Lib/test/test_poll.py

   1 # Test case for the os.poll() function
   2
   3 import sys, os, select, random
   4 from test.test_support import verify, verbose, TestSkipped, TESTFN
   5
   6 try:
   7     select.poll
   8 except AttributeError:
   9     raise TestSkipped, "select.poll not defined -- skipping test_poll"
  10
  11
  12 def find_ready_matching(ready, flag):
  13     match = []
  14     for fd, mode in ready:
  15         if mode & flag:
  16             match.append(fd)
  17     return match
  18
  19 def test_poll1():
  20     """Basic functional test of poll object
  21
  22     Create a bunch of pipe and test that poll works with them.
  23     """
  24     print 'Running poll test 1'
  25     p = select.poll()
  26
  27     NUM_PIPES = 12
  28     MSG = " This is a test."
  29     MSG_LEN = len(MSG)
  30     readers = []
  31     writers = []
  32     r2w = {}
  33     w2r = {}
  34
  35     for i in range(NUM_PIPES):
  36         rd, wr = os.pipe()
  37         p.register(rd, select.POLLIN)
  38         p.register(wr, select.POLLOUT)
  39         readers.append(rd)
  40         writers.append(wr)
  41         r2w[rd] = wr
  42         w2r[wr] = rd
  43
  44     while writers:
  45         ready = p.poll()
  46         ready_writers = find_ready_matching(ready, select.POLLOUT)
  47         if not ready_writers:
  48             raise RuntimeError, "no pipes ready for writing"
  49         wr = random.choice(ready_writers)
  50         os.write(wr, MSG)
  51
  52         ready = p.poll()
  53         ready_readers = find_ready_matching(ready, select.POLLIN)
  54         if not ready_readers:
  55             raise RuntimeError, "no pipes ready for reading"
  56         rd = random.choice(ready_readers)
  57         buf = os.read(rd, MSG_LEN)
  58         verify(len(buf) == MSG_LEN)
  59         print buf
  60         os.close(r2w[rd]) ; os.close( rd )
  61         p.unregister( r2w[rd] )
  62         p.unregister( rd )
  63         writers.remove(r2w[rd])
  64
  65     poll_unit_tests()
  66     print 'Poll test 1 complete'
  67
  68 def poll_unit_tests():
  69     # returns NVAL for invalid file descriptor
  70     FD = 42
  71     try:
  72         os.close(FD)
  73     except OSError:
  74         pass
  75     p = select.poll()
  76     p.register(FD)
  77     r = p.poll()
  78     verify(r[0] == (FD, select.POLLNVAL))
  79
  80     f = open(TESTFN, 'w')
  81     fd = f.fileno()
  82     p = select.poll()
  83     p.register(f)
  84     r = p.poll()
  85     verify(r[0][0] == fd)
  86     f.close()
  87     r = p.poll()
  88     verify(r[0] == (fd, select.POLLNVAL))
  89     os.unlink(TESTFN)
  90
  91     # type error for invalid arguments
  92     p = select.poll()
  93     try:
  94         p.register(p)
  95     except TypeError:
  96         pass
  97     else:
  98         print "Bogus register call did not raise TypeError"
  99     try:
 100         p.unregister(p)
 101     except TypeError:
 102         pass
 103     else:
 104         print "Bogus unregister call did not raise TypeError"
 105
 106     # can't unregister non-existent object
 107     p = select.poll()
 108     try:
 109         p.unregister(3)
 110     except KeyError:
 111         pass
 112     else:
 113         print "Bogus unregister call did not raise KeyError"
 114
 115     # Test error cases
 116     pollster = select.poll()
 117     class Nope:
 118         pass
 119
 120     class Almost:
 121         def fileno(self):
 122             return 'fileno'
 123
 124     try:
 125         pollster.register( Nope(), 0 )
 126     except TypeError: pass
 127     else: print 'expected TypeError exception, not raised'
 128
 129     try:
 130         pollster.register( Almost(), 0 )
 131     except TypeError: pass
 132     else: print 'expected TypeError exception, not raised'
 133
 134
 135 # Another test case for poll().  This is copied from the test case for
 136 # select(), modified to use poll() instead.
 137
 138 def test_poll2():
 139     print 'Running poll test 2'
 140     cmd = 'for i in 0 1 2 3 4 5 6 7 8 9; do echo testing...; sleep 1; done'
 141     p = os.popen(cmd, 'r')
 142     pollster = select.poll()
 143     pollster.register( p, select.POLLIN )
 144     for tout in (0, 1000, 2000, 4000, 8000, 16000) + (-1,)*10:
 145         if verbose:
 146             print 'timeout =', tout
 147         fdlist = pollster.poll(tout)
 148         if (fdlist == []):
 149             continue
 150         fd, flags = fdlist[0]
 151         if flags & select.POLLHUP:
 152             line = p.readline()
 153             if line != "":
 154                 print 'error: pipe seems to be closed, but still returns data'
 155             continue
 156
 157         elif flags & select.POLLIN:
 158             line = p.readline()
 159             if verbose:
 160                 print repr(line)
 161             if not line:
 162                 if verbose:
 163                     print 'EOF'
 164                 break
 165             continue
 166         else:
 167             print 'Unexpected return value from select.poll:', fdlist
 168     p.close()
 169     print 'Poll test 2 complete'
 170
 171 def test_poll3():
 172     # test int overflow
 173     print 'Running poll test 3'
 174     pollster = select.poll()
 175     pollster.register(1)
 176
 177     try:
 178         pollster.poll(1L << 64)
 179     except OverflowError:
 180         pass
 181     else:
 182         print 'Expected OverflowError with excessive timeout'
 183
 184     x = 2 + 3
 185     if x != 5:
 186         print 'Overflow must have occurred'
 187     print 'Poll test 3 complete'
 188
 189
 190 test_poll1()
 191 test_poll2()
 192 test_poll3()