Re-fix ITS#4720, use rwlock

diff --git a/servers/slapd/overlays/syncprov.c b/servers/slapd/overlays/syncprov.c
index 012c8df31215fb2d69ddfe0a2baff80336f7d258..6ac3bceac17f1026a51ce33466b45d8f2b47fbf6 100644 (file)
--- a/servers/slapd/overlays/syncprov.c
+++ b/servers/slapd/overlays/syncprov.c
@@ -131,7 +131,7 @@ typedef struct syncprov_info_t {
        time_t  si_chklast;     /* time of last checkpoint */
        Avlnode *si_mods;       /* entries being modified */
        sessionlog      *si_logs;
-       ldap_pvt_thread_mutex_t si_csn_mutex;
+       ldap_pvt_thread_rdwr_t  si_csn_rwlock;
        ldap_pvt_thread_mutex_t si_ops_mutex;
        ldap_pvt_thread_mutex_t si_mods_mutex;
 } syncprov_info_t;
@@ -1548,11 +1548,10 @@ syncprov_op_response( Operation *op, SlapReply *rs )
        {
                struct berval maxcsn = BER_BVNULL;
                char cbuf[LDAP_LUTIL_CSNSTR_BUFSIZE];
-               int do_check = 0;
 
                /* Update our context CSN */
                cbuf[0] = '\0';
-               ldap_pvt_thread_mutex_lock( &si->si_csn_mutex );
+               ldap_pvt_thread_rdwr_wlock( &si->si_csn_rwlock );
                slap_get_commit_csn( op, &maxcsn );
                if ( !BER_BVISNULL( &maxcsn ) ) {
                        int i, sid;
@@ -1579,12 +1578,13 @@ syncprov_op_response( Operation *op, SlapReply *rs )
                /* Don't do any processing for consumer contextCSN updates */
                if ( SLAP_SYNC_SHADOW( op->o_bd ) && 
                        op->o_msgid == SLAP_SYNC_UPDATE_MSGID ) {
-                       ldap_pvt_thread_mutex_unlock( &si->si_csn_mutex );
+                       ldap_pvt_thread_rdwr_wunlock( &si->si_csn_rwlock );
                        return SLAP_CB_CONTINUE;
                }
 
                si->si_numops++;
                if ( si->si_chkops || si->si_chktime ) {
+                       int do_check = 0;
                        if ( si->si_chkops && si->si_numops >= si->si_chkops ) {
                                do_check = 1;
                                si->si_numops = 0;
@@ -1594,16 +1594,15 @@ syncprov_op_response( Operation *op, SlapReply *rs )
                                do_check = 1;
                                si->si_chklast = op->o_time;
                        }
+                       if ( do_check ) {
+                               syncprov_checkpoint( op, rs, on );
+                       }
                }
-               ldap_pvt_thread_mutex_unlock( &si->si_csn_mutex );
+               ldap_pvt_thread_rdwr_wunlock( &si->si_csn_rwlock );
 
                opc->sctxcsn.bv_len = maxcsn.bv_len;
                opc->sctxcsn.bv_val = cbuf;
 
-               if ( do_check ) {
-                       syncprov_checkpoint( op, rs, on );
-               }
-
                /* Handle any persistent searches */
                if ( si->si_ops ) {
                        switch(op->o_tag) {
@@ -1658,7 +1657,7 @@ syncprov_op_compare( Operation *op, SlapReply *rs )
 
                a.a_desc = slap_schema.si_ad_contextCSN;
 
-               ldap_pvt_thread_mutex_lock( &si->si_csn_mutex );
+               ldap_pvt_thread_rdwr_rlock( &si->si_csn_rwlock );
 
                a.a_vals = si->si_ctxcsn;
                a.a_nvals = a.a_vals;
@@ -1690,7 +1689,7 @@ syncprov_op_compare( Operation *op, SlapReply *rs )
 
 return_results:;
 
-               ldap_pvt_thread_mutex_unlock( &si->si_csn_mutex );
+               ldap_pvt_thread_rdwr_runlock( &si->si_csn_rwlock );
 
                send_ldap_result( op, rs );
 
@@ -2073,7 +2072,7 @@ syncprov_op_search( Operation *op, SlapReply *rs )
        }
 
        /* snapshot the ctxcsn */
-       ldap_pvt_thread_mutex_lock( &si->si_csn_mutex );
+       ldap_pvt_thread_rdwr_rlock( &si->si_csn_rwlock );
        numcsns = si->si_numcsns;
        if ( numcsns ) {
                ber_bvarray_dup_x( &ctxcsn, si->si_ctxcsn, op->o_tmpmemctx );
@@ -2084,7 +2083,7 @@ syncprov_op_search( Operation *op, SlapReply *rs )
                ctxcsn = NULL;
                sids = NULL;
        }
-       ldap_pvt_thread_mutex_unlock( &si->si_csn_mutex );
+       ldap_pvt_thread_rdwr_runlock( &si->si_csn_rwlock );
        
        /* If we have a cookie, handle the PRESENT lookups */
        if ( srs->sr_state.ctxcsn ) {
@@ -2270,7 +2269,7 @@ syncprov_operational(
                                        break;
                        }
 
-                       ldap_pvt_thread_mutex_lock( &si->si_csn_mutex );
+                       ldap_pvt_thread_rdwr_rlock( &si->si_csn_rwlock );
                        if ( si->si_ctxcsn ) {
                                if ( !a ) {
                                        for ( ap = &rs->sr_operational_attrs; *ap;
@@ -2293,7 +2292,7 @@ syncprov_operational(
                                ber_bvarray_dup_x( &a->a_vals, si->si_ctxcsn, NULL );
                                a->a_nvals = a->a_vals;
                        }
-                       ldap_pvt_thread_mutex_unlock( &si->si_csn_mutex );
+                       ldap_pvt_thread_rdwr_runlock( &si->si_csn_rwlock );
                }
        }
        return SLAP_CB_CONTINUE;
@@ -2628,7 +2627,7 @@ syncprov_db_init(
 
        si = ch_calloc(1, sizeof(syncprov_info_t));
        on->on_bi.bi_private = si;
-       ldap_pvt_thread_mutex_init( &si->si_csn_mutex );
+       ldap_pvt_thread_rdwr_init( &si->si_csn_rwlock );
        ldap_pvt_thread_mutex_init( &si->si_ops_mutex );
        ldap_pvt_thread_mutex_init( &si->si_mods_mutex );
 
@@ -2665,7 +2664,7 @@ syncprov_db_destroy(
                }
                ldap_pvt_thread_mutex_destroy( &si->si_mods_mutex );
                ldap_pvt_thread_mutex_destroy( &si->si_ops_mutex );
-               ldap_pvt_thread_mutex_destroy( &si->si_csn_mutex );
+               ldap_pvt_thread_rdwr_destroy( &si->si_csn_rwlock );
                ch_free( si );
        }