/*
* __split_stash_add --
* Add a new entry into the session's split stash list.
*/
static int
__split_stash_add(WT_SESSION_IMPL *session, void *p, size_t len)
{
WT_SPLIT_STASH *stash;
WT_ASSERT(session, p != NULL);
/* Grow the list as necessary. */
WT_RET(__wt_realloc_def(session, &session->split_stash_alloc,
session->split_stash_cnt + 1, &session->split_stash));
stash = session->split_stash + session->split_stash_cnt++;
stash->split_gen = WT_ATOMIC_ADD(S2C(session)->split_gen, 1);
stash->p = p;
stash->len = len;
WT_STAT_FAST_CONN_ATOMIC_INCRV(session, rec_split_stashed_bytes, len);
WT_STAT_FAST_CONN_ATOMIC_INCR(session, rec_split_stashed_objects);
/* See if we can free any previous entries. */
if (session->split_stash_cnt > 1)
__wt_split_stash_discard(session);
return (0);
}
/*
* __wt_lsm_tree_switch --
* Switch to a new in-memory tree.
*/
int
__wt_lsm_tree_switch(
WT_SESSION_IMPL *session, WT_LSM_TREE *lsm_tree)
{
WT_DECL_RET;
WT_LSM_CHUNK *chunk;
uint32_t new_id;
new_id = WT_ATOMIC_ADD(lsm_tree->last, 1);
WT_VERBOSE_RET(session, lsm, "Tree switch to: %d", new_id);
if ((lsm_tree->nchunks + 1) * sizeof(*lsm_tree->chunk) >
lsm_tree->chunk_alloc)
WT_ERR(__wt_realloc(session,
&lsm_tree->chunk_alloc,
WT_MAX(10 * sizeof(*lsm_tree->chunk),
2 * lsm_tree->chunk_alloc),
&lsm_tree->chunk));
WT_ERR(__wt_calloc_def(session, 1, &chunk));
chunk->id = new_id;
lsm_tree->chunk[lsm_tree->nchunks++] = chunk;
WT_ERR(__wt_lsm_tree_setup_chunk(session, lsm_tree, chunk));
++lsm_tree->dsk_gen;
WT_ERR(__wt_lsm_meta_write(session, lsm_tree));
err: /* TODO: mark lsm_tree bad on error(?) */
return (ret);
}
/*
* __wt_lsm_tree_switch --
* Switch to a new in-memory tree.
*/
int
__wt_lsm_tree_switch(
WT_SESSION_IMPL *session, WT_LSM_TREE *lsm_tree)
{
WT_DECL_RET;
WT_LSM_CHUNK *chunk, **cp;
uint32_t in_memory, new_id;
new_id = WT_ATOMIC_ADD(lsm_tree->last, 1);
if ((lsm_tree->nchunks + 1) * sizeof(*lsm_tree->chunk) >
lsm_tree->chunk_alloc)
WT_ERR(__wt_realloc(session,
&lsm_tree->chunk_alloc,
WT_MAX(10 * sizeof(*lsm_tree->chunk),
2 * lsm_tree->chunk_alloc),
&lsm_tree->chunk));
/*
* In the steady state, we expect that the checkpoint worker thread
* will keep up with inserts. If not, we throttle the insert rate to
* avoid filling the cache with in-memory chunks. Threads sleep every
* 100 operations, so take that into account in the calculation.
*/
for (in_memory = 1, cp = lsm_tree->chunk + lsm_tree->nchunks - 1;
in_memory < lsm_tree->nchunks && !F_ISSET(*cp, WT_LSM_CHUNK_ONDISK);
++in_memory, --cp)
;
if (!F_ISSET(lsm_tree, WT_LSM_TREE_THROTTLE) || in_memory <= 2)
lsm_tree->throttle_sleep = 0;
else if (in_memory == lsm_tree->nchunks ||
F_ISSET(*cp, WT_LSM_CHUNK_STABLE)) {
/*
* No checkpoint has completed this run. Keep slowing down
* inserts until one does.
