summaryrefslogtreecommitdiff
path: root/Lib/test/test_fcntl.py
blob: 9ab68c67241f464e0cf115389407ea48e616b378 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
"""Test program for the fcntl C module.
"""
import platform
import os
import struct
import sys
import unittest
from multiprocessing import Process
from test.support import (verbose, TESTFN, unlink, run_unittest, import_module,
                          cpython_only)

# Skip test if no fcntl module.
fcntl = import_module('fcntl')



def get_lockdata():
    try:
        os.O_LARGEFILE
    except AttributeError:
        start_len = "ll"
    else:
        start_len = "qq"

    if (sys.platform.startswith(('netbsd', 'freebsd', 'openbsd'))
        or sys.platform == 'darwin'):
        if struct.calcsize('l') == 8:
            off_t = 'l'
            pid_t = 'i'
        else:
            off_t = 'lxxxx'
            pid_t = 'l'
        lockdata = struct.pack(off_t + off_t + pid_t + 'hh', 0, 0, 0,
                               fcntl.F_WRLCK, 0)
    elif sys.platform.startswith('gnukfreebsd'):
        lockdata = struct.pack('qqihhi', 0, 0, 0, fcntl.F_WRLCK, 0, 0)
    elif sys.platform in ['hp-uxB', 'unixware7']:
        lockdata = struct.pack('hhlllii', fcntl.F_WRLCK, 0, 0, 0, 0, 0, 0)
    else:
        lockdata = struct.pack('hh'+start_len+'hh', fcntl.F_WRLCK, 0, 0, 0, 0, 0)
    if lockdata:
        if verbose:
            print('struct.pack: ', repr(lockdata))
    return lockdata

lockdata = get_lockdata()

class BadFile:
    def __init__(self, fn):
        self.fn = fn
    def fileno(self):
        return self.fn

def try_lockf_on_other_process_fail(fname, cmd):
    f = open(fname, 'wb+')
    try:
        fcntl.lockf(f, cmd)
    except BlockingIOError:
        pass
    finally:
        f.close()

def try_lockf_on_other_process(fname, cmd):
    f = open(fname, 'wb+')
    fcntl.lockf(f, cmd)
    fcntl.lockf(f, fcntl.LOCK_UN)
    f.close()

class TestFcntl(unittest.TestCase):

    def setUp(self):
        self.f = None

    def tearDown(self):
        if self.f and not self.f.closed:
            self.f.close()
        unlink(TESTFN)

    def test_fcntl_fileno(self):
        # the example from the library docs
        self.f = open(TESTFN, 'wb')
        rv = fcntl.fcntl(self.f.fileno(), fcntl.F_SETFL, os.O_NONBLOCK)
        if verbose:
            print('Status from fcntl with O_NONBLOCK: ', rv)
        rv = fcntl.fcntl(self.f.fileno(), fcntl.F_SETLKW, lockdata)
        if verbose:
            print('String from fcntl with F_SETLKW: ', repr(rv))
        self.f.close()

    def test_fcntl_file_descriptor(self):
        # again, but pass the file rather than numeric descriptor
        self.f = open(TESTFN, 'wb')
        rv = fcntl.fcntl(self.f, fcntl.F_SETFL, os.O_NONBLOCK)
        if verbose:
            print('Status from fcntl with O_NONBLOCK: ', rv)
        rv = fcntl.fcntl(self.f, fcntl.F_SETLKW, lockdata)
        if verbose:
            print('String from fcntl with F_SETLKW: ', repr(rv))
        self.f.close()

    def test_fcntl_bad_file(self):
        with self.assertRaises(ValueError):
            fcntl.fcntl(-1, fcntl.F_SETFL, os.O_NONBLOCK)
        with self.assertRaises(ValueError):
            fcntl.fcntl(BadFile(-1), fcntl.F_SETFL, os.O_NONBLOCK)
        with self.assertRaises(TypeError):
            fcntl.fcntl('spam', fcntl.F_SETFL, os.O_NONBLOCK)
        with self.assertRaises(TypeError):
            fcntl.fcntl(BadFile('spam'), fcntl.F_SETFL, os.O_NONBLOCK)

