libpulp: make pulp_tick() delay result optional

Sometimes it's inconvenient for the caller to do anything useful
with the delay value and will simply be running another tick as
soon as possible.

I see no point in interfering with this usage by requiring the
caller to store the variable it won't be making use of anyways.
So make next_tick_delay_us optional; when NULL this will be
ignored.

1 files changed, 3 insertions, 2 deletions

diff --git a/src/pulp.c b/src/pulp.c
index e472fb9..f57f077 100644
--- a/src/pulp.c
+++ b/src/pulp.c
@@ -410,7 +410,7 @@ static void pulp_schedule(pulp_t *pulp)
 /* Tick a pulp scheduler - runs fibers until all are idle/sleeping.
  *
  * An estimate of how much time may pass before the next tick should occur is
- * stored in next_tick_delay_us.
+ * stored in next_tick_delay_us (if non-NULL).
  *
  * If pulp_exit() is called by a fiber, or no more fibers exist, the return
  * value is -1, and next_tick_delay_us is ignored.
@@ -442,7 +442,8 @@ int pulp_tick(pulp_t *pulp, unsigned *next_tick_delay_us)
 
 	if (!list_empty(&pulp->fibers.sleep)) {
 		/* TODO: get delay from the sleep queue when it's a priority queue */
-		*next_tick_delay_us = 333;
+		if (next_tick_delay_us)
+			*next_tick_delay_us = 333;
 
 		return 1;
 	}