*: 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, 8 deletions

diff --git a/pimd/pim_pim.c b/pimd/pim_pim.c
index 9886cd6ad..57b9e6c79 100644
--- a/pimd/pim_pim.c
+++ b/pimd/pim_pim.c
@@ -383,8 +383,8 @@ static void pim_sock_read_on(struct interface *ifp)
 	       pim_ifp->pim_sock_fd);
   }
   pim_ifp->t_pim_sock_read = NULL;
-  THREAD_READ_ON(master, pim_ifp->t_pim_sock_read, pim_sock_read, ifp,
-		 pim_ifp->pim_sock_fd);
+  thread_add_read(master, pim_sock_read, ifp, pim_ifp->pim_sock_fd,
+                  &pim_ifp->t_pim_sock_read);
 }
 
 static int pim_sock_open(struct interface *ifp)
@@ -703,9 +703,8 @@ static void hello_resched(struct interface *ifp)
 	       pim_ifp->pim_hello_period, ifp->name);
   }
   THREAD_OFF(pim_ifp->t_pim_hello_timer);
-  THREAD_TIMER_ON(master, pim_ifp->t_pim_hello_timer,
-		  on_pim_hello_send,
-		  ifp, pim_ifp->pim_hello_period);
+  thread_add_timer(master, on_pim_hello_send, ifp, pim_ifp->pim_hello_period,
+                   &pim_ifp->t_pim_hello_timer);
 }
 
 /*
@@ -814,9 +813,8 @@ void pim_hello_restart_triggered(struct interface *ifp)
 	       random_msec, ifp->name);
   }
 
-  THREAD_TIMER_MSEC_ON(master, pim_ifp->t_pim_hello_timer,
-		       on_pim_hello_send,
-		       ifp, random_msec);
+  thread_add_timer_msec(master, on_pim_hello_send, ifp, random_msec,
+                        &pim_ifp->t_pim_hello_timer);
 }
 
 int pim_sock_add(struct interface *ifp)