open_toontown_panda3d/panda/src/event/asyncFuture_ext.cxx

319 lines
10 KiB
C++

/**
* PANDA 3D SOFTWARE
* Copyright (c) Carnegie Mellon University. All rights reserved.
*
* All use of this software is subject to the terms of the revised BSD
* license. You should have received a copy of this license along
* with this source code in a file named "LICENSE."
*
* @file asyncFuture_ext.h
* @author rdb
* @date 2017-10-29
*/
#include "asyncFuture_ext.h"
#include "asyncTaskSequence.h"
#include "eventParameter.h"
#include "paramValue.h"
#include "pythonTask.h"
#ifdef HAVE_PYTHON
#ifndef CPPPARSER
extern struct Dtool_PyTypedObject Dtool_AsyncFuture;
extern struct Dtool_PyTypedObject Dtool_ParamValueBase;
extern struct Dtool_PyTypedObject Dtool_TypedObject;
#endif
/**
* Get the result of a future, which may be a PythonTask. Assumes that the
* future is already done.
*/
static PyObject *get_done_result(const AsyncFuture *future) {
if (!future->cancelled()) {
if (future->is_of_type(PythonTask::get_class_type())) {
// If it's a PythonTask, defer to its get_result(), since it may store
// any PyObject value or raise an exception.
const PythonTask *task = (const PythonTask *)future;
return task->get_result();
} else if (future->is_of_type(AsyncTaskSequence::get_class_type())) {
// If it's an AsyncTaskSequence, get the result for each task.
const AsyncTaskSequence *task = (const AsyncTaskSequence *)future;
Py_ssize_t num_tasks = (Py_ssize_t)task->get_num_tasks();
PyObject *results = PyTuple_New(num_tasks);
for (Py_ssize_t i = 0; i < num_tasks; ++i) {
PyObject *result = get_done_result(task->get_task(i));
if (result != nullptr) {
// This steals a reference.
PyTuple_SET_ITEM(results, i, result);
} else {
Py_DECREF(results);
return nullptr;
}
}
return results;
} else if (future->is_of_type(AsyncGatheringFuture::get_class_type())) {
// If it's an AsyncGatheringFuture, get the result for each future.
const AsyncGatheringFuture *gather = (const AsyncGatheringFuture *)future;
Py_ssize_t num_futures = (Py_ssize_t)gather->get_num_futures();
PyObject *results = PyTuple_New(num_futures);
for (Py_ssize_t i = 0; i < num_futures; ++i) {
PyObject *result = get_done_result(gather->get_future((size_t)i));
if (result != nullptr) {
// This steals a reference.
PyTuple_SET_ITEM(results, i, result);
} else {
Py_DECREF(results);
return nullptr;
}
}
return results;
} else {
// It's any other future.
ReferenceCount *ref_ptr;
TypedObject *ptr;
future->get_result(ptr, ref_ptr);
if (ptr == nullptr) {
Py_INCREF(Py_None);
return Py_None;
}
TypeHandle type = ptr->get_type();
if (type.is_derived_from(ParamValueBase::get_class_type())) {
// If this is a ParamValueBase, return the 'value' property.
// EventStoreInt and Double are not exposed to Python for some reason.
if (type == EventStoreInt::get_class_type()) {
return Dtool_WrapValue(((EventStoreInt *)ptr)->get_value());
} else if (type == EventStoreDouble::get_class_type()) {
return Dtool_WrapValue(((EventStoreDouble *)ptr)->get_value());
}
ParamValueBase *value = (ParamValueBase *)ptr;
PyObject *wrap = DTool_CreatePyInstanceTyped
((void *)value, Dtool_ParamValueBase, false, false, type.get_index());
if (wrap != nullptr) {
PyObject *value = PyObject_GetAttrString(wrap, "value");
if (value != nullptr) {
return value;
}
PyErr_Restore(nullptr, nullptr, nullptr);
Py_DECREF(wrap);
}
}
if (ref_ptr != nullptr) {
ref_ptr->ref();
}
return DTool_CreatePyInstanceTyped
((void *)ptr, Dtool_TypedObject, (ref_ptr != nullptr), false,
type.get_index());
}
} else {
// If the future was cancelled, we should raise an exception.
static PyObject *exc_type = nullptr;
if (exc_type == nullptr) {
// Get the CancelledError that asyncio uses, too.
PyObject *module = PyImport_ImportModule("concurrent.futures._base");
if (module != nullptr) {
exc_type = PyObject_GetAttrString(module, "CancelledError");
Py_DECREF(module);
}
// If we can't get that, we should pretend and make our own.
if (exc_type == nullptr) {
exc_type = PyErr_NewExceptionWithDoc((char*)"concurrent.futures._base.CancelledError",
(char*)"The Future was cancelled.",
nullptr, nullptr);
}
}
Py_INCREF(exc_type);
PyErr_Restore(exc_type, nullptr, nullptr);
return nullptr;
}
}
/**
* Yields continuously until the task has finished.
*/
static PyObject *gen_next(PyObject *self) {
const AsyncFuture *future = nullptr;
if (!Dtool_Call_ExtractThisPointer(self, Dtool_AsyncFuture, (void **)&future)) {
return nullptr;
}
if (!future->done()) {
// Continue awaiting the result.
