Hallvard B. Furuseth's patch for cache lock and mutex

[openldap] / servers / slapd / back-bdb / cache.c

diff --git a/servers/slapd/back-bdb/cache.c b/servers/slapd/back-bdb/cache.c
index 1dd74f1cd8e873509b565e0b7f21a135aeee19a0..5038db4bc799bacf7dbe6f7982e621f379a1a0db 100644 (file)
--- a/servers/slapd/back-bdb/cache.c
+++ b/servers/slapd/back-bdb/cache.c
@@ -167,7 +167,7 @@ bdb_cache_return_entry_rw( Cache *cache, Entry *e, int rw )
        ID id;
        int refcnt, freeit = 1;
 
-       /* set cache mutex */
+       /* set cache write lock */
        ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
 
        assert( e->e_private );
@@ -183,8 +183,10 @@ bdb_cache_return_entry_rw( Cache *cache, Entry *e, int rw )
         * for instance)
         */
        if (  BEI(e)->bei_state == CACHE_ENTRY_CREATING ) {
+               /* set lru mutex */
                ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
                bdb_cache_delete_entry_internal( cache, e );
+               /* free lru mutex */
                ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
                freeit = 0;
                /* now the entry is in DELETED state */
@@ -193,7 +195,7 @@ bdb_cache_return_entry_rw( Cache *cache, Entry *e, int rw )
        if ( BEI(e)->bei_state == CACHE_ENTRY_COMMITTED ) {
                BEI(e)->bei_state = CACHE_ENTRY_READY;
 
-               /* free cache mutex */
+               /* free cache write lock */
                ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
@@ -209,7 +211,7 @@ 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 */
+                       /* free cache write lock */
                        ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
@@ -228,7 +230,7 @@ bdb_cache_return_entry_rw( Cache *cache, Entry *e, int rw )
                                bdb_entry_return( e );
                        }
 
-                       /* free cache mutex */
+                       /* free cache write lock */
                        ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
@@ -243,7 +245,7 @@ bdb_cache_return_entry_rw( Cache *cache, Entry *e, int rw )
                }
 
        } else {
-               /* free cache mutex */
+               /* free cache write lock */
                ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
@@ -304,14 +306,14 @@ bdb_cache_add_entry_rw(
                   "bdb_cache_add_entry_rw: add (%s):%s to cache\n",
                   e->e_dn, rw ? "w" : "r" ));
 #endif
-       /* set cache mutex */
+       /* set cache write lock */
        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->lru_mutex );
+               /* free cache write lock */
+               ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
                LDAP_LOG(( "cache", LDAP_LEVEL_ERR,
@@ -330,7 +332,7 @@ bdb_cache_add_entry_rw(
        if ( avl_insert( &cache->c_dntree, (caddr_t) e,
                (AVL_CMP) entry_dn_cmp, avl_dup_error ) != 0 )
        {
-               /* free cache mutex */
+               /* free cache write lock */
                ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
@@ -378,7 +380,7 @@ bdb_cache_add_entry_rw(
 
                bdb_cache_entry_private_destroy(e);
 
-               /* free cache mutex */
+               /* free cache write lock */
                ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
                return( -1 );
        }
@@ -390,6 +392,7 @@ bdb_cache_add_entry_rw(
        BEI(e)->bei_state = CACHE_ENTRY_CREATING;
        BEI(e)->bei_refcnt = 1;
 
+       /* set lru mutex */
        ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
        /* lru */
        LRU_ADD( cache, e );
@@ -429,8 +432,9 @@ bdb_cache_add_entry_rw(
                }
        }
 
-       /* free cache mutex */
+       /* free lru mutex */
        ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
+       /* free cache write lock */
        ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
        return( 0 );
 }
@@ -450,7 +454,7 @@ bdb_cache_update_entry(
        int     i, rc;
        Entry   *ee;
 
-       /* set cache mutex */
+       /* set cache write lock */
        ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
 
        assert( e->e_private );
@@ -468,7 +472,7 @@ bdb_cache_update_entry(
                    e->e_id, e->e_dn, 0 );
 #endif
 
-               /* free cache mutex */
+               /* free cache write lock */
                ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
                return( 1 );
        }
@@ -501,7 +505,7 @@ bdb_cache_update_entry(
 #endif
                }
 
-               /* free cache mutex */
+               /* free cache write lock */
                ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
                return( -1 );
        }
@@ -511,6 +515,7 @@ bdb_cache_update_entry(
        /* will be marked after when entry is returned */
        BEI(e)->bei_state = CACHE_ENTRY_CREATING;
 
