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-rw-r--r--servers/slapd/back-bdb/cache.c1692
1 files changed, 1692 insertions, 0 deletions
diff --git a/servers/slapd/back-bdb/cache.c b/servers/slapd/back-bdb/cache.c
new file mode 100644
index 0000000..83aaa62
--- /dev/null
+++ b/servers/slapd/back-bdb/cache.c
@@ -0,0 +1,1692 @@
+/* cache.c - routines to maintain an in-core cache of entries */
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 2000-2021 The OpenLDAP Foundation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+
+#include "portable.h"
+
+#include <stdio.h>
+
+#include <ac/errno.h>
+#include <ac/string.h>
+#include <ac/socket.h>
+
+#include "slap.h"
+
+#include "back-bdb.h"
+
+#include "ldap_rq.h"
+
+#ifdef BDB_HIER
+#define bdb_cache_lru_purge hdb_cache_lru_purge
+#endif
+static void bdb_cache_lru_purge( struct bdb_info *bdb );
+
+static int bdb_cache_delete_internal(Cache *cache, EntryInfo *e, int decr);
+#ifdef LDAP_DEBUG
+#define SLAPD_UNUSED
+#ifdef SLAPD_UNUSED
+static void bdb_lru_print(Cache *cache);
+static void bdb_idtree_print(Cache *cache);
+#endif
+#endif
+
+/* For concurrency experiments only! */
+#if 0
+#define ldap_pvt_thread_rdwr_wlock(a) 0
+#define ldap_pvt_thread_rdwr_wunlock(a) 0
+#define ldap_pvt_thread_rdwr_rlock(a) 0
+#define ldap_pvt_thread_rdwr_runlock(a) 0
+#endif
+
+#if 0
+#define ldap_pvt_thread_mutex_trylock(a) 0
+#endif
+
+static EntryInfo *
+bdb_cache_entryinfo_new( Cache *cache )
+{
+ EntryInfo *ei = NULL;
+
+ if ( cache->c_eifree ) {
+ ldap_pvt_thread_mutex_lock( &cache->c_eifree_mutex );
+ if ( cache->c_eifree ) {
+ ei = cache->c_eifree;
+ cache->c_eifree = ei->bei_lrunext;
+ ei->bei_finders = 0;
+ ei->bei_lrunext = NULL;
+ }
+ ldap_pvt_thread_mutex_unlock( &cache->c_eifree_mutex );
+ }
+ if ( !ei ) {
+ ei = ch_calloc(1, sizeof(EntryInfo));
+ ldap_pvt_thread_mutex_init( &ei->bei_kids_mutex );
+ }
+
+ ei->bei_state = CACHE_ENTRY_REFERENCED;
+
+ return ei;
+}
+
+static void
+bdb_cache_entryinfo_free( Cache *cache, EntryInfo *ei )
+{
+ free( ei->bei_nrdn.bv_val );
+ BER_BVZERO( &ei->bei_nrdn );
+#ifdef BDB_HIER
+ free( ei->bei_rdn.bv_val );
+ BER_BVZERO( &ei->bei_rdn );
+ 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;
+
+#if 0
+ ldap_pvt_thread_mutex_lock( &cache->c_eifree_mutex );
+ ei->bei_lrunext = cache->c_eifree;
+ cache->c_eifree = ei;
+ ldap_pvt_thread_mutex_unlock( &cache->c_eifree_mutex );
+#else
+ ldap_pvt_thread_mutex_destroy( &ei->bei_kids_mutex );
+ ch_free( ei );
+#endif
+}
+
+#define LRU_DEL( c, e ) do { \
+ if ( e == e->bei_lruprev ) { \
+ (c)->c_lruhead = (c)->c_lrutail = NULL; \
+ } else { \
+ if ( e == (c)->c_lruhead ) (c)->c_lruhead = e->bei_lruprev; \
+ if ( e == (c)->c_lrutail ) (c)->c_lrutail = e->bei_lruprev; \
+ e->bei_lrunext->bei_lruprev = e->bei_lruprev; \
+ e->bei_lruprev->bei_lrunext = e->bei_lrunext; \
+ } \
+ e->bei_lruprev = NULL; \
+} while ( 0 )
+
+/* Note - we now use a Second-Chance / Clock algorithm instead of
+ * Least-Recently-Used. This tremendously improves concurrency
+ * because we no longer need to manipulate the lists every time an
+ * entry is touched. We only need to lock the lists when adding
+ * or deleting an entry. It's now a circular doubly-linked list.
+ * We always append to the tail, but the head traverses the circle
+ * during a purge operation.
+ */
+static void
+bdb_cache_lru_link( struct bdb_info *bdb, EntryInfo *ei )
+{
+
+ /* Already linked, ignore */
+ if ( ei->bei_lruprev )
+ return;
+
+ /* Insert into circular LRU list */
+ ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_lru_mutex );
+
+ ei->bei_lruprev = bdb->bi_cache.c_lrutail;
+ if ( bdb->bi_cache.c_lrutail ) {
+ ei->bei_lrunext = bdb->bi_cache.c_lrutail->bei_lrunext;
+ bdb->bi_cache.c_lrutail->bei_lrunext = ei;
+ if ( ei->bei_lrunext )
+ ei->bei_lrunext->bei_lruprev = ei;
+ } else {
+ ei->bei_lrunext = ei->bei_lruprev = ei;
+ bdb->bi_cache.c_lruhead = ei;
+ }
+ bdb->bi_cache.c_lrutail = ei;
+ ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_lru_mutex );
+}
+
+#ifdef NO_THREADS
+#define NO_DB_LOCK
+#endif
+
+/* #define NO_DB_LOCK 1 */
+/* Note: The BerkeleyDB locks are much slower than regular
+ * mutexes or rdwr locks. But the BDB implementation has the
+ * advantage of using a fixed size lock table, instead of
+ * allocating a lock object per entry in the DB. That's a
+ * key benefit for scaling. It also frees us from worrying
+ * about undetectable deadlocks between BDB activity and our
+ * own cache activity. It's still worth exploring faster
+ * alternatives though.
