*: 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, 2 insertions, 3 deletions

diff --git a/pimd/pim_assert.c b/pimd/pim_assert.c
index 17f5fcfe0..a11cce943 100644
--- a/pimd/pim_assert.c
+++ b/pimd/pim_assert.c
@@ -576,9 +576,8 @@ static void pim_assert_timer_set(struct pim_ifchannel *ch,
 	       ch->sg_str, interval, ch->interface->name);
   }
 
-  THREAD_TIMER_ON(master, ch->t_ifassert_timer,
-		  on_assert_timer,
-		  ch, interval);
+  thread_add_timer(master, on_assert_timer, ch, interval,
+                   &ch->t_ifassert_timer);
 }
 
 static void pim_assert_timer_reset(struct pim_ifchannel *ch)