl_end = env->me_reclaimed_pglist + rpl_left;
if (!lifo) { if (!lifo) {
rc = mdbx_cursor_first(&mc, &key, &data); rc = mdbx_cursor_first(&mc, &key, &data);
if (unlikely(rc)) if (unlikely(rc))
goto bailout; goto bailout;
} }
for (;;) { while (1) {
txnid_t id; txnid_t id;
ssize_t len;
pgno_t save;
if (!lifo) { if (!lifo) {
id = *(txnid_t *)key.iov_base; id = *(txnid_t *)key.iov_base;
mdbx_tassert(txn, id <= env->me_last_reclaimed); mdbx_tassert(txn, id <= env->me_last_reclaimed);
@ -3158,25 +3154,30 @@ again_on_freelist_change:
txn, cleanup_reclaimed_pos == txn, cleanup_reclaimed_pos ==
(txn->mt_lifo_reclaimed ? txn->mt_lifo_reclaimed[0] : 0)); (txn->mt_lifo_reclaimed ? txn->mt_lifo_reclaimed[0] : 0));
len = (ssize_t)(data.iov_len / sizeof(pgno_t)) - 1; mdbx_tassert(txn, data.iov_len >= sizeof(pgno_t) * 2);
mdbx_tassert(txn, len >= 0); size_t chunk_len = (data.iov_len / sizeof(pgno_t)) - 1;
if (len > mop_len) if (chunk_len > rpl_left)
len = mop_len; chunk_len = rpl_left;
data.iov_len = (len + 1) * sizeof(pgno_t); data.iov_len = (chunk_len + 1) * sizeof(pgno_t);
key.iov_base = &id; key.iov_base = &id;
key.iov_len = sizeof(id); key.iov_len = sizeof(id);
data.iov_base = mop -= len;
save = mop[0]; rpl_end -= chunk_len;
mop[0] = (pgno_t)len; data.iov_base = rpl_end;
pgno_t save = rpl_end[0];
rpl_end[0] = (pgno_t)chunk_len;
rc = mdbx_cursor_put(&mc, &key, &data, MDBX_CURRENT); rc = mdbx_cursor_put(&mc, &key, &data, MDBX_CURRENT);
mdbx_tassert( mdbx_tassert(
txn, cleanup_reclaimed_pos == txn, cleanup_reclaimed_pos ==
(txn->mt_lifo_reclaimed ? txn->mt_lifo_reclaimed[0] : 0)); (txn->mt_lifo_reclaimed ? txn->mt_lifo_reclaimed[0] : 0));
mop[0] = save; rpl_end[0] = save;
if (unlikely(rc || (mop_len -= len) == 0)) if (unlikely(rc))
goto bailout; goto bailout;
rpl_left -= chunk_len;
if (rpl_left == 0)
break;
if (!lifo) { if (!lifo) {
rc = mdbx_cursor_next(&mc, &key, &data, MDBX_NEXT); rc = mdbx_cursor_next(&mc, &key, &data, MDBX_NEXT);
if (unlikely(rc)) if (unlikely(rc))