Add wait_group_wait_with_timeout; Allow Sema to be implemented as a Wait_Group

core/sync/sync2/extended.odin

@@ -1,5 +1,7 @@
 package sync2
 
+import "core:time"
+
 // A Wait_Group waits for a collection of threads to finish
 //
 // A Wait_Group must not be copied after first use
@@ -45,6 +47,24 @@ wait_group_wait :: proc(wg: ^Wait_Group) {
 	}
 }
 
+wait_group_wait_with_timeout :: proc(wg: ^Wait_Group, duration: time.Duration) -> bool {
+	if duration <= 0 {
+		return false
+	}
+	mutex_lock(&wg.mutex)
+	defer mutex_unlock(&wg.mutex)
+
+	if wg.counter != 0 {
+		if !cond_wait_with_timeout(&wg.cond, &wg.mutex, duration) {
+			return false
+		}
+		if wg.counter != 0 {
+			panic("sync.Wait_Group misuse: sync.wait_group_add called concurrently with sync.wait_group_wait")
+		}
+	}
+	return true
+}
+
 
 
 // A barrier enabling multiple threads to synchronize the beginning of some computation