+ */
+
+/* Atomically release and reacquire a lock */
+int
+bdb_cache_entry_db_relock(
+ struct bdb_info *bdb,
+ DB_TXN *txn,
+ EntryInfo *ei,
+ int rw,
+ int tryOnly,
+ DB_LOCK *lock )
+{
+#ifdef NO_DB_LOCK
+ return 0;
+#else
+ int rc;
+ DBT lockobj;
+ DB_LOCKREQ list[2];
+
+ if ( !lock ) return 0;
+
+ DBTzero( &lockobj );
+ lockobj.data = &ei->bei_id;
+ lockobj.size = sizeof(ei->bei_id) + 1;
+
+ list[0].op = DB_LOCK_PUT;
+ list[0].lock = *lock;
+ list[1].op = DB_LOCK_GET;
+ list[1].lock = *lock;
+ list[1].mode = rw ? DB_LOCK_WRITE : DB_LOCK_READ;
+ list[1].obj = &lockobj;
+ rc = bdb->bi_dbenv->lock_vec(bdb->bi_dbenv, TXN_ID(txn), tryOnly ? DB_LOCK_NOWAIT : 0,
+ list, 2, NULL );
+
+ if (rc && !tryOnly) {
+ Debug( LDAP_DEBUG_TRACE,
+ "bdb_cache_entry_db_relock: entry %ld, rw %d, rc %d\n",
+ ei->bei_id, rw, rc );
+ } else {
+ *lock = list[1].lock;
+ }
+ return rc;
+#endif
+}
+
+static int
+bdb_cache_entry_db_lock( struct bdb_info *bdb, DB_TXN *txn, EntryInfo *ei,
+ int rw, int tryOnly, DB_LOCK *lock )
+{
+#ifdef NO_DB_LOCK
+ return 0;
+#else
+ int rc;
+ DBT lockobj;
+ int db_rw;
+
+ if ( !lock ) return 0;
+
+ if (rw)
+ db_rw = DB_LOCK_WRITE;
+ else
+ db_rw = DB_LOCK_READ;
+
+ DBTzero( &lockobj );
+ lockobj.data = &ei->bei_id;
+ lockobj.size = sizeof(ei->bei_id) + 1;
+
+ rc = LOCK_GET(bdb->bi_dbenv, TXN_ID(txn), tryOnly ? DB_LOCK_NOWAIT : 0,
+ &lockobj, db_rw, lock);
+ if (rc && !tryOnly) {
+ Debug( LDAP_DEBUG_TRACE,
+ "bdb_cache_entry_db_lock: entry %ld, rw %d, rc %d\n",
+ ei->bei_id, rw, rc );
+ }
+ return rc;
+#endif /* NO_DB_LOCK */
+}
+
+int
+bdb_cache_entry_db_unlock ( struct bdb_info *bdb, DB_LOCK *lock )
+{
+#ifdef NO_DB_LOCK
+ return 0;
+#else
+ int rc;
+
+ if ( !lock || lock->mode == DB_LOCK_NG ) return 0;
+
+ rc = LOCK_PUT ( bdb->bi_dbenv, lock );
+ return rc;
+#endif
+}
+
+void
+bdb_cache_return_entry_rw( struct bdb_info *bdb, Entry *e,
+ int rw, DB_LOCK *lock )
+{
+ EntryInfo *ei;
+ int free = 0;
+
+ ei = e->e_private;
+ if ( ei && ( ei->bei_state & CACHE_ENTRY_NOT_CACHED )) {
+ bdb_cache_entryinfo_lock( ei );
+ if ( ei->bei_state & CACHE_ENTRY_NOT_CACHED ) {
+ /* Releasing the entry can only be done when
+ * we know that nobody else is using it, i.e we
+ * should have an entry_db writelock. But the
+ * flag is only set by the thread that loads the
+ * entry, and only if no other threads has found
+ * it while it was working. All other threads
+ * clear the flag, which mean that we should be
+ * the only thread using the entry if the flag
+ * is set here.
+ */
+ ei->bei_e = NULL;
+ ei->bei_state ^= CACHE_ENTRY_NOT_CACHED;
+ free = 1;
+ }
+ bdb_cache_entryinfo_unlock( ei );
+ }
+ bdb_cache_entry_db_unlock( bdb, lock );
+ if ( free ) {
+ e->e_private = NULL;
+ bdb_entry_return( e );
+ }
+}
+
+static int
+bdb_cache_entryinfo_destroy( EntryInfo *e )
+{
+ ldap_pvt_thread_mutex_destroy( &e->bei_kids_mutex );
+ free( e->bei_nrdn.bv_val );
+#ifdef BDB_HIER
+ free( e->bei_rdn.bv_val );
+#endif
+ free( e );
+ return 0;
+}
+
+/* Do a length-ordered sort on normalized RDNs */
+static int
+bdb_rdn_cmp( const void *v_e1, const void *v_e2 )
+{
+ const EntryInfo *e1 = v_e1, *e2 = v_e2;
+ int rc = e1->bei_nrdn.bv_len - e2->bei_nrdn.bv_len;
+ if (rc == 0) {
+ rc = strncmp( e1->bei_nrdn.bv_val, e2->bei_nrdn.bv_val,
+ e1->bei_nrdn.bv_len );
+ }
+ return rc;
+}
+
+static int
+bdb_id_cmp( const void *v_e1, const void *v_e2 )
+{
+ const EntryInfo *e1 = v_e1, *e2 = v_e2;
+ return e1->bei_id - e2->bei_id;
+}
+
+static int
+bdb_id_dup_err( void *v1, void *v2 )
+{
+ EntryInfo *e2 = v2;
+ e2->bei_lrunext = v1;
+ return -1;
+}
+
+/* Create an entryinfo in the cache. Caller must release the locks later.
+ */
+static int
+bdb_entryinfo_add_internal(
+ struct bdb_info *bdb,
+ EntryInfo *ei,
+ EntryInfo **res )
+{
+ EntryInfo *ei2 = NULL;
+
+ *res = NULL;
+
+ ei2 = bdb_cache_entryinfo_new( &bdb->bi_cache );
+
+ bdb_cache_entryinfo_lock( ei->bei_parent );
+ ldap_pvt_thread_rdwr_wlock( &bdb->bi_cache.c_rwlock );
+
+ ei2->bei_id = ei->bei_id;
+ ei2->bei_parent = ei->bei_parent;
+#ifdef BDB_HIER
+ ei2->bei_rdn = ei->bei_rdn;
+#endif
+#ifdef SLAP_ZONE_ALLOC
+ ei2->bei_bdb = bdb;
+#endif
+
+ /* Add to cache ID tree */
+ if (avl_insert( &bdb->bi_cache.c_idtree, ei2, bdb_id_cmp,
+ bdb_id_dup_err )) {
+ EntryInfo *eix = ei2->bei_lrunext;
+ bdb_cache_entryinfo_free( &bdb->bi_cache, ei2 );
+ ei2 = eix;
+#ifdef BDB_HIER
+ /* It got freed above because its value was
+ * assigned to ei2.
+ */
+ ei->bei_rdn.bv_val = NULL;
+#endif
+ } else {
+ int rc;
+
+ bdb->bi_cache.c_eiused++;
+ ber_dupbv( &ei2->bei_nrdn, &ei->bei_nrdn );
+
+ /* This is a new leaf node. But if parent had no kids, then it was
+ * a leaf and we would be decrementing that. So, only increment if
+ * the parent already has kids.
