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
|
"""Drop-in replacement for the thread module.
Meant to be used as a brain-dead substitute so that threaded code does
not need to be rewritten for when the thread module is not present.
Suggested usage is::
try:
import thread
except ImportError:
import dummy_thread as thread
"""
__author__ = "Brett Cannon"
__email__ = "brett@python.org"
# Exports only things specified by thread documentation
# (skipping obsolete synonyms allocate(), start_new(), exit_thread())
__all__ = ['error', 'start_new_thread', 'exit', 'get_ident', 'allocate_lock',
'interrupt_main', 'LockType']
import traceback as _traceback
class error(Exception):
"""Dummy implementation of thread.error."""
def __init__(self, *args):
self.args = args
def start_new_thread(function, args, kwargs={}):
"""Dummy implementation of thread.start_new_thread().
Compatibility is maintained by making sure that ``args`` is a
tuple and ``kwargs`` is a dictionary. If an exception is raised
and it is SystemExit (which can be done by thread.exit()) it is
caught and nothing is done; all other exceptions are printed out
by using traceback.print_exc().
If the executed function calls interrupt_main the KeyboardInterrupt will be
raised when the function returns.
"""
if type(args) != type(tuple()):
raise TypeError("2nd arg must be a tuple")
if type(kwargs) != type(dict()):
raise TypeError("3rd arg must be a dict")
try:
function(*args, **kwargs)
except SystemExit:
pass
except:
_traceback.print_exc()
if _interrupt:
global _interrupt
_interrupt = False
raise KeyboardInterrupt
def exit():
"""Dummy implementation of thread.exit()."""
raise SystemExit
def get_ident():
"""Dummy implementation of thread.get_ident().
Since this module should only be used when threadmodule is not
available, it is safe to assume that the current process is the
only thread. Thus a constant can be safely returned.
"""
return -1
def allocate_lock():
"""Dummy implementation of thread.allocate_lock()."""
return LockType()
class LockType(object):
"""Class implementing dummy implementation of thread.LockType.
Compatibility is maintained by maintaining self.locked_status
which is a boolean that stores the state of the lock. Pickling of
the lock, though, should not be done since if the thread module is
then used with an unpickled ``lock()`` from here problems could
occur from this class not having atomic methods.
"""
def __init__(self):
self.locked_status = False
def acquire(self, waitflag=None):
"""Dummy implementation of acquire().
For blocking calls, self.locked_status is automatically set to
True and returned appropriately based on value of
``waitflag``. If it is non-blocking, then the value is
actually checked and not set if it is already acquired. This
is all done so that threading.Condition's assert statements
aren't triggered and throw a little fit.
"""
if waitflag is None:
self.locked_status = True
return None
elif not waitflag:
if not self.locked_status:
self.locked_status = True
return True
else:
return False
else:
self.locked_status = True
return True
def release(self):
"""Release the dummy lock."""
# XXX Perhaps shouldn't actually bother to test? Could lead
# to problems for complex, threaded code.
if not self.locked_status:
raise error
self.locked_status = False
return True
def locked(self):
return self.locked_status
_interrupt = False
def interrupt_main():
"""Set _interrupt flag to True to have start_new_thread raise
KeyboardInterrupt upon exiting."""
global _interrupt
_interrupt = True
|