*/
lsm_tree->throttle_sleep =
WT_MAX(20, 2 * lsm_tree->throttle_sleep);
} else {
chunk = lsm_tree->chunk[lsm_tree->nchunks - 1];
lsm_tree->throttle_sleep = (long)((in_memory - 2) *
WT_TIMEDIFF(chunk->create_ts, (*cp)->create_ts) /
(20 * in_memory * chunk->count));
}
WT_VERBOSE_ERR(session, lsm, "Tree switch to: %d, throttle %d",
new_id, (int)lsm_tree->throttle_sleep);
WT_ERR(__wt_calloc_def(session, 1, &chunk));
chunk->id = new_id;
lsm_tree->chunk[lsm_tree->nchunks++] = chunk;
WT_ERR(__wt_lsm_tree_setup_chunk(session, lsm_tree, chunk));
++lsm_tree->dsk_gen;
F_CLR(lsm_tree, WT_LSM_TREE_NEED_SWITCH);
WT_ERR(__wt_lsm_meta_write(session, lsm_tree));
err: /* TODO: mark lsm_tree bad on error(?) */
return (ret);
}
/*
* __wt_lsm_tree_truncate --
* Truncate an LSM tree.
*/
int
__wt_lsm_tree_truncate(
WT_SESSION_IMPL *session, const char *name, const char *cfg[])
{
WT_DECL_RET;
WT_LSM_CHUNK *chunk;
WT_LSM_TREE *lsm_tree;
int locked;
WT_UNUSED(cfg);
chunk = NULL;
locked = 0;
/* Get the LSM tree. */
WT_RET(__wt_lsm_tree_get(session, name, 1, &lsm_tree));
/* Shut down the LSM worker. */
WT_RET(__lsm_tree_close(session, lsm_tree));
/* Prevent any new opens. */
WT_RET(__wt_lsm_tree_lock(session, lsm_tree, 1));
locked = 1;
/* Create the new chunk. */
WT_ERR(__wt_calloc_def(session, 1, &chunk));
chunk->id = WT_ATOMIC_ADD(lsm_tree->last, 1);
WT_ERR(__wt_lsm_tree_setup_chunk(session, lsm_tree, chunk));
/* Mark all chunks old. */
WT_ERR(__wt_lsm_merge_update_tree(
session, lsm_tree, 0, lsm_tree->nchunks, chunk));
WT_ERR(__wt_lsm_meta_write(session, lsm_tree));
WT_ERR(__lsm_tree_start_worker(session, lsm_tree));
locked = 0;
WT_ERR(__wt_lsm_tree_unlock(session, lsm_tree));
__wt_lsm_tree_release(session, lsm_tree);
err: if (locked)
WT_TRET(__wt_lsm_tree_unlock(session, lsm_tree));
if (ret != 0) {
if (chunk != NULL) {
(void)__wt_schema_drop(session, chunk->uri, NULL);
__wt_free(session, chunk);
}
/*
* Discard the LSM tree structure on error. This will force the
* LSM tree to be re-opened the next time it is accessed and
* the last good version of the metadata will be used, resulting
* in a valid (not truncated) tree.
*/
WT_TRET(__lsm_tree_discard(session, lsm_tree));
}
return (ret);
}
/*
* __wt_cond_wait --
* Wait on a mutex, optionally timing out.
*/
int
__wt_cond_wait(WT_SESSION_IMPL *session, WT_CONDVAR *cond, long usecs)
{
struct timespec ts;
WT_DECL_RET;
int locked;
locked = 0;
WT_ASSERT(session, usecs >= 0);
/* Fast path if already signalled. */
if (WT_ATOMIC_ADD(cond->waiters, 1) == 0)
return (0);
/*
* !!!
* This function MUST handle a NULL session handle.
*/
if (session != NULL) {
WT_VERBOSE_RET(
session, mutex, "wait %s cond (%p)", cond->name, cond);
WT_STAT_FAST_CONN_INCR(session, cond_wait);
}
WT_ERR(pthread_mutex_lock(&cond->mtx));
locked = 1;
if (usecs > 0) {
WT_ERR(__wt_epoch(session, &ts));
ts.tv_sec += (ts.tv_nsec + 1000 * usecs) / WT_BILLION;
ts.tv_nsec = (ts.tv_nsec + 1000 * usecs) % WT_BILLION;
ret = pthread_cond_timedwait(&cond->cond, &cond->mtx, &ts);
} else
ret = pthread_cond_wait(&cond->cond, &cond->mtx);
/*
* Check pthread_cond_wait() return for EINTR, ETIME and
* ETIMEDOUT, some systems return these errors.