+ */
+ if ( ei->bei_parent->bei_kids || !ei->bei_parent->bei_id )
+ bdb->bi_cache.c_leaves++;
+ rc = avl_insert( &ei->bei_parent->bei_kids, ei2, bdb_rdn_cmp,
+ avl_dup_error );
+#ifdef BDB_HIER
+ /* it's possible for hdb_cache_find_parent to beat us to it */
+ if ( !rc ) {
+ ei->bei_parent->bei_ckids++;
+ }
+#endif
+ }
+
+ *res = ei2;
+ return 0;
+}
+
+/* Find the EntryInfo for the requested DN. If the DN cannot be found, return
+ * the info for its closest ancestor. *res should be NULL to process a
+ * complete DN starting from the tree root. Otherwise *res must be the
+ * immediate parent of the requested DN, and only the RDN will be searched.
+ * The EntryInfo is locked upon return and must be unlocked by the caller.
+ */
+int
+bdb_cache_find_ndn(
+ Operation *op,
+ DB_TXN *txn,
+ struct berval *ndn,
+ EntryInfo **res )
+{
+ struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;
+ EntryInfo ei, *eip, *ei2;
+ int rc = 0;
+ char *ptr;
+
+ /* this function is always called with normalized DN */
+ if ( *res ) {
+ /* we're doing a onelevel search for an RDN */
+ ei.bei_nrdn.bv_val = ndn->bv_val;
+ ei.bei_nrdn.bv_len = dn_rdnlen( op->o_bd, ndn );
+ eip = *res;
+ } else {
+ /* we're searching a full DN from the root */
+ ptr = ndn->bv_val + ndn->bv_len - op->o_bd->be_nsuffix[0].bv_len;
+ ei.bei_nrdn.bv_val = ptr;
+ ei.bei_nrdn.bv_len = op->o_bd->be_nsuffix[0].bv_len;
+ /* Skip to next rdn if suffix is empty */
+ if ( ei.bei_nrdn.bv_len == 0 ) {
+ for (ptr = ei.bei_nrdn.bv_val - 2; ptr > ndn->bv_val
+ && !DN_SEPARATOR(*ptr); ptr--) /* empty */;
+ if ( ptr >= ndn->bv_val ) {
+ if (DN_SEPARATOR(*ptr)) ptr++;
+ ei.bei_nrdn.bv_len = ei.bei_nrdn.bv_val - ptr;
+ ei.bei_nrdn.bv_val = ptr;
+ }
+ }
+ eip = &bdb->bi_cache.c_dntree;
+ }
+
+ for ( bdb_cache_entryinfo_lock( eip ); eip; ) {
+ eip->bei_state |= CACHE_ENTRY_REFERENCED;
+ ei.bei_parent = eip;
+ ei2 = (EntryInfo *)avl_find( eip->bei_kids, &ei, bdb_rdn_cmp );
+ if ( !ei2 ) {
+ DBC *cursor;
+ int len = ei.bei_nrdn.bv_len;
+
+ if ( BER_BVISEMPTY( ndn )) {
+ *res = eip;
+ return LDAP_SUCCESS;
+ }
+
+ ei.bei_nrdn.bv_len = ndn->bv_len -
+ (ei.bei_nrdn.bv_val - ndn->bv_val);
+ eip->bei_finders++;
+ bdb_cache_entryinfo_unlock( eip );
+
+ BDB_LOG_PRINTF( bdb->bi_dbenv, NULL, "slapd Reading %s",
+ ei.bei_nrdn.bv_val );
+
+ cursor = NULL;
+ rc = bdb_dn2id( op, &ei.bei_nrdn, &ei, txn, &cursor );
+ if (rc) {
+ bdb_cache_entryinfo_lock( eip );
+ eip->bei_finders--;
+ if ( cursor ) cursor->c_close( cursor );
+ *res = eip;
+ return rc;
+ }
+
+ BDB_LOG_PRINTF( bdb->bi_dbenv, NULL, "slapd Read got %s(%d)",
+ ei.bei_nrdn.bv_val, ei.bei_id );
+
+ /* DN exists but needs to be added to cache */
+ ei.bei_nrdn.bv_len = len;
+ rc = bdb_entryinfo_add_internal( bdb, &ei, &ei2 );
+ /* add_internal left eip and c_rwlock locked */
+ eip->bei_finders--;
+ ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
+ if ( cursor ) cursor->c_close( cursor );
+ if ( rc ) {
+ *res = eip;
+ return rc;
+ }
+ }
+ bdb_cache_entryinfo_lock( ei2 );
+ if ( ei2->bei_state & CACHE_ENTRY_DELETED ) {
+ /* In the midst of deleting? Give it a chance to
+ * complete.
+ */
+ bdb_cache_entryinfo_unlock( ei2 );
+ bdb_cache_entryinfo_unlock( eip );
+ ldap_pvt_thread_yield();
+ bdb_cache_entryinfo_lock( eip );
+ *res = eip;
+ return DB_NOTFOUND;
+ }
+ bdb_cache_entryinfo_unlock( eip );
+
+ eip = ei2;
+
+ /* Advance to next lower RDN */
+ for (ptr = ei.bei_nrdn.bv_val - 2; ptr > ndn->bv_val
+ && !DN_SEPARATOR(*ptr); ptr--) /* empty */;
+ if ( ptr >= ndn->bv_val ) {
+ if (DN_SEPARATOR(*ptr)) ptr++;
+ ei.bei_nrdn.bv_len = ei.bei_nrdn.bv_val - ptr - 1;
+ ei.bei_nrdn.bv_val = ptr;
+ }
+ if ( ptr < ndn->bv_val ) {
+ *res = eip;
+ break;
+ }
+ }
+
+ return rc;
+}
+
+#ifdef BDB_HIER
+/* Walk up the tree from a child node, looking for an ID that's already
+ * been linked into the cache.
+ */
+int
+hdb_cache_find_parent(
+ Operation *op,
+ DB_TXN *txn,
+ ID id,
+ EntryInfo **res )
+{
+ struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;
+ EntryInfo ei, eip, *ei2 = NULL, *ein = NULL, *eir = NULL;
+ int rc, add;
+
+ ei.bei_id = id;
+ ei.bei_kids = NULL;
+ ei.bei_ckids = 0;
+
+ for (;;) {
+ rc = hdb_dn2id_parent( op, txn, &ei, &eip.bei_id );
+ if ( rc ) break;
+
+ /* Save the previous node, if any */
+ ei2 = ein;
+
+ /* Create a new node for the current ID */
+ ein = bdb_cache_entryinfo_new( &bdb->bi_cache );
+ ein->bei_id = ei.bei_id;
+ ein->bei_kids = ei.bei_kids;
+ ein->bei_nrdn = ei.bei_nrdn;
+ ein->bei_rdn = ei.bei_rdn;
+ ein->bei_ckids = ei.bei_ckids;
+#ifdef SLAP_ZONE_ALLOC
+ ein->bei_bdb = bdb;
+#endif
+ ei.bei_ckids = 0;
+ add = 1;
+
+ /* This node is not fully connected yet */
+ ein->bei_state |= CACHE_ENTRY_NOT_LINKED;
+
+ /* If this is the first time, save this node
+ * to be returned later.
