static void *
ops(void *arg)
{
TINFO *tinfo;
WT_CONNECTION *conn;
WT_CURSOR *cursor, *cursor_insert;
WT_SESSION *session;
WT_ITEM key, value;
uint64_t keyno, ckpt_op, reset_op, session_op;
uint32_t op;
uint8_t *keybuf, *valbuf;
u_int np;
int ckpt_available, dir, insert, intxn, notfound, readonly;
char *ckpt_config, ckpt_name[64];
tinfo = arg;
conn = g.wts_conn;
keybuf = valbuf = NULL;
readonly = 0; /* -Wconditional-uninitialized */
/* Initialize the per-thread random number generator. */
__wt_random_init(&tinfo->rnd);
/* Set up the default key and value buffers. */
key_gen_setup(&keybuf);
val_gen_setup(&tinfo->rnd, &valbuf);
/* Set the first operation where we'll create sessions and cursors. */
session_op = 0;
session = NULL;
cursor = cursor_insert = NULL;
/* Set the first operation where we'll perform checkpoint operations. */
ckpt_op = g.c_checkpoints ? mmrand(&tinfo->rnd, 100, 10000) : 0;
ckpt_available = 0;
/* Set the first operation where we'll reset the session. */
reset_op = mmrand(&tinfo->rnd, 100, 10000);
for (intxn = 0; !tinfo->quit; ++tinfo->ops) {
/*
* We can't checkpoint or swap sessions/cursors while in a
* transaction, resolve any running transaction.
*/
if (intxn &&
(tinfo->ops == ckpt_op || tinfo->ops == session_op)) {
testutil_check(
session->commit_transaction(session, NULL));
++tinfo->commit;
intxn = 0;
}
/* Open up a new session and cursors. */
if (tinfo->ops == session_op ||
session == NULL || cursor == NULL) {
if (session != NULL)
testutil_check(session->close(session, NULL));
testutil_check(conn->open_session(conn, NULL,
ops_session_config(&tinfo->rnd), &session));
/*
* 10% of the time, perform some read-only operations
* from a checkpoint.
*
* Skip that if we single-threaded and doing checks
* against a Berkeley DB database, because that won't
* work because the Berkeley DB database records won't
* match the checkpoint. Also skip if we are using
* LSM, because it doesn't support reads from
* checkpoints.
*/
if (!SINGLETHREADED && !DATASOURCE("lsm") &&
ckpt_available && mmrand(&tinfo->rnd, 1, 10) == 1) {
testutil_check(session->open_cursor(session,
g.uri, NULL, ckpt_name, &cursor));
/* Pick the next session/cursor close/open. */
session_op += 250;
/* Checkpoints are read-only. */
readonly = 1;
} else {
/*
* Open two cursors: one for overwriting and one
* for append (if it's a column-store).
*
* The reason is when testing with existing
* records, we don't track if a record was
* deleted or not, which means we must use
* cursor->insert with overwriting configured.
* But, in column-store files where we're
* testing with new, appended records, we don't
* want to have to specify the record number,
* which requires an append configuration.
*/
testutil_check(session->open_cursor(session,
g.uri, NULL, "overwrite", &cursor));
if (g.type == FIX || g.type == VAR)
testutil_check(session->open_cursor(
session, g.uri,
NULL, "append", &cursor_insert));
/* Pick the next session/cursor close/open. */
session_op += mmrand(&tinfo->rnd, 100, 5000);
/* Updates supported. */
readonly = 0;
}
}
/* Checkpoint the database. */
if (tinfo->ops == ckpt_op && g.c_checkpoints) {
/*
* LSM and data-sources don't support named checkpoints,
* and we can't drop a named checkpoint while there's a
* cursor open on it, otherwise 20% of the time name the
* checkpoint.
