Provide the classic runner system from waf 1.x as an extension

waflib/extras/classic_runner.py

@@ -0,0 +1,68 @@
+#!/usr/bin/env python
+# encoding: utf-8
+# Thomas Nagy, 2021 (ita)
+
+from waflib import Utils, Runner
+
+"""
+Re-enable the classic threading system from waf 1.x
+
+def configure(conf):
+	conf.load('classic_runner')
+"""
+
+class TaskConsumer(Utils.threading.Thread):
+	"""
+	Task consumers belong to a pool of workers
+
+	They wait for tasks in the queue and then use ``task.process(...)``
+	"""
+	def __init__(self, spawner):
+		Utils.threading.Thread.__init__(self)
+		"""
+		Obtain :py:class:`waflib.Task.TaskBase` instances from this queue.
+		"""
+		self.spawner = spawner
+		self.daemon = True
+		self.start()
+
+	def run(self):
+		"""
+		Loop over the tasks to execute
+		"""
+		try:
+			self.loop()
+		except Exception:
+			pass
+
+	def loop(self):
+		"""
+		Obtain tasks from :py:attr:`waflib.Runner.TaskConsumer.ready` and call
+		:py:meth:`waflib.Task.TaskBase.process`. If the object is a function, execute it.
+		"""
+		master = self.spawner.master
+		while 1:
+			if not master.stop:
+				try:
+					tsk = master.ready.get()
+					if tsk:
+						tsk.log_display(tsk.generator.bld)
+						master.process_task(tsk)
+					else:
+						break
+				finally:
+					master.out.put(tsk)
+
+class Spawner(object):
+	"""
+	Daemon thread that consumes tasks from :py:class:`waflib.Runner.Parallel` producer and
+	spawns a consuming thread :py:class:`waflib.Runner.Consumer` for each
+	:py:class:`waflib.Task.Task` instance.
+	"""
+	def __init__(self, master):
+		self.master = master
+		""":py:class:`waflib.Runner.Parallel` producer instance"""
+
+		self.pool = [TaskConsumer(self) for i in range(master.numjobs)]
+
+Runner.Spawner = Spawner