    @cpython_only
    def test_fcntl_bad_file_overflow(self):
        from _testcapi import INT_MAX, INT_MIN
        # Issue 15989
        with self.assertRaises(OverflowError):
            fcntl.fcntl(INT_MAX + 1, fcntl.F_SETFL, os.O_NONBLOCK)
        with self.assertRaises(OverflowError):
            fcntl.fcntl(BadFile(INT_MAX + 1), fcntl.F_SETFL, os.O_NONBLOCK)
        with self.assertRaises(OverflowError):
            fcntl.fcntl(INT_MIN - 1, fcntl.F_SETFL, os.O_NONBLOCK)
        with self.assertRaises(OverflowError):
            fcntl.fcntl(BadFile(INT_MIN - 1), fcntl.F_SETFL, os.O_NONBLOCK)

    @unittest.skipIf(
        platform.machine().startswith('arm') and platform.system() == 'Linux',
        "ARM Linux returns EINVAL for F_NOTIFY DN_MULTISHOT")
    def test_fcntl_64_bit(self):
        # Issue #1309352: fcntl shouldn't fail when the third arg fits in a
        # C 'long' but not in a C 'int'.
        try:
            cmd = fcntl.F_NOTIFY
            # This flag is larger than 2**31 in 64-bit builds
            flags = fcntl.DN_MULTISHOT
        except AttributeError:
            self.skipTest("F_NOTIFY or DN_MULTISHOT unavailable")
        fd = os.open(os.path.dirname(os.path.abspath(TESTFN)), os.O_RDONLY)
        try:
            fcntl.fcntl(fd, cmd, flags)
        finally:
            os.close(fd)

    def test_flock(self):
        # Solaris needs readable file for shared lock
        self.f = open(TESTFN, 'wb+')
        fileno = self.f.fileno()
        fcntl.flock(fileno, fcntl.LOCK_SH)
        fcntl.flock(fileno, fcntl.LOCK_UN)
        fcntl.flock(self.f, fcntl.LOCK_SH | fcntl.LOCK_NB)
        fcntl.flock(self.f, fcntl.LOCK_UN)
        fcntl.flock(fileno, fcntl.LOCK_EX)
        fcntl.flock(fileno, fcntl.LOCK_UN)

        self.assertRaises(ValueError, fcntl.flock, -1, fcntl.LOCK_SH)
        self.assertRaises(TypeError, fcntl.flock, 'spam', fcntl.LOCK_SH)

    @unittest.skipIf(platform.system() == "AIX", "AIX returns PermissionError")
    def test_lockf_exclusive(self):
        self.f = open(TESTFN, 'wb+')
        cmd = fcntl.LOCK_EX | fcntl.LOCK_NB
        fcntl.lockf(self.f, cmd)
        p = Process(target=try_lockf_on_other_process_fail, args=(TESTFN, cmd))
        p.start()
        p.join()
        fcntl.lockf(self.f, fcntl.LOCK_UN)
        self.assertEqual(p.exitcode, 0)

    @unittest.skipIf(platform.system() == "AIX", "AIX returns PermissionError")
    def test_lockf_share(self):
        self.f = open(TESTFN, 'wb+')
        cmd = fcntl.LOCK_SH | fcntl.LOCK_NB
        fcntl.lockf(self.f, cmd)
        p = Process(target=try_lockf_on_other_process, args=(TESTFN, cmd))
        p.start()
        p.join()
        fcntl.lockf(self.f, fcntl.LOCK_UN)
        self.assertEqual(p.exitcode, 0)

    @cpython_only
    def test_flock_overflow(self):
        import _testcapi
        self.assertRaises(OverflowError, fcntl.flock, _testcapi.INT_MAX+1,
                          fcntl.LOCK_SH)

    @unittest.skipIf(sys.platform != 'darwin', "F_GETPATH is only available on macos")
    def test_fcntl_f_getpath(self):
        self.f = open(TESTFN, 'wb')
        expected = os.path.abspath(TESTFN).encode('utf-8')
        res = fcntl.fcntl(self.f.fileno(), fcntl.F_GETPATH, bytes(len(expected)))
        self.assertEqual(expected, res)

def test_main():
    run_unittest(TestFcntl)

if __name__ == '__main__':
    test_main()