|
1 """Thread module emulating a subset of Java's threading model.""" |
|
2 |
|
3 import sys as _sys |
|
4 |
|
5 try: |
|
6 import thread |
|
7 except ImportError: |
|
8 del _sys.modules[__name__] |
|
9 raise |
|
10 |
|
11 import warnings |
|
12 |
|
13 from functools import wraps |
|
14 from time import time as _time, sleep as _sleep |
|
15 from traceback import format_exc as _format_exc |
|
16 from collections import deque |
|
17 |
|
18 # Note regarding PEP 8 compliant aliases |
|
19 # This threading model was originally inspired by Java, and inherited |
|
20 # the convention of camelCase function and method names from that |
|
21 # language. While those names are not in any imminent danger of being |
|
22 # deprecated, starting with Python 2.6, the module now provides a |
|
23 # PEP 8 compliant alias for any such method name. |
|
24 # Using the new PEP 8 compliant names also facilitates substitution |
|
25 # with the multiprocessing module, which doesn't provide the old |
|
26 # Java inspired names. |
|
27 |
|
28 |
|
29 # Rename some stuff so "from threading import *" is safe |
|
30 __all__ = ['activeCount', 'active_count', 'Condition', 'currentThread', |
|
31 'current_thread', 'enumerate', 'Event', |
|
32 'Lock', 'RLock', 'Semaphore', 'BoundedSemaphore', 'Thread', |
|
33 'Timer', 'setprofile', 'settrace', 'local', 'stack_size'] |
|
34 |
|
35 _start_new_thread = thread.start_new_thread |
|
36 _allocate_lock = thread.allocate_lock |
|
37 _get_ident = thread.get_ident |
|
38 ThreadError = thread.error |
|
39 del thread |
|
40 |
|
41 |
|
42 # sys.exc_clear is used to work around the fact that except blocks |
|
43 # don't fully clear the exception until 3.0. |
|
44 warnings.filterwarnings('ignore', category=DeprecationWarning, |
|
45 module='threading', message='sys.exc_clear') |
|
46 |
|
47 # Debug support (adapted from ihooks.py). |
|
48 # All the major classes here derive from _Verbose. We force that to |
|
49 # be a new-style class so that all the major classes here are new-style. |
|
50 # This helps debugging (type(instance) is more revealing for instances |
|
51 # of new-style classes). |
|
52 |
|
53 _VERBOSE = False |
|
54 |
|
55 if __debug__: |
|
56 |
|
57 class _Verbose(object): |
|
58 |
|
59 def __init__(self, verbose=None): |
|
60 if verbose is None: |
|
61 verbose = _VERBOSE |
|
62 self.__verbose = verbose |
|
63 |
|
64 def _note(self, format, *args): |
|
65 if self.__verbose: |
|
66 format = format % args |
|
67 format = "%s: %s\n" % ( |
|
68 current_thread().name, format) |
|
69 _sys.stderr.write(format) |
|
70 |
|
71 else: |
|
72 # Disable this when using "python -O" |
|
73 class _Verbose(object): |
|
74 def __init__(self, verbose=None): |
|
75 pass |
|
76 def _note(self, *args): |
|
77 pass |
|
78 |
|
79 # Support for profile and trace hooks |
|
80 |
|
81 _profile_hook = None |
|
82 _trace_hook = None |
|
83 |
|
84 def setprofile(func): |
|
85 global _profile_hook |
|
86 _profile_hook = func |
|
87 |
|
88 def settrace(func): |
|
89 global _trace_hook |
|
90 _trace_hook = func |
|
91 |
|
92 # Synchronization classes |
|
93 |
|
94 Lock = _allocate_lock |
|
95 |
|
96 def RLock(*args, **kwargs): |
|
97 return _RLock(*args, **kwargs) |
|
98 |
|
99 class _RLock(_Verbose): |
|
100 |
|
101 def __init__(self, verbose=None): |
|
102 _Verbose.__init__(self, verbose) |
|
103 self.__block = _allocate_lock() |
|
104 self.__owner = None |
|
105 self.__count = 0 |
|
106 |
|
107 def __repr__(self): |
|
108 owner = self.__owner |
|
109 return "<%s(%s, %d)>" % ( |
|
110 self.__class__.__name__, |
|
111 owner and owner.name, |
|
112 self.__count) |
|
113 |
|
114 def acquire(self, blocking=1): |
|
115 me = current_thread() |
|
116 if self.__owner is me: |
|
117 self.__count = self.__count + 1 |
|
118 if __debug__: |
|
119 self._note("%s.acquire(%s): recursive success", self, blocking) |
|
120 return 1 |
|
121 rc = self.__block.acquire(blocking) |
