Replace delay by deadline in timedwait()

The function sc_cond_timedwait() accepted a parameter representing the
max duration to wait, because it internally uses SDL_CondWaitTimeout().

Instead, accept a deadline, to be consistent with
pthread_cond_timedwait().

app/src/fps_counter.c

@@ -84,11 +84,9 @@ run_fps_counter(void *data) {
             sc_tick now = sc_tick_now();
             check_interval_expired(counter, now);
 
-            assert(counter->next_timestamp > now);
-            sc_tick remaining = counter->next_timestamp - now;
-
             // ignore the reason (timeout or signaled), we just loop anyway
-            sc_cond_timedwait(&counter->state_cond, &counter->mutex, remaining);
+            sc_cond_timedwait(&counter->state_cond, &counter->mutex,
+                              counter->next_timestamp);
         }
     }
     sc_mutex_unlock(&counter->mutex);

app/src/server.c

@@ -557,7 +557,7 @@ server_stop(struct server *server) {
 #define WATCHDOG_DELAY SC_TICK_FROM_SEC(1)
         signaled = sc_cond_timedwait(&server->process_terminated_cond,
                                      &server->mutex,
-                                     WATCHDOG_DELAY);
+                                     sc_tick_now() + WATCHDOG_DELAY);
     }
     sc_mutex_unlock(&server->mutex);
 

app/src/util/thread.c

@@ -123,12 +123,13 @@ sc_cond_wait(sc_cond *cond, sc_mutex *mutex) {
 }
 
 bool
-sc_cond_timedwait(sc_cond *cond, sc_mutex *mutex, sc_tick delay) {
+sc_cond_timedwait(sc_cond *cond, sc_mutex *mutex, sc_tick deadline) {
-    if (delay < 0) {
+    sc_tick now = sc_tick_now();
+    if (deadline <= now) {
         return false; // timeout
     }
 
-    uint32_t ms = SC_TICK_TO_MS(delay);
+    uint32_t ms = SC_TICK_TO_MS(deadline - now);
     int r = SDL_CondWaitTimeout(cond->cond, mutex->mutex, ms);
 #ifndef NDEBUG
     if (r < 0) {

app/src/util/thread.h

@@ -73,7 +73,7 @@ sc_cond_wait(sc_cond *cond, sc_mutex *mutex);
 
 // return true on signaled, false on timeout
 bool
-sc_cond_timedwait(sc_cond *cond, sc_mutex *mutex, sc_tick ms);
+sc_cond_timedwait(sc_cond *cond, sc_mutex *mutex, sc_tick deadline);
 
 void
 sc_cond_signal(sc_cond *cond);