*: 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, 6 insertions, 9 deletions

diff --git a/pimd/pim_neighbor.c b/pimd/pim_neighbor.c
index de0f75e38..5dccc3cfb 100644
--- a/pimd/pim_neighbor.c
+++ b/pimd/pim_neighbor.c
@@ -262,9 +262,8 @@ void pim_neighbor_timer_reset(struct pim_neighbor *neigh, uint16_t holdtime)
 	       neigh->holdtime, src_str, neigh->interface->name);
   }
 
-  THREAD_TIMER_ON(master, neigh->t_expire_timer,
-		  on_neighbor_timer,
-		  neigh, neigh->holdtime);
+  thread_add_timer(master, on_neighbor_timer, neigh, neigh->holdtime,
+                   &neigh->t_expire_timer);
 }
 
 static int
@@ -286,9 +285,8 @@ on_neighbor_jp_timer (struct thread *t)
   rpf.rpf_addr.u.prefix4 = neigh->source_addr;
   pim_joinprune_send(&rpf, neigh->upstream_jp_agg);
 
-  THREAD_TIMER_ON(master, neigh->jp_timer,
-                  on_neighbor_jp_timer,
-                  neigh, qpim_t_periodic);
+  thread_add_timer(master, on_neighbor_jp_timer, neigh, qpim_t_periodic,
+                   &neigh->jp_timer);
 
   return 0;
 }
@@ -297,9 +295,8 @@ static void
 pim_neighbor_start_jp_timer (struct pim_neighbor *neigh)
 {
   THREAD_TIMER_OFF(neigh->jp_timer);
-  THREAD_TIMER_ON(master, neigh->jp_timer,
-                  on_neighbor_jp_timer,
-                  neigh, qpim_t_periodic);
+  thread_add_timer(master, on_neighbor_jp_timer, neigh, qpim_t_periodic,
+                   &neigh->jp_timer);
 }
 
 static struct pim_neighbor *pim_neighbor_new(struct interface *ifp,