1 files changed, 114 insertions, 99 deletions

diff --git a/Mailman/bin/master.py b/Mailman/bin/master.py
index e4de11acc..83ec4508d 100644
--- a/Mailman/bin/master.py
+++ b/Mailman/bin/master.py
@@ -17,6 +17,13 @@
 
 from __future__ import with_statement
 
+__metaclass__ = type
+__all__ = [
+    'Loop',
+    'get_lock_data',
+    ]
+
+
 import os
 import sys
 import errno
@@ -40,7 +47,6 @@ from Mailman.initialize import initialize
 DOT = '.'
 LOCK_LIFETIME = Defaults.days(1) + Defaults.hours(6)
 
-log = None
 parser = None
 
 
@@ -205,91 +211,100 @@ Exiting.""")
 
 
 
-def start_runner(qrname, slice, count):
-    """Start a queue runner.
+class Loop:
+    """Main control loop class."""
 
-    All arguments are passed to the qrunner process.
+    def __init__(self, lock=None, restartable=None, config_file=None):
+        self._lock = lock
+        self._restartable = restartable
+        self._config_file = config_file
+        self._kids = {}
 
-    :param qrname: The name of the queue runner.
-    :param slice: The slice number.
-    :param count: The total number of slices.
-    :return: The process id of the child queue runner.
-    """
-    pid = os.fork()
-    if pid:
-        # Parent.
-        return pid
-    # Child.
-    #
-    # Craft the command line arguments for the exec() call.
-    rswitch = '--runner=%s:%d:%d' % (qrname, slice, count)
-    # Wherever mailmanctl lives, so too must live the qrunner script.
-    exe = os.path.join(config.BIN_DIR, 'qrunner')
-    # config.PYTHON, which is the absolute path to the Python interpreter,
-    # must be given as argv[0] due to Python's library search algorithm.
-    args = [sys.executable, sys.executable, exe, rswitch, '-s']
-    if parser.options.config:
-        args.extend(['-C', parser.options.config])
-    log.debug('starting: %s', args)
-    os.execl(*args)
-    # We should never get here.
-    raise RuntimeError('os.execl() failed')
+    def install_signal_handlers(self):
+        """Install various signals handlers for control from mailmanctl."""
+        log = logging.getLogger('mailman.qrunner')
+        # Set up our signal handlers.  Also set up a SIGALRM handler to
+        # refresh the lock once per day.  The lock lifetime is 1 day + 6 hours
+        # so this should be plenty.
+        def sigalrm_handler(signum, frame):
+            self._lock.refresh()
+            signal.alarm(int(Defaults.days(1)))
+        signal.signal(signal.SIGALRM, sigalrm_handler)
+        signal.alarm(int(Defaults.days(1)))
+        # SIGHUP tells the qrunners to close and reopen their log files.
+        def sighup_handler(signum, frame):
+            loginit.reopen()
+            for pid in self._kids:
+                os.kill(pid, signal.SIGHUP)
+            log.info('Master watcher caught SIGHUP.  Re-opening log files.')
+        signal.signal(signal.SIGHUP, sighup_handler)
+        # SIGUSR1 is used by 'mailman restart'.
+        def sigusr1_handler(signum, frame):
+            for pid in self._kids:
+                os.kill(pid, signal.SIGUSR1)
+            log.info('Master watcher caught SIGUSR1.  Exiting.')
+        signal.signal(signal.SIGUSR1, sigusr1_handler)
+        # SIGTERM is what init will kill this process with when changing run
+        # levels.  It's also the signal 'mailmanctl stop' uses.
+        def sigterm_handler(signum, frame):
+            for pid in self._kids:
+                os.kill(pid, signal.SIGTERM)
+            log.info('Master watcher caught SIGTERM.  Exiting.')
+        signal.signal(signal.SIGTERM, sigterm_handler)
+        # SIGINT is what control-C gives.
+        def sigint_handler(signum, frame):
+            for pid in self._kids:
+                os.kill(pid, signal.SIGINT)
+            log.info('Master watcher caught SIGINT.  Restarting.')
+        signal.signal(signal.SIGINT, sigint_handler)
 
+    def _start_runner(self, qrname, slice, count):
+        """Start a queue runner.
 
-
-def control_loop(lock):
-    """The main control loop.
+        All arguments are passed to the qrunner process.
 
