1 files changed, 91 insertions, 0 deletions
diff --git a/core/sync_windows.odin b/core/sync_windows.odin
new file mode 100644
index 000000000..ad64746f5
--- /dev/null
+++ b/core/sync_windows.odin
@@ -0,0 +1,91 @@
+#import win32 "sys/windows.odin" when ODIN_OS == "windows";
+#import "atomics.odin";
+
+Semaphore :: struct {
+	_handle: win32.Handle,
+}
+
+Mutex :: struct {
+	_semaphore: Semaphore,
+	_counter:   i32,
+	_owner:     i32,
+	_recursion: i32,
+}
+
+current_thread_id :: proc() -> i32 {
+	return i32(win32.GetCurrentThreadId());
+}
+
+semaphore_init :: proc(s: ^Semaphore) {
+	s._handle = win32.CreateSemaphoreA(nil, 0, 1<<31-1, nil);
+}
+
+semaphore_destroy :: proc(s: ^Semaphore) {
+	win32.CloseHandle(s._handle);
+}
+
+semaphore_post :: proc(s: ^Semaphore, count: int) {
+	win32.ReleaseSemaphore(s._handle, i32(count), nil);
+}
+
+semaphore_release :: proc(s: ^Semaphore) #inline { semaphore_post(s, 1); }
+
+semaphore_wait :: proc(s: ^Semaphore) {
+	win32.WaitForSingleObject(s._handle, win32.INFINITE);
+}
+
+
+mutex_init :: proc(m: ^Mutex) {
+	atomics.store(&m._counter, 0);
+	atomics.store(&m._owner, current_thread_id());
+	semaphore_init(&m._semaphore);
+	m._recursion = 0;
+}
+mutex_destroy :: proc(m: ^Mutex) {
+	semaphore_destroy(&m._semaphore);
+}
+mutex_lock :: proc(m: ^Mutex) {
+	thread_id := current_thread_id();
+	if atomics.fetch_add(&m._counter, 1) > 0 {
+		if thread_id != atomics.load(&m._owner) {
+			semaphore_wait(&m._semaphore);
+		}
+	}
+	atomics.store(&m._owner, thread_id);
+	m._recursion++;
+}
+mutex_try_lock :: proc(m: ^Mutex) -> bool {
+	thread_id := current_thread_id();
+	if atomics.load(&m._owner) == thread_id {
+		atomics.fetch_add(&m._counter, 1);
+	} else {
+		expected: i32 = 0;
+		if atomics.load(&m._counter) != 0 {
+			return false;
+		}
+		if atomics.compare_exchange(&m._counter, expected, 1) == 0 {
+			return false;
+		}
+		atomics.store(&m._owner, thread_id);
+	}
+	m._recursion++;
+	return true;
+}
+mutex_unlock :: proc(m: ^Mutex) {
+	recursion: i32;
+	thread_id := current_thread_id();
+	assert(thread_id == atomics.load(&m._owner));
+
+	m._recursion--;
+	recursion = m._recursion;
+	if recursion == 0 {
+		atomics.store(&m._owner, thread_id);
+	}
+
+	if atomics.fetch_add(&m._counter, -1) > 1 {
+		if recursion == 0 {
+			semaphore_release(&m._semaphore);
+		}
+	}
+}
+