Merge feature/multithreading (#58)

🎉 Runs GUI and Kernel on separate threads
CAUTION application crashes if multiple executions are launched at the same time due to the lack of execution flow

Author: MathisFederico

opencodeblocks/graphics/blocks/codeblock.py

@@ -3,15 +3,15 @@
 
 """ Module for the base OCB Code Block. """
 
-
-from PyQt5.QtCore import QCoreApplication, QByteArray
+from PyQt5.QtCore import QByteArray
 from PyQt5.QtGui import QPixmap
 from PyQt5.QtWidgets import QPushButton, QTextEdit
 
 from ansi2html import Ansi2HTMLConverter
 
 from opencodeblocks.graphics.blocks.block import OCBBlock
 from opencodeblocks.graphics.pyeditor import PythonEditor
+from opencodeblocks.graphics.worker import Worker
 
 conv = Ansi2HTMLConverter()
 
@@ -144,19 +144,17 @@ def init_run_button(self):
     def run_code(self):
         """Run the code in the block"""
         code = self.source_editor.text()
-        kernel = self.source_editor.kernel
         self.source = code
-        # Execute the code
-        kernel.client.execute(code)
-        done = False
-        # While the kernel sends messages
-        while done is False:
-            # Keep the GUI alive
-            QCoreApplication.processEvents()
-            # Save kernel message and display it
-            output, output_type, done = kernel.update_output()
-            if done is False:
-                if output_type == 'text':
-                    self.stdout = output
-                elif output_type == 'image':
-                    self.image = output
+        # Create a worker to handle execution
+        worker = Worker(self.source_editor.kernel, self.source)
+        worker.signals.stdout.connect(self.handle_stdout)
+        worker.signals.image.connect(self.handle_image)
+        self.source_editor.threadpool.start(worker)
+
+    def handle_stdout(self, stdout):
+        """ Handle the stdout signal """
+        self.stdout = stdout
+
+    def handle_image(self, image):
+        """ Handle the image signal """
+        self.image = image

opencodeblocks/graphics/pyeditor.py

@@ -4,7 +4,7 @@
 """ Module for OCB in block python editor. """
 
 from typing import TYPE_CHECKING, List
-from PyQt5.QtCore import Qt
+from PyQt5.QtCore import QThreadPool, Qt
 from PyQt5.QtGui import QFocusEvent, QFont, QFontMetrics, QColor
 from PyQt5.Qsci import QsciScintilla, QsciLexerPython
 from opencodeblocks.graphics.theme_manager import theme_manager
@@ -13,7 +13,7 @@
 from opencodeblocks.graphics.kernel import Kernel
 
 kernel = Kernel()
-
+threadpool = QThreadPool()
 
 if TYPE_CHECKING:
     from opencodeblocks.graphics.view import OCBView
@@ -33,6 +33,7 @@ def __init__(self, block: OCBBlock):
         super().__init__(None)
         self.block = block
         self.kernel = kernel
+        self.threadpool = threadpool
         self.setText(self.block.source)
 
         self.update_theme()

opencodeblocks/graphics/worker.py

@@ -0,0 +1,47 @@
+# OpenCodeBlock an open-source tool for modular visual programing in python
+# Copyright (C) 2021 Mathïs FEDERICO <https://www.gnu.org/licenses/>
+
+""" Module to create and manage multi-threading workers """
+
+import asyncio
+from PyQt5.QtCore import QObject, pyqtSignal, QRunnable
+
+
+class WorkerSignals(QObject):
+    """ Defines the signals available from a running worker thread. """
+    stdout = pyqtSignal(str)
+    image = pyqtSignal(str)
+
+
+class Worker(QRunnable):
+    """ Worker thread """
+
+    def __init__(self, kernel, code):
+        """ Initialize the worker object. """
+        super(Worker, self).__init__()
+
+        self.kernel = kernel
+        self.code = code
+        self.signals = WorkerSignals()
+
+    async def run_code(self):
+        """ Run the code in the block """
+        # Execute the code
+        self.kernel.client.execute(self.code)
+        done = False
+        # While the kernel sends messages
+        while done is False:
+            # Save kernel message and send it to the GUI
+            output, output_type, done = self.kernel.update_output()
+            if done is False:
+                if output_type == 'text':
+                    self.signals.stdout.emit(output)
+                elif output_type == 'image':
+                    self.signals.image.emit(output)
+
+    def run(self):
+        """ Execute the run_code method asynchronously. """
+        loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(loop)
+        loop.run_until_complete(self.run_code())
+        loop.close()