*/
if (ret == EINTR ||
#ifdef ETIME
ret == ETIME ||
#endif
ret == ETIMEDOUT)
ret = 0;
(void)WT_ATOMIC_SUB(cond->waiters, 1);
err: if (locked)
WT_TRET(pthread_mutex_unlock(&cond->mtx));
if (ret == 0)
return (0);
WT_RET_MSG(session, ret, "pthread_cond_wait");
}
/*
* __wt_lsm_tree_truncate --
* Truncate an LSM tree.
*/
int
__wt_lsm_tree_truncate(
WT_SESSION_IMPL *session, const char *name, const char *cfg[])
{
WT_DECL_RET;
WT_LSM_CHUNK *chunk;
WT_LSM_TREE *lsm_tree;
int locked;
WT_UNUSED(cfg);
locked = 0;
/* Get the LSM tree. */
WT_RET(__wt_lsm_tree_get(session, name, 1, &lsm_tree));
/* Shut down the LSM worker. */
WT_RET(__lsm_tree_close(session, lsm_tree));
/* Prevent any new opens. */
WT_RET(__wt_try_writelock(session, lsm_tree->rwlock));
locked = 1;
/* Create the new chunk. */
WT_ERR(__wt_calloc_def(session, 1, &chunk));
chunk->id = WT_ATOMIC_ADD(lsm_tree->last, 1);
WT_ERR(__wt_lsm_tree_setup_chunk(session, lsm_tree, chunk));
/* Mark all chunks old. */
WT_ERR(__wt_lsm_merge_update_tree(
session, lsm_tree, 0, lsm_tree->nchunks, chunk));
WT_ERR(__wt_lsm_meta_write(session, lsm_tree));
WT_ERR(__lsm_tree_start_worker(session, lsm_tree));
ret = __wt_rwunlock(session, lsm_tree->rwlock);
locked = 0;
if (ret == 0)
__wt_lsm_tree_release(session, lsm_tree);
err: if (locked)
WT_TRET(__wt_rwunlock(session, lsm_tree->rwlock));
/*
* Don't discard the LSM tree structure unless there has been an
* error. The handle remains valid for future operations.
*/
if (ret != 0)
WT_TRET(__lsm_tree_discard(session, lsm_tree));
return (ret);
}
/*
* __wt_lsm_tree_switch --
* Switch to a new in-memory tree.
*/
int
__wt_lsm_tree_switch(WT_SESSION_IMPL *session, WT_LSM_TREE *lsm_tree)
{
WT_DECL_RET;
WT_LSM_CHUNK *chunk;
uint32_t nchunks, new_id;
WT_RET(__wt_lsm_tree_lock(session, lsm_tree, 1));
/*
* Check if a switch is still needed: we may have raced while waiting
* for a lock.
*/
if ((nchunks = lsm_tree->nchunks) != 0 &&
(chunk = lsm_tree->chunk[nchunks - 1]) != NULL &&
!F_ISSET_ATOMIC(chunk, WT_LSM_CHUNK_ONDISK) &&
!F_ISSET(lsm_tree, WT_LSM_TREE_NEED_SWITCH))
goto err;
/* Update the throttle time. */
__wt_lsm_tree_throttle(session, lsm_tree);
new_id = WT_ATOMIC_ADD(lsm_tree->last, 1);
WT_ERR(__wt_realloc_def(session, &lsm_tree->chunk_alloc,
nchunks + 1, &lsm_tree->chunk));
WT_VERBOSE_ERR(session, lsm,
"Tree switch to: %" PRIu32 ", throttle %ld",
new_id, lsm_tree->throttle_sleep);
WT_ERR(__wt_calloc_def(session, 1, &chunk));
chunk->id = new_id;
chunk->txnid_max = WT_TXN_NONE;
lsm_tree->chunk[lsm_tree->nchunks++] = chunk;
WT_ERR(__wt_lsm_tree_setup_chunk(session, lsm_tree, chunk));
WT_ERR(__wt_lsm_meta_write(session, lsm_tree));
F_CLR(lsm_tree, WT_LSM_TREE_NEED_SWITCH);
++lsm_tree->dsk_gen;
lsm_tree->modified = 1;
err: /* TODO: mark lsm_tree bad on error(?) */
WT_TRET(__wt_lsm_tree_unlock(session, lsm_tree));
return (ret);
}
/*
* __lsm_copy_chunks --
* Take a copy of part of the LSM tree chunk array so that we can work on
* the contents without holding the LSM tree handle lock long term.