+ */
+ if ( eir == NULL ) {
+ eir = ein;
+ ein->bei_finders++;
+ }
+
+again:
+ /* Insert this node into the ID tree */
+ ldap_pvt_thread_rdwr_wlock( &bdb->bi_cache.c_rwlock );
+ if ( avl_insert( &bdb->bi_cache.c_idtree, (caddr_t)ein,
+ bdb_id_cmp, bdb_id_dup_err ) ) {
+ EntryInfo *eix = ein->bei_lrunext;
+
+ if ( bdb_cache_entryinfo_trylock( eix )) {
+ ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
+ ldap_pvt_thread_yield();
+ goto again;
+ }
+ ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
+
+ /* Someone else created this node just before us.
+ * Free our new copy and use the existing one.
+ */
+ bdb_cache_entryinfo_free( &bdb->bi_cache, ein );
+
+ /* if it was the node we were looking for, just return it */
+ if ( eir == ein ) {
+ *res = eix;
+ rc = 0;
+ break;
+ }
+
+ ein = ei2;
+ ei2 = eix;
+ add = 0;
+
+ /* otherwise, link up what we have and return */
+ goto gotparent;
+ }
+
+ /* If there was a previous node, link it to this one */
+ if ( ei2 ) ei2->bei_parent = ein;
+
+ /* Look for this node's parent */
+par2:
+ if ( eip.bei_id ) {
+ ei2 = (EntryInfo *) avl_find( bdb->bi_cache.c_idtree,
+ (caddr_t) &eip, bdb_id_cmp );
+ } else {
+ ei2 = &bdb->bi_cache.c_dntree;
+ }
+ if ( ei2 && bdb_cache_entryinfo_trylock( ei2 )) {
+ ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
+ ldap_pvt_thread_yield();
+ ldap_pvt_thread_rdwr_wlock( &bdb->bi_cache.c_rwlock );
+ goto par2;
+ }
+ if ( add )
+ bdb->bi_cache.c_eiused++;
+ if ( ei2 && ( ei2->bei_kids || !ei2->bei_id ))
+ bdb->bi_cache.c_leaves++;
+ ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
+
+gotparent:
+ /* Got the parent, link in and we're done. */
+ if ( ei2 ) {
+ bdb_cache_entryinfo_lock( eir );
+ ein->bei_parent = ei2;
+
+ if ( avl_insert( &ei2->bei_kids, (caddr_t)ein, bdb_rdn_cmp,
+ avl_dup_error) == 0 )
+ ei2->bei_ckids++;
+
+ /* Reset all the state info */
+ for (ein = eir; ein != ei2; ein=ein->bei_parent)
+ ein->bei_state &= ~CACHE_ENTRY_NOT_LINKED;
+
+ bdb_cache_entryinfo_unlock( ei2 );
+ eir->bei_finders--;
+
+ *res = eir;
+ break;
+ }
+ ei.bei_kids = NULL;
+ ei.bei_id = eip.bei_id;
+ ei.bei_ckids = 1;
+ avl_insert( &ei.bei_kids, (caddr_t)ein, bdb_rdn_cmp,
+ avl_dup_error );
+ }
+ return rc;
+}
+
+/* Used by hdb_dn2idl when loading the EntryInfo for all the children
+ * of a given node
+ */
+int hdb_cache_load(
+ struct bdb_info *bdb,
+ EntryInfo *ei,
+ EntryInfo **res )
+{
+ EntryInfo *ei2;
+ int rc;
+
+ /* See if we already have this one */
+ bdb_cache_entryinfo_lock( ei->bei_parent );
+ ei2 = (EntryInfo *)avl_find( ei->bei_parent->bei_kids, ei, bdb_rdn_cmp );
+ bdb_cache_entryinfo_unlock( ei->bei_parent );
+
+ if ( !ei2 ) {
+ /* Not found, add it */
+ struct berval bv;
+
+ /* bei_rdn was not malloc'd before, do it now */
+ ber_dupbv( &bv, &ei->bei_rdn );
+ ei->bei_rdn = bv;
+
+ rc = bdb_entryinfo_add_internal( bdb, ei, res );
+ bdb_cache_entryinfo_unlock( ei->bei_parent );
+ ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
+ } else {
+ /* Found, return it */
+ *res = ei2;
+ return 0;
+ }
+ return rc;
+}
+#endif
+
+/* This is best-effort only. If all entries in the cache are
+ * busy, they will all be kept. This is unlikely to happen
+ * unless the cache is very much smaller than the working set.
+ */
+static void
+bdb_cache_lru_purge( struct bdb_info *bdb )
+{
+ DB_LOCK lock, *lockp;
+ EntryInfo *elru, *elnext = NULL;
+ int islocked;
+ ID eicount, ecount;
+ ID count, efree, eifree = 0;
+#ifdef LDAP_DEBUG
+ int iter;
+#endif
+
+ /* Wait for the mutex; we're the only one trying to purge. */
+ ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_lru_mutex );
+
+ if ( bdb->bi_cache.c_cursize > bdb->bi_cache.c_maxsize ) {
+ efree = bdb->bi_cache.c_cursize - bdb->bi_cache.c_maxsize;
+ efree += bdb->bi_cache.c_minfree;
+ } else {
+ efree = 0;
+ }
+
+ /* maximum number of EntryInfo leaves to cache. In slapcat
+ * we always free all leaf nodes.
+ */
+
+ if ( slapMode & SLAP_TOOL_READONLY ) {
+ eifree = bdb->bi_cache.c_leaves;
+ } else if ( bdb->bi_cache.c_eimax &&
+ bdb->bi_cache.c_leaves > bdb->bi_cache.c_eimax ) {
+ eifree = bdb->bi_cache.c_minfree * 10;
+ if ( eifree >= bdb->bi_cache.c_leaves )
+ eifree /= 2;
+ }
+
+ if ( !efree && !eifree ) {
+ ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_lru_mutex );
+ bdb->bi_cache.c_purging = 0;
+ return;
+ }
+
+ if ( bdb->bi_cache.c_txn ) {
+ lockp = &lock;
+ } else {
+ lockp = NULL;
+ }
+
+ count = 0;
+ eicount = 0;
+ ecount = 0;
+#ifdef LDAP_DEBUG
+ iter = 0;
+#endif
+
+ /* Look for an unused entry to remove */
+ for ( elru = bdb->bi_cache.c_lruhead; elru; elru = elnext ) {
+ elnext = elru->bei_lrunext;
+
+ if ( bdb_cache_entryinfo_trylock( elru ))
+ goto bottom;
+
+ /* This flag implements the clock replacement behavior */
+ if ( elru->bei_state & ( CACHE_ENTRY_REFERENCED )) {
+ elru->bei_state &= ~CACHE_ENTRY_REFERENCED;
+ bdb_cache_entryinfo_unlock( elru );
+ goto bottom;
+ }
+
+ /* If this node is in the process of linking into the cache,
+ * or this node is being deleted, skip it.
