diff --git a/core/sync/sync.odin b/core/sync/sync.odin
index 6ac349cb4..d74f88a09 100644
--- a/core/sync/sync.odin
+++ b/core/sync/sync.odin
@@ -2,7 +2,7 @@ package sync
 
 import "core:intrinsics"
 
-cpu_relax :: inline proc() {
+cpu_relax :: inline proc "contextless" () {
 	intrinsics.cpu_relax();
 }
 
@@ -29,3 +29,35 @@ ticket_mutex_lock :: inline proc(m: ^Ticket_Mutex) {
 ticket_mutex_unlock :: inline proc(m: ^Ticket_Mutex) {
 	atomic_add(&m.serving, 1, .Relaxed);
 }
+
+
+Benaphore :: struct {
+	counter: int,
+	sema: Semaphore,
+}
+
+benaphore_init :: proc(b: ^Benaphore) {
+	intrinsics.atomic_store(&b.counter, 0);
+	semaphore_init(&b.sema);
+}
+
+benaphore_destroy :: proc(b: ^Benaphore) {
+	semaphore_destroy(&b.sema);
+}
+
+benaphore_lock :: proc(b: ^Benaphore) {
+	if intrinsics.atomic_add_acq(&b.counter, 1) > 1 {
+		semaphore_wait_for(&b.sema);
+	}
+}
+
+benaphore_try_lock :: proc(b: ^Benaphore) -> bool {
+	v, _ := intrinsics.atomic_cxchg_acq(&b.counter, 1, 0);
+	return v == 0;
+}
+
+benaphore_unlock :: proc(b: ^Benaphore) {
+	if intrinsics.atomic_sub_rel(&b.counter, 1) > 0 {
+		semaphore_post(&b.sema);
+	}
+}
diff --git a/core/sync/sync_windows.odin b/core/sync/sync_windows.odin
index 885174279..0fc8f3298 100644
--- a/core/sync/sync_windows.odin
+++ b/core/sync/sync_windows.odin
@@ -61,7 +61,7 @@ Blocking_Mutex :: struct {
 
 
 blocking_mutex_init :: proc(m: ^Blocking_Mutex) {
-	//
+	m^ = Blocking_Mutex{};
 }
 
 blocking_mutex_destroy :: proc(m: ^Blocking_Mutex) {