fix: [Mail module] replace signal by multiprocessing (https://docs.python.org/3.4/library/signal.html#execution-of-python-signal-handlers)

Author: Terrtia

bin/Mail.py

@@ -21,25 +21,14 @@
 import dns.resolver
 import dns.exception
 
+from multiprocessing import Process as Proc
+from multiprocessing import Queue
+
 from pubsublogger import publisher
 from Helper import Process
 
 from pyfaup.faup import Faup
 
-## REGEX TIMEOUT ##
-import signal
-
-def timeout_handler(signum, frame):
-    raise TimeoutException()
-
-class TimeoutException(Exception):
-    pass
-
-
-signal.signal(signal.SIGALRM, timeout_handler)
-max_execution_time = 20
-## -- ##
-
 sys.path.append(os.path.join(os.environ['AIL_BIN'], 'packages'))
 import Item
 
@@ -55,6 +44,7 @@ class TimeoutException(Exception):
 
 config_loader = None
 ## -- ##
+
 def is_mxdomain_in_cache(mxdomain):
     return r_serv_cache.exists('mxdomain:{}'.format(mxdomain))
 
@@ -120,6 +110,9 @@ def check_mx_record(set_mxdomains, dns_server):
                 print(e)
     return valid_mxdomain
 
+def extract_all_emails(queue, item_content):
+    queue.put(re.findall(email_regex, item_content))
+
 if __name__ == "__main__":
     publisher.port = 6380
     publisher.channel = "Script"
@@ -135,32 +128,37 @@ def check_mx_record(set_mxdomains, dns_server):
     # Numbers of Mails needed to Tags
     mail_threshold = 10
 
+    max_execution_time = 30
+
     email_regex = "[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,6}"
 
+    q = Queue()
+
     while True:
         message = p.get_from_set()
 
         if message is not None:
             item_id, score = message.split()
 
             item_content = Item.get_item_content(item_id)
-            item_date = Item.get_item_date(item_id)
 
-            #print(item_id)
-
-            # Get all emails address
-            signal.alarm(30)
+            proc = Proc(target=extract_all_emails, args=(q, item_content))
+            proc.start()
             try:
-                all_emails = re.findall(email_regex, item_content)
-            except TimeoutException:
-                p.incr_module_timeout_statistic()
-                err_mess = "Mails: processing timeout: {}".format(item_id)
-                print(err_mess)
-                publisher.info(err_mess)
-                signal.signal(signal.SIGALRM, timeout_handler)
-                continue
-            finally:
-                signal.alarm(0)
+                proc.join(max_execution_time)
+                if proc.is_alive():
+                    proc.terminate()
+                    p.incr_module_timeout_statistic()
+                    err_mess = "Mails: processing timeout: {}".format(item_id)
+                    print(err_mess)
+                    publisher.info(err_mess)
+                    continue
+                else:
+                    all_emails = q.get()
+            except KeyboardInterrupt:
+                print("Caught KeyboardInterrupt, terminating workers")
+                proc.terminate()
+                sys.exit(0)
 
             # filtering duplicate
             all_emails = set(all_emails)
@@ -179,6 +177,8 @@ def check_mx_record(set_mxdomains, dns_server):
 
             valid_mx = check_mx_record(set_mxdomains, dns_server)
 
+            item_date = Item.get_item_date(item_id)
+
             num_valid_email = 0
             for domain_mx in valid_mx:
                 num_valid_email += len(dict_mxdomains_email[domain_mx])