*/
static int
__lsm_copy_chunks(WT_SESSION_IMPL *session,
WT_LSM_TREE *lsm_tree, WT_LSM_WORKER_COOKIE *cookie, int old_chunks)
{
WT_DECL_RET;
u_int i, nchunks;
size_t alloc;
/* Always return zero chunks on error. */
cookie->nchunks = 0;
WT_RET(__wt_lsm_tree_lock(session, lsm_tree, 0));
if (!F_ISSET(lsm_tree, WT_LSM_TREE_WORKING))
return (__wt_lsm_tree_unlock(session, lsm_tree));
/* Take a copy of the current state of the LSM tree. */
nchunks = old_chunks ? lsm_tree->nold_chunks : lsm_tree->nchunks;
alloc = old_chunks ? lsm_tree->old_alloc : lsm_tree->chunk_alloc;
/*
* If the tree array of active chunks is larger than our current buffer,
* increase the size of our current buffer to match.
*/
if (cookie->chunk_alloc < alloc)
WT_ERR(__wt_realloc(session,
&cookie->chunk_alloc, alloc, &cookie->chunk_array));
if (nchunks > 0)
memcpy(cookie->chunk_array,
old_chunks ? lsm_tree->old_chunks : lsm_tree->chunk,
nchunks * sizeof(*cookie->chunk_array));
/*
* Mark each chunk as active, so we don't drop it until after we know
* it's safe.
*/
for (i = 0; i < nchunks; i++)
(void)WT_ATOMIC_ADD(cookie->chunk_array[i]->refcnt, 1);
err: WT_TRET(__wt_lsm_tree_unlock(session, lsm_tree));
if (ret == 0)
cookie->nchunks = nchunks;
return (ret);
}
/*
* __wt_lsm_tree_get --
* get an LSM tree structure for the given name.
*/
int
__wt_lsm_tree_get(WT_SESSION_IMPL *session,
const char *uri, int exclusive, WT_LSM_TREE **treep)
{
WT_LSM_TREE *lsm_tree;
/* See if the tree is already open. */
TAILQ_FOREACH(lsm_tree, &S2C(session)->lsmqh, q)
if (strcmp(uri, lsm_tree->name) == 0) {
if (exclusive && lsm_tree->refcnt)
return (EBUSY);
(void)WT_ATOMIC_ADD(lsm_tree->refcnt, 1);
*treep = lsm_tree;
return (0);
}
/* Open a new tree. */
return (__lsm_tree_open(session, uri, treep));
}
/*
* __wt_lsm_tree_get --
* get an LSM tree structure for the given name.
*/
int
__wt_lsm_tree_get(WT_SESSION_IMPL *session,
const char *uri, int exclusive, WT_LSM_TREE **treep)
{
WT_LSM_TREE *lsm_tree;
TAILQ_FOREACH(lsm_tree, &S2C(session)->lsmqh, q)
if (strcmp(uri, lsm_tree->name) == 0) {
if (exclusive && lsm_tree->refcnt)
return (EBUSY);
(void)WT_ATOMIC_ADD(lsm_tree->refcnt, 1);
*treep = lsm_tree;
return (0);
}
/*
* If we don't already hold the schema lock, get it now so that we
* can find and/or open the handle.
*/
return (__lsm_tree_open(session, uri, treep));
}
/*
* __wt_page_alloc --
* Create or read a page into the cache.
*/
int
__wt_page_alloc(WT_SESSION_IMPL *session,
uint8_t type, uint32_t alloc_entries, WT_PAGE **pagep)
{
WT_CACHE *cache;
WT_PAGE *page;
size_t size;
void *p;
*pagep = NULL;
cache = S2C(session)->cache;
/*
* Allocate a page, and for most page types, the additional information
* it needs to describe the disk image.