*/
if (DATASOURCE("helium") || DATASOURCE("kvsbdb") ||
DATASOURCE("lsm") ||
readonly || mmrand(&tinfo->rnd, 1, 5) == 1)
ckpt_config = NULL;
else {
(void)snprintf(ckpt_name, sizeof(ckpt_name),
"name=thread-%d", tinfo->id);
ckpt_config = ckpt_name;
}
/* Named checkpoints lock out backups */
if (ckpt_config != NULL)
testutil_check(
pthread_rwlock_wrlock(&g.backup_lock));
testutil_checkfmt(
session->checkpoint(session, ckpt_config),
"%s", ckpt_config == NULL ? "" : ckpt_config);
if (ckpt_config != NULL)
testutil_check(
pthread_rwlock_unlock(&g.backup_lock));
/* Rephrase the checkpoint name for cursor open. */
if (ckpt_config == NULL)
strcpy(ckpt_name,
"checkpoint=WiredTigerCheckpoint");
else
(void)snprintf(ckpt_name, sizeof(ckpt_name),
"checkpoint=thread-%d", tinfo->id);
ckpt_available = 1;
/* Pick the next checkpoint operation. */
ckpt_op += mmrand(&tinfo->rnd, 5000, 20000);
}
/*
* Reset the session every now and then, just to make sure that
* operation gets tested. Note the test is not for equality, we
* have to do the reset outside of a transaction.
*/
if (tinfo->ops > reset_op && !intxn) {
testutil_check(session->reset(session));
/* Pick the next reset operation. */
reset_op += mmrand(&tinfo->rnd, 20000, 50000);
}
/*
* If we're not single-threaded and we're not in a transaction,
* start a transaction 20% of the time.
*/
if (!SINGLETHREADED &&
!intxn && mmrand(&tinfo->rnd, 1, 10) >= 8) {
testutil_check(
session->begin_transaction(session, NULL));
intxn = 1;
}
insert = notfound = 0;
keyno = mmrand(&tinfo->rnd, 1, (u_int)g.rows);
key.data = keybuf;
value.data = valbuf;
/*
* Perform some number of operations: the percentage of deletes,
* inserts and writes are specified, reads are the rest. The
* percentages don't have to add up to 100, a high percentage
* of deletes will mean fewer inserts and writes. Modifications
* are always followed by a read to confirm it worked.
*/
op = readonly ? UINT32_MAX : mmrand(&tinfo->rnd, 1, 100);
if (op < g.c_delete_pct) {
++tinfo->remove;
switch (g.type) {
case ROW:
/*
* If deleting a non-existent record, the cursor
* won't be positioned, and so can't do a next.
*/
if (row_remove(cursor, &key, keyno, ¬found))
goto deadlock;
break;
case FIX:
case VAR:
if (col_remove(cursor, &key, keyno, ¬found))
goto deadlock;
break;
}
} else if (op < g.c_delete_pct + g.c_insert_pct) {
++tinfo->insert;
switch (g.type) {
case ROW:
if (row_insert(
tinfo, cursor, &key, &value, keyno))
goto deadlock;
insert = 1;
break;
case FIX:
case VAR:
/*
* We can only append so many new records, if
* we've reached that limit, update a record
* instead of doing an insert.
*/
if (g.append_cnt >= g.append_max)
goto skip_insert;
/* Insert, then reset the insert cursor. */
if (col_insert(tinfo,
cursor_insert, &key, &value, &keyno))
goto deadlock;
testutil_check(
cursor_insert->reset(cursor_insert));
insert = 1;
break;
}
} else if (
op < g.c_delete_pct + g.c_insert_pct + g.c_write_pct) {
++tinfo->update;
switch (g.type) {
case ROW:
if (row_update(
tinfo, cursor, &key, &value, keyno))
goto deadlock;
break;
case FIX:
case VAR:
skip_insert:
if (col_update(tinfo,
cursor, &key, &value, keyno))
goto deadlock;
break;
}
} else {
++tinfo->search;
if (read_row(cursor, &key, keyno, 0))
if (intxn)
goto deadlock;
continue;
}
/*
* The cursor is positioned if we did any operation other than
* insert, do a small number of next/prev cursor operations in
* a random direction.
