/Lib/test/test_resource.py

  1import unittest
  2from test import test_support
  3
  4import resource
  5import time
  6
  7# This test is checking a few specific problem spots with the resource module.
  8
  9class ResourceTest(unittest.TestCase):
 10
 11    def test_args(self):
 12        self.assertRaises(TypeError, resource.getrlimit)
 13        self.assertRaises(TypeError, resource.getrlimit, 42, 42)
 14        self.assertRaises(TypeError, resource.setrlimit)
 15        self.assertRaises(TypeError, resource.setrlimit, 42, 42, 42)
 16
 17    def test_fsize_ismax(self):
 18        try:
 19            (cur, max) = resource.getrlimit(resource.RLIMIT_FSIZE)
 20        except AttributeError:
 21            pass
 22        else:
 23            # RLIMIT_FSIZE should be RLIM_INFINITY, which will be a really big
 24            # number on a platform with large file support.  On these platforms,
 25            # we need to test that the get/setrlimit functions properly convert
 26            # the number to a C long long and that the conversion doesn't raise
 27            # an error.
 28            self.assertEqual(resource.RLIM_INFINITY, max)
 29            resource.setrlimit(resource.RLIMIT_FSIZE, (cur, max))
 30
 31    def test_fsize_enforced(self):
 32        try:
 33            (cur, max) = resource.getrlimit(resource.RLIMIT_FSIZE)
 34        except AttributeError:
 35            pass
 36        else:
 37            # Check to see what happens when the RLIMIT_FSIZE is small.  Some
 38            # versions of Python were terminated by an uncaught SIGXFSZ, but
 39            # pythonrun.c has been fixed to ignore that exception.  If so, the
 40            # write() should return EFBIG when the limit is exceeded.
 41
 42            # At least one platform has an unlimited RLIMIT_FSIZE and attempts
 43            # to change it raise ValueError instead.
 44            try:
 45                try:
 46                    resource.setrlimit(resource.RLIMIT_FSIZE, (1024, max))
 47                    limit_set = True
 48                except ValueError:
 49                    limit_set = False
 50                f = open(test_support.TESTFN, "wb")
 51                try:
 52                    f.write("X" * 1024)
 53                    try:
 54                        f.write("Y")
 55                        f.flush()
 56                        # On some systems (e.g., Ubuntu on hppa) the flush()
 57                        # doesn't always cause the exception, but the close()
 58                        # does eventually.  Try flushing several times in
 59                        # an attempt to ensure the file is really synced and
 60                        # the exception raised.
 61                        for i in range(5):
 62                            time.sleep(.1)
 63                            f.flush()
 64                    except IOError:
 65                        if not limit_set:
 66                            raise
 67                    if limit_set:
 68                        # Close will attempt to flush the byte we wrote
 69                        # Restore limit first to avoid getting a spurious error
 70                        resource.setrlimit(resource.RLIMIT_FSIZE, (cur, max))
 71                finally:
 72                    f.close()
 73            finally:
 74                if limit_set:
 75                    resource.setrlimit(resource.RLIMIT_FSIZE, (cur, max))
 76                test_support.unlink(test_support.TESTFN)
 77
 78    def test_fsize_toobig(self):
 79        # Be sure that setrlimit is checking for really large values
 80        too_big = 10L**50
 81        try:
 82            (cur, max) = resource.getrlimit(resource.RLIMIT_FSIZE)
 83        except AttributeError:
 84            pass
 85        else:
 86            try:
 87                resource.setrlimit(resource.RLIMIT_FSIZE, (too_big, max))
 88            except (OverflowError, ValueError):
 89                pass
 90            try:
 91                resource.setrlimit(resource.RLIMIT_FSIZE, (max, too_big))
 92            except (OverflowError, ValueError):
 93                pass
 94
 95    def test_getrusage(self):
 96        self.assertRaises(TypeError, resource.getrusage)
 97        self.assertRaises(TypeError, resource.getrusage, 42, 42)
 98        usageself = resource.getrusage(resource.RUSAGE_SELF)
 99        usagechildren = resource.getrusage(resource.RUSAGE_CHILDREN)
100        # May not be available on all systems.
101        try:
102            usageboth = resource.getrusage(resource.RUSAGE_BOTH)
103        except (ValueError, AttributeError):
104            pass
105
106def test_main(verbose=None):
107    test_support.run_unittest(ResourceTest)
108
109if __name__ == "__main__":
110    test_main()