*: remove THREAD_ON macros, add nullity check

The way thread.c is written, a caller who wishes to be able to cancel a
thread or avoid scheduling it twice must keep a reference to the thread.
Typically this is done with a long lived pointer whose value is checked
for null in order to know if the thread is currently scheduled.  The
check-and-schedule idiom is so common that several wrapper macros in
thread.h existed solely to provide it.

This patch removes those macros and adds a new parameter to all
thread_add_* functions which is a pointer to the struct thread * to
store the result of a scheduling call. If the value passed is non-null,
the thread will only be scheduled if the value is null. This helps with
consistency.

A Coccinelle spatch has been used to transform code of the form:

  if (t == NULL)
    t = thread_add_* (...)

to the form

  thread_add_* (..., &t)

The THREAD_ON macros have also been transformed to the underlying
thread.c calls.

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>

1 files changed, 7 insertions, 8 deletions

diff --git a/ospfd/ospf_opaque.c b/ospfd/ospf_opaque.c
index 56efa2ebd..0c1830166 100644
--- a/ospfd/ospf_opaque.c
+++ b/ospfd/ospf_opaque.c
@@ -1343,7 +1343,8 @@ ospf_opaque_lsa_originate_schedule (struct ospf_interface *oi, int *delay0)
       if (IS_DEBUG_OSPF_EVENT)
         zlog_debug ("Schedule Type-9 Opaque-LSA origination in %d ms later.", delay);
       oi->t_opaque_lsa_self =
-	thread_add_timer_msec (master, ospf_opaque_type9_lsa_originate, oi, delay);
+	thread_add_timer_msec(master, ospf_opaque_type9_lsa_originate, oi,
+                              delay, NULL);
       delay += top->min_ls_interval;
     }
 
@@ -1359,8 +1360,8 @@ ospf_opaque_lsa_originate_schedule (struct ospf_interface *oi, int *delay0)
       if (IS_DEBUG_OSPF_EVENT)
         zlog_debug ("Schedule Type-10 Opaque-LSA origination in %d ms later.", delay);
       area->t_opaque_lsa_self =
-        thread_add_timer_msec (master, ospf_opaque_type10_lsa_originate,
-			       area, delay);
+        thread_add_timer_msec(master, ospf_opaque_type10_lsa_originate, area,
+                              delay, NULL);
       delay += top->min_ls_interval;
     }
 
@@ -1376,8 +1377,8 @@ ospf_opaque_lsa_originate_schedule (struct ospf_interface *oi, int *delay0)
       if (IS_DEBUG_OSPF_EVENT)
         zlog_debug ("Schedule Type-11 Opaque-LSA origination in %d ms later.", delay);
       top->t_opaque_lsa_self =
-        thread_add_timer_msec (master, ospf_opaque_type11_lsa_originate,
-			       top, delay);
+        thread_add_timer_msec(master, ospf_opaque_type11_lsa_originate, top,
+                              delay, NULL);
       delay += top->min_ls_interval;
     }
 
@@ -1654,9 +1655,7 @@ ospf_opaque_lsa_refresh (struct ospf_lsa *lsa)
  * triggered by external interventions (vty session, signaling, etc).
  *------------------------------------------------------------------------*/
 
-#define OSPF_OPAQUE_TIMER_ON(T,F,L,V) \
-      if (!(T)) \
-        (T) = thread_add_timer_msec (master, (F), (L), (V))
+#define OSPF_OPAQUE_TIMER_ON(T,F,L,V) thread_add_timer_msec (master, (F), (L), (V), &(T))
 
 static struct ospf_lsa *pseudo_lsa (struct ospf_interface *oi, struct ospf_area *area, u_char lsa_type, u_char opaque_type);
 static int ospf_opaque_type9_lsa_reoriginate_timer (struct thread *t);