Refactor the python system_impl module.

mojo/public/python/src/python_system_helper.cc

 // 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.
 
 #include "mojo/public/python/src/python_system_helper.h"
 
 #include "Python.h"
 
-#include "mojo/public/cpp/environment/environment.h"
-#include "mojo/public/cpp/environment/logging.h"
-#include "mojo/public/cpp/system/macros.h"
 #include "mojo/public/cpp/utility/run_loop.h"
+#include "mojo/public/python/src/common.h"
 
 namespace {
-
-class ScopedGIL {
+class QuitCurrentRunLoop : public mojo::Closure::Runnable {
  public:
-  ScopedGIL() { state_ = PyGILState_Ensure(); }
-
-  ~ScopedGIL() { PyGILState_Release(state_); }
-
- private:
-  PyGILState_STATE state_;
-
-  MOJO_DISALLOW_COPY_AND_ASSIGN(ScopedGIL);
-};
-
-enum ScopedPyRefAcquire {
-  kAcquire,
-};
-
-class ScopedPyRef {
- public:
-  ScopedPyRef(PyObject* object) : object_(object) {}
-  ScopedPyRef(PyObject* object, ScopedPyRefAcquire) : object_(object) {
-    Py_XINCREF(object_);
+  void Run() const override {
+    mojo::RunLoop::current()->Quit();
   }
 
-  ~ScopedPyRef() {
-    if (object_) {
-      ScopedGIL acquire_gil;
-      Py_DECREF(object_);
-    }
+  static mojo::Closure NewQuitClosure() {
+    return mojo::Closure(
+        static_cast<mojo::Closure::Runnable*>(new QuitCurrentRunLoop()));
   }
-
-  operator PyObject*() const { return object_; }
-
- private:
-  PyObject* object_;
-
-  MOJO_DISALLOW_COPY_AND_ASSIGN(ScopedPyRef);
 };
 
-class PythonClosure : public mojo::Closure::Runnable {
- public:
-  PythonClosure(PyObject* callable) : callable_(callable, kAcquire) {
-    MOJO_DCHECK(callable);
-  }
-
-  void Run() const override {
-    ScopedGIL acquire_gil;
-    ScopedPyRef empty_tuple(PyTuple_New(0));
-    if (!empty_tuple) {
-      mojo::RunLoop::current()->Quit();
-      return;
-    }
-
-    ScopedPyRef result(PyObject_CallObject(callable_, empty_tuple));
-    if (!result) {
-      mojo::RunLoop::current()->Quit();
-      return;
-    }
-  }
-
- private:
-  ScopedPyRef callable_;
-
-  MOJO_DISALLOW_COPY_AND_ASSIGN(PythonClosure);
-};
-
-void AsyncCallbackForwarder(void* closure, MojoResult result) {
-  mojo::Callback<void(MojoResult)>* callback =
-      static_cast<mojo::Callback<void(MojoResult)>*>(closure);
-  // callback will be deleted when it is run.
-  callback->Run(result);
-}
-
 }  // namespace
 
 namespace mojo {
 namespace python {
 
-class PythonAsyncWaiter::AsyncWaiterRunnable
-    : public mojo::Callback<void(MojoResult)>::Runnable {
- public:
-  AsyncWaiterRunnable(PyObject* callable, CallbackMap* callbacks)
-      : wait_id_(0), callable_(callable, kAcquire), callbacks_(callbacks) {
-    MOJO_DCHECK(callable);
-    MOJO_DCHECK(callbacks_);
-  }
-
-  void set_wait_id(int wait_id) { wait_id_ = wait_id; }
-
-  void Run(MojoResult mojo_result) const override {
-    MOJO_DCHECK(wait_id_);
-
-    // Remove to reference to this object from PythonAsyncWaiter and ensure this
-    // object will be destroyed when this method exits.
-    MOJO_DCHECK(callbacks_->find(wait_id_) != callbacks_->end());
-    internal::SharedPtr<mojo::Callback<void(MojoResult)>> self =
-        (*callbacks_)[wait_id_];
-    callbacks_->erase(wait_id_);
-
-    ScopedGIL acquire_gil;
-    ScopedPyRef args_tuple(Py_BuildValue("(i)", mojo_result));
-    if (!args_tuple) {
-      mojo::RunLoop::current()->Quit();
-      return;
-    }
-
-    ScopedPyRef result(PyObject_CallObject(callable_, args_tuple));
-    if (!result) {
-      mojo::RunLoop::current()->Quit();
-      return;
-    }
-  }
-
- private:
-  MojoAsyncWaitID wait_id_;
-  ScopedPyRef callable_;
-  CallbackMap* callbacks_;
-
-  MOJO_DISALLOW_COPY_AND_ASSIGN(AsyncWaiterRunnable);
-};
-
 Closure BuildClosure(PyObject* callable) {
   if (!PyCallable_Check(callable))
     return Closure();
 
-  return Closure(
-      static_cast<mojo::Closure::Runnable*>(new PythonClosure(callable)));
+  return mojo::Closure(
+      NewRunnableFromCallable(callable, QuitCurrentRunLoop::NewQuitClosure()));
 }
 
-PythonAsyncWaiter::PythonAsyncWaiter() {
-  async_waiter_ = Environment::GetDefaultAsyncWaiter();
-}
-
-PythonAsyncWaiter::~PythonAsyncWaiter() {
-  for (CallbackMap::const_iterator it = callbacks_.begin();
-       it != callbacks_.end();
-       ++it) {
-    async_waiter_->CancelWait(it->first);
-  }
-}
-
-MojoAsyncWaitID PythonAsyncWaiter::AsyncWait(MojoHandle handle,
-                                             MojoHandleSignals signals,
-                                             MojoDeadline deadline,
-                                             PyObject* callable) {
-  AsyncWaiterRunnable* runner = new AsyncWaiterRunnable(callable, &callbacks_);
-  internal::SharedPtr<mojo::Callback<void(MojoResult)>> callback(
-      new mojo::Callback<void(MojoResult)>(
-          static_cast<mojo::Callback<void(MojoResult)>::Runnable*>(runner)));
-  MojoAsyncWaitID wait_id = async_waiter_->AsyncWait(
-      handle, signals, deadline, &AsyncCallbackForwarder, callback.get());
-  callbacks_[wait_id] = callback;
-  runner->set_wait_id(wait_id);
-  return wait_id;
-}
-
-void PythonAsyncWaiter::CancelWait(MojoAsyncWaitID wait_id) {
-  if (callbacks_.find(wait_id) != callbacks_.end()) {
-    async_waiter_->CancelWait(wait_id);
-    callbacks_.erase(wait_id);
-  }
+PythonAsyncWaiter* NewAsyncWaiter() {
+  return new PythonAsyncWaiter(QuitCurrentRunLoop::NewQuitClosure());
 }
 
 }  // namespace python
 }  // namespace mojo