*: 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, 1 deletions

diff --git a/zebra/irdp_packet.c b/zebra/irdp_packet.c
index 4c58b6b35d..ecca40393f 100644
--- a/zebra/irdp_packet.c
+++ b/zebra/irdp_packet.c
@@ -232,7 +232,8 @@ int irdp_read_raw(struct thread *r)
   int ret, ifindex = 0;
   
   int irdp_sock = THREAD_FD (r);
-  t_irdp_raw = thread_add_read (zebrad.master, irdp_read_raw, NULL, irdp_sock);
+  t_irdp_raw = thread_add_read(zebrad.master, irdp_read_raw, NULL, irdp_sock,
+                               NULL);
   
   ret = irdp_recvmsg (irdp_sock, (u_char *) buf, IRDP_RX_BUF,  &ifindex);