Mojo: AsyncWaiter and mojo/public/environment

mojo/public/environment/async_waiter.h

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MOJO_PUBLIC_ENVIRONMENT_ASYNC_WAITER_H_
+#define MOJO_PUBLIC_ENVIRONMENT_ASYNC_WAITER_H_
+
+#include "mojo/public/system/core.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef uintptr_t MojoAsyncWaitID;
+
+typedef void (*MojoAsyncWaitCallback)(uintptr_t user_data, MojoResult result);
+
+struct MojoAsyncWaiter {
+  // Asynchronously call MojoWait on a background thread, and pass the result
+  // of MojoWait to the given MojoAsyncWaitCallback on the current thread.
+  // Returns a non-zero MojoAsyncWaitID that can be used with CancelWait to
+  // stop waiting. This identifier becomes invalid once the callback runs.
+  MojoAsyncWaitID (*AsyncWait)(MojoAsyncWaiter* waiter,
+                               MojoHandle handle,
+                               MojoWaitFlags flags,
+                               MojoDeadline deadline,
+                               MojoAsyncWaitCallback callback,
+                               uintptr_t user_data);
+
+  // Cancel an existing call to AsyncWait with the given MojoAsyncWaitID. The
+  // corresponding MojoAsyncWaitCallback will not be called in this case.
+  void (*CancelWait)(MojoAsyncWaiter* waiter,
+                     MojoAsyncWaitID wait_id);
+};
+
+// Returns the default MojoAsyncWaiter implementation.
+MojoAsyncWaiter* MojoGetDefaultAsyncWaiter();

[viettrungluu, 2014/01/13 21:47:44]

Will this be needed by the GL library? (As in, will it ever need to pick up the
default async waiter from the application?)

If not (and it's only needed for the bindings), maybe it shouldn't be in this
file (and could even be a C++ function).

+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // MOJO_PUBLIC_ENVIRONMENT_ASYNC_WAITER_H_