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/*-
* Copyright (c) 2008-2012 WiredTiger, Inc.
* All rights reserved.
*
* See the file LICENSE for redistribution information.
*/
#include "wt_internal.h"
static int
__lsm_free_chunks(WT_SESSION_IMPL *session, WT_LSM_TREE *lsm_tree);
/*
* __wt_lsm_worker --
* The worker thread for an LSM tree, responsible for writing in-memory
* trees to disk and merging on-disk trees.
*/
void *
__wt_lsm_worker(void *arg)
{
WT_DECL_RET;
WT_LSM_CHUNK *chunk, **chunk_array;
WT_LSM_TREE *lsm_tree;
WT_SESSION_IMPL *session;
const char *cfg[] = API_CONF_DEFAULTS(session, checkpoint, NULL);
size_t chunk_alloc;
int i, nchunks, progress;
lsm_tree = arg;
session = lsm_tree->worker_session;
chunk_array = NULL;
chunk_alloc = 0;
while (F_ISSET(lsm_tree, WT_LSM_TREE_WORKING)) {
progress = 0;
__wt_spin_lock(session, &lsm_tree->lock);
if (!F_ISSET(lsm_tree, WT_LSM_TREE_WORKING)) {
__wt_spin_unlock(session, &lsm_tree->lock);
break;
}
/*
* Take a copy of the current state of the LSM tree. Skip
* the last chunk - since it is the active one and not relevant
* to merge operations.
*/
for (nchunks = lsm_tree->nchunks - 1;
nchunks > 0 && lsm_tree->chunk[nchunks - 1]->ncursor > 0;
--nchunks)
;
if (chunk_alloc < lsm_tree->chunk_alloc)
ret = __wt_realloc(session,
&chunk_alloc, lsm_tree->chunk_alloc,
&chunk_array);
if (ret == 0 && nchunks > 0)
memcpy(chunk_array, lsm_tree->chunk,
nchunks * sizeof(*lsm_tree->chunk));
__wt_spin_unlock(session, &lsm_tree->lock);
WT_ERR(ret);
/*
* Write checkpoints in all completed files, then find
* something to merge.
*/
for (i = 0; i < nchunks; i++) {
chunk = chunk_array[i];
if (F_ISSET(chunk, WT_LSM_CHUNK_ONDISK) ||
chunk->ncursor > 0)
continue;
/* XXX durability: need to checkpoint the metadata? */
/*
* NOTE: we pass a non-NULL config, because otherwise
* __wt_checkpoint thinks we're closing the file.
*/
WT_WITH_SCHEMA_LOCK(session, ret =
__wt_schema_worker(session, chunk->uri,
__wt_checkpoint, cfg, 0));
if (ret == 0) {
__wt_spin_lock(session, &lsm_tree->lock);
F_SET(lsm_tree->chunk[i], WT_LSM_CHUNK_ONDISK);
lsm_tree->dsk_gen++;
__wt_spin_unlock(session, &lsm_tree->lock);
progress = 1;
}
}
/* Clear any state from previous worker thread iterations. */
session->btree = NULL;
if (nchunks > 0 && __wt_lsm_major_merge(session, lsm_tree) == 0)
progress = 1;
/* Clear any state from previous worker thread iterations. */
session->btree = NULL;
if (lsm_tree->nold_chunks != lsm_tree->old_avail &&
__lsm_free_chunks(session, lsm_tree) == 0)
progress = 1;
if (!progress)
__wt_sleep(0, 10);
}
err: __wt_free(session, chunk_array);
return (NULL);
}
static int
__lsm_free_chunks(WT_SESSION_IMPL *session, WT_LSM_TREE *lsm_tree)
{
WT_DECL_RET;
WT_LSM_CHUNK *chunk;
const char *drop_cfg[] = { NULL };
int found, i;
found = 0;
for (i = 0; i < lsm_tree->nold_chunks; i++) {
if ((chunk = lsm_tree->old_chunks[i]) == NULL)
continue;
if (!found) {
found = 1;
/* TODO: Do we need the lsm_tree lock for all drops? */
__wt_spin_lock(session, &lsm_tree->lock);
}
if (chunk->bloom_uri != NULL) {
WT_WITH_SCHEMA_LOCK(session, ret = __wt_schema_drop(
session, chunk->bloom_uri, drop_cfg));
/*
* An EBUSY return is acceptable - a cursor may still
* be positioned on this old chunk.
*/
if (ret == 0) {
__wt_free(session, chunk->bloom_uri);
chunk->bloom_uri = NULL;
} else if (ret != EBUSY)
goto err;
}
if (chunk->uri != NULL) {
WT_WITH_SCHEMA_LOCK(session, ret =
__wt_schema_drop(session, chunk->uri, drop_cfg));
/*
* An EBUSY return is acceptable - a cursor may still
* be positioned on this old chunk.
*/
if (ret == 0) {
__wt_free(session, chunk->uri);
chunk->uri = NULL;
} else if (ret != EBUSY)
goto err;
}
if (chunk->uri == NULL && chunk->bloom_uri == NULL) {
__wt_free(session, lsm_tree->old_chunks[i]);
++lsm_tree->old_avail;
}
}
if (found) {
err: ret = __wt_lsm_meta_write(session, lsm_tree);
__wt_spin_unlock(session, &lsm_tree->lock);
}
/* Returning non-zero means there is no work to do. */
return (found ? 0 : WT_NOTFOUND);
}
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