change the way the waker works: let others register to be called by it

[saartuer.git] / libtuer.py

diff --git a/libtuer.py b/libtuer.py
index 097a25abb6894eb1079cfe26802f7fd876d0ebe8..835bf6d51003e22dd8a2d5e3b9ed72e85fae0577 100644 (file)
--- a/libtuer.py
+++ b/libtuer.py
@@ -10,7 +10,8 @@ printLevel  = logging.DEBUG
 
 # Mail logging handler
 def sendeMail(subject, text, receivers, sender='sphinx@hacksaar.de', replyTo=None):
-       if not isinstance(type(receivers), list): receivers = [receivers]
+       assert isinstance(receivers, list)
+       if not len(receivers): return # nothing to do
        # construct content
        msg = email.mime.text.MIMEText(text.encode('UTF-8'), 'plain', 'UTF-8')
        msg['Subject'] = subject
@@ -57,16 +58,26 @@ class Logger:
 
 logger = Logger()
 
+# run a Python command asynchronously
+def fire_and_forget(f):
+       def _fire_and_forget():
+               try:
+                       f()
+               except Exception as e:
+                       logger.critical("fire_and_forget: Got exception out of callback: %s" % str(e))
+                       logger.debug(traceback.format_exc())
+       t = threading.Thread(target=_fire_and_forget)
+       t.start()
+
 # run a command asynchronously and log the return value if not 0
 # prefix must be a string identifying the code position where the call came from
-def fire_and_forget (cmd, log, prefix):
-       def _fire_and_forget ():
+def fire_and_forget_cmd (cmd, log, prefix):
+       def _fire_and_forget_cmd ():
                with open("/dev/null", "w") as fnull:
                        retcode = subprocess.call(cmd, stdout=fnull, stderr=fnull)
                        if retcode is not 0:
                                logger.error("%sReturn code %d at command: %s" % (prefix,retcode,str(cmd)))
-       t = threading.Thread(target=_fire_and_forget)
-       t.start()
+       fire_and_forget(_fire_and_forget_cmd)
 
 # Threaded callback class
 class ThreadFunction():