f

app.py

@@ -10,6 +10,7 @@ from PIL import Image
 import mimetypes
 import logging
 from logging.handlers import RotatingFileHandler
+import time
 
 app = Flask(__name__)
 
@@ -79,19 +80,36 @@ def print_address_label(pdf_path):
             cut=True
         )
 
-        app.logger.info("Waiting to acquire printer lock...")
-        with printer_lock:  # Ensure only one thread sends a job at a time
-            app.logger.info("Sending to printer...")
-            try:
-                send(
-                    instructions=instructions, 
-                    printer_identifier=printer, 
-                    backend_identifier=backend, 
-                    blocking=True
-                )
-                app.logger.info("Print job sent successfully")
-            except Exception as e:
-                app.logger.error(f"Error during printing: {str(e)}")
+        # Try to acquire the printer lock with a timeout
+        max_retries = 3
+        retry_delay = 2  # seconds
+        for attempt in range(max_retries):
+            if printer_lock.acquire(timeout=5):  # 5 seconds timeout
+                try:
+                    app.logger.info(f"Attempting to send print job (Attempt {attempt + 1})...")
+                    send(
+                        instructions=instructions, 
+                        printer_identifier=printer, 
+                        backend_identifier=backend, 
+                        blocking=True
+                    )
+                    app.logger.info("Print job sent successfully")
+                    break
+                except Exception as e:
+                    app.logger.error(f"Error during printing: {str(e)}")
+                    if attempt < max_retries - 1:
+                        app.logger.info(f"Retrying after {retry_delay} seconds...")
+                        time.sleep(retry_delay)
+                    else:
+                        app.logger.error("Max retries reached. Failed to send print job.")
+            else:
+                app.logger.error(f"Failed to acquire printer lock (Attempt {attempt + 1}). Printer is busy.")
+                if attempt < max_retries - 1:
+                    app.logger.info(f"Retrying after {retry_delay} seconds...")
+                    time.sleep(retry_delay)
+                else:
+                    app.logger.error("Printer is still busy after retries.")
+                    raise Exception("Printer is busy. Try again later.")
     
     except Exception as e:
         app.logger.error(f"Error during label printing: {str(e)}")