-    This starts up the queue runners, watching for their exit and restarting
-    them if need be.
-    """
-    restartable = parser.options.restartable
-    # Start all the qrunners.  Keep a dictionary mapping process ids to
-    # information about the child processes.
-    kids = {}
-    # Set up our signal handlers.  Also set up a SIGALRM handler to refresh
-    # the lock once per day.  The lock lifetime is 1 day + 6 hours so this
-    # should be plenty.
-    def sigalrm_handler(signum, frame):
-        lock.refresh()
-        signal.alarm(int(Defaults.days(1)))
-    signal.signal(signal.SIGALRM, sigalrm_handler)
-    signal.alarm(int(Defaults.days(1)))
-    # SIGHUP tells the qrunners to close and reopen their log files.
-    def sighup_handler(signum, frame):
-        loginit.reopen()
-        for pid in kids:
-            os.kill(pid, signal.SIGHUP)
-        log.info('Master watcher caught SIGHUP.  Re-opening log files.')
-    signal.signal(signal.SIGHUP, sighup_handler)
-    # SIGUSR1 is used by 'mailman restart'.
-    def sigusr1_handler(signum, frame):
-        for pid in kids:
-            os.kill(pid, signal.SIGUSR1)
-        log.info('Master watcher caught SIGUSR1.  Exiting.')
-    signal.signal(signal.SIGUSR1, sigusr1_handler)
-    # SIGTERM is what init will kill this process with when changing run
-    # levels.  It's also the signal 'mailmanctl stop' uses.
-    def sigterm_handler(signum, frame):
-        for pid in kids:
-            os.kill(pid, signal.SIGTERM)
-        log.info('Master watcher caught SIGTERM.  Exiting.')
-    signal.signal(signal.SIGTERM, sigterm_handler)
-    # SIGINT is what control-C gives.
-    def sigint_handler(signum, frame):
-        for pid in kids:
-            os.kill(pid, signal.SIGINT)
-        log.info('Master watcher caught SIGINT.  Restarting.')
-    signal.signal(signal.SIGINT, sigint_handler)
-    # Start all the child qrunners.
-    for qrname, count in config.qrunners.items():
-        for slice_number in range(count):
-            # queue runner name, slice number, number of slices, restart count
-            info = (qrname, slice_number, count, 0)
-            pid = start_runner(qrname, slice_number, count)
-            kids[pid] = info
-    # Enter the main wait loop.
-    try:
+        :param qrname: The name of the queue runner.
+        :param slice: The slice number.
+        :param count: The total number of slices.
+        :return: The process id of the child queue runner.
+        """
+        pid = os.fork()
+        if pid:
+            # Parent.
+            return pid
+        # Child.
+        #
+        # Craft the command line arguments for the exec() call.
+        rswitch = '--runner=%s:%d:%d' % (qrname, slice, count)
+        # Wherever mailmanctl lives, so too must live the qrunner script.
+        exe = os.path.join(config.BIN_DIR, 'qrunner')
+        # config.PYTHON, which is the absolute path to the Python interpreter,
+        # must be given as argv[0] due to Python's library search algorithm.
+        args = [sys.executable, sys.executable, exe, rswitch, '-s']
+        if self._config_file is not None:
+            args.extend(['-C', self._config_file])
+        log = logging.getLogger('mailman.qrunner')
+        log.debug('starting: %s', args)
+        os.execl(*args)
+        # We should never get here.
+        raise RuntimeError('os.execl() failed')
+
+    def start_qrunners(self):
+        """Start all the configured qrunners."""
+        for qrname, count in config.qrunners.items():
+            for slice_number in range(count):
+                # qrunner name, slice #, # of slices, restart count
+                info = (qrname, slice_number, count, 0)
+                pid = self._start_runner(qrname, slice_number, count)
+                self._kids[pid] = info
+
+    def loop(self):
+        """Main loop.
+
+        Wait until all the qrunners have exited, restarting them if necessary
+        and configured to do so.
+        """
+        log = logging.getLogger('mailman.qrunner')
         while True:
             try:
                 pid, status = os.wait()
@@ -314,9 +329,9 @@ def control_loop(lock):
             # because of a failure (i.e. no exit signal), and the no-restart
             # command line switch was not given.  This lets us better handle
             # runaway restarts (e.g.  if the subprocess had a syntax error!)
-            qrname, slice, count, restarts = kids.pop(pid)
+            qrname, slice, count, restarts = self._kids.pop(pid)
             restart = False
-            if why == signal.SIGUSR1 and restartable:
+            if why == signal.SIGUSR1 and self._restartable:
                 restart = True
             # Have we hit the maximum number of restarts?
             restarts += 1
@@ -337,12 +352,14 @@ qrunner %s reached maximum restart limit of %d, not restarting.""",
             # SIGTERM or we aren't restarting.
             if restart:
                 newpid = start_runner(qrname, slice, count)
-                kids[newpid] = (qrname, slice, count, restarts)
-    finally:
-        # Should we leave the main loop for any reason, we want to be sure
-        # all of our children are exited cleanly.  Send SIGTERMs to all
-        # the child processes and wait for them all to exit.
-        for pid in kids:
+                self._kids[newpid] = (qrname, slice, count, restarts)
+
+    def cleanup(self):
+        """Ensure that all children have exited."""
+        log = logging.getLogger('mailman.qrunner')
+        # Send SIGTERMs to all the child processes and wait for them all to
+        # exit.
+        for pid in self._kids:
             try:
                 os.kill(pid, signal.SIGTERM)
             except OSError, error:
@@ -350,10 +367,10 @@ qrunner %s reached maximum restart limit of %d, not restarting.""",
                     # The child has already exited.
                     log.info('ESRCH on pid: %d', pid)
         # Wait for all the children to go away.
-        while kids:
+        while self._kids:
             try:
                 pid, status = os.wait()
-                del kids[pid]
+                del self._kids[pid]
             except OSError, e:
                 if e.errno == errno.ECHILD:
                     break
@@ -370,9 +387,6 @@ def main():
     parser = parseargs()
     initialize(parser.options.config)
 
-    # We can't grab the logger until after everything's been initialized.
-    log = logging.getLogger('mailman.qrunner')
-
     # Acquire the master lock, exiting if we can't acquire it.  We'll let the
     # caller handle any clean up or lock breaking.  No with statement here
     # because Lock's constructor doesn't support a timeout.
@@ -380,9 +394,13 @@ def main():
     try:
         with open(config.PIDFILE, 'w') as fp:
             print >> fp, os.getpid()
+        loop = Loop(lock, parser.options.restartable, parser.options.config)
+        loop.install_signal_handlers()
         try:
-            control_loop(lock)
+            loop.start_qrunners()
+            loop.loop()
         finally:
+            loop.cleanup()
             os.remove(config.PIDFILE)
     finally:
         lock.unlock()
@@ -390,7 +408,4 @@ def main():
 
 
 if __name__ == '__main__':
-    try:
-        main()
-    except KeyboardInterrupt:
-        pass
+    main()