src/plugin.c: Make the context cloning a bit more implicit.

The plugin_set_ctx() call has been moved into the plugin_write_dequeue()
function. Comments describing the unavailability of the context have
been updated.

diff --git a/src/plugin.c b/src/plugin.c
index e7f8c6f..7037234 100644 (file)
--- a/src/plugin.c
+++ b/src/plugin.c
@@ -633,11 +633,7 @@ static value_list_t *plugin_value_list_clone (value_list_t const *vl_orig) /* {{
        if (vl->time == 0)
                vl->time = cdtime ();
 
-       /* Once this gets dequeued by a write thread, we don't have access to
-        * the thread context anymore. We therefore fill in the interval here,
-        * if required. An alternative would be to copy the context and clone
-        * the context in the write thread, but that seems overly complicated
-        * for the interval alone. */
+       /* Fill in the interval from the thread context, if it is zero. */
        if (vl->interval == 0)
        {
                plugin_ctx_t ctx = plugin_get_ctx ();
@@ -662,15 +658,6 @@ static value_list_t *plugin_value_list_clone (value_list_t const *vl_orig) /* {{
        return (vl);
 } /* }}} value_list_t *plugin_value_list_clone */
 
-static void plugin_write_queue_item_free (write_queue_t *q) /* {{{ */
-{
-       if (q == NULL)
-               return;
-
-       plugin_value_list_free (q->vl);
-       sfree (q);
-} /* }}} void plugin_write_queue_item_free */
-
 static int plugin_write_enqueue (value_list_t const *vl) /* {{{ */
 {
        write_queue_t *q;
@@ -687,9 +674,9 @@ static int plugin_write_enqueue (value_list_t const *vl) /* {{{ */
                return (ENOMEM);
        }
 
-       /* store context of caller (read plugin); else, the write plugins
-        * won't have the right interval settings available when actually
-        * dispatching the value-list later on */
+       /* Store context of caller (read plugin); otherwise, it would not be
+        * available to the write plugins when actually dispatching the
+        * value-list later on. */
        q->ctx = plugin_get_ctx ();
 
        pthread_mutex_lock (&write_lock);
@@ -711,9 +698,10 @@ static int plugin_write_enqueue (value_list_t const *vl) /* {{{ */
        return (0);
 } /* }}} int plugin_write_enqueue */
 
-static write_queue_t *plugin_write_dequeue (void) /* {{{ */
+static value_list_t *plugin_write_dequeue (void) /* {{{ */
 {
        write_queue_t *q;
+       value_list_t *vl;
 
        pthread_mutex_lock (&write_lock);
 
@@ -733,28 +721,24 @@ static write_queue_t *plugin_write_dequeue (void) /* {{{ */
 
        pthread_mutex_unlock (&write_lock);
 
-       q->next = NULL;
+       (void) plugin_set_ctx (q->ctx);
 
-       return (q);
+       vl = q->vl;
+       sfree (q);
+       return (vl);
 } /* }}} value_list_t *plugin_write_dequeue */
 
 static void *plugin_write_thread (void __attribute__((unused)) *args) /* {{{ */
 {
        while (write_loop)
        {
-               write_queue_t *q = plugin_write_dequeue ();
-               plugin_ctx_t old_ctx;
-
-               if (q == NULL)
+               value_list_t *vl = plugin_write_dequeue ();
+               if (vl == NULL)
                        continue;
 
-               old_ctx = plugin_set_ctx (q->ctx);
+               plugin_dispatch_values_internal (vl);
 
-               if (q->vl != NULL)
-                       plugin_dispatch_values_internal (q->vl);
-
-               plugin_write_queue_item_free (q);
-               plugin_set_ctx (old_ctx);
+               plugin_value_list_free (vl);
        }
 
        pthread_exit (NULL);
@@ -1827,9 +1811,8 @@ static int plugin_dispatch_values_internal (value_list_t *vl)
                return (-1);
        }
 
-       /* Assured by plugin_value_list_clone(). The write thread doesn't have
-        * access to the thread context, so the interval has to be filled in
-        * already. The time is determined at _enqueue_ time. */
+       /* Assured by plugin_value_list_clone(). The time is determined at
+        * _enqueue_ time. */
        assert (vl->time != 0);
        assert (vl->interval != 0);