Cannot retrieve `Future` from python on Windows #116

vSLG · 2020-07-14T18:25:26Z

Description

Python.call() does not receive anything if the called function returns asyncio.Future, only on Windows platform.

Environment 1

OS: Windows 8.1
Architecture: x86_64
pyotherside compiled manually in a MSYS2 environment
C compiler: MinGW-w64 (GCC 10.1.0), obtained from MSYS2 repository
QT version: 5.15, obtained from MSYS2 repository (shared lib version)
Python version: 3.8.3, obtained from MSYS2 repository

Environment 2

OS: Void Linux, kernel 5.6.18
Architecture: x86_64
pyotherside compiled manually
C compiler: GCC 9.3.0
QT version: 5.15
Python version: 3.8.3

Steps to reproduce (Environment 1)

Write a python function that returns an asyncio.Future
Run it on QML by using Python.call()
Returned object by python function is blank

Programs used

main.py

import pyotherside
import sys
import asyncio as aio

from threading import Thread

class QMLTest:
    def __init__(self) -> None:
        # This is needed, else an exception is thrown on aio.get_event_loop()
        if sys.platform == "win32" and sys.version_info >= (3, 8, 0):
            aio.set_event_loop_policy(
                aio.WindowsSelectorEventLoopPolicy(),
            )
        
        try:
            self._loop = aio.get_event_loop()
        except RuntimeError:
            self._loop = aio.new_event_loop()
            aio.set_event_loop(self._loop)

        Thread(target=self._start_asyncio_loop).start()

    def _start_asyncio_loop(self) -> None:
        aio.set_event_loop(self._loop)
        self._loop.run_forever()

    async def testfunc(self) -> None:
        pass

    def test(self) -> aio.Future:
        future = aio.run_coroutine_threadsafe(self.testfunc(), self._loop)
        print("Python future: " + str(future))
        return future

print("sys.pratform: " + sys.platform)
print("Python: " + sys.version)
print("Using pyotherside version " + pyotherside.version)
QMLTEST = QMLTest()

main.qml

import QtQuick 2.15
import io.thp.pyotherside 1.5

Rectangle {
    color: 'grey'
    width: 400
    height: 400

    Python {
        id: py

        Component.onCompleted: {
            // Add the directory of this .qml file to the search path
            addImportPath(Qt.resolvedUrl('.'));
            importNames("main", ["QMLTEST"], () => {
                call("QMLTEST.test", [], pyFuture => {
                    print(`future: ${pyFuture}`)
                })
            })
        }
    }
}

Output

Environment 1 (Windows)

$ qml.exe main.qml
sys.pratform: win32
Python: 3.8.3 (default, Jun 17 2020, 06:11:06)  [GCC 10.1.0 64 bit (AMD64)]
Using pyotherside version 1.5.9
Python future: <Future at 0x6bbaf10 state=pending>
qml: future:

Environment 2 (Linux)

$ qml main.qml
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-j'
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-j'
Got library name:  "/usr/lib/qt5/qml/io/thp/pyotherside/libpyothersideplugin.so"
sys.pratform: linux
Python: 3.8.3 (default, Jul  3 2020, 22:42:34) 
[GCC 9.3.0]
Using pyotherside version 1.5.9
Python future: <Future at 0x7efc057e10d0 state=pending>
qml: future: QVariant(PyObjectRef, )

Expected behavior

It is expected that on a Windows system we may be able to get the Future object on QML. It is expected that Environment 1 have the same behavior as on Environment 2.

The text was updated successfully, but these errors were encountered:

thp · 2020-07-15T06:01:43Z

Have you checked if you pass it back to the Python environment (e.g. as a parameter to another call ()) and print it there, what is the value of it? vSLG <notifications@github.com> schrieb am Di., 14. Juli 2020, 20:25:

…

Description Python.call() does not receive anything if the called function returns asyncio.Future, only on Windows platform. Environment 1 - OS: Windows 8.1 - Architecture: x86_64 - pyotherside compiled manually in a MSYS2 environment - C compiler: MinGW-w64 (GCC 10.1.0), obtained from MSYS2 repository - QT version: 5.15, obtained from MSYS2 repository (shared lib version) - Python version: 3.8.3, obtained from MSYS2 repository Environment 2 - OS: Void Linux, kernel 5.6.18 - Architecture: x86_64 - pyotherside compiled manually - C compiler: GCC 9.3.0 - QT version: 5.15 - Python version: 3.8.3 Steps to reproduce (Environment 1) 1. Write a python function that returns an asyncio.Future 2. Run it on QML by using Python.call() 3. Returned object by python function is blank Programs used main.py import pyothersideimport sysimport asyncio as aio from threading import Thread class QMLTest: def __init__(self) -> None: # This is needed, else an exception is thrown on aio.get_event_loop() if sys.platform == "win32" and sys.version_info >= (3, 8, 0): aio.set_event_loop_policy( aio.WindowsSelectorEventLoopPolicy(), ) try: self._loop = aio.get_event_loop() except RuntimeError: self._loop = aio.new_event_loop() aio.set_event_loop(self._loop) Thread(target=self._start_asyncio_loop).start() def _start_asyncio_loop(self) -> None: aio.set_event_loop(self._loop) self._loop.run_forever() async def testfunc(self) -> None: pass def test(self) -> aio.Future: future = aio.run_coroutine_threadsafe(self.testfunc(), self._loop) print("Python future: " + str(future)) return future print("sys.pratform: " + sys.platform)print("Python: " + sys.version)print("Using pyotherside version " + pyotherside.version)QMLTEST = QMLTest() main.qml import QtQuick 2.15import io.thp.pyotherside 1.5 Rectangle { color: 'grey' width: 400 height: 400 Python { id: py Component.onCompleted: { // Add the directory of this .qml file to the search path addImportPath(Qt.resolvedUrl('.')); importNames("main", ["QMLTEST"], () => { call("QMLTEST.test", [], pyFuture => { print(`future: ${pyFuture}`) }) }) } } } Output Environment 1 (Windows) $ qml.exe main.qml sys.pratform: win32 Python: 3.8.3 (default, Jun 17 2020, 06:11:06) [GCC 10.1.0 64 bit (AMD64)] Using pyotherside version 1.5.9 Python future: <Future at 0x6bbaf10 state=pending> qml: future: Environment 2 (Linux) $ qml main.qml QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-j' QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-j' Got library name: "/usr/lib/qt5/qml/io/thp/pyotherside/libpyothersideplugin.so" sys.pratform: linux Python: 3.8.3 (default, Jul 3 2020, 22:42:34) [GCC 9.3.0] Using pyotherside version 1.5.9 Python future: <Future at 0x7efc057e10d0 state=pending> qml: future: QVariant(PyObjectRef, ) Expected behavior It is expected that on a Windows system we may be able to get the Future object on QML. It is expected that Environment 1 have the same behavior as on Environment 2. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#116>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AABBASJVL6BWC2GBNJNZEPTR3SPKLANCNFSM4OZY4R5A> .

vSLG · 2020-07-15T16:34:21Z

Added this function to QMLTest Python:

def print_future(self, future: aio.Future) -> None:
        print("QMLTEST.print_future(): " + str(future))
        print("QMLTEST.print_future(): type(future) = " + str(type(future)))

And on QML:

Component.onCompleted: {
    // Add the directory of this .qml file to the search path
    addImportPath(Qt.resolvedUrl('.'));
    importNames("main", ["QMLTEST"], () => {
        call("QMLTEST.test", [], pyFuture => {
            print(`future: ${pyFuture}`)
            
            call("QMLTEST.print_future", [pyFuture], null)
        })
    })
}

Output

Environment 1 (Windows)

$ qml main.qml
sys.pratform: win32
Python: 3.8.3 (default, Jun 17 2020, 06:11:06)  [GCC 10.1.0 64 bit (AMD64)]
Using pyotherside version 1.5.9
Python future: <Future at 0x6b9bf40 state=pending>
qml: future:
QMLTEST.print_future(): []
QMLTEST.print_future(): type(future) = <class 'list'>

Environment 2 (Linux)

$ qml main.qml
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-j'
QStandardPaths: XDG_RUNTIME_DIR not set, defaulting to '/tmp/runtime-j'
Got library name:  "/usr/lib/qt5/qml/io/thp/pyotherside/libpyothersideplugin.so"
sys.pratform: linux
Python: 3.8.3 (default, Jul  3 2020, 22:42:34) 
[GCC 9.3.0]
Using pyotherside version 1.5.9
Python future: <Future at 0x7f6caf3e90d0 state=pending>
qml: future: QVariant(PyObjectRef, )
QMLTEST.print_future(): <Future at 0x7f6caf3e90d0 state=finished returned NoneType>
QMLTEST.print_future(): type(future) = <class 'concurrent.futures._base.Future'>

Returning a Future doesn't work on Windows for some reason (thp/pyotherside#116). Instead of using these objects from QML to cancel running coroutines, call a Python QMLBridge function that takes a coroutine UUID and will take care of the cancelling.

vSLG mentioned this issue Jul 14, 2020

Question: What hinders a macOS/Windows port? mirukana/mirage#24

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Cannot retrieve `Future` from python on Windows #116

Cannot retrieve `Future` from python on Windows #116

vSLG commented Jul 14, 2020

thp commented Jul 15, 2020 via email

vSLG commented Jul 15, 2020

Cannot retrieve Future from python on Windows #116

Cannot retrieve Future from python on Windows #116

Comments

vSLG commented Jul 14, 2020

Description

Environment 1

Environment 2

Steps to reproduce (Environment 1)

Programs used

main.py

main.qml

Output

Environment 1 (Windows)

Environment 2 (Linux)

Expected behavior

thp commented Jul 15, 2020 via email

vSLG commented Jul 15, 2020

Output

Environment 1 (Windows)

Environment 2 (Linux)

Cannot retrieve `Future` from python on Windows #116

Cannot retrieve `Future` from python on Windows #116