* Fixed a concurrency bug which crashed the server when multiple sessions

[citadel.git] / citadel / citserver.c

diff --git a/citadel/citserver.c b/citadel/citserver.c
index b3e862afe9ab0df53d5eddf9d14ee8d35124d8f3..243985722c16535d5f6a315611c0a64e8ad34f34 100644 (file)
--- a/citadel/citserver.c
+++ b/citadel/citserver.c
@@ -129,25 +129,10 @@ void RemoveContext (struct CitContext *con)
                return;
                }
 
-       lprintf(7, "Calling logout(%d)\n", con->cs_pid);
-       logout(con);
-
-       rec_log(CL_TERMINATE, con->curr_user);
-       unlink(con->temp);
-       lprintf(3, "citserver[%3d]: ended.\n", con->cs_pid);
-       
-       /* Run any cleanup routines registered by loadable modules */
-       PerformSessionHooks(EVT_STOP);
-
-       syslog(LOG_NOTICE,"session %d ended", con->cs_pid);
-       
-       /* Deallocate any user-data attached to this session */
-       deallocate_user_data(con);
-
-       /* delete context */
-
-       lprintf(7, "Removing context\n");
-
+       /* Remove the context from the global context list.  This needs
+        * to get done FIRST to avoid concurrency problems.
+        */
+       lprintf(7, "Removing context for session %d\n", con->cs_pid);
        begin_critical_section(S_SESSION_TABLE);
        if (ContextList == con) {
                ToFree = ContextList;
@@ -163,8 +148,30 @@ void RemoveContext (struct CitContext *con)
                }
        end_critical_section(S_SESSION_TABLE);
 
-       lprintf(7, "Closing socket %d\n", ToFree->client_socket);
-       close(ToFree->client_socket);
+       if (ToFree == NULL) {
+               lprintf(9, "RemoveContext() found nothing to remove\n");
+               return;
+       }
+
+       /* Now handle all of the administrivia. */
+       lprintf(7, "Calling logout(%d)\n", con->cs_pid);
+       logout(con);
+
+       rec_log(CL_TERMINATE, con->curr_user);
+       unlink(con->temp);
+       lprintf(3, "citserver[%3d]: ended.\n", con->cs_pid);
+       
+       /* Run any cleanup routines registered by loadable modules */
+       PerformSessionHooks(EVT_STOP);
+
+       syslog(LOG_NOTICE,"session %d ended", con->cs_pid);
+       
+       /* Deallocate any user-data attached to this session */
+       deallocate_user_data(con);
+
+       /* If the client is still connected, blow 'em away. */
+       lprintf(7, "Closing socket %d\n", con->client_socket);
+       close(con->client_socket);
 
         /* Tell the housekeeping thread to check to see if this is the time
          * to initiate a scheduled shutdown event.
@@ -172,7 +179,7 @@ void RemoveContext (struct CitContext *con)
         enter_housekeeping_cmd("SCHED_SHUTDOWN");
 
        /* Free up the memory used by this context */
-       phree(ToFree);
+       phree(con);
 
        lprintf(7, "Done with RemoveContext()\n");
 }