*/
size = sizeof(WT_PAGE);
switch (type) {
case WT_PAGE_COL_FIX:
break;
case WT_PAGE_COL_INT:
case WT_PAGE_ROW_INT:
size += alloc_entries * sizeof(WT_REF);
break;
case WT_PAGE_COL_VAR:
size += alloc_entries * sizeof(WT_COL);
break;
case WT_PAGE_ROW_LEAF:
size += alloc_entries * sizeof(WT_ROW);
break;
WT_ILLEGAL_VALUE(session);
}
WT_RET(__wt_calloc(session, 1, size, &page));
p = (uint8_t *)page + sizeof(WT_PAGE);
switch (type) {
case WT_PAGE_COL_FIX:
break;
case WT_PAGE_COL_INT:
case WT_PAGE_ROW_INT:
page->u.intl.t = p;
break;
case WT_PAGE_COL_VAR:
page->u.col_var.d = p;
break;
case WT_PAGE_ROW_LEAF:
page->u.row.d = p;
break;
WT_ILLEGAL_VALUE(session);
}
/* Increment the cache statistics. */
__wt_cache_page_inmem_incr(session, page, size);
(void)WT_ATOMIC_ADD(cache->pages_inmem, 1);
/* The one page field we set is the type. */
page->type = type;
*pagep = page;
return (0);
}
/*
* __wt_txn_begin --
* Begin a transaction.
*/
int
__wt_txn_begin(WT_SESSION_IMPL *session, const char *cfg[])
{
WT_CONFIG_ITEM cval;
WT_CONNECTION_IMPL *conn;
WT_TXN *txn;
WT_TXN_GLOBAL *txn_global;
WT_TXN_STATE *s, *txn_state;
wt_txnid_t id, oldest_snap_min;
uint32_t i, n, session_cnt;
conn = S2C(session);
txn = &session->txn;
txn_global = &conn->txn_global;
txn_state = &txn_global->states[session->id];
WT_ASSERT(session, txn_state->id == WT_TXN_NONE);
WT_RET(__wt_config_gets_defno(session, cfg, "isolation", &cval));
if (cval.len == 0)
txn->isolation = session->isolation;
else
txn->isolation =
WT_STRING_MATCH("snapshot", cval.str, cval.len) ?
TXN_ISO_SNAPSHOT :
WT_STRING_MATCH("read-committed", cval.str, cval.len) ?
TXN_ISO_READ_COMMITTED : TXN_ISO_READ_UNCOMMITTED;
F_SET(txn, TXN_RUNNING);
do {
/*
* Allocate a transaction ID.
*
* We use an atomic increment to ensure that we get a unique
* ID, then publish that to the global state table.
*
* If two threads race to allocate an ID, only the latest ID
* will proceed. The winning thread can be sure its snapshot
* contains all of the earlier active IDs. Threads that race
* and get an earlier ID may not appear in the snapshot,
* but they will loop and allocate a new ID before proceeding
* to make any updates.
*
* This potentially wastes transaction IDs when threads race to
* begin transactions, but that is the price we pay to keep
* this path latch free.
*/
do {
txn->id = WT_ATOMIC_ADD(txn_global->current, 1);
} while (txn->id == WT_TXN_NONE || txn->id == WT_TXN_ABORTED);
WT_PUBLISH(txn_state->id, txn->id);
/*
* If we are starting a snapshot isolation transaction, get
* a snapshot of the running transactions.
*
* If we already have a snapshot (e.g., for an auto-commit
* operation), update it so that the newly-allocated ID is
* visible.
*/
if (txn->isolation == TXN_ISO_SNAPSHOT) {
txn->last_gen = txn->last_oldest_gen = txn_global->gen;
oldest_snap_min = txn->id;
/* Copy the array of concurrent transactions. */
WT_ORDERED_READ(session_cnt, conn->session_cnt);
for (i = n = 0, s = txn_global->states;
i < session_cnt;
i++, s++) {
if ((id = s->snap_min) != WT_TXN_NONE)
if (TXNID_LT(id, oldest_snap_min))
oldest_snap_min = id;
if ((id = s->id) == WT_TXN_NONE)
continue;
else
txn->snapshot[n++] = id;
}
__txn_sort_snapshot(
session, n, txn->id, oldest_snap_min);
txn_state->snap_min = txn->snap_min;
}
/*
* Ensure the snapshot reads are complete before re-checking
* the global current ID.
*/
WT_READ_BARRIER();
} while (txn->id != txn_global->current);
return (0);
}
