cache.c

ldap服务器源码

	/* bdb_csn_commit can cause this when adding the database root entry */
	if ( new->bei_e ) {
		new->bei_e->e_private = NULL;
#ifdef SLAP_ZONE_ALLOC
		bdb_entry_return( bdb, new->bei_e, new->bei_zseq );
#else
		bdb_entry_return( new->bei_e );
#endif
	}
	new->bei_e = e;
	e->e_private = new;
	new->bei_state = CACHE_ENTRY_NO_KIDS | CACHE_ENTRY_NO_GRANDKIDS;
	eip->bei_state &= ~CACHE_ENTRY_NO_KIDS;
	if (eip->bei_parent) {
		eip->bei_parent->bei_state &= ~CACHE_ENTRY_NO_GRANDKIDS;
	}
	bdb_cache_entryinfo_unlock( eip );

	++bdb->bi_cache.c_cursize;
	ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );

	/* set lru mutex */
	ldap_pvt_thread_mutex_lock( &bdb->bi_cache.lru_head_mutex );

	/* lru_head_mutex is unlocked for us */
	bdb_cache_lru_add( bdb, new );

	return rc;
}

int
bdb_cache_modify(
	Entry *e,
	Attribute *newAttrs,
	DB_ENV *env,
	u_int32_t locker,
	DB_LOCK *lock )
{
	EntryInfo *ei = BEI(e);
	int rc;
	/* Get write lock on data */
	rc = bdb_cache_entry_db_relock( env, locker, ei, 1, 0, lock );

	/* If we've done repeated mods on a cached entry, then e_attrs
	 * is no longer contiguous with the entry, and must be freed.
	 */
	if ( ! rc ) {
		if ( (void *)e->e_attrs != (void *)(e+1) ) {
			attrs_free( e->e_attrs ); 
		}
		e->e_attrs = newAttrs;
	}
	return rc;
}

/*
 * Change the rdn in the entryinfo. Also move to a new parent if needed.
 */
int
bdb_cache_modrdn(
	struct bdb_info *bdb,
	Entry *e,
	struct berval *nrdn,
	Entry *new,
	EntryInfo *ein,
	u_int32_t locker,
	DB_LOCK *lock )
{
	EntryInfo *ei = BEI(e), *pei;
	int rc;
#ifdef BDB_HIER
	struct berval rdn;
#endif

	/* Get write lock on data */
	rc =  bdb_cache_entry_db_relock( bdb->bi_dbenv, locker, ei, 1, 0, lock );
	if ( rc ) return rc;

	/* If we've done repeated mods on a cached entry, then e_attrs
	 * is no longer contiguous with the entry, and must be freed.
	 */
	if ( (void *)e->e_attrs != (void *)(e+1) ) {
		attrs_free( e->e_attrs );
	}
	e->e_attrs = new->e_attrs;
	if( e->e_nname.bv_val < e->e_bv.bv_val ||
		e->e_nname.bv_val > e->e_bv.bv_val + e->e_bv.bv_len )
	{
		ch_free(e->e_name.bv_val);
		ch_free(e->e_nname.bv_val);
	}
	e->e_name = new->e_name;
	e->e_nname = new->e_nname;

	/* Lock the parent's kids AVL tree */
	pei = ei->bei_parent;
	bdb_cache_entryinfo_lock( pei );
	avl_delete( &pei->bei_kids, (caddr_t) ei, bdb_rdn_cmp );
	free( ei->bei_nrdn.bv_val );
	ber_dupbv( &ei->bei_nrdn, nrdn );

	if ( !pei->bei_kids )
		pei->bei_state |= CACHE_ENTRY_NO_KIDS | CACHE_ENTRY_NO_GRANDKIDS;

