*: 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, 5 insertions, 6 deletions

diff --git a/zebra/irdp_main.c b/zebra/irdp_main.c
index 7fa4ad4cb..963c330af 100644
--- a/zebra/irdp_main.c
+++ b/zebra/irdp_main.c
@@ -114,7 +114,7 @@ irdp_sock_init (void)
     return ret;
   };
 
-  t_irdp_raw = thread_add_read (zebrad.master, irdp_read_raw, NULL, sock); 
+  t_irdp_raw = thread_add_read(zebrad.master, irdp_read_raw, NULL, sock, NULL);
 
   return sock;
 }
@@ -244,7 +244,8 @@ int irdp_send_thread(struct thread *t_advert)
   if(irdp->flags & IF_DEBUG_MISC)
     zlog_debug("IRDP: New timer for %s set to %u\n", ifp->name, timer);
 
-  irdp->t_advertise = thread_add_timer(zebrad.master, irdp_send_thread, ifp, timer);
+  irdp->t_advertise = thread_add_timer(zebrad.master, irdp_send_thread, ifp,
+                                       timer, NULL);
   return 0;
 }
 
@@ -296,10 +297,8 @@ void process_solicit (struct interface *ifp)
 
   timer =  (random () % MAX_RESPONSE_DELAY) + 1;
 
-  irdp->t_advertise = thread_add_timer(zebrad.master, 
-				       irdp_send_thread, 
-				       ifp, 
-				       timer);
+  irdp->t_advertise = thread_add_timer(zebrad.master, irdp_send_thread, ifp,
+                                       timer, NULL);
 }
 
 void irdp_finish()