+ */
+ if (( elru->bei_state & ( CACHE_ENTRY_NOT_LINKED |
+ CACHE_ENTRY_DELETED | CACHE_ENTRY_LOADING |
+ CACHE_ENTRY_ONELEVEL )) ||
+ elru->bei_finders > 0 ) {
+ bdb_cache_entryinfo_unlock( elru );
+ goto bottom;
+ }
+
+ if ( bdb_cache_entryinfo_trylock( elru->bei_parent )) {
+ bdb_cache_entryinfo_unlock( elru );
+ goto bottom;
+ }
+
+ /* entryinfo is locked */
+ islocked = 1;
+
+ /* If we can successfully writelock it, then
+ * the object is idle.
+ */
+ if ( bdb_cache_entry_db_lock( bdb,
+ bdb->bi_cache.c_txn, elru, 1, 1, lockp ) == 0 ) {
+
+ /* Free entry for this node if it's present */
+ if ( elru->bei_e ) {
+ ecount++;
+
+ /* the cache may have gone over the limit while we
+ * weren't looking, so double check.
+ */
+ if ( !efree && ecount > bdb->bi_cache.c_maxsize )
+ efree = bdb->bi_cache.c_minfree;
+
+ if ( count < efree ) {
+ elru->bei_e->e_private = NULL;
+#ifdef SLAP_ZONE_ALLOC
+ bdb_entry_return( bdb, elru->bei_e, elru->bei_zseq );
+#else
+ bdb_entry_return( elru->bei_e );
+#endif
+ elru->bei_e = NULL;
+ count++;
+ } else {
+ /* Keep this node cached, skip to next */
+ bdb_cache_entry_db_unlock( bdb, lockp );
+ goto next;
+ }
+ }
+ bdb_cache_entry_db_unlock( bdb, lockp );
+
+ /*
+ * If it is a leaf node, and we're over the limit, free it.
+ */
+ if ( elru->bei_kids ) {
+ /* Drop from list, we ignore it... */
+ LRU_DEL( &bdb->bi_cache, elru );
+ } else if ( eicount < eifree ) {
+ /* Too many leaf nodes, free this one */
+ bdb_cache_delete_internal( &bdb->bi_cache, elru, 0 );
+ bdb_cache_delete_cleanup( &bdb->bi_cache, elru );
+ islocked = 0;
+ eicount++;
+ } /* Leave on list until we need to free it */
+ }
+
+next:
+ if ( islocked ) {
+ bdb_cache_entryinfo_unlock( elru );
+ bdb_cache_entryinfo_unlock( elru->bei_parent );
+ }
+
+ if ( count >= efree && eicount >= eifree )
+ break;
+bottom:
+ if ( elnext == bdb->bi_cache.c_lruhead )
+ break;
+#ifdef LDAP_DEBUG
+ iter++;
+#endif
+ }
+
+ if ( count || ecount > bdb->bi_cache.c_cursize ) {
+ ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_count_mutex );
+ /* HACK: we seem to be losing track, fix up now */
+ if ( ecount > bdb->bi_cache.c_cursize )
+ bdb->bi_cache.c_cursize = ecount;
+ bdb->bi_cache.c_cursize -= count;
+ ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_count_mutex );
+ }
+ bdb->bi_cache.c_lruhead = elnext;
+ ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_lru_mutex );
+ bdb->bi_cache.c_purging = 0;
+}
+
+/*
+ * cache_find_id - find an entry in the cache, given id.
+ * The entry is locked for Read upon return. Call with flag ID_LOCKED if
+ * the supplied *eip was already locked.
+ */
+
+int
+bdb_cache_find_id(
+ Operation *op,
+ DB_TXN *tid,
+ ID id,
+ EntryInfo **eip,
+ int flag,
+ DB_LOCK *lock )
+{
+ struct bdb_info *bdb = (struct bdb_info *) op->o_bd->be_private;
+ Entry *ep = NULL;
+ int rc = 0, load = 0;
+ EntryInfo ei = { 0 };
+
+ ei.bei_id = id;
+
+#ifdef SLAP_ZONE_ALLOC
+ slap_zh_rlock(bdb->bi_cache.c_zctx);
+#endif
+ /* If we weren't given any info, see if we have it already cached */
+ if ( !*eip ) {
+again: ldap_pvt_thread_rdwr_rlock( &bdb->bi_cache.c_rwlock );
+ *eip = (EntryInfo *) avl_find( bdb->bi_cache.c_idtree,
+ (caddr_t) &ei, bdb_id_cmp );
+ if ( *eip ) {
+ /* If the lock attempt fails, the info is in use */
+ if ( bdb_cache_entryinfo_trylock( *eip )) {
+ int del = (*eip)->bei_state & CACHE_ENTRY_DELETED;
+ ldap_pvt_thread_rdwr_runlock( &bdb->bi_cache.c_rwlock );
+ /* If this node is being deleted, treat
+ * as if the delete has already finished
+ */
+ if ( del ) {
+ return DB_NOTFOUND;
+ }
+ /* otherwise, wait for the info to free up */
+ ldap_pvt_thread_yield();
+ goto again;
+ }
+ /* If this info isn't hooked up to its parent yet,
+ * unlock and wait for it to be fully initialized
+ */
+ if ( (*eip)->bei_state & CACHE_ENTRY_NOT_LINKED ) {
+ bdb_cache_entryinfo_unlock( *eip );
+ ldap_pvt_thread_rdwr_runlock( &bdb->bi_cache.c_rwlock );
+ ldap_pvt_thread_yield();
+ goto again;
+ }
+ flag |= ID_LOCKED;
+ }
+ ldap_pvt_thread_rdwr_runlock( &bdb->bi_cache.c_rwlock );
+ }
+
+ /* See if the ID exists in the database; add it to the cache if so */
+ if ( !*eip ) {
+#ifndef BDB_HIER
+ rc = bdb_id2entry( op->o_bd, tid, id, &ep );
+ if ( rc == 0 ) {
+ rc = bdb_cache_find_ndn( op, tid,
+ &ep->e_nname, eip );
+ if ( *eip ) flag |= ID_LOCKED;
+ if ( rc ) {
+ ep->e_private = NULL;
+#ifdef SLAP_ZONE_ALLOC
+ bdb_entry_return( bdb, ep, (*eip)->bei_zseq );
+#else
+ bdb_entry_return( ep );
+#endif
+ ep = NULL;
+ }
+ }
+#else
+ rc = hdb_cache_find_parent(op, tid, id, eip );
+ if ( rc == 0 ) flag |= ID_LOCKED;
+#endif
+ }
+
+ /* Ok, we found the info, do we have the entry? */
+ if ( rc == 0 ) {
+ if ( !( flag & ID_LOCKED )) {
+ bdb_cache_entryinfo_lock( *eip );
+ flag |= ID_LOCKED;
+ }
+
+ if ( (*eip)->bei_state & CACHE_ENTRY_DELETED ) {
+ rc = DB_NOTFOUND;
+ } else {
+ (*eip)->bei_finders++;
+ (*eip)->bei_state |= CACHE_ENTRY_REFERENCED;
+ if ( flag & ID_NOENTRY ) {
+ bdb_cache_entryinfo_unlock( *eip );
+ return 0;
+ }
+ /* Make sure only one thread tries to load the entry */
+load1:
+#ifdef SLAP_ZONE_ALLOC
+ if ((*eip)->bei_e && !slap_zn_validate(
+ bdb->bi_cache.c_zctx, (*eip)->bei_e, (*eip)->bei_zseq)) {
+ (*eip)->bei_e = NULL;
+ (*eip)->bei_zseq = 0;
+ }
+#endif
+ if ( !(*eip)->bei_e && !((*eip)->bei_state & CACHE_ENTRY_LOADING)) {
+ load = 1;
+ (*eip)->bei_state |= CACHE_ENTRY_LOADING;
+ flag |= ID_CHKPURGE;
+ }
+
+ if ( !load ) {
+ /* Clear the uncached state if we are not
+ * loading it, i.e it is already cached or
+ * another thread is currently loading it.
