/*
* __session_checkpoint --
* WT_SESSION->checkpoint method.
*/
static int
__session_checkpoint(WT_SESSION *wt_session, const char *config)
{
WT_DECL_RET;
WT_SESSION_IMPL *session;
WT_TXN *txn;
session = (WT_SESSION_IMPL *)wt_session;
txn = &session->txn;
WT_CSTAT_INCR(session, checkpoint);
SESSION_API_CALL(session, checkpoint, config, cfg);
/*
* Checkpoints require a snapshot to write a transactionally consistent
* snapshot of the data.
*
* We can't use an application's transaction: if it has uncommitted
* changes, they will be written in the checkpoint and may appear after
* a crash.
*
* Use a real snapshot transaction: we don't want any chance of the
* snapshot being updated during the checkpoint. Eviction is prevented
* from evicting anything newer than this because we track the oldest
* transaction ID in the system that is not visible to all readers.
*/
if (F_ISSET(txn, TXN_RUNNING))
WT_ERR_MSG(session, EINVAL,
"Checkpoint not permitted in a transaction");
/*
* Reset open cursors.
*
* We do this here explicitly even though it will happen implicitly in
* the call to begin_transaction for the checkpoint, in case some
* implementation of WT_CURSOR::reset needs the schema lock.
*/
WT_ERR(__session_reset_cursors(session));
WT_WITH_SCHEMA_LOCK(session,
ret = __wt_txn_checkpoint(session, cfg));
err: API_END_NOTFOUND_MAP(session, ret);
}
/*
* __compact_checkpoint --
* Perform a checkpoint for compaction.
*/
static int
__compact_checkpoint(WT_SESSION_IMPL *session)
{
WT_DECL_RET;
WT_TXN_GLOBAL *txn_global;
uint64_t txn_gen;
/*
* Force compaction checkpoints: we don't want to skip it because the
* work we need to have done is done in the underlying block manager.
*/
const char *checkpoint_cfg[] = {
WT_CONFIG_BASE(session, WT_SESSION_checkpoint), "force=1", NULL };
/* Checkpoints take a lot of time, check if we've run out. */
WT_RET(__wt_session_compact_check_timeout(session));
if ((ret = __wt_txn_checkpoint(session, checkpoint_cfg, false)) == 0)
return (0);
WT_RET_BUSY_OK(ret);
/*
* If there's a checkpoint running, wait for it to complete, checking if
* we're out of time. If there's no checkpoint running or the checkpoint
* generation number changes, the checkpoint blocking us has completed.
*/
txn_global = &S2C(session)->txn_global;
for (txn_gen = __wt_gen(session, WT_GEN_CHECKPOINT);;) {
/*
* This loop only checks objects that are declared volatile,
* therefore no barriers are needed.
*/
if (!txn_global->checkpoint_running ||
txn_gen != __wt_gen(session, WT_GEN_CHECKPOINT))
break;
WT_RET(__wt_session_compact_check_timeout(session));
__wt_sleep(2, 0);
}
return (0);
}