#ifdef BDB_HIER
	free( ei->bei_rdn.bv_val );

	rdn = e->e_name;
	if ( nrdn->bv_len != e->e_nname.bv_len ) {
		char *ptr = ber_bvchr(&rdn, ',');
		assert( ptr != NULL );
		rdn.bv_len = ptr - rdn.bv_val;
	}
	ber_dupbv( &ei->bei_rdn, &rdn );
	pei->bei_ckids--;
	if ( pei->bei_dkids ) pei->bei_dkids--;
#endif

	if (!ein) {
		ein = ei->bei_parent;
	} else {
		ei->bei_parent = ein;
		bdb_cache_entryinfo_unlock( pei );
		bdb_cache_entryinfo_lock( ein );
	}
	/* parent now has kids */
	if ( ein->bei_state & CACHE_ENTRY_NO_KIDS )
		ein->bei_state ^= CACHE_ENTRY_NO_KIDS;
#ifdef BDB_HIER
	/* parent might now have grandkids */
	if ( ein->bei_state & CACHE_ENTRY_NO_GRANDKIDS &&
		!(ei->bei_state & (CACHE_ENTRY_NO_KIDS)))
		ein->bei_state ^= CACHE_ENTRY_NO_GRANDKIDS;

	{
		/* Record the generation number of this change */
		ldap_pvt_thread_mutex_lock( &bdb->bi_modrdns_mutex );
		bdb->bi_modrdns++;
		ei->bei_modrdns = bdb->bi_modrdns;
		ldap_pvt_thread_mutex_unlock( &bdb->bi_modrdns_mutex );
	}
	ein->bei_ckids++;
	if ( ein->bei_dkids ) ein->bei_dkids++;
#endif
	avl_insert( &ein->bei_kids, ei, bdb_rdn_cmp, avl_dup_error );
	bdb_cache_entryinfo_unlock( ein );
	return rc;
}
/*
 * cache_delete - delete the entry e from the cache. 
 *
 * returns:	0	e was deleted ok
 *		1	e was not in the cache
 *		-1	something bad happened
 */
int
bdb_cache_delete(
    Cache	*cache,
    Entry		*e,
    DB_ENV	*env,
    u_int32_t	locker,
    DB_LOCK	*lock )
{
	EntryInfo *ei = BEI(e);
	int	rc;

	assert( e->e_private != NULL );

	/* Set this early, warn off any queriers */
	ei->bei_state |= CACHE_ENTRY_DELETED;

	/* Lock the entry's info */
	bdb_cache_entryinfo_lock( ei );

	/* Get write lock on the data */
	rc = bdb_cache_entry_db_relock( env, locker, ei, 1, 0, lock );
	if ( rc ) {
		/* couldn't lock, undo and give up */
		ei->bei_state ^= CACHE_ENTRY_DELETED;
		bdb_cache_entryinfo_unlock( ei );
		return rc;
	}

	Debug( LDAP_DEBUG_TRACE, "====> bdb_cache_delete( %ld )\n",
		e->e_id, 0, 0 );

	/* set lru mutex */
	ldap_pvt_thread_mutex_lock( &cache->lru_tail_mutex );

	/* set cache write lock */
	ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );

	rc = bdb_cache_delete_internal( cache, e->e_private, 1 );

	/* free cache write lock */
	ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );

	/* free lru mutex */
	ldap_pvt_thread_mutex_unlock( &cache->lru_tail_mutex );

	/* Leave entry info locked */

	return( rc );
}

void
bdb_cache_delete_cleanup(
	Cache *cache,
	EntryInfo *ei )
{
	if ( ei->bei_e ) {
		ei->bei_e->e_private = NULL;
#ifdef SLAP_ZONE_ALLOC
		bdb_entry_return( ei->bei_bdb, ei->bei_e, ei->bei_zseq );
#else
		bdb_entry_return( ei->bei_e );
#endif
		ei->bei_e = NULL;
	}

	free( ei->bei_nrdn.bv_val );
	ei->bei_nrdn.bv_val = NULL;
#ifdef BDB_HIER
	free( ei->bei_rdn.bv_val );
	ei->bei_rdn.bv_val = NULL;
	ei->bei_modrdns = 0;
	ei->bei_ckids = 0;
	ei->bei_dkids = 0;
#endif
	ei->bei_parent = NULL;
	ei->bei_kids = NULL;
	ei->bei_lruprev = NULL;

	ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
	ei->bei_lrunext = cache->c_eifree;
	cache->c_eifree = ei;
	ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
	bdb_cache_entryinfo_unlock( ei );
}

static int
bdb_cache_delete_internal(
    Cache	*cache,
    EntryInfo		*e,
    int		decr )
{
	int rc = 0;	/* return code */

	/* Lock the parent's kids tree */
	bdb_cache_entryinfo_lock( e->bei_parent );

#ifdef BDB_HIER
	e->bei_parent->bei_ckids--;
	if ( decr && e->bei_parent->bei_dkids ) e->bei_parent->bei_dkids--;
#endif
	/* dn tree */
	if ( avl_delete( &e->bei_parent->bei_kids, (caddr_t) e, bdb_rdn_cmp )
		== NULL )
	{
		rc = -1;
	}
	if ( e->bei_parent->bei_kids )
		cache->c_leaves--;

	/* id tree */
	if ( avl_delete( &cache->c_idtree, (caddr_t) e, bdb_id_cmp ) == NULL ) {
		rc = -1;
	}

	if ( rc == 0 ){
		cache->c_eiused--;

		/* lru */
		LRU_DELETE( cache, e );
		if ( e->bei_e ) cache->c_cursize--;
	}

	bdb_cache_entryinfo_unlock( e->bei_parent );

	return( rc );
}

static void
bdb_entryinfo_release( void *data )
{
	EntryInfo *ei = (EntryInfo *)data;
	if ( ei->bei_kids ) {
		avl_free( ei->bei_kids, NULL );
	}
	if ( ei->bei_e ) {
		ei->bei_e->e_private = NULL;
#ifdef SLAP_ZONE_ALLOC
		bdb_entry_return( ei->bei_bdb, ei->bei_e, ei->bei_zseq );
#else
		bdb_entry_return( ei->bei_e );
#endif
	}
	bdb_cache_entryinfo_destroy( ei );
}

void
bdb_cache_release_all( Cache *cache )
{
	/* set cache write lock */
	ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
	/* set lru mutex */
	ldap_pvt_thread_mutex_lock( &cache->lru_tail_mutex );

	Debug( LDAP_DEBUG_TRACE, "====> bdb_cache_release_all\n", 0, 0, 0 );

	avl_free( cache->c_dntree.bei_kids, NULL );
	avl_free( cache->c_idtree, bdb_entryinfo_release );
	for (;cache->c_eifree;cache->c_eifree = cache->c_lruhead) {
		cache->c_lruhead = cache->c_eifree->bei_lrunext;
		bdb_cache_entryinfo_destroy(cache->c_eifree);
	}
	cache->c_cursize = 0;
	cache->c_eiused = 0;
	cache->c_leaves = 0;
	cache->c_idtree = NULL;
	cache->c_lruhead = NULL;
	cache->c_lrutail = NULL;
	cache->c_dntree.bei_kids = NULL;

	/* free lru mutex */
	ldap_pvt_thread_mutex_unlock( &cache->lru_tail_mutex );
	/* free cache write lock */
	ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
}

#ifdef LDAP_DEBUG
#ifdef SLAPD_UNUSED
static void
bdb_lru_print( Cache *cache )
{
	EntryInfo	*e;

	fprintf( stderr, "LRU queue (head to tail):\n" );
	for ( e = cache->c_lruhead; e != NULL; e = e->bei_lrunext ) {
		fprintf( stderr, "\trdn \"%20s\" id %ld\n",
			e->bei_nrdn.bv_val, e->bei_id );
	}
	fprintf( stderr, "LRU queue (tail to head):\n" );
	for ( e = cache->c_lrutail; e != NULL; e = e->bei_lruprev ) {
		fprintf( stderr, "\trdn \"%20s\" id %ld\n",
			e->bei_nrdn.bv_val, e->bei_id );
	}
}
#endif
#endif