+ */
+ if ( (*eip)->bei_state & CACHE_ENTRY_NOT_CACHED ) {
+ (*eip)->bei_state ^= CACHE_ENTRY_NOT_CACHED;
+ flag |= ID_CHKPURGE;
+ }
+ }
+
+ if ( flag & ID_LOCKED ) {
+ bdb_cache_entryinfo_unlock( *eip );
+ flag ^= ID_LOCKED;
+ }
+ rc = bdb_cache_entry_db_lock( bdb, tid, *eip, load, 0, lock );
+ if ( (*eip)->bei_state & CACHE_ENTRY_DELETED ) {
+ rc = DB_NOTFOUND;
+ bdb_cache_entry_db_unlock( bdb, lock );
+ bdb_cache_entryinfo_lock( *eip );
+ (*eip)->bei_finders--;
+ bdb_cache_entryinfo_unlock( *eip );
+ } else if ( rc == 0 ) {
+ if ( load ) {
+ if ( !ep) {
+ rc = bdb_id2entry( op->o_bd, tid, id, &ep );
+ }
+ if ( rc == 0 ) {
+ ep->e_private = *eip;
+#ifdef BDB_HIER
+ while ( (*eip)->bei_state & CACHE_ENTRY_NOT_LINKED )
+ ldap_pvt_thread_yield();
+ bdb_fix_dn( ep, 0 );
+#endif
+ bdb_cache_entryinfo_lock( *eip );
+
+ (*eip)->bei_e = ep;
+#ifdef SLAP_ZONE_ALLOC
+ (*eip)->bei_zseq = *((ber_len_t *)ep - 2);
+#endif
+ ep = NULL;
+ if ( flag & ID_NOCACHE ) {
+ /* Set the cached state only if no other thread
+ * found the info while we were loading the entry.
+ */
+ if ( (*eip)->bei_finders == 1 ) {
+ (*eip)->bei_state |= CACHE_ENTRY_NOT_CACHED;
+ flag ^= ID_CHKPURGE;
+ }
+ }
+ bdb_cache_entryinfo_unlock( *eip );
+ bdb_cache_lru_link( bdb, *eip );
+ }
+ if ( rc == 0 ) {
+ /* If we succeeded, downgrade back to a readlock. */
+ rc = bdb_cache_entry_db_relock( bdb, tid,
+ *eip, 0, 0, lock );
+ } else {
+ /* Otherwise, release the lock. */
+ bdb_cache_entry_db_unlock( bdb, lock );
+ }
+ } else if ( !(*eip)->bei_e ) {
+ /* Some other thread is trying to load the entry,
+ * wait for it to finish.
+ */
+ bdb_cache_entry_db_unlock( bdb, lock );
+ bdb_cache_entryinfo_lock( *eip );
+ flag |= ID_LOCKED;
+ goto load1;
+#ifdef BDB_HIER
+ } else {
+ /* Check for subtree renames
+ */
+ rc = bdb_fix_dn( (*eip)->bei_e, 1 );
+ if ( rc ) {
+ bdb_cache_entry_db_relock( bdb,
+ tid, *eip, 1, 0, lock );
+ /* check again in case other modifier did it already */
+ if ( bdb_fix_dn( (*eip)->bei_e, 1 ) )
+ rc = bdb_fix_dn( (*eip)->bei_e, 2 );
+ bdb_cache_entry_db_relock( bdb,
+ tid, *eip, 0, 0, lock );
+ }
+#endif
+ }
+ bdb_cache_entryinfo_lock( *eip );
+ (*eip)->bei_finders--;
+ if ( load )
+ (*eip)->bei_state ^= CACHE_ENTRY_LOADING;
+ bdb_cache_entryinfo_unlock( *eip );
+ }
+ }
+ }
+ if ( flag & ID_LOCKED ) {
+ bdb_cache_entryinfo_unlock( *eip );
+ }
+ if ( ep ) {
+ ep->e_private = NULL;
+#ifdef SLAP_ZONE_ALLOC
+ bdb_entry_return( bdb, ep, (*eip)->bei_zseq );
+#else
+ bdb_entry_return( ep );
+#endif
+ }
+ if ( rc == 0 ) {
+ int purge = 0;
+
+ if (( flag & ID_CHKPURGE ) || bdb->bi_cache.c_eimax ) {
+ ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_count_mutex );
+ if ( flag & ID_CHKPURGE ) {
+ bdb->bi_cache.c_cursize++;
+ if ( !bdb->bi_cache.c_purging && bdb->bi_cache.c_cursize > bdb->bi_cache.c_maxsize ) {
+ purge = 1;
+ bdb->bi_cache.c_purging = 1;
+ }
+ } else if ( !bdb->bi_cache.c_purging && bdb->bi_cache.c_eimax && bdb->bi_cache.c_leaves > bdb->bi_cache.c_eimax ) {
+ purge = 1;
+ bdb->bi_cache.c_purging = 1;
+ }
+ ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_count_mutex );
+ }
+ if ( purge )
+ bdb_cache_lru_purge( bdb );
+ }
+
+#ifdef SLAP_ZONE_ALLOC
+ if (rc == 0 && (*eip)->bei_e) {
+ slap_zn_rlock(bdb->bi_cache.c_zctx, (*eip)->bei_e);
+ }
+ slap_zh_runlock(bdb->bi_cache.c_zctx);
+#endif
+ return rc;
+}
+
+int
+bdb_cache_children(
+ Operation *op,
+ DB_TXN *txn,
+ Entry *e )
+{
+ int rc;
+
+ if ( BEI(e)->bei_kids ) {
+ return 0;
+ }
+ if ( BEI(e)->bei_state & CACHE_ENTRY_NO_KIDS ) {
+ return DB_NOTFOUND;
+ }
+ rc = bdb_dn2id_children( op, txn, e );
+ if ( rc == DB_NOTFOUND ) {
+ BEI(e)->bei_state |= CACHE_ENTRY_NO_KIDS | CACHE_ENTRY_NO_GRANDKIDS;
+ }
+ return rc;
+}
+
+/* Update the cache after a successful database Add. */
+int
+bdb_cache_add(
+ struct bdb_info *bdb,
+ EntryInfo *eip,
+ Entry *e,
+ struct berval *nrdn,
+ DB_TXN *txn,
+ DB_LOCK *lock )
+{
+ EntryInfo *new, ei;
+ int rc, purge = 0;
+#ifdef BDB_HIER
+ struct berval rdn = e->e_name;
+#endif
+
+ ei.bei_id = e->e_id;
+ ei.bei_parent = eip;
+ ei.bei_nrdn = *nrdn;
+ ei.bei_lockpad = 0;
+
+#if 0
+ /* Lock this entry so that bdb_add can run to completion.