+       /* set lru mutex */
        ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
        /* lru */
        LRU_ADD( cache, e );
@@ -550,8 +555,9 @@ bdb_cache_update_entry(
                }
        }
 
-       /* free cache mutex */
+       /* free lru mutex */
        ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
+       /* free cache write lock */
        ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
        return( 0 );
 }
@@ -571,7 +577,7 @@ bdb_cache_find_entry_ndn2id(
        e.e_nname = *ndn;
 
 try_again:
-       /* set cache mutex */
+       /* set cache read lock */
        ldap_pvt_thread_rdwr_rlock( &cache->c_rwlock );
 
        if ( (ep = (Entry *) avl_find( cache->c_dntree, (caddr_t) &e,
@@ -598,7 +604,7 @@ try_again:
                if ( state != CACHE_ENTRY_READY ) {
                        assert(state != CACHE_ENTRY_UNDEFINED);
 
-                       /* free cache mutex */
+                       /* free cache read lock */
                        ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
@@ -616,15 +622,17 @@ try_again:
                        goto try_again;
                }
 
+               /* free cache read lock */
                ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 
+               /* set lru mutex */
                ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
 
                /* lru */
                LRU_DELETE( cache, ep );
                LRU_ADD( cache, ep );
                
-               /* free cache mutex */
+               /* free lru mutex */
                ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 
 #ifdef NEW_LOGGING
@@ -638,7 +646,7 @@ try_again:
 #endif
 
        } else {
-               /* free cache mutex */
+               /* free cache read lock */
                ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 
                id = NOID;
@@ -665,7 +673,7 @@ bdb_cache_find_entry_id(
        e.e_id = id;
 
 try_again:
-       /* set cache mutex */
+       /* set cache read lock */
        ldap_pvt_thread_rdwr_rlock( &cache->c_rwlock );
 
        if ( (ep = (Entry *) avl_find( cache->c_idtree, (caddr_t) &e,
@@ -688,7 +696,7 @@ try_again:
 
                        assert(state != CACHE_ENTRY_UNDEFINED);
 
-                       /* free cache mutex */
+                       /* free cache read lock */
                        ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
@@ -713,7 +721,7 @@ try_again:
                         * so, unlock the cache, yield, and try again.
                         */
 
-                       /* free cache mutex */
+                       /* free cache read lock */
                        ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 
 #ifdef NEW_LOGGING
@@ -730,7 +738,9 @@ try_again:
                        goto try_again;
                }
 
+               /* free cache read lock */
                ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
+               /* set lru mutex */
                ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
                /* lru */
                LRU_DELETE( cache, ep );
@@ -738,7 +748,7 @@ try_again:
                
                BEI(ep)->bei_refcnt++;
 
-               /* free cache mutex */
+               /* free lru mutex */
                ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 
 #ifdef NEW_LOGGING
@@ -755,7 +765,7 @@ try_again:
                return( ep );
        }
 
-       /* free cache mutex */
+       /* free cache read lock */
        ldap_pvt_thread_rdwr_runlock( &cache->c_rwlock );
 
        return( NULL );
@@ -780,7 +790,7 @@ bdb_cache_delete_entry(
 {
        int     rc;
 
-       /* set cache mutex */
+       /* set cache write lock */
        ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
 
        assert( e->e_private );
@@ -793,11 +803,13 @@ bdb_cache_delete_entry(
                e->e_id, 0, 0 );
 #endif
 
+       /* set lru mutex */
        ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
        rc = bdb_cache_delete_entry_internal( cache, e );
+       /* free lru mutex */
        ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
 
-       /* free cache mutex */
+       /* free cache write lock */
        ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
        return( rc );
 }
@@ -846,8 +858,9 @@ bdb_cache_release_all( Cache *cache )
        Entry *e;
        int rc;
 
-       /* set cache mutex */
+       /* set cache write lock */
        ldap_pvt_thread_rdwr_wlock( &cache->c_rwlock );
+       /* set lru mutex */
        ldap_pvt_thread_mutex_lock( &cache->lru_mutex );
 
 #ifdef NEW_LOGGING
@@ -879,8 +892,9 @@ bdb_cache_release_all( Cache *cache )
 
        }
 
-       /* free cache mutex */
+       /* free lru mutex */
        ldap_pvt_thread_mutex_unlock( &cache->lru_mutex );
+       /* free cache write lock */
        ldap_pvt_thread_rdwr_wunlock( &cache->c_rwlock );
 }