*: 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, 2 deletions

diff --git a/nhrpd/nhrp_packet.c b/nhrpd/nhrp_packet.c
index 36dbdfd77..76c5f1517 100644
--- a/nhrpd/nhrp_packet.c
+++ b/nhrpd/nhrp_packet.c
@@ -269,7 +269,7 @@ static int nhrp_packet_recvraw(struct thread *t)
 	uint8_t addr[64];
 	size_t len, addrlen;
 
-	thread_add_read(master, nhrp_packet_recvraw, 0, fd);
+	thread_add_read(master, nhrp_packet_recvraw, 0, fd, NULL);
 
 	zb = zbuf_alloc(1500);
 	if (!zb) return 0;
@@ -307,6 +307,6 @@ err:
 
 int nhrp_packet_init(void)
 {
-	thread_add_read(master, nhrp_packet_recvraw, 0, os_socket());
+	thread_add_read(master, nhrp_packet_recvraw, 0, os_socket(), NULL);
 	return 0;
 }