*: 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/zebra/label_manager.c b/zebra/label_manager.c
index bf67141cd4..f7d2dce8f3 100644
--- a/zebra/label_manager.c
+++ b/zebra/label_manager.c
@@ -141,9 +141,8 @@ static int zclient_connect(struct thread *t)
 
 	if (zclient_socket_connect(zclient) < 0) {
 		zlog_err("Error connecting synchronous zclient!");
-		THREAD_TIMER_ON(zebrad.master, zclient->t_connect,
-						zclient_connect,
-						zclient, CONNECTION_DELAY);
+		thread_add_timer(zebrad.master, zclient_connect, zclient,
+				 CONNECTION_DELAY, &zclient->t_connect);
 		return -1;
 	}