+ * It can only fail if BDB has run out of lock resources.
+ */
+ rc = bdb_cache_entry_db_lock( bdb, txn, &ei, 0, 0, lock );
+ if ( rc ) {
+ bdb_cache_entryinfo_unlock( eip );
+ return rc;
+ }
+#endif
+
+#ifdef BDB_HIER
+ 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 );
+ if ( eip->bei_dkids ) eip->bei_dkids++;
+#endif
+
+ if (eip->bei_parent) {
+ bdb_cache_entryinfo_lock( eip->bei_parent );
+ eip->bei_parent->bei_state &= ~CACHE_ENTRY_NO_GRANDKIDS;
+ bdb_cache_entryinfo_unlock( eip->bei_parent );
+ }
+
+ rc = bdb_entryinfo_add_internal( bdb, &ei, &new );
+ /* 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;
+ bdb_cache_entryinfo_unlock( eip );
+
+ ldap_pvt_thread_rdwr_wunlock( &bdb->bi_cache.c_rwlock );
+ ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_count_mutex );
+ ++bdb->bi_cache.c_cursize;
+ if ( bdb->bi_cache.c_cursize > bdb->bi_cache.c_maxsize &&
+ !bdb->bi_cache.c_purging ) {
+ purge = 1;
+ bdb->bi_cache.c_purging = 1;
+ }
+ ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_count_mutex );
+
+ new->bei_finders = 1;
+ bdb_cache_lru_link( bdb, new );
+
+ if ( purge )
+ bdb_cache_lru_purge( bdb );
+
+ return rc;
+}
+
+void bdb_cache_deref(
+ EntryInfo *ei
+ )
+{
+ bdb_cache_entryinfo_lock( ei );
+ ei->bei_finders--;
+ bdb_cache_entryinfo_unlock( ei );
+}
+
+int
+bdb_cache_modify(
+ struct bdb_info *bdb,
+ Entry *e,
+ Attribute *newAttrs,
+ DB_TXN *txn,
+ DB_LOCK *lock )
+{
+ EntryInfo *ei = BEI(e);
+ int rc;
+ /* Get write lock on data */
+ rc = bdb_cache_entry_db_relock( bdb, txn, 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,
+ DB_TXN *txn,
+ 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, txn, 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 );
+
+#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 );
+
+ /* If new parent, decrement kid counts */
+ if ( ein ) {
+ pei->bei_ckids--;
+ if ( pei->bei_dkids ) {
+ pei->bei_dkids--;
+ if ( pei->bei_dkids < 2 )
+ pei->bei_state |= CACHE_ENTRY_NO_KIDS | CACHE_ENTRY_NO_GRANDKIDS;
+ }
+ }
+#endif
+
+ if (!ein) {
+ ein = ei->bei_parent;
+ } else {
+ ei->bei_parent = ein;
+ bdb_cache_entryinfo_unlock( pei );
+ bdb_cache_entryinfo_lock( ein );
+
+ /* new parent now has kids */
+ if ( ein->bei_state & CACHE_ENTRY_NO_KIDS )
+ ein->bei_state ^= CACHE_ENTRY_NO_KIDS;
+ /* grandparent has grandkids */
+ if ( ein->bei_parent )
+ ein->bei_parent->bei_state &= ~CACHE_ENTRY_NO_GRANDKIDS;
+#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;
+
+ ein->bei_ckids++;
+ if ( ein->bei_dkids ) ein->bei_dkids++;
+#endif
+ }
+
+#ifdef BDB_HIER
+ /* 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 );
+#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(
+ struct bdb_info *bdb,
+ Entry *e,
+ DB_TXN *txn,
+ DB_LOCK *lock )
+{
+ EntryInfo *ei = BEI(e);
+ int rc, busy = 0, counter = 0;
+
+ assert( e->e_private != NULL );
+
+ /* Lock the entry's info */
+ bdb_cache_entryinfo_lock( ei );
+
+ /* Set this early, warn off any queriers */
+ ei->bei_state |= CACHE_ENTRY_DELETED;
+
+ if (( ei->bei_state & ( CACHE_ENTRY_NOT_LINKED |
+ CACHE_ENTRY_LOADING | CACHE_ENTRY_ONELEVEL )) ||
+ ei->bei_finders > 0 )
+ busy = 1;
+
+ bdb_cache_entryinfo_unlock( ei );
+
+ while ( busy && counter < 1000) {
+ ldap_pvt_thread_yield();
+ busy = 0;
+ bdb_cache_entryinfo_lock( ei );
+ if (( ei->bei_state & ( CACHE_ENTRY_NOT_LINKED |
+ CACHE_ENTRY_LOADING | CACHE_ENTRY_ONELEVEL )) ||
+ ei->bei_finders > 0 )
+ busy = 1;
+ bdb_cache_entryinfo_unlock( ei );
+ counter ++;
+ }
+ if( busy ) {
+ bdb_cache_entryinfo_lock( ei );
+ ei->bei_state ^= CACHE_ENTRY_DELETED;
+ bdb_cache_entryinfo_unlock( ei );
+ return DB_LOCK_DEADLOCK;
+ }
+
+ /* Get write lock on the data */
+ rc = bdb_cache_entry_db_relock( bdb, txn, ei, 1, 0, lock );
+ if ( rc ) {
+ bdb_cache_entryinfo_lock( ei );
+ /* 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( &bdb->bi_cache.c_lru_mutex );
+
+ bdb_cache_entryinfo_lock( ei->bei_parent );
+ bdb_cache_entryinfo_lock( ei );
+ rc = bdb_cache_delete_internal( &bdb->bi_cache, e->e_private, 1 );
+ bdb_cache_entryinfo_unlock( ei );
+
+ /* free lru mutex */
+ ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_lru_mutex );
+
+ return( rc );
+}
+
+void
+bdb_cache_delete_cleanup(