|
122 if rc: |
|
123 self.__owner = me |
|
124 self.__count = 1 |
|
125 if __debug__: |
|
126 self._note("%s.acquire(%s): initial success", self, blocking) |
|
127 else: |
|
128 if __debug__: |
|
129 self._note("%s.acquire(%s): failure", self, blocking) |
|
130 return rc |
|
131 |
|
132 __enter__ = acquire |
|
133 |
|
134 def release(self): |
|
135 if self.__owner is not current_thread(): |
|
136 raise RuntimeError("cannot release un-aquired lock") |
|
137 self.__count = count = self.__count - 1 |
|
138 if not count: |
|
139 self.__owner = None |
|
140 self.__block.release() |
|
141 if __debug__: |
|
142 self._note("%s.release(): final release", self) |
|
143 else: |
|
144 if __debug__: |
|
145 self._note("%s.release(): non-final release", self) |
|
146 |
|
147 def __exit__(self, t, v, tb): |
|
148 self.release() |
|
149 |
|
150 # Internal methods used by condition variables |
|
151 |
|
152 def _acquire_restore(self, count_owner): |
|
153 count, owner = count_owner |
|
154 self.__block.acquire() |
|
155 self.__count = count |
|
156 self.__owner = owner |
|
157 if __debug__: |
|
158 self._note("%s._acquire_restore()", self) |
|
159 |
|
160 def _release_save(self): |
|
161 if __debug__: |
|
162 self._note("%s._release_save()", self) |
|
163 count = self.__count |
|
164 self.__count = 0 |
|
165 owner = self.__owner |
|
166 self.__owner = None |
|
167 self.__block.release() |
|
168 return (count, owner) |
|
169 |
|
170 def _is_owned(self): |
|
171 return self.__owner is current_thread() |
|
172 |
|
173 |
|
174 def Condition(*args, **kwargs): |
|
175 return _Condition(*args, **kwargs) |
|
176 |
|
177 class _Condition(_Verbose): |
|
178 |
|
179 def __init__(self, lock=None, verbose=None): |
|
180 _Verbose.__init__(self, verbose) |
|
181 if lock is None: |
|
182 lock = RLock() |
|
183 self.__lock = lock |
|
184 # Export the lock's acquire() and release() methods |
|
185 self.acquire = lock.acquire |
|
186 self.release = lock.release |
|
187 # If the lock defines _release_save() and/or _acquire_restore(), |
|
188 # these override the default implementations (which just call |
|
189 # release() and acquire() on the lock). Ditto for _is_owned(). |
|
190 try: |
|
191 self._release_save = lock._release_save |
|
192 except AttributeError: |
|
193 pass |
|
194 try: |
|
195 self._acquire_restore = lock._acquire_restore |
|
196 except AttributeError: |
|
197 pass |
|
198 try: |
|
199 self._is_owned = lock._is_owned |
|
200 except AttributeError: |
|
201 pass |
|
202 self.__waiters = [] |
|
203 |
|
204 def __enter__(self): |
|
205 return self.__lock.__enter__() |
|
206 |
|
207 def __exit__(self, *args): |
|
208 return self.__lock.__exit__(*args) |
|
209 |
|
210 def __repr__(self): |
|
211 return "<Condition(%s, %d)>" % (self.__lock, len(self.__waiters)) |
|
212 |
|
213 def _release_save(self): |
|
214 self.__lock.release() # No state to save |
|
215 |
|
216 def _acquire_restore(self, x): |
|
217 self.__lock.acquire() # Ignore saved state |
|
218 |
|
219 def _is_owned(self): |
|
220 # Return True if lock is owned by current_thread. |
|
221 # This method is called only if __lock doesn't have _is_owned(). |
|
222 if self.__lock.acquire(0): |
|
223 self.__lock.release() |
|
224 return False |
|
225 else: |
|
226 return True |
|
227 |
|
228 def wait(self, timeout=None): |
|
229 if not self._is_owned(): |
|
230 raise RuntimeError("cannot wait on un-aquired lock") |
|
231 waiter = _allocate_lock() |
|
232 waiter.acquire() |
|
233 self.__waiters.append(waiter) |
|
234 saved_state = self._release_save() |
|
235 try: # restore state no matter what (e.g., KeyboardInterrupt) |
|
236 if timeout is None: |
|
237 waiter.acquire() |
|
238 if __debug__: |
|
239 self._note("%s.wait(): got it", self) |
|
240 else: |
|
241 # Balancing act: We can't afford a pure busy loop, so we |
|
242 # have to sleep; but if we sleep the whole timeout time, |
|
