1 files changed, 70 insertions, 0 deletions
diff --git a/gr-uhd/apps/msgq_runner.py b/gr-uhd/apps/msgq_runner.py
new file mode 100644
index 0000000000..31bebcf0df
--- /dev/null
+++ b/gr-uhd/apps/msgq_runner.py
@@ -0,0 +1,70 @@
+#
+# Copyright 2009 Free Software Foundation, Inc.
+#
+# This file is part of GNU Radio
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+#
+
+"""
+Convenience class for dequeuing messages from a gr.msg_queue and
+invoking a callback.
+
+Creates a Python thread that does a blocking read on the supplied
+gr.msg_queue, then invokes callback each time a msg is received.
+
+If the msg type is not 0, then it is treated as a signal to exit
+its loop.
+
+If the callback raises an exception, and the runner was created
+with 'exit_on_error' equal to True, then the runner will store the
+exception and exit its loop, otherwise the exception is ignored.
+
+To get the exception that the callback raised, if any, call
+exit_error() on the object.
+
+To manually stop the runner, call stop() on the object.
+
+To determine if the runner has exited, call exited() on the object.
+"""
+
+from gnuradio import gr
+import threading
+
+class msgq_runner(threading.Thread):
+
+    def __init__(self, msgq, callback, exit_on_error=False):
+        threading.Thread.__init__(self)
+
+        self._msgq = msgq
+        self._callback = callback
+        self._exit_on_error = exit_on_error
+        self._done = False
+        self._exited = False
+        self._exit_error = None
+        self.setDaemon(1)
+        self.start()
+
+    def run(self):
+        while not self._done:
+            msg = self._msgq.delete_head()
+            if msg.type() != 0:
+                self.stop()
+            else:
+                try:
+                    self._callback(msg)
+                except Exception as e:
+                    if self._exit_on_error:
+                        self._exit_error = e
+                        self.stop()
+        self._exited = True
+
+    def stop(self):
+        self._done = True
+
+    def exited(self):
+        return self._exited
+
+    def exit_error(self):
+        return self._exit_error