Attempt to prevent thread lock that is causing freeze.

src/fenrirscreenreader/screenDriver/ptyDriver.py

@@ -9,6 +9,7 @@ import getpass
 import os
 import pty
 import shlex
+from queue import Full
 import signal
 import struct
 import sys
@@ -316,19 +317,26 @@ class driver(screenDriver):
 
         event_time = time.time()
         for event_state in [1, 0]:
-            event_queue.put(
-                {
-                    "Type": FenrirEventType.keyboard_input,
-                    "data": {
-                        "event_name": "KEY_BACKSPACE",
-                        "event_value": 0,
-                        "event_sec": int(event_time),
-                        "event_usec": int((event_time % 1) * 1000000),
-                        "event_state": event_state,
-                        "event_type": 0,
+            try:
+                event_queue.put(
+                    {
+                        "Type": FenrirEventType.keyboard_input,
+                        "data": {
+                            "event_name": "KEY_BACKSPACE",
+                            "event_value": 0,
+                            "event_sec": int(event_time),
+                            "event_usec": int((event_time % 1) * 1000000),
+                            "event_state": event_state,
+                            "event_type": 0,
+                        },
                     },
-                }
-            )
+                    block=False,
+                )
+            except Full:
+                self.env["runtime"]["DebugManager"].write_debug_out(
+                    "ptyDriver synthesize_backspace_shortcut: Event queue full, dropping backspace events",
+                    debug.DebugLevel.WARNING,
+                )
         return True
 
     def get_session_information(self):