+ Cache *cache,
+ EntryInfo *ei )
+{
+ /* Enter with ei locked */
+
+ /* already freed? */
+ if ( !ei->bei_parent ) return;
+
+ 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;
+ }
+
+ bdb_cache_entryinfo_unlock( ei );
+ bdb_cache_entryinfo_free( cache, ei );
+}
+
+static int
+bdb_cache_delete_internal(
+ Cache *cache,
+ EntryInfo *e,
+ int decr )
+{
+ int rc = 0; /* return code */
+ int decr_leaf = 0;
+
+ /* already freed? */
+ if ( !e->bei_parent ) {
+ assert(0);
+ return -1;
+ }
+
+#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;
+ assert(0);
+ }
+ if ( e->bei_parent->bei_kids )
+ decr_leaf = 1;
+
+ ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
+ /* id tree */
+ if ( avl_delete( &cache->c_idtree, (caddr_t) e, bdb_id_cmp )) {
+ cache->c_eiused--;
+ if ( decr_leaf )
+ cache->c_leaves--;
+ } else {
+ rc = -1;
+ assert(0);
+ }
+ ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
+ bdb_cache_entryinfo_unlock( e->bei_parent );
+
+ if ( rc == 0 ){
+ /* lru */
+ LRU_DEL( cache, e );
+
+ if ( e->bei_e ) {
+ ldap_pvt_thread_mutex_lock( &cache->c_count_mutex );
+ cache->c_cursize--;
+ ldap_pvt_thread_mutex_unlock( &cache->c_count_mutex );
+ }
+ }
+
+ 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->c_lru_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->c_lru_mutex );
+ /* free cache write lock */
+ ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
+}
+
+#ifdef LDAP_DEBUG
+static void
+bdb_lru_count( Cache *cache )
+{
+ EntryInfo *e;
+ int ei = 0, ent = 0, nc = 0;
+
+ for ( e = cache->c_lrutail; ; ) {
+ ei++;
+ if ( e->bei_e ) {
+ ent++;
+ if ( e->bei_state & CACHE_ENTRY_NOT_CACHED )
+ nc++;
+ fprintf( stderr, "ei %d entry %p dn %s\n", ei, (void *) e->bei_e, e->bei_e->e_name.bv_val );
+ }
+ e = e->bei_lrunext;
+ if ( e == cache->c_lrutail )
+ break;
+ }
+ fprintf( stderr, "counted %d entryInfos and %d entries, %d notcached\n",
+ ei, ent, nc );
+ ei = 0;
+ for ( e = cache->c_lrutail; ; ) {
+ ei++;
+ e = e->bei_lruprev;
+ if ( e == cache->c_lrutail )
+ break;
+ }
+ fprintf( stderr, "counted %d entryInfos (on lruprev)\n", ei );
+}
+
+#ifdef SLAPD_UNUSED
+static void
+bdb_lru_print( Cache *cache )
+{
+ EntryInfo *e;
+
+ fprintf( stderr, "LRU circle head: %p\n", (void *) cache->c_lruhead );
+ fprintf( stderr, "LRU circle (tail forward):\n" );
+ for ( e = cache->c_lrutail; ; ) {
+ fprintf( stderr, "\t%p, %p id %ld rdn \"%s\"\n",
+ (void *) e, (void *) e->bei_e, e->bei_id, e->bei_nrdn.bv_val );
+ e = e->bei_lrunext;
+ if ( e == cache->c_lrutail )
+ break;
+ }
+ fprintf( stderr, "LRU circle (tail backward):\n" );
+ for ( e = cache->c_lrutail; ; ) {
+ fprintf( stderr, "\t%p, %p id %ld rdn \"%s\"\n",
+ (void *) e, (void *) e->bei_e, e->bei_id, e->bei_nrdn.bv_val );
+ e = e->bei_lruprev;
+ if ( e == cache->c_lrutail )
+ break;
+ }
+}
+
+static int
+bdb_entryinfo_print(void *data, void *arg)
+{
+ EntryInfo *e = data;
+ fprintf( stderr, "\t%p, %p id %ld rdn \"%s\"\n",
+ (void *) e, (void *) e->bei_e, e->bei_id, e->bei_nrdn.bv_val );
+ return 0;
+}
+
+static void
+bdb_idtree_print(Cache *cache)
+{
+ avl_apply( cache->c_idtree, bdb_entryinfo_print, NULL, -1, AVL_INORDER );
+}
+#endif
+#endif
+
+static void
+bdb_reader_free( void *key, void *data )
+{
+ /* DB_ENV *env = key; */
+ DB_TXN *txn = data;
+
+ if ( txn ) TXN_ABORT( txn );
+}
+
+/* free up any keys used by the main thread */
+void
+bdb_reader_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, 0, NULL, NULL );
+ bdb_reader_free( env, data );
+ }
+}
+
+int
+bdb_reader_get( Operation *op, DB_ENV *env, DB_TXN **txn )
+{
+ int i, rc;
+ void *data;
+ void *ctx;
+
+ if ( !env || !txn ) 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 ) {
+ *txn = NULL;
+ return 0;
+ }
+
+ if ( ldap_pvt_thread_pool_getkey( ctx, env, &data, NULL ) ) {
+ for ( i=0, rc=1; rc != 0 && i<4; i++ ) {
+ rc = TXN_BEGIN( env, NULL, txn, DB_READ_COMMITTED );
+ if (rc) ldap_pvt_thread_yield();
+ }
+ if ( rc != 0) {
+ return rc;
+ }
+ data = *txn;
+ if ( ( rc = ldap_pvt_thread_pool_setkey( ctx, env,
+ data, bdb_reader_free, NULL, NULL ) ) ) {
+ TXN_ABORT( *txn );
+ Debug( LDAP_DEBUG_ANY, "bdb_reader_get: err %s(%d)\n",
+ db_strerror(rc), rc, 0 );
+
+ return rc;
+ }
+ } else {
+ *txn = data;
+ }
+ return 0;
+}