243 # we'll be unresponsive. The scheme here sleeps very |
|
244 # little at first, longer as time goes on, but never longer |
|
245 # than 20 times per second (or the timeout time remaining). |
|
246 endtime = _time() + timeout |
|
247 delay = 0.0005 # 500 us -> initial delay of 1 ms |
|
248 while True: |
|
249 gotit = waiter.acquire(0) |
|
250 if gotit: |
|
251 break |
|
252 remaining = endtime - _time() |
|
253 if remaining <= 0: |
|
254 break |
|
255 delay = min(delay * 2, remaining, .05) |
|
256 _sleep(delay) |
|
257 if not gotit: |
|
258 if __debug__: |
|
259 self._note("%s.wait(%s): timed out", self, timeout) |
|
260 try: |
|
261 self.__waiters.remove(waiter) |
|
262 except ValueError: |
|
263 pass |
|
264 else: |
|
265 if __debug__: |
|
266 self._note("%s.wait(%s): got it", self, timeout) |
|
267 finally: |
|
268 self._acquire_restore(saved_state) |
|
269 |
|
270 def notify(self, n=1): |
|
271 if not self._is_owned(): |
|
272 raise RuntimeError("cannot notify on un-aquired lock") |
|
273 __waiters = self.__waiters |
|
274 waiters = __waiters[:n] |
|
275 if not waiters: |
|
276 if __debug__: |
|
277 self._note("%s.notify(): no waiters", self) |
|
278 return |
|
279 self._note("%s.notify(): notifying %d waiter%s", self, n, |
|
280 n!=1 and "s" or "") |
|
281 for waiter in waiters: |
|
282 waiter.release() |
|
283 try: |
|
284 __waiters.remove(waiter) |
|
285 except ValueError: |
|
286 pass |
|
287 |
|
288 def notifyAll(self): |
|
289 self.notify(len(self.__waiters)) |
|
290 |
|
291 notify_all = notifyAll |
|
292 |
|
293 |
|
294 def Semaphore(*args, **kwargs): |
|
295 return _Semaphore(*args, **kwargs) |
|
296 |
|
297 class _Semaphore(_Verbose): |
|
298 |
|
299 # After Tim Peters' semaphore class, but not quite the same (no maximum) |
|
300 |
|
301 def __init__(self, value=1, verbose=None): |
|
302 if value < 0: |
|
303 raise ValueError("semaphore initial value must be >= 0") |
|
304 _Verbose.__init__(self, verbose) |
|
305 self.__cond = Condition(Lock()) |
|
306 self.__value = value |
|
307 |
|
308 def acquire(self, blocking=1): |
|
309 rc = False |
|
310 self.__cond.acquire() |
|
311 while self.__value == 0: |
|
312 if not blocking: |
|
313 break |
|
314 if __debug__: |
|
315 self._note("%s.acquire(%s): blocked waiting, value=%s", |
|
316 self, blocking, self.__value) |
|
317 self.__cond.wait() |
|
318 else: |
|
319 self.__value = self.__value - 1 |
|
320 if __debug__: |
|
321 self._note("%s.acquire: success, value=%s", |
|
322 self, self.__value) |
|
323 rc = True |
|
324 self.__cond.release() |
|
325 return rc |
|
326 |
|
327 __enter__ = acquire |
|
328 |
|
329 def release(self): |
|
330 self.__cond.acquire() |
|
331 self.__value = self.__value + 1 |
|
332 if __debug__: |
|
333 self._note("%s.release: success, value=%s", |
|
334 self, self.__value) |
|
335 self.__cond.notify() |
|
336 self.__cond.release() |
|
337 |
|
338 def __exit__(self, t, v, tb): |
|
339 self.release() |
|
340 |
|
341 |
|
342 def BoundedSemaphore(*args, **kwargs): |
|
343 return _BoundedSemaphore(*args, **kwargs) |
|
344 |
|
345 class _BoundedSemaphore(_Semaphore): |
|
346 """Semaphore that checks that # releases is <= # acquires""" |
|
347 def __init__(self, value=1, verbose=None): |
|
348 _Semaphore.__init__(self, value, verbose) |
|
349 self._initial_value = value |
|
350 |
|
351 def release(self): |
|
352 if self._Semaphore__value >= self._initial_value: |
|
353 raise ValueError, "Semaphore released too many times" |
|
354 return _Semaphore.release(self) |
|
355 |
|
356 |
|
357 def Event(*args, **kwargs): |
|
358 return _Event(*args, **kwargs) |
|
359 |
|
360 class _Event(_Verbose): |
|
361 |
|
362 # After Tim Peters' event class (without is_posted()) |
|
363 |
|
364 def __init__(self, verbose=None): |
|
365 _Verbose.__init__(self, verbose) |
|
366 self.__cond = Condition(Lock()) |
|
367 self.__flag = False |
|
368 |
|
369 def isSet(self): |
|
370 return self.__flag |
|
371 |