Lib/test/test_signal.py

   1 # Test the signal module
   2 from test.test_support import verbose, TestSkipped, TestFailed
   3 import signal
   4 import os, sys, time
   5
   6 if sys.platform[:3] in ('win', 'os2') or sys.platform=='riscos':
   7     raise TestSkipped, "Can't test signal on %s" % sys.platform
   8
   9 if verbose:
  10     x = '-x'
  11 else:
  12     x = '+x'
  13 pid = os.getpid()
  14
  15 # Shell script that will send us asynchronous signals
  16 script = """
  17  (
  18         set %(x)s
  19         sleep 2
  20         kill -5 %(pid)d
  21         sleep 2
  22         kill -2 %(pid)d
  23         sleep 2
  24         kill -3 %(pid)d
  25  ) &
  26 """ % vars()
  27
  28 def handlerA(*args):
  29     if verbose:
  30         print "handlerA", args
  31
  32 HandlerBCalled = "HandlerBCalled"       # Exception
  33
  34 def handlerB(*args):
  35     if verbose:
  36         print "handlerB", args
  37     raise HandlerBCalled, args
  38
  39 signal.alarm(20)                        # Entire test lasts at most 20 sec.
  40 signal.signal(5, handlerA)
  41 signal.signal(2, handlerB)
  42 signal.signal(3, signal.SIG_IGN)
  43 signal.signal(signal.SIGALRM, signal.default_int_handler)
  44
  45 os.system(script)
  46
  47 print "starting pause() loop..."
  48
  49 try:
  50     while 1:
  51         if verbose:
  52             print "call pause()..."
  53         try:
  54             signal.pause()
  55             if verbose:
  56                 print "pause() returned"
  57         except HandlerBCalled:
  58             if verbose:
  59                 print "HandlerBCalled exception caught"
  60             else:
  61                 pass
  62
  63 except KeyboardInterrupt:
  64     if verbose:
  65         print "KeyboardInterrupt (assume the alarm() went off)"
  66
  67
  68 if hasattr(signal, "sigprocmask"):
  69     class HupDelivered(Exception):
  70         pass
  71     def hup(signum, frame):
  72         raise HupDelivered
  73     def hup2(signum, frame):
  74         signal.signal(signal.SIGHUP, hup)
  75         return
  76     signal.signal(signal.SIGHUP, hup)
  77
  78     if verbose:
  79         print "blocking SIGHUP"
  80
  81     defaultmask = signal.sigprocmask(signal.SIG_BLOCK, [signal.SIGHUP])
  82
  83     if verbose:
  84         print "sending SIGHUP"
  85
  86     try:
  87         os.kill(pid, signal.SIGHUP)
  88     except HupDelivered:
  89         raise TestFailed, "HUP not blocked"
  90
  91     if signal.SIGHUP not in signal.sigpending():
  92         raise TestFailed, "HUP not pending"
  93
  94     if verbose:
  95         print "unblocking SIGHUP"
  96
  97     try:
  98         signal.sigprocmask(signal.SIG_UNBLOCK, [signal.SIGHUP])
  99     except HupDelivered:
 100         pass
 101     else:
 102         raise TestFailed, "HUP not delivered"
 103
 104     if verbose:
 105         print "testing sigsuspend"
 106
 107     signal.sigprocmask(signal.SIG_BLOCK, [signal.SIGHUP])
 108     signal.signal(signal.SIGHUP, hup2)
 109
 110     if not os.fork():
 111         time.sleep(2)
 112         os.kill(pid, signal.SIGHUP)
 113         time.sleep(2)
 114         os.kill(pid, signal.SIGHUP)
 115         os._exit(0)
 116     else:
 117         try:
 118             signal.sigsuspend(defaultmask)
 119         except:
 120             raise TestFailed, "sigsuspend erroneously raised"
 121
 122         try:
 123             signal.sigsuspend(defaultmask)
 124         except HupDelivered:
 125             pass
 126         else:
 127             raise TestFailed, "sigsupsend didn't raise"