summaryrefslogtreecommitdiffstats
path: root/Lib/test/libregrtest/refleak.py
blob: d9f72208cfda0e2de85c6d64e9aa410c4e92fe09 (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
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
import errno
import os
import re
import sys
import warnings
from inspect import isabstract
from test import support


try:
    MAXFD = os.sysconf("SC_OPEN_MAX")
except Exception:
    MAXFD = 256


def fd_count():
    """Count the number of open file descriptors"""
    if sys.platform.startswith(('linux', 'freebsd')):
        try:
            names = os.listdir("/proc/self/fd")
            return len(names)
        except FileNotFoundError:
            pass

    count = 0
    for fd in range(MAXFD):
        try:
            # Prefer dup() over fstat(). fstat() can require input/output
            # whereas dup() doesn't.
            fd2 = os.dup(fd)
        except OSError as e:
            if e.errno != errno.EBADF:
                raise
        else:
            os.close(fd2)
            count += 1
    return count


def dash_R(the_module, test, indirect_test, huntrleaks):
    """Run a test multiple times, looking for reference leaks.

    Returns:
        False if the test didn't leak references; True if we detected refleaks.
    """
    # This code is hackish and inelegant, but it seems to do the job.
    import copyreg
    import collections.abc

    if not hasattr(sys, 'gettotalrefcount'):
        raise Exception("Tracking reference leaks requires a debug build "
                        "of Python")

    # Save current values for dash_R_cleanup() to restore.
    fs = warnings.filters[:]
    ps = copyreg.dispatch_table.copy()
    pic = sys.path_importer_cache.copy()
    try:
        import zipimport
    except ImportError:
        zdc = None # Run unmodified on platforms without zipimport support
    else:
        zdc = zipimport._zip_directory_cache.copy()
    abcs = {}
    for abc in [getattr(collections.abc, a) for a in collections.abc.__all__]:
        if not isabstract(abc):
            continue
        for obj in abc.__subclasses__() + [abc]:
            abcs[obj] = obj._abc_registry.copy()

    nwarmup, ntracked, fname = huntrleaks
    fname = os.path.join(support.SAVEDCWD, fname)
    repcount = nwarmup + ntracked
    rc_deltas = [0] * repcount
    alloc_deltas = [0] * repcount
    fd_deltas = [0] * repcount

    print("beginning", repcount, "repetitions", file=sys.stderr)
    print(("1234567890"*(repcount//10 + 1))[:repcount], file=sys.stderr,
          flush=True)
    # initialize variables to make pyflakes quiet
    rc_before = alloc_before = fd_before = 0
    for i in range(repcount):
        indirect_test()
        alloc_after, rc_after, fd_after = dash_R_cleanup(fs, ps, pic, zdc,
                                                         abcs)
        print('.', end='', file=sys.stderr, flush=True)
        if i >= nwarmup:
            rc_deltas[i] = rc_after - rc_before
            alloc_deltas[i] = alloc_after - alloc_before
            fd_deltas[i] = fd_after - fd_before
        alloc_before = alloc_after
        rc_before = rc_after
        fd_before = fd_after
    print(file=sys.stderr)
    # These checkers return False on success, True on failure
    def check_rc_deltas(deltas):
        return any(deltas)
    def check_alloc_deltas(deltas):
        # At least 1/3rd of 0s
        if 3 * deltas.count(0) < len(deltas):
            return True
        # Nothing else than 1s, 0s and -1s
        if not set(deltas) <= {1,0,-1}:
            return True
        return False
    failed = False
    for deltas, item_name, checker in [
        (rc_deltas, 'references', check_rc_deltas),
        (alloc_deltas, 'memory blocks', check_alloc_deltas),
        (fd_deltas, 'file descriptors', check_rc_deltas)]:
        if checker(deltas):
            msg = '%s leaked %s %s, sum=%s' % (
                test, deltas[nwarmup:], item_name, sum(deltas))
            print(msg, file=sys.stderr, flush=True)
            with open(fname, "a") as refrep:
                print(msg, file=refrep)
                refrep.flush()
            failed = True
    return failed


def dash_R_cleanup(fs, ps, pic, zdc, abcs):
    import gc, copyreg
    import collections.abc
    from weakref import WeakSet

    # Restore some original values.
    warnings.filters[:] = fs
    copyreg.dispatch_table.clear()
    copyreg.dispatch_table.update(ps)
    sys.path_importer_cache.clear()
    sys.path_importer_cache.update(pic)
    try:
        import zipimport
    except ImportError:
        pass # Run unmodified on platforms without zipimport support
    else:
        zipimport._zip_directory_cache.clear()
        zipimport._zip_directory_cache.update(zdc)

    # clear type cache
    sys._clear_type_cache()

    # Clear ABC registries, restoring previously saved ABC registries.
    for abc in [getattr(collections.abc, a) for a in collections.abc.__all__]:
        if not isabstract(abc):
            continue
        for obj in abc.__subclasses__() + [abc]:
            obj._abc_registry = abcs.get(obj, WeakSet()).copy()
            obj._abc_cache.clear()
            obj._abc_negative_cache.clear()

    clear_caches()

    # Collect cyclic trash and read memory statistics immediately after.
    func1 = sys.getallocatedblocks
    func2 = sys.gettotalrefcount
    gc.collect()
    return func1(), func2(), fd_count()


def clear_caches():
    import gc

    # Clear the warnings registry, so they can be displayed again
    for mod in sys.modules.values():
        if hasattr(mod, '__warningregistry__'):
            del mod.__warningregistry__

    # Flush standard output, so that buffered data is sent to the OS and
    # associated Python objects are reclaimed.
    for stream in (sys.stdout, sys.stderr, sys.__stdout__, sys.__stderr__):
        if stream is not None:
            stream.flush()

    # Clear assorted module caches.
    # Don't worry about resetting the cache if the module is not loaded
    try:
        distutils_dir_util = sys.modules['distutils.dir_util']
    except KeyError:
        pass
    else:
        distutils_dir_util._path_created.clear()
    re.purge()

    try:
        _strptime = sys.modules['_strptime']
    except KeyError:
        pass
    else:
        _strptime._regex_cache.clear()

    try:
        urllib_parse = sys.modules['urllib.parse']
    except KeyError:
        pass
    else:
        urllib_parse.clear_cache()

    try:
        urllib_request = sys.modules['urllib.request']
    except KeyError:
        pass
    else:
        urllib_request.urlcleanup()

    try:
        linecache = sys.modules['linecache']
    except KeyError:
        pass
    else:
        linecache.clearcache()

    try:
        mimetypes = sys.modules['mimetypes']
    except KeyError:
        pass
    else:
        mimetypes._default_mime_types()

    try:
        filecmp = sys.modules['filecmp']
    except KeyError:
        pass
    else:
        filecmp._cache.clear()

    try:
        struct = sys.modules['struct']
    except KeyError:
        pass
    else:
        struct._clearcache()

    try:
        doctest = sys.modules['doctest']
    except KeyError:
        pass
    else:
        doctest.master = None

    try:
        ctypes = sys.modules['ctypes']
    except KeyError:
        pass
    else:
        ctypes._reset_cache()

    try:
        typing = sys.modules['typing']
    except KeyError:
        pass
    else:
        for f in typing._cleanups:
            f()

    gc.collect()


def warm_caches():
    # char cache
    s = bytes(range(256))
    for i in range(256):
        s[i:i+1]
    # unicode cache
    [chr(i) for i in range(256)]
    # int cache
    list(range(-5, 257))