Source Code for Module buildbot.util.misc

 1  # This file is part of Buildbot.  Buildbot is free software: you can 
 2  # redistribute it and/or modify it under the terms of the GNU General Public 
 3  # License as published by the Free Software Foundation, version 2. 
 4  # 
 5  # This program is distributed in the hope that it will be useful, but WITHOUT 
 6  # ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 
 7  # FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more 
 8  # details. 
 9  # 
10  # You should have received a copy of the GNU General Public License along with 
11  # this program; if not, write to the Free Software Foundation, Inc., 51 
12  # Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 
13  # 
14  # Copyright Buildbot Team Members 
15   
16  """ 
17  Miscellaneous utilities; these should be imported from C{buildbot.util}, not 
18  directly from this module. 
19  """ 
20   
21  from twisted.python import log 
22  from twisted.internet import defer 
23   
24 -def deferredLocked(lock_or_attr): 
25      def decorator(fn): 
26          def wrapper(*args, **kwargs): 
27              lock = lock_or_attr 
28              if isinstance(lock, basestring): 
29                  lock = getattr(args[0], lock) 
30              d = lock.acquire() 
31              d.addCallback(lambda _ : fn(*args, **kwargs)) 
32              def release(val): 
33                  lock.release() 
34                  return val 
35              d.addBoth(release) 
36              return d 
37          return wrapper 
38      return decorator 
39   
40 -class SerializedInvocation(object): 
41 -    def __init__(self, method): 
42          self.method = method 
43          self.running = False 
44          self.pending_deferreds = [] 
45   
46 -    def __call__(self): 
47          d = defer.Deferred() 
48          self.pending_deferreds.append(d) 
49          if not self.running: 
50              self.start() 
51          return d 
52   
53 -    def start(self): 
54          self.running = True 
55          invocation_deferreds = self.pending_deferreds 
56          self.pending_deferreds = [] 
57          d = self.method() 
58          d.addErrback(log.err, 'in invocation of %r' % (self.method,)) 
59   
60          def notify_callers(_): 
61              for d in invocation_deferreds: 
62                  d.callback(None) 
63          d.addCallback(notify_callers) 
64   
65          def next(_): 
66              self.running = False 
67              if self.pending_deferreds: 
68                  self.start() 
69              else: 
70                  self._quiet() 
71          d.addBoth(next) 
72   
73 -    def _quiet(self): # hook for tests 
74          pass 
75