test_fcntl.py revision cdaafe0f9eb82630de0c4083b6d76dbaea0db231 
1"""Test program for the fcntl C module.
2
3OS/2+EMX doesn't support the file locking operations.
4
5"""
6import os
7import struct
8import sys
9import unittest
10from test.test_support import (verbose, TESTFN, unlink, run_unittest,
11    import_module)
12
13# Skip test if no fnctl module.
14fcntl = import_module('fcntl')
15
16
17# TODO - Write tests for flock() and lockf().
18
19def get_lockdata():
20    if sys.platform.startswith('atheos'):
21        start_len = "qq"
22    else:
23        try:
24            os.O_LARGEFILE
25        except AttributeError:
26            start_len = "ll"
27        else:
28            start_len = "qq"
29
30    if (sys.platform.startswith(('netbsd', 'freebsd', 'openbsd', 'bsdos'))
31        or sys.platform == 'darwin'):
32        if struct.calcsize('l') == 8:
33            off_t = 'l'
34            pid_t = 'i'
35        else:
36            off_t = 'lxxxx'
37            pid_t = 'l'
38        lockdata = struct.pack(off_t + off_t + pid_t + 'hh', 0, 0, 0,
39                               fcntl.F_WRLCK, 0)
40    elif sys.platform in ['aix3', 'aix4', 'hp-uxB', 'unixware7']:
41        lockdata = struct.pack('hhlllii', fcntl.F_WRLCK, 0, 0, 0, 0, 0, 0)
42    elif sys.platform in ['os2emx']:
43        lockdata = None
44    else:
45        lockdata = struct.pack('hh'+start_len+'hh', fcntl.F_WRLCK, 0, 0, 0, 0, 0)
46    if lockdata:
47        if verbose:
48            print 'struct.pack: ', repr(lockdata)
49    return lockdata
50
51lockdata = get_lockdata()
52
53
54class TestFcntl(unittest.TestCase):
55
56    def setUp(self):
57        self.f = None
58
59    def tearDown(self):
60        if self.f and not self.f.closed:
61            self.f.close()
62        unlink(TESTFN)
63
64    def test_fcntl_fileno(self):
65        # the example from the library docs
66        self.f = open(TESTFN, 'w')
67        rv = fcntl.fcntl(self.f.fileno(), fcntl.F_SETFL, os.O_NONBLOCK)
68        if verbose:
69            print 'Status from fcntl with O_NONBLOCK: ', rv
70        if sys.platform not in ['os2emx']:
71            rv = fcntl.fcntl(self.f.fileno(), fcntl.F_SETLKW, lockdata)
72            if verbose:
73                print 'String from fcntl with F_SETLKW: ', repr(rv)
74        self.f.close()
75
76    def test_fcntl_file_descriptor(self):
77        # again, but pass the file rather than numeric descriptor
78        self.f = open(TESTFN, 'w')
79        rv = fcntl.fcntl(self.f, fcntl.F_SETFL, os.O_NONBLOCK)
80        if sys.platform not in ['os2emx']:
81            rv = fcntl.fcntl(self.f, fcntl.F_SETLKW, lockdata)
82        self.f.close()
83
84    def test_fcntl_64_bit(self):
85        # Issue #1309352: fcntl shouldn't fail when the third arg fits in a
86        # C 'long' but not in a C 'int'.
87        try:
88            cmd = fcntl.F_NOTIFY
89            # This flag is larger than 2**31 in 64-bit builds
90            flags = fcntl.DN_MULTISHOT
91        except AttributeError:
92            self.skipTest("F_NOTIFY or DN_MULTISHOT unavailable")
93        fd = os.open(os.path.dirname(os.path.abspath(TESTFN)), os.O_RDONLY)
94        try:
95            fcntl.fcntl(fd, cmd, flags)
96        finally:
97            os.close(fd)
98
99
100def test_main():
101    run_unittest(TestFcntl)
102
103if __name__ == '__main__':
104    test_main()
105