#ifdef BDB_REUSE_LOCKERS
static void
bdb_locker_id_free( void *key, void *data )
{
	DB_ENV *env = key;
	u_int32_t lockid = (long)data;
	int rc;

	rc = XLOCK_ID_FREE( env, lockid );
	if ( rc == EINVAL ) {
		DB_LOCKREQ lr;
		Debug( LDAP_DEBUG_ANY,
			"bdb_locker_id_free: %lu err %s(%d)\n",
			(unsigned long) lockid, db_strerror(rc), rc );
		/* release all locks held by this locker. */
		lr.op = DB_LOCK_PUT_ALL;
		lr.obj = NULL;
		env->lock_vec( env, lockid, 0, &lr, 1, NULL );
		XLOCK_ID_FREE( env, lockid );
	}
}

/* free up any keys used by the main thread */
void
bdb_locker_flush( DB_ENV *env )
{
	void *data;
	void *ctx = ldap_pvt_thread_pool_context();

	if ( !ldap_pvt_thread_pool_getkey( ctx, env, &data, NULL ) ) {
		ldap_pvt_thread_pool_setkey( ctx, env, NULL, NULL );
		bdb_locker_id_free( env, data );
	}
}

int
bdb_locker_id( Operation *op, DB_ENV *env, u_int32_t *locker )
{
	int i, rc;
	u_int32_t lockid;
	void *data;
	void *ctx;

	if ( !env || !locker ) return -1;

	/* If no op was provided, try to find the ctx anyway... */
	if ( op ) {
		ctx = op->o_threadctx;
	} else {
		ctx = ldap_pvt_thread_pool_context();
	}

	/* Shouldn't happen unless we're single-threaded */
	if ( !ctx ) {
		*locker = 0;
		return 0;
	}

	if ( ldap_pvt_thread_pool_getkey( ctx, env, &data, NULL ) ) {
		for ( i=0, rc=1; rc != 0 && i<4; i++ ) {
			rc = XLOCK_ID( env, &lockid );
			if (rc) ldap_pvt_thread_yield();
		}
		if ( rc != 0) {
			return rc;
		}
		data = (void *)((long)lockid);
		if ( ( rc = ldap_pvt_thread_pool_setkey( ctx, env,
			data, bdb_locker_id_free ) ) ) {
			XLOCK_ID_FREE( env, lockid );
			Debug( LDAP_DEBUG_ANY, "bdb_locker_id: err %s(%d)\n",
				db_strerror(rc), rc, 0 );

			return rc;
		}
	} else {
		lockid = (long)data;
	}
	*locker = lockid;
	return 0;
}
#endif /* BDB_REUSE_LOCKERS */

void
bdb_cache_delete_entry(
	struct bdb_info *bdb,
	EntryInfo *ei,
	u_int32_t locker,
	DB_LOCK *lock )
{
	ldap_pvt_thread_rdwr_wlock( &bdb->bi_cache.c_rwlock );
	if ( bdb_cache_entry_db_lock( bdb->bi_dbenv, bdb->bi_cache.c_locker, ei, 1, 1, lock ) == 0 )
	{
		if ( ei->bei_e && !(ei->bei_state & CACHE_ENTRY_NOT_LINKED )) {
			LRU_DELETE( &bdb->bi_cache, ei );
			ei->bei_e->e_private = NULL;
#ifdef SLAP_ZONE_ALLOC
			bdb_entry_return( bdb, ei->bei_e, ei->bei_zseq );
#else
			bdb_entry_return( ei->bei_e );
#endif
			ei->bei_e = NULL;
			--bdb->bi_cache.c_cursize;
		}
		bdb_cache_entry_db_unlock( bdb->bi_dbenv, lock );
	}
	ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
}