1 files changed, 43 insertions, 0 deletions
diff --git a/lib/std/event/locked.zig b/lib/std/event/locked.zig
new file mode 100644
index 0000000000..aeedf3558a
--- /dev/null
+++ b/lib/std/event/locked.zig
@@ -0,0 +1,43 @@
+const std = @import("../std.zig");
+const Lock = std.event.Lock;
+const Loop = std.event.Loop;
+
+/// Thread-safe async/await lock that protects one piece of data.
+/// Functions which are waiting for the lock are suspended, and
+/// are resumed when the lock is released, in order.
+pub fn Locked(comptime T: type) type {
+    return struct {
+        lock: Lock,
+        private_data: T,
+
+        const Self = @This();
+
+        pub const HeldLock = struct {
+            value: *T,
+            held: Lock.Held,
+
+            pub fn release(self: HeldLock) void {
+                self.held.release();
+            }
+        };
+
+        pub fn init(loop: *Loop, data: T) Self {
+            return Self{
+                .lock = Lock.init(loop),
+                .private_data = data,
+            };
+        }
+
+        pub fn deinit(self: *Self) void {
+            self.lock.deinit();
+        }
+
+        pub async fn acquire(self: *Self) HeldLock {
+            return HeldLock{
+                // TODO guaranteed allocation elision
+                .held = await (async self.lock.acquire() catch unreachable),
+                .value = &self.private_data,
+            };
+        }
+    };
+}