Py_INCREF(self);
return self;
} else {
PyObject *result = get_done_result(future);
if (result != nullptr) {
Py_INCREF(PyExc_StopIteration);
PyErr_Restore(PyExc_StopIteration, result, nullptr);
}
return nullptr;
}
}
/**
* Returns a generator that continuously yields an awaitable until the task
* has finished. This allows syntax like `model = await loader.load...` to be
* used in a Python coroutine.
*/
PyObject *Extension<AsyncFuture>::
__await__(PyObject *self) {
Dtool_GeneratorWrapper *gen;
gen = (Dtool_GeneratorWrapper *)PyType_GenericAlloc(&Dtool_GeneratorWrapper_Type, 0);
if (gen != nullptr) {
Py_INCREF(self);
gen->_base._self = self;
gen->_iternext_func = &gen_next;
}
return (PyObject *)gen;
}
/**
* Returns the result of this future, unless it was cancelled, in which case
* it returns CancelledError.
* If the future is not yet done, waits until the result is available. If a
* timeout is passed and the future is not done within the given timeout,
* raises TimeoutError.
*/
PyObject *Extension<AsyncFuture>::
result(PyObject *timeout) const {
if (!_this->done()) {
// Not yet done? Wait until it is done, or until a timeout occurs. But
// first check to make sure we're not trying to deadlock the thread.
Thread *current_thread = Thread::get_current_thread();
if (_this == (const AsyncFuture *)current_thread->get_current_task()) {
PyErr_SetString(PyExc_RuntimeError, "cannot call task.result() from within the task");
return nullptr;
}
// Release the GIL for the duration.
#if defined(HAVE_THREADS) && !defined(SIMPLE_THREADS)
PyThreadState *_save;
Py_UNBLOCK_THREADS
#endif
if (timeout == Py_None) {
_this->wait();
} else {
PyObject *num = PyNumber_Float(timeout);
if (num != nullptr) {
_this->wait(PyFloat_AS_DOUBLE(num));
} else {
return Dtool_Raise_ArgTypeError(timeout, 0, "result", "float");
}
}
#if defined(HAVE_THREADS) && !defined(SIMPLE_THREADS)
Py_BLOCK_THREADS
#endif
if (!_this->done()) {
// It timed out. Raise an exception.
static PyObject *exc_type = nullptr;
if (exc_type == nullptr) {
// Get the TimeoutError that asyncio uses, too.
PyObject *module = PyImport_ImportModule("concurrent.futures._base");
if (module != nullptr) {
exc_type = PyObject_GetAttrString(module, "TimeoutError");
Py_DECREF(module);
}
// If we can't get that, we should pretend and make our own.
if (exc_type == nullptr) {
exc_type = PyErr_NewExceptionWithDoc((char*)"concurrent.futures._base.TimeoutError",
(char*)"The operation exceeded the given deadline.",
nullptr, nullptr);
}
}
Py_INCREF(exc_type);
PyErr_Restore(exc_type, nullptr, nullptr);
return nullptr;
}
}
return get_done_result(_this);
}
/**
* Schedules the given function to be run as soon as the future is complete.
* This is also called if the future is cancelled.
* If the future is already done, the callback is scheduled right away.
*/
PyObject *Extension<AsyncFuture>::
add_done_callback(PyObject *self, PyObject *fn) {
if (!PyCallable_Check(fn)) {
return Dtool_Raise_ArgTypeError(fn, 0, "add_done_callback", "callable");
}
PythonTask *task = new PythonTask(fn);
Py_DECREF(task->_args);
task->_args = PyTuple_Pack(1, self);
task->_append_task = false;
task->_ignore_return = true;
// If this is an AsyncTask, make sure it is scheduled on the same chain.
if (_this->is_task()) {
AsyncTask *this_task = (AsyncTask *)_this;
task->set_task_chain(this_task->get_task_chain());
}
_this->add_waiting_task(task);
Py_INCREF(Py_None);
return Py_None;
}
/**
* Creates a new future that returns `done()` when all of the contained
* futures are done.
*
* Calling `cancel()` on the returned future will result in all contained
* futures that have not yet finished to be cancelled.
*/
PyObject *Extension<AsyncFuture>::
gather(PyObject *args) {
if (!PyTuple_Check(args)) {
return Dtool_Raise_TypeError("args is not a tuple");
}
Py_ssize_t size = Py_SIZE(args);
AsyncFuture::Futures futures;
futures.reserve(size);
for (Py_ssize_t i = 0; i < size; ++i) {
PyObject *item = PyTuple_GET_ITEM(args, i);
if (DtoolInstance_Check(item)) {
AsyncFuture *fut = (AsyncFuture *)DtoolInstance_UPCAST(item, Dtool_AsyncFuture);
if (fut != nullptr) {
futures.push_back(fut);
continue;
}
#if PY_VERSION_HEX >= 0x03050000
} else if (PyCoro_CheckExact(item)) {
// We allow passing in a coroutine instead of a future. This causes it
// to be scheduled as a task.
futures.push_back(new PythonTask(item));
continue;
#endif
}
return Dtool_Raise_ArgTypeError(item, i, "gather", "coroutine, task or future");
}
AsyncFuture *future = AsyncFuture::gather(move(futures));
if (future != nullptr) {
future->ref();
return DTool_CreatePyInstanceTyped((void *)future, Dtool_AsyncFuture, true, false, future->get_type_index());
} else {
return PyErr_NoMemory();
}
}
#endif