*/
if (!insert) {
dir = (int)mmrand(&tinfo->rnd, 0, 1);
for (np = 0; np < mmrand(&tinfo->rnd, 1, 100); ++np) {
if (notfound)
break;
if (nextprev(cursor, dir, ¬found))
goto deadlock;
}
}
/* Read to confirm the operation. */
++tinfo->search;
if (read_row(cursor, &key, keyno, 0))
goto deadlock;
/* Reset the cursor: there is no reason to keep pages pinned. */
testutil_check(cursor->reset(cursor));
/*
* If we're in the transaction, commit 40% of the time and
* rollback 10% of the time.
*/
if (intxn)
switch (mmrand(&tinfo->rnd, 1, 10)) {
case 1:
case 2:
case 3:
case 4: /* 40% */
testutil_check(session->commit_transaction(
session, NULL));
++tinfo->commit;
intxn = 0;
break;
case 5: /* 10% */
if (0) {
deadlock:
++tinfo->deadlock;
}
testutil_check(session->rollback_transaction(
session, NULL));
++tinfo->rollback;
intxn = 0;
break;
default:
break;
}
}
if (session != NULL)
testutil_check(session->close(session, NULL));
free(keybuf);
free(valbuf);
tinfo->state = TINFO_COMPLETE;
return (NULL);
}
void WiredTigerSessionCache::releaseSession(WiredTigerSession* session) {
invariant(session);
invariant(session->cursorsOut() == 0);
const int shuttingDown = _shuttingDown.fetchAndAdd(1);
ON_BLOCK_EXIT([this] { _shuttingDown.fetchAndSubtract(1); });
if (shuttingDown & kShuttingDownMask) {
// There is a race condition with clean shutdown, where the storage engine is ripped from
// underneath OperationContexts, which are not "active" (i.e., do not have any locks), but
// are just about to delete the recovery unit. See SERVER-16031 for more information. Since
// shutting down the WT_CONNECTION will close all WT_SESSIONS, we shouldn't also try to
// directly close this session.
session->_session = nullptr; // Prevents calling _session->close() in destructor.
delete session;
return;
}
{
WT_SESSION* ss = session->getSession();
uint64_t range;
// This checks that we are only caching idle sessions and not something which might hold
// locks or otherwise prevent truncation.
invariantWTOK(ss->transaction_pinned_range(ss, &range));
invariant(range == 0);
// Release resources in the session we're about to cache.
// If we are using hybrid caching, then close cursors now and let them
// be cached at the WiredTiger level.
if (kWiredTigerCursorCacheSize.load() < 0) {
session->closeAllCursors("");
}
invariantWTOK(ss->reset(ss));
}
// If the cursor epoch has moved on, close all cursors in the session.
uint64_t cursorEpoch = _cursorEpoch.load();
if (session->_getCursorEpoch() != cursorEpoch)
session->closeCursorsForQueuedDrops(_engine);
bool returnedToCache = false;
uint64_t currentEpoch = _epoch.load();
bool dropQueuedIdentsAtSessionEnd = session->isDropQueuedIdentsAtSessionEndAllowed();
// Reset this session's flag for dropping queued idents to default, before returning it to
// session cache.
session->dropQueuedIdentsAtSessionEndAllowed(true);
if (session->_getEpoch() == currentEpoch) { // check outside of lock to reduce contention
stdx::lock_guard<stdx::mutex> lock(_cacheLock);
if (session->_getEpoch() == _epoch.load()) { // recheck inside the lock for correctness
returnedToCache = true;
_sessions.push_back(session);
}
} else
invariant(session->_getEpoch() < currentEpoch);
if (!returnedToCache)
delete session;
if (dropQueuedIdentsAtSessionEnd && _engine && _engine->haveDropsQueued())
_engine->dropSomeQueuedIdents();
}
