*: 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>

4 files changed, 9 insertions, 8 deletions

diff --git a/tests/helpers/c/main.c b/tests/helpers/c/main.c
index b3e6e706ff..e422c7e621 100644
--- a/tests/helpers/c/main.c
+++ b/tests/helpers/c/main.c
@@ -59,14 +59,14 @@ test_timer (struct thread *thread)
   int *count = THREAD_ARG(thread);
   
   printf ("run %d of timer\n", (*count)++);
-  thread_add_timer (master, test_timer, count, 5);
+  thread_add_timer(master, test_timer, count, 5, NULL);
   return 0;
 }
 
 static void
 test_timer_init()
 {
-  thread_add_timer (master, test_timer, &timer_count, 10);
+  thread_add_timer(master, test_timer, &timer_count, 10, NULL);
 }
 
 static void
diff --git a/tests/lib/test_heavy_thread.c b/tests/lib/test_heavy_thread.c
index c43fa76c0e..57f0a6070a 100644
--- a/tests/lib/test_heavy_thread.c
+++ b/tests/lib/test_heavy_thread.c
@@ -91,7 +91,7 @@ clear_something (struct thread *thread)
       ws->i++;
       if (thread_should_yield(thread))
         {
-	  thread_add_background(master, clear_something, ws, 0);
+	  thread_add_background(master, clear_something, ws, 0, NULL);
 	  return 0;
         }
     }
@@ -135,7 +135,7 @@ DEFUN (clear_foo,
   ws->vty = vty;
   ws->i = ITERS_FIRST;
 
-  thread_add_background(master, clear_something, ws, 0);
+  thread_add_background(master, clear_something, ws, 0, NULL);
 
   return CMD_SUCCESS;
 }
diff --git a/tests/lib/test_timer_correctness.c b/tests/lib/test_timer_correctness.c
index e523929be1..600aef6f46 100644
--- a/tests/lib/test_timer_correctness.c
+++ b/tests/lib/test_timer_correctness.c
@@ -139,7 +139,8 @@ int main(int argc, char **argv)
       /* Schedule timers to expire in 0..5 seconds */
       interval_msec = prng_rand(prng) % 5000;
       arg = XMALLOC(MTYPE_TMP, TIMESTR_LEN + 1);
-      timers[i] = thread_add_timer_msec(master, timer_func, arg, interval_msec);
+      timers[i] = thread_add_timer_msec(master, timer_func, arg,
+                                        interval_msec, NULL);
       ret = snprintf(arg, TIMESTR_LEN + 1, "%lld.%06lld",
                      (long long)timers[i]->u.sands.tv_sec,
                      (long long)timers[i]->u.sands.tv_usec);
diff --git a/tests/lib/test_timer_performance.c b/tests/lib/test_timer_performance.c
index a7d09beecc..d1db4fd1bf 100644
--- a/tests/lib/test_timer_performance.c
+++ b/tests/lib/test_timer_performance.c
@@ -57,7 +57,7 @@ int main(int argc, char **argv)
   /* create thread structures so they won't be allocated during the
    * time measurement */
   for (i = 0; i < SCHEDULE_TIMERS; i++)
-    timers[i] = thread_add_timer_msec(master, dummy_func, NULL, 0);
+    timers[i] = thread_add_timer_msec(master, dummy_func, NULL, 0, NULL);
   for (i = 0; i < SCHEDULE_TIMERS; i++)
     thread_cancel(timers[i]);
 
@@ -68,8 +68,8 @@ int main(int argc, char **argv)
       long interval_msec;
 
       interval_msec = prng_rand(prng) % (100 * SCHEDULE_TIMERS);
-      timers[i] = thread_add_timer_msec(master, dummy_func,
-                                        NULL, interval_msec);
+      timers[i] = thread_add_timer_msec(master, dummy_func, NULL,
+                                        interval_msec, NULL);
     }
 
   monotime(&tv_lap);