Refactor the python system_impl module.

mojo/public/python/src/common.h

Index: mojo/public/python/src/common.h
diff --git a/mojo/public/python/src/common.h b/mojo/public/python/src/common.h
new file mode 100644
index 0000000000000000000000000000000000000000..03ed73b4d64aef7d41d2422e13523b12972e35f8
--- /dev/null
+++ b/mojo/public/python/src/common.h
@@ -0,0 +1,103 @@
+// 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_PYTHON_SRC_COMMON_H_
+#define MOJO_PUBLIC_PYTHON_SRC_COMMON_H_
+
+#include <Python.h>
+
+#include <map>
+
+#include "mojo/public/c/environment/async_waiter.h"
+#include "mojo/public/cpp/bindings/callback.h"
+#include "mojo/public/cpp/bindings/lib/shared_ptr.h"
+#include "mojo/public/cpp/system/core.h"
+
+namespace mojo {
+namespace python {
+
+class ScopedGIL {
+ public:
+  ScopedGIL();
+
+  ~ScopedGIL();
+
+ private:
+  PyGILState_STATE state_;
+
+  MOJO_DISALLOW_COPY_AND_ASSIGN(ScopedGIL);
+};
+
+enum ScopedPyRefAcquire {
+  kAcquire,
+};
+
+class ScopedPyRef {
+ public:
+  explicit ScopedPyRef(PyObject* object);
+  ScopedPyRef(PyObject* object, ScopedPyRefAcquire);
+
+  ~ScopedPyRef();
+
+  operator PyObject*() const;
+
+ private:
+  PyObject* object_;
+
+  MOJO_DISALLOW_COPY_AND_ASSIGN(ScopedPyRef);
+};
+
+
+class PythonClosure : public mojo::Closure::Runnable {
+ public:
+  PythonClosure(PyObject* callable, const mojo::Closure& quit);
+  ~PythonClosure();
+
+  void Run() const override;
+
+ private:
+  ScopedPyRef callable_;
+  const mojo::Closure quit_;
+
+  MOJO_DISALLOW_COPY_AND_ASSIGN(PythonClosure);
+};
+
+// Create a mojo::Closure from a callable python object.
+Closure::Runnable* NewRunnableFromCallable(PyObject* callable,
+                                           const Closure& quit_closure);
+
+// AsyncWaiter for python, used to execute a python closure after waiting. If an
+// error occurs while executing the closure, the current message loop will be
+// exited. See |AsyncWaiter| in mojo/public/c/environment/async_waiter.h for
+// more details.
+class PythonAsyncWaiter {
+ public:
+  explicit PythonAsyncWaiter(const mojo::Closure& quit_closure);
+  ~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_;
+  const mojo::Closure quit_;
+
+  MOJO_DISALLOW_COPY_AND_ASSIGN(PythonAsyncWaiter);
+};
+
+}  // namespace python
+}  // namespace mojo
+
+#endif  // MOJO_PUBLIC_PYTHON_SRC_COMMON_H_
+