1 files changed, 39 insertions, 0 deletions
diff --git a/core/sync/sync_darwin.odin b/core/sync/sync_darwin.odin
new file mode 100644
index 000000000..2c86e21db
--- /dev/null
+++ b/core/sync/sync_darwin.odin
@@ -0,0 +1,39 @@
+package sync
+
+import "core:sys/darwin"
+
+import "core:c"
+
+// The Darwin docs say it best:
+// A semaphore is much like a lock, except that a finite number of threads can hold it simultaneously.
+// Semaphores can be thought of as being much like piles of tokens; multiple threads can take these tokens, 
+// but when there are none left, a thread must wait until another thread returns one.
+Semaphore :: struct #align 16 {
+	handle: darwin.semaphore_t,
+}
+// TODO(tetra): Only marked with alignment because we cannot mark distinct integers with alignments.
+// See core/sys/unix/pthread_linux.odin/pthread_t.
+
+semaphore_init :: proc(s: ^Semaphore, initial_count := 0) {
+	ct := darwin.mach_task_self();
+	res := darwin.semaphore_create(ct, &s.handle, 0, c.int(initial_count));
+	assert(res == 0);
+}
+
+semaphore_destroy :: proc(s: ^Semaphore) {
+	ct := darwin.mach_task_self();
+	res := darwin.semaphore_destroy(ct, s.handle);
+	assert(res == 0);
+	s.handle = {};
+}
+
+semaphore_post :: proc(s: ^Semaphore, count := 1) {
+	assert(count == 1);
+	res := darwin.semaphore_signal(s.handle);
+	assert(res == 0);
+}
+
+semaphore_wait_for :: proc(s: ^Semaphore) {
+	res := darwin.semaphore_wait(s.handle);
+	assert(res == 0);
+}