ITS#6660 preliminary fix. debug additions need to be cleaned up.

diff --git a/servers/slapd/back-bdb/cache.c b/servers/slapd/back-bdb/cache.c
index a42db5c5a20cace55b8d41d309ae599368dbc3aa..6da626682055a2bd7ae33a16d2e2ebfa8a1a21ef 100644 (file)
--- a/servers/slapd/back-bdb/cache.c
+++ b/servers/slapd/back-bdb/cache.c
@@ -257,6 +257,11 @@ bdb_cache_entry_db_unlock ( struct bdb_info *bdb, DB_LOCK *lock )
 #endif
 }
 
+/* These should move behind SLAPD_UNUSED */
+static ldap_pvt_thread_mutex_t bdb_ncmutex;
+static int bdb_notcached;
+static int bdb_ncfreed;
+
 void
 bdb_cache_return_entry_rw( struct bdb_info *bdb, Entry *e,
        int rw, DB_LOCK *lock )
@@ -265,9 +270,10 @@ bdb_cache_return_entry_rw( struct bdb_info *bdb, Entry *e,
        int free = 0;
 
        ei = e->e_private;
-       if ( ei &&
-               ( ei->bei_state & CACHE_ENTRY_NOT_CACHED ) &&
-               ( bdb_cache_entryinfo_trylock( ei ) == 0 )) {
+       if ( ei && ( ei->bei_state & CACHE_ENTRY_NOT_CACHED )) {
+               ldap_pvt_thread_mutex_lock(&bdb_ncmutex);
+               bdb_notcached++;
+               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
@@ -282,8 +288,10 @@ bdb_cache_return_entry_rw( struct bdb_info *bdb, Entry *e,
                        ei->bei_e = NULL;
                        ei->bei_state ^= CACHE_ENTRY_NOT_CACHED;
                        free = 1;
+                       bdb_ncfreed++;
                }
                bdb_cache_entryinfo_unlock( ei );
+               ldap_pvt_thread_mutex_unlock(&bdb_ncmutex);
        }
        bdb_cache_entry_db_unlock( bdb, lock );
        if ( free ) {
@@ -968,20 +976,7 @@ load1:
                        if ( !(*eip)->bei_e && !((*eip)->bei_state & CACHE_ENTRY_LOADING)) {
                                load = 1;
                                (*eip)->bei_state |= CACHE_ENTRY_LOADING;
-                       }
-
-                       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;
-                                       ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_count_mutex );
-                                       ++bdb->bi_cache.c_cursize;
-                                       ldap_pvt_thread_mutex_unlock( &bdb->bi_cache.c_count_mutex );
-                               }
-                               flag &= ~ID_NOCACHE;
+                               flag |= ID_CHKPURGE;
                        }
 
                        if ( flag & ID_LOCKED ) {
@@ -1007,21 +1002,24 @@ load1:
                                                        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;
-                                               bdb_cache_lru_link( bdb, *eip );
-                                               if (( flag & ID_NOCACHE ) &&
-                                                       ( bdb_cache_entryinfo_trylock( *eip ) == 0 )) {
+                                               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 )
+                                                       if ( (*eip)->bei_finders == 1 ) {
                                                                (*eip)->bei_state |= CACHE_ENTRY_NOT_CACHED;
-                                                       bdb_cache_entryinfo_unlock( *eip );
+                                                               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. */
@@ -1057,8 +1055,17 @@ load1:
                                }
                                bdb_cache_entryinfo_lock( *eip );
                                (*eip)->bei_finders--;
-                               if ( load )
+                               if ( load ) {
                                        (*eip)->bei_state ^= CACHE_ENTRY_LOADING;
+                               } else {
+                                       /* Clear the uncached state if we didn't
+                                        * load it, i.e it was already cached.
+                                        */
+                                       if ( (*eip)->bei_state & CACHE_ENTRY_NOT_CACHED ) {
+                                               (*eip)->bei_state ^= CACHE_ENTRY_NOT_CACHED;
+                                               flag |= ID_CHKPURGE;
+                                       }
+                               }
                                bdb_cache_entryinfo_unlock( *eip );
                        }
                }
@@ -1077,9 +1084,9 @@ load1:
        if ( rc == 0 ) {
                int purge = 0;
 
-               if (( load && !( flag & ID_NOCACHE )) || bdb->bi_cache.c_eimax ) {
+               if (( flag & ID_CHKPURGE ) || bdb->bi_cache.c_eimax ) {
                        ldap_pvt_thread_mutex_lock( &bdb->bi_cache.c_count_mutex );
-                       if ( load && !( flag & ID_NOCACHE )) {
+                       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;
@@ -1533,6 +1540,36 @@ bdb_cache_release_all( Cache *cache )
 }
 
 #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, 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 )

diff --git a/servers/slapd/back-bdb/proto-bdb.h b/servers/slapd/back-bdb/proto-bdb.h
index b0243553a233d2305819711830daa161ae0191e7..a321dca0b77e3960c57eaae6257728b62c894ac5 100644 (file)
--- a/servers/slapd/back-bdb/proto-bdb.h
+++ b/servers/slapd/back-bdb/proto-bdb.h
@@ -547,6 +547,7 @@ int bdb_cache_find_ndn(
 #define        ID_LOCKED       1
 #define        ID_NOCACHE      2
 #define        ID_NOENTRY      4
+#define        ID_CHKPURGE     8
 int bdb_cache_find_id(
        Operation *op,
        DB_TXN  *tid,