indmanager: Properly detach the manage thread from CIMOM

Accomplished that by registering a pthread cleanup handler that gets
called on thread cancellation as well as on normal exit.

A minor code shuffle had to be done since the cleanup handlers are macros
in fact and no control flow commands (return, continue) should be called
within.

1 files changed, 41 insertions, 20 deletions

diff --git a/src/indmanager/ind_manager.c b/src/indmanager/ind_manager.c
index d6cd650..fcd232f 100644
--- a/src/indmanager/ind_manager.c
+++ b/src/indmanager/ind_manager.c
@@ -657,30 +657,19 @@ bool send_indication(CMPIInstance *old, CMPIInstance *new, IMManager *manager)
 /*
  * Run in separate thread
  */
-static void *manage(void *data)
+static IMError manage(IMManager *manager)
 {
-    // TODO: Switch Enable/Disable state on some places?
-    IMManager *manager = (IMManager *)data;
     IMError err = IM_ERR_OK; // TODO - How to handle potential errors?
-    DEBUG("manage thread started");
-
     IMPolledDiffs diffs = {NULL};
     CMPIInstance *iold = NULL, *inew = NULL;
 
-    pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
-    pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL);
-
-    DEBUG("manage thread - attaching thread manager context = %p", manager->ctx_manage);
-    CBAttachThread(manager->broker, manager->ctx_manage);
-
     while (1) {
         DEBUG("manage thread in infinite loop");
         // wait until manager is running
         pthread_mutex_lock(&manager->_t_mutex);
         if (manager->cancelled) {
             pthread_mutex_unlock(&manager->_t_mutex);
-            err = IM_ERR_CANCELLED;
-            return (void *)err;
+            return IM_ERR_CANCELLED;
         }
         while (!manager->running) {
             DEBUG("manage thread waiting to indication start");
@@ -690,7 +679,7 @@ static void *manage(void *data)
         if (manager->polling) {
             if (!first_poll(manager, &err)) {
                 pthread_mutex_unlock(&manager->_t_mutex);
-                return (void *)err;
+                return err;
             }
         }
         pthread_mutex_unlock(&manager->_t_mutex);
@@ -702,19 +691,18 @@ static void *manage(void *data)
         pthread_mutex_lock(&manager->_t_mutex);
         if (manager->cancelled) {
             pthread_mutex_unlock(&manager->_t_mutex);
-            err = IM_ERR_CANCELLED;
-            return (void *)err;
+            return IM_ERR_CANCELLED;
         }
         if (manager->polling) {
             // poll enumerations
             if (!_im_poll(manager, &err)) {
                 pthread_mutex_unlock(&manager->_t_mutex);
-                return (void *)err;
+                return err;
             }
             // create list of diffs
             if (!gen_diffs(manager, &diffs, &err)) {
                 pthread_mutex_unlock(&manager->_t_mutex);
-                return (void *)err;
+                return err;
             }
             manager->data = &diffs;
         }
@@ -726,6 +714,40 @@ static void *manage(void *data)
     }
 }
 
+static void manage_cleanup(void *data)
+{
+    IMManager *manager = (IMManager *)data;
+
+    DEBUG("manage thread - detaching thread manager context = %p", manager->ctx_manage);
+    CBDetachThread(manager->broker, manager->ctx_manage);
+}
+
+/* Wrapper thread function, to isolate code control flow due to sensitive pthread_cleanup_ macros */
+static void *manage_wrapper(void *data)
+{
+    // TODO: Switch Enable/Disable state on some places?
+    IMManager *manager = (IMManager *)data;
+    IMError err;
+
+    DEBUG("manage thread started");
+
+    /* Allow thread cancellation */
+    pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
+    pthread_setcanceltype(PTHREAD_CANCEL_DEFERRED, NULL);
+
+    DEBUG("manage thread - attaching thread manager context = %p", manager->ctx_manage);
+    CBAttachThread(manager->broker, manager->ctx_manage);
+
+    /* Main execution block closed in a cleanup handler */
+    pthread_cleanup_push(manage_cleanup, data);
+    err = manage(manager);
+    pthread_cleanup_pop(1);
+
+    DEBUG("manage thread stopped");
+
+    return (void *)err;
+}
+
 /*
  * Default gather function using polling
  * It is going thru all polled instances. If there is some pair (previous enum
@@ -1191,7 +1213,7 @@ bool im_start_ind(IMManager *manager, const CMPIContext *ctx, IMError *err)
     manager->ctx_manage = CBPrepareAttachThread(manager->broker,
                                                 manager->ctx_main);
     DEBUG("Creating second thread");
-    if (pthread_create(&manager->_t_manage, NULL, manage, manager)) {
+    if (pthread_create(&manager->_t_manage, NULL, manage_wrapper, manager)) {
         *err = IM_ERR_THREAD;
         return false;
     }
@@ -1244,7 +1266,6 @@ bool im_stop_ind(IMManager *manager, const CMPIContext *ctx, IMError *err)
     /* Cleanup */
     remove_all_enums(manager, err);
     manager->data = NULL;
-    /* TODO: properly detach the thread using CBAttachThread(), needs to be called from the thread */
     manager->ctx_manage = NULL;
     manager->cancelled = false;