mojo: Add async waiter for python bindings

mojo/public/python/src/python_system_helper.h

Index: mojo/public/python/src/python_system_helper.h
diff --git a/mojo/public/python/src/python_system_helper.h b/mojo/public/python/src/python_system_helper.h
index 1962ba787fa067f5c95f79960eefecee041d56a7..e0d83ca4b7d827ef5f01bd0b0844d9744854ff12 100644
--- a/mojo/public/python/src/python_system_helper.h
+++ b/mojo/public/python/src/python_system_helper.h
@@ -5,18 +5,46 @@
 #ifndef MOJO_PUBLIC_PYTHON_SRC_PYTHON_SYSTEM_HELPER_H_
 #define MOJO_PUBLIC_PYTHON_SRC_PYTHON_SYSTEM_HELPER_H_
 
-#include "Python.h"
+// Python must be the first include, as it defines preprocessor variable without
+// checking if they already exist.
+#include <Python.h>
 
+#include <map>
+
+#include "mojo/public/c/environment/async_waiter.h"
+#include "mojo/public/c/system/types.h"
 #include "mojo/public/cpp/bindings/callback.h"
+#include "mojo/public/cpp/bindings/lib/shared_ptr.h"
 
 namespace mojo {
+namespace python {
 
 // Create a mojo::Closure from a callable python object.
 mojo::Closure BuildClosure(PyObject* callable);
 
-// Initalize mojo::RunLoop
-void InitRunLoop();
+class PythonAsyncWaiter {
+ public:
+  PythonAsyncWaiter();
+  ~PythonAsyncWaiter();
+  MojoAsyncWaitID AsyncWait(MojoHandle handle,
+                            MojoHandleSignals signals,
+                            MojoDeadline deadline,
+                            PyObject* callable);
+
+  void CancelWait(MojoAsyncWaitID wait_id);
+
+ private:
+  class AsyncWaiterRunnable;
+
+  typedef std::map<MojoAsyncWaitID,
+                   internal::SharedPtr<mojo::Callback<void(MojoResult)> > >
+      CallbackMap;
+
+  CallbackMap callbacks_;
+  const MojoAsyncWaiter* async_waiter_;
+};
 
+}  // namespace python
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_PYTHON_SRC_PYTHON_SYSTEM_HELPER_H_