*: 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, 12 insertions, 8 deletions

diff --git a/nhrpd/nhrp_event.c b/nhrpd/nhrp_event.c
index aab9ec642f..da86c585a4 100644
--- a/nhrpd/nhrp_event.c
+++ b/nhrpd/nhrp_event.c
@@ -40,8 +40,8 @@ static void evmgr_connection_error(struct event_manager *evmgr)
 		close(evmgr->fd);
 	evmgr->fd = -1;
 	if (nhrp_event_socket_path)
-		THREAD_TIMER_MSEC_ON(master, evmgr->t_reconnect, evmgr_reconnect,
-				     evmgr, 10);
+		thread_add_timer_msec(master, evmgr_reconnect, evmgr, 10,
+				      &evmgr->t_reconnect);
 }
 
 static void evmgr_recv_message(struct event_manager *evmgr, struct zbuf *zb)
@@ -85,7 +85,7 @@ static int evmgr_read(struct thread *t)
 	while (zbuf_may_pull_until(ibuf, "\n\n", &msg))
 		evmgr_recv_message(evmgr, &msg);
 
-	THREAD_READ_ON(master, evmgr->t_read, evmgr_read, evmgr, evmgr->fd);
+	thread_add_read(master, evmgr_read, evmgr, evmgr->fd, &evmgr->t_read);
 	return 0;
 }
 
@@ -97,7 +97,8 @@ static int evmgr_write(struct thread *t)
 	evmgr->t_write = NULL;
 	r = zbufq_write(&evmgr->obuf, evmgr->fd);
 	if (r > 0) {
-		THREAD_WRITE_ON(master, evmgr->t_write, evmgr_write, evmgr, evmgr->fd);
+		thread_add_write(master, evmgr_write, evmgr, evmgr->fd,
+				 &evmgr->t_write);
 	} else if (r < 0) {
 		evmgr_connection_error(evmgr);
 	}
@@ -170,7 +171,8 @@ static void evmgr_submit(struct event_manager *evmgr, struct zbuf *obuf)
 	zbuf_put(obuf, "\n", 1);
 	zbufq_queue(&evmgr->obuf, obuf);
 	if (evmgr->fd >= 0)
-		THREAD_WRITE_ON(master, evmgr->t_write, evmgr_write, evmgr, evmgr->fd);
+		thread_add_write(master, evmgr_write, evmgr, evmgr->fd,
+				 &evmgr->t_write);
 }
 
 static int evmgr_reconnect(struct thread *t)
@@ -186,13 +188,14 @@ static int evmgr_reconnect(struct thread *t)
 		zlog_warn("%s: failure connecting nhrp-event socket: %s",
 			__PRETTY_FUNCTION__, strerror(errno));
 		zbufq_reset(&evmgr->obuf);
-		THREAD_TIMER_ON(master, evmgr->t_reconnect, evmgr_reconnect, evmgr, 10);
+		thread_add_timer(master, evmgr_reconnect, evmgr, 10,
+				 &evmgr->t_reconnect);
 		return 0;
 	}
 
 	zlog_info("Connected to Event Manager");
 	evmgr->fd = fd;
-	THREAD_READ_ON(master, evmgr->t_read, evmgr_read, evmgr, evmgr->fd);
+	thread_add_read(master, evmgr_read, evmgr, evmgr->fd, &evmgr->t_read);
 
 	return 0;
 }
@@ -206,7 +209,8 @@ void evmgr_init(void)
 	evmgr->fd = -1;
 	zbuf_init(&evmgr->ibuf, evmgr->ibuf_data, sizeof(evmgr->ibuf_data), 0);
 	zbufq_init(&evmgr->obuf);
-	THREAD_TIMER_MSEC_ON(master, evmgr->t_reconnect, evmgr_reconnect, evmgr, 10);
+	thread_add_timer_msec(master, evmgr_reconnect, evmgr, 10,
+			      &evmgr->t_reconnect);
 }
 
 void evmgr_set_socket(const char *socket)