Very scary test here. Trying to see if we can boost speed on very large terminals.

src/fenrirscreenreader/screenDriver/vcsaDriver.py

@@ -10,6 +10,7 @@
 # blink = 5 if attr & 1 else 0
 # bold = 1 if attr & 16 else 0
 
+import errno
 import fcntl
 import glob
 import os
@@ -53,6 +54,9 @@ class driver(screenDriver):
         fgColorValues: Foreground color value mappings
         hichar: High character mask for Unicode support
     """
+    read_retry_attempts = 10
+    read_retry_delay = 0.05
+
     def __init__(self):
         screenDriver.__init__(self)
         self.ListSessions = None
@@ -251,24 +255,40 @@ class driver(screenDriver):
             bytes: File content as bytes
         """
         d = b""
-        file.seek(0)
-        try:
-            d = file.read()
-        except Exception as e:
-            self.env["runtime"]["DebugManager"].write_debug_out(
-                "vcsaDriver get_screen_text: Error reading file: " + str(e),
-                debug.DebugLevel.ERROR,
-            )
+        for attempt in range(self.read_retry_attempts + 1):
             file.seek(0)
-            while True:
-                # Read from file
-                try:
-                    chunk = file.readline(1)
-                    if not chunk:
-                        break
-                    d += chunk
-                except Exception as e:
+            try:
+                return file.read()
+            except OSError as e:
+                if (
+                    e.errno == errno.EINVAL
+                    and attempt < self.read_retry_attempts
+                ):
+                    time.sleep(self.read_retry_delay)
+                    continue
+                self.env["runtime"]["DebugManager"].write_debug_out(
+                    "vcsaDriver get_screen_text: Error reading file: "
+                    + str(e),
+                    debug.DebugLevel.ERROR,
+                )
+                break
+            except Exception as e:
+                self.env["runtime"]["DebugManager"].write_debug_out(
+                    "vcsaDriver get_screen_text: Error reading file: "
+                    + str(e),
+                    debug.DebugLevel.ERROR,
+                )
+                break
+
+        file.seek(0)
+        while True:
+            try:
+                chunk = file.readline(1)
+                if not chunk:
                     break
+                d += chunk
+            except Exception:
+                break
         return d
 
     def update_watchdog(self, active, event_queue):