*: 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, 22 deletions

diff --git a/ospf6d/ospf6_intra.h b/ospf6d/ospf6_intra.h
index c9660b6a5c..9975bbd627 100644
--- a/ospf6d/ospf6_intra.h
+++ b/ospf6d/ospf6_intra.h
@@ -156,40 +156,30 @@ struct ospf6_intra_prefix_lsa
 
 #define OSPF6_ROUTER_LSA_SCHEDULE(oa) \
   do { \
-    if (! (oa)->thread_router_lsa \
-        && CHECK_FLAG((oa)->flag, OSPF6_AREA_ENABLE)) \
-      (oa)->thread_router_lsa = \
-        thread_add_event (master, ospf6_router_lsa_originate, oa, 0); \
+    if (CHECK_FLAG((oa)->flag, OSPF6_AREA_ENABLE)) \
+      thread_add_event (master, ospf6_router_lsa_originate, oa, 0, &(oa)->thread_router_lsa); \
   } while (0)
 #define OSPF6_NETWORK_LSA_SCHEDULE(oi) \
   do { \
-    if (! (oi)->thread_network_lsa \
-        && ! CHECK_FLAG((oi)->flag, OSPF6_INTERFACE_DISABLE)) \
-      (oi)->thread_network_lsa = \
-        thread_add_event (master, ospf6_network_lsa_originate, oi, 0); \
+    if (!CHECK_FLAG((oi)->flag, OSPF6_INTERFACE_DISABLE)) \
+      thread_add_event (master, ospf6_network_lsa_originate, oi, 0, &(oi)->thread_network_lsa); \
   } while (0)
 #define OSPF6_LINK_LSA_SCHEDULE(oi) \
   do { \
-    if (! (oi)->thread_link_lsa \
-        && ! CHECK_FLAG((oi)->flag, OSPF6_INTERFACE_DISABLE)) \
-      (oi)->thread_link_lsa = \
-        thread_add_event (master, ospf6_link_lsa_originate, oi, 0); \
+    if (!CHECK_FLAG((oi)->flag, OSPF6_INTERFACE_DISABLE)) \
+      thread_add_event (master, ospf6_link_lsa_originate, oi, 0, &(oi)->thread_link_lsa); \
   } while (0)
 #define OSPF6_INTRA_PREFIX_LSA_SCHEDULE_STUB(oa) \
   do { \
-    if (! (oa)->thread_intra_prefix_lsa \
-        && CHECK_FLAG((oa)->flag, OSPF6_AREA_ENABLE)) \
-      (oa)->thread_intra_prefix_lsa = \
-        thread_add_event (master, ospf6_intra_prefix_lsa_originate_stub, \
-                          oa, 0); \
+    if (CHECK_FLAG((oa)->flag, OSPF6_AREA_ENABLE)) \
+      thread_add_event (master, ospf6_intra_prefix_lsa_originate_stub, \
+                        oa, 0, &(oa)->thread_intra_prefix_lsa); \
   } while (0)
 #define OSPF6_INTRA_PREFIX_LSA_SCHEDULE_TRANSIT(oi) \
   do { \
-    if (! (oi)->thread_intra_prefix_lsa \
-        && ! CHECK_FLAG((oi)->flag, OSPF6_INTERFACE_DISABLE)) \
-      (oi)->thread_intra_prefix_lsa = \
-        thread_add_event (master, ospf6_intra_prefix_lsa_originate_transit, \
-                          oi, 0); \
+    if (!CHECK_FLAG((oi)->flag, OSPF6_INTERFACE_DISABLE)) \
+      thread_add_event (master, ospf6_intra_prefix_lsa_originate_transit, \
+                        oi, 0, &(oi)->thread_intra_prefix_lsa); \
   } while (0)
 
 #define OSPF6_NETWORK_LSA_EXECUTE(oi) \