Try move from Qthreads to qasync

Signed-off-by: Egor Savkin <es@m-labs.hk>

flake.nix

@@ -55,9 +55,45 @@
 
         dontFixup = true;
       };
+
+      qasync = pkgs.python3Packages.buildPythonPackage rec {
+        pname = "qasync";
+        version = "0.24.0";
+        src = pkgs.fetchFromGitHub {
+          owner = "CabbageDevelopment";
+          repo = "qasync";
+          rev = "v${version}";
+          sha256 = "sha256-ls5F+VntXXa3n+dULaYWK9sAmwly1nk/5+RGWLrcf2Y=";
+        };
+        propagatedBuildInputs = [ pkgs.python3Packages.pyqt6 ];
+        nativeCheckInputs = [ pkgs.python3Packages.pytest ];
+        checkPhase = ''
+          pytest -k 'test_qthreadexec.py' # the others cause the test execution to be aborted, I think because of asyncio
+        '';
+      };
+      thermostat_gui = pkgs.python3Packages.buildPythonPackage rec {
+        pname = "thermostat_gui";
+        version = "0.0.0";
+        src = self;
+
+        preBuild =
+          ''
+          export VERSIONEER_OVERRIDE=${version}
+          export VERSIONEER_REV=v0.0.0
+          '';
+
+        nativeBuildInputs = [ pkgs.qt6.wrapQtAppsHook ];
+        propagatedBuildInputs = (with pkgs.python3Packages; [ pyqtgraph pyqt6 qasync]);
+
+        dontWrapQtApps = true;
+        postFixup = ''
+          ls -al $out/
+          wrapQtApp "$out/pytec/tec_qt"
+        '';
+      };
     in {
       packages.x86_64-linux = {
-        inherit thermostat;
+        inherit thermostat qasync thermostat_gui;
       };
 
       hydraJobs = {
@@ -69,7 +105,7 @@
         buildInputs = with pkgs; [
           rust openocd dfu-util
           ] ++ (with python3Packages; [
-            numpy matplotlib pyqtgraph setuptools pyqt6
+            numpy matplotlib pyqtgraph setuptools pyqt6 qasync
           ]);
           shellHook=
           ''

pytec/pytec/client.py

@@ -40,6 +40,7 @@ class Client:
 
         line = self._read_line()
         response = json.loads(line)
+        logging.debug(f"{command}: {response}")
         if "error" in response:
             raise CommandError(response["error"])
         return response

pytec/tec_qt.py

@@ -6,7 +6,10 @@ import pyqtgraph as pg
 import sys
 import argparse
 import logging
+import asyncio
+import atexit
 from pytec.client import Client
+from qasync import QEventLoop
 
 # pyuic6 -x tec_qt.ui  -o ui_tec_qt.py
 from ui_tec_qt import Ui_MainWindow
@@ -16,7 +19,7 @@ tec_client: Client = None
 # ui = None
 ui: Ui_MainWindow = None
 
-thread_pool = QThreadPool.globalInstance()
+queue = None
 connection_watcher = None
 client_watcher = None
 app: QtWidgets.QApplication = None
@@ -35,7 +38,43 @@ def get_argparser():
     return parser
 
 
-class WatchConnectTask(QThread):
+def wrap_client_task(func, *args, **kwargs):
+    loop = asyncio.get_event_loop()
+    task = ClientTask(func, *args, **kwargs)
+    asyncio.ensure_future(queue.put(task), loop=loop)
+
+
+async def process_client_tasks():
+    global queue
+    if queue is None:
+        queue = asyncio.Queue()
+    loop = asyncio.get_event_loop()
+    while True:
+        task = await queue.get()
+        await task.run()
+        queue.task_done()
+
+
+class ClientTask:
+    def __init__(self, func, *args, **kwargs):
+        self.func = func
+        self.args = args
+        self.kwargs = kwargs
+        super().__init__()
+
+    async def run(self):
+        try:
+            lock = asyncio.Lock()
+            async with lock:
+                self.func(*self.args, **self.kwargs)
+        except (TimeoutError, OSError):
+            logging.warning("Client connection error, disconnecting", exc_info=True)
+            if connection_watcher:
+                #thread_pool.clear()  # clearing all next requests
+                connection_watcher.client_disconnected()
+
+
+class WatchConnectTask(QObject):
     connected = pyqtSignal(bool)
     hw_rev = pyqtSignal(dict)
     connecting = pyqtSignal()
@@ -57,8 +96,8 @@ class WatchConnectTask(QThread):
                 self.connecting.emit()
                 tec_client = Client(host=self.ip, port=self.port, timeout=30)
                 self.connected.emit(True)
-                thread_pool.start(ClientTask(lambda: self.hw_rev.emit(tec_client.hw_rev())))
+                wrap_client_task(lambda: self.hw_rev.emit(tec_client.hw_rev()))
-                #thread_pool.start(ClientTask(lambda: self.fan_update.emit(tec_client.fan())))
+                # wrap_client_task(lambda: self.fan_update.emit(tec_client.fan()))
         except Exception as e:
             logging.error(f"Failed communicating to the {self.ip}:{self.port}: {e}")
             self.connected.emit(False)
@@ -72,7 +111,8 @@ class WatchConnectTask(QThread):
             self.connected.emit(False)
 
 
-class ClientWatcher(QThread):
+
+class ClientWatcher(QObject):
     fan_update = pyqtSignal(object)
     pwm_update = pyqtSignal(object)
     report_update = pyqtSignal(object)
@@ -83,10 +123,10 @@ class ClientWatcher(QThread):
         self.running = True
         super().__init__(parent)
 
-    def run(self):
+    async def run(self):
         while self.running:
-            thread_pool.start(ClientTask(lambda: self.update_params()))
+            wrap_client_task(lambda: self.update_params())
-            self.msleep(int(self.update_s * 1000))
+            await asyncio.sleep(int(self.update_s * 1000))
 
     def update_params(self):
         self.fan_update.emit(tec_client.fan())
@@ -94,34 +134,17 @@ class ClientWatcher(QThread):
     @pyqtSlot()
     def stop_watching(self):
         self.running = False
-        deadline = QDeadlineTimer()
+        #deadline = QDeadlineTimer()
-        deadline.setDeadline(100)
+        #deadline.setDeadline(100)
-        self.wait(deadline)
+        #self.wait(deadline)
-        self.terminate()
+        #self.terminate()
 
     @pyqtSlot()
     def set_update_s(self):
         self.update_s = ui.report_refresh_spin.value()
 
 
-class ClientTask(QRunnable):
+def on_connection_changed(result):
-    def __init__(self, func, *args, **kwargs):
-        self.func = func
-        self.args = args
-        self.kwargs = kwargs
-        super().__init__()
-
-    def run(self):
-        try:
-            self.func(*self.args, **self.kwargs)
-        except (TimeoutError, OSError):
-            logging.warning("Client connection error, disconnecting", exc_info=True)
-            if connection_watcher:
-                thread_pool.clear()  # clearing all next requests
-                connection_watcher.client_disconnected()
-
-
-def connected(result):
     global client_watcher, connection_watcher
     ui.graph_group.setEnabled(result)
     ui.hw_rev_lbl.setEnabled(result)
@@ -143,7 +166,7 @@ def connected(result):
         client_watcher.fan_update.connect(fan_update)
         ui.report_apply_btn.clicked.connect(client_watcher.set_update_s)
         app.aboutToQuit.connect(client_watcher.stop_watching)
-        client_watcher.start()
+        wrap_client_task(client_watcher.run)
 
 
 def hw_rev(hw_rev_d: dict):
@@ -173,7 +196,7 @@ def fan_set():
     global tec_client
     if tec_client is None or ui.fan_auto_box.isChecked():
         return
-    thread_pool.start(ClientTask(lambda: tec_client.set_param("fan", ui.fan_power_slider.value())))
+    wrap_client_task(lambda: tec_client.set_param("fan", ui.fan_power_slider.value()))
 
 
 def fan_auto_set(enabled):
@@ -182,37 +205,41 @@ def fan_auto_set(enabled):
         return
     ui.fan_power_slider.setEnabled(not enabled)
     if enabled:
-        thread_pool.start(ClientTask(lambda: tec_client.set_param("fan", "auto")))
+        wrap_client_task(lambda: tec_client.set_param("fan", "auto"))
     else:
-        thread_pool.start(ClientTask(lambda: tec_client.set_param("fan", ui.fan_power_slider.value())))
+        wrap_client_task(lambda: tec_client.set_param("fan", ui.fan_power_slider.value()))
 
 
 def connect():
     global connection_watcher
     connection_watcher = WatchConnectTask(ui.main_widget, ui.ip_set_line.text(), ui.port_set_spin.value())
-    connection_watcher.connected.connect(connected)
+    connection_watcher.connected.connect(on_connection_changed)
     connection_watcher.connecting.connect(lambda: ui.status_lbl.setText("Connecting..."))
     connection_watcher.hw_rev.connect(hw_rev)
     connection_watcher.fan_update.connect(fan_update)
-    connection_watcher.start()
+    wrap_client_task(connection_watcher.run)
-    app.aboutToQuit.connect(connection_watcher.terminate)
+    #app.aboutToQuit.connect(connection_watcher.terminate)
 
 
 def main():
-    global ui, thread_pool, app
+    global ui, app, queue
     args = get_argparser().parse_args()
     if args.logLevel:
         logging.basicConfig(level=getattr(logging, args.logLevel))
 
     app = QtWidgets.QApplication(sys.argv)
+
+    loop = QEventLoop(app)
+    asyncio.set_event_loop(loop)
+    atexit.register(loop.close)
+
+    loop.create_task(process_client_tasks())
+
     main_window = QtWidgets.QMainWindow()
     ui = Ui_MainWindow()
     ui.setupUi(main_window)
     # ui = uic.loadUi('tec_qt.ui', main_window)
 
-    thread_pool = QThreadPool(parent=ui.main_widget)
-    thread_pool.setMaxThreadCount(1)  # avoid concurrent requests
-
     ui.connect_btn.clicked.connect(lambda _checked: connect())
     ui.fan_power_slider.valueChanged.connect(fan_set)
     ui.fan_auto_box.stateChanged.connect(fan_auto_set)
@@ -225,7 +252,8 @@ def main():
         ui.connect_btn.click()
 
     main_window.show()
-    sys.exit(app.exec())
+
+    loop.run_until_complete(app.exec())
 
 
 if __name__ == '__main__':