concurrent cache access: separation of cache lock (reader/writer) and lru lock (mutex)

diff --git a/servers/slapd/back-bdb/back-bdb.h b/servers/slapd/back-bdb/back-bdb.h
index d5584225902139bfc7a61ed29f5b57e16c3af6a5..832a6bb95958ad226542cf967540dd079b490f17 100644 (file)
--- a/servers/slapd/back-bdb/back-bdb.h
+++ b/servers/slapd/back-bdb/back-bdb.h
@@ -76,7 +76,8 @@ typedef struct bdb_cache {
         Avlnode         *c_idtree;
         Entry           *c_lruhead;     /* lru - add accessed entries here */
         Entry           *c_lrutail;     /* lru - rem lru entries from here */
-        ldap_pvt_thread_mutex_t c_mutex;
+        ldap_pvt_thread_rdwr_t c_rwlock;
+        ldap_pvt_thread_mutex_t lru_mutex;
 } Cache;
  
 #define CACHE_READ_LOCK                0

diff --git a/servers/slapd/back-bdb/cache.c b/servers/slapd/back-bdb/cache.c
index f26541a57c92b009d97dc56d21aec5a6b54e4413..1dd74f1cd8e873509b565e0b7f21a135aeee19a0 100644 (file)
--- a/servers/slapd/back-bdb/cache.c
+++ b/servers/slapd/back-bdb/cache.c
@@ -168,7 +168,7 @@ bdb_cache_return_entry_rw( Cache *cache, Entry *e, int rw )
        int refcnt, freeit = 1;
 
        /* set cache mutex */
-       ldap_pvt_thread_mutex_lock( &cache->c_mutex );
+       ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
 
        assert( e->e_private );
 
@@ -183,7 +183,9 @@ bdb_cache_return_entry_rw( Cache *cache, Entry *e, int rw )
         * for instance)
         */
        if (  BEI(e)->bei_state == CACHE_ENTRY_CREATING ) {
+               ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
                bdb_cache_delete_entry_internal( cache, e );
+               ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
                freeit = 0;
                /* now the entry is in DELETED state */
        }
@@ -192,7 +194,7 @@ bdb_cache_return_entry_rw( Cache *cache, Entry *e, int rw )
                BEI(e)->bei_state = CACHE_ENTRY_READY;
 
                /* free cache mutex */
-               ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+               ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
                LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
@@ -208,7 +210,7 @@ bdb_cache_return_entry_rw( Cache *cache, Entry *e, int rw )
        } else if ( BEI(e)->bei_state == CACHE_ENTRY_DELETED ) {
                if( refcnt > 0 ) {
                        /* free cache mutex */
-                       ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+                       ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
                        LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
@@ -227,7 +229,7 @@ bdb_cache_return_entry_rw( Cache *cache, Entry *e, int rw )
                        }
 
                        /* free cache mutex */
-                       ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+                       ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
                        LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
@@ -242,7 +244,7 @@ bdb_cache_return_entry_rw( Cache *cache, Entry *e, int rw )
 
        } else {
                /* free cache mutex */
-               ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+               ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
                LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
@@ -303,13 +305,13 @@ bdb_cache_add_entry_rw(
                   e->e_dn, rw ? "w" : "r" ));
 #endif
        /* set cache mutex */
-       ldap_pvt_thread_mutex_lock( &cache->c_mutex );
+       ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
 
        assert( e->e_private == NULL );
 
        if( bdb_cache_entry_private_init(e) != 0 ) {
                /* free cache mutex */
-               ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+               ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 
 #ifdef NEW_LOGGING
                LDAP_LOG(( "cache", LDAP_LEVEL_ERR,
@@ -329,7 +331,7 @@ bdb_cache_add_entry_rw(
                (AVL_CMP) entry_dn_cmp, avl_dup_error ) != 0 )
        {
                /* free cache mutex */
-               ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+               ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
                LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
@@ -377,7 +379,7 @@ bdb_cache_add_entry_rw(
                bdb_cache_entry_private_destroy(e);
 
                /* free cache mutex */
-               ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+               ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
                return( -1 );
        }
 
@@ -388,6 +390,7 @@ bdb_cache_add_entry_rw(
        BEI(e)->bei_state = CACHE_ENTRY_CREATING;
        BEI(e)->bei_refcnt = 1;
 
+       ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
        /* lru */
        LRU_ADD( cache, e );
        if ( ++cache->c_cursize > cache->c_maxsize ) {
@@ -427,7 +430,8 @@ bdb_cache_add_entry_rw(
        }
 
        /* free cache mutex */
-       ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+       ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
+       ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
        return( 0 );
 }
 
@@ -447,7 +451,7 @@ bdb_cache_update_entry(
        Entry   *ee;
 
        /* set cache mutex */
-       ldap_pvt_thread_mutex_lock( &cache->c_mutex );
+       ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
 
        assert( e->e_private );
 
@@ -465,7 +469,7 @@ bdb_cache_update_entry(
 #endif
 
                /* free cache mutex */
-               ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+               ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
                return( 1 );
        }
 
@@ -498,7 +502,7 @@ bdb_cache_update_entry(
                }
 
                /* free cache mutex */
-               ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+               ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
                return( -1 );
        }
 
@@ -507,6 +511,7 @@ bdb_cache_update_entry(
        /* will be marked after when entry is returned */
        BEI(e)->bei_state = CACHE_ENTRY_CREATING;
 
+       ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
        /* lru */
        LRU_ADD( cache, e );
        if ( ++cache->c_cursize > cache->c_maxsize ) {
@@ -546,7 +551,8 @@ bdb_cache_update_entry(
        }
 
        /* free cache mutex */
-       ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+       ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
+       ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
        return( 0 );
 }
 
@@ -566,7 +572,7 @@ bdb_cache_find_entry_ndn2id(
 
 try_again:
        /* set cache mutex */
-       ldap_pvt_thread_mutex_lock( &cache->c_mutex );
+       ldap_pvt_thread_rdwr_rlock( &cache->c_rwlock );
 
        if ( (ep = (Entry *) avl_find( cache->c_dntree, (caddr_t) &e,
                (AVL_CMP) entry_dn_cmp )) != NULL )
@@ -593,7 +599,7 @@ try_again:
                        assert(state != CACHE_ENTRY_UNDEFINED);
 
                        /* free cache mutex */
-                       ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+                       ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
                        LDAP_LOG(( "cache", LDAP_LEVEL_INFO,
@@ -610,12 +616,16 @@ try_again:
                        goto try_again;
                }
 
+               ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
+
+               ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
+
                /* lru */
                LRU_DELETE( cache, ep );
                LRU_ADD( cache, ep );
                
                /* free cache mutex */
-               ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+               ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 
 #ifdef NEW_LOGGING
                LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
@@ -629,7 +639,7 @@ try_again:
 
        } else {
                /* free cache mutex */
-               ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+               ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 
                id = NOID;
        }
@@ -656,7 +666,7 @@ bdb_cache_find_entry_id(
 
 try_again:
        /* set cache mutex */
-       ldap_pvt_thread_mutex_lock( &cache->c_mutex );
+       ldap_pvt_thread_rdwr_rlock( &cache->c_rwlock );
 
        if ( (ep = (Entry *) avl_find( cache->c_idtree, (caddr_t) &e,
                (AVL_CMP) entry_id_cmp )) != NULL )
@@ -679,7 +689,7 @@ try_again:
                        assert(state != CACHE_ENTRY_UNDEFINED);
 
                        /* free cache mutex */
-                       ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+                       ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
                        LDAP_LOG(( "cache", LDAP_LEVEL_INFO,
@@ -704,7 +714,7 @@ try_again:
                         */
 
                        /* free cache mutex */
-                       ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+                       ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
                        LDAP_LOG(( "cache", LDAP_LEVEL_INFO,
@@ -720,6 +730,8 @@ try_again:
                        goto try_again;
                }
 
+               ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
+               ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
                /* lru */
                LRU_DELETE( cache, ep );
                LRU_ADD( cache, ep );
@@ -727,7 +739,7 @@ try_again:
                BEI(ep)->bei_refcnt++;
 
                /* free cache mutex */
-               ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+               ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 
 #ifdef NEW_LOGGING
                LDAP_LOG(( "cache", LDAP_LEVEL_DETAIL1,
@@ -744,7 +756,7 @@ try_again:
        }
 
        /* free cache mutex */
-       ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+       ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 
        return( NULL );
 }
@@ -769,7 +781,7 @@ bdb_cache_delete_entry(
        int     rc;
 
        /* set cache mutex */
-       ldap_pvt_thread_mutex_lock( &cache->c_mutex );
+       ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
 
        assert( e->e_private );
 
@@ -781,10 +793,12 @@ bdb_cache_delete_entry(
                e->e_id, 0, 0 );
 #endif
 
+       ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
        rc = bdb_cache_delete_entry_internal( cache, e );
+       ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 
        /* free cache mutex */
-       ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+       ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
        return( rc );
 }
 
@@ -833,7 +847,8 @@ bdb_cache_release_all( Cache *cache )
        int rc;
 
        /* set cache mutex */
-       ldap_pvt_thread_mutex_lock( &cache->c_mutex );
+       ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
+       ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
 
 #ifdef NEW_LOGGING
        LDAP_LOG(( "cache", LDAP_LEVEL_ENTRY,
@@ -865,7 +880,8 @@ bdb_cache_release_all( Cache *cache )
        }
 
        /* free cache mutex */
-       ldap_pvt_thread_mutex_unlock( &cache->c_mutex );
+       ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
+       ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 }
 
 #ifdef LDAP_DEBUG

diff --git a/servers/slapd/back-bdb/init.c b/servers/slapd/back-bdb/init.c
index 0aa13316f0a1ac2536b4d68009ee8113d3035d25..d0c27ba340abb03ddcbce38eb1d1d22cf8948d6a 100644 (file)
--- a/servers/slapd/back-bdb/init.c
+++ b/servers/slapd/back-bdb/init.c
@@ -98,7 +98,8 @@ bdb_db_init( BackendDB *be )
 
        ldap_pvt_thread_mutex_init( &bdb->bi_database_mutex );
        ldap_pvt_thread_mutex_init( &bdb->bi_lastid_mutex );
-       ldap_pvt_thread_mutex_init( &bdb->bi_cache.c_mutex );
+       ldap_pvt_thread_mutex_init( &bdb->bi_cache.lru_mutex );
+       ldap_pvt_thread_rdwr_init ( &bdb->bi_cache.c_rwlock );
 #ifdef BDB_HIER
        ldap_pvt_thread_rdwr_init( &bdb->bi_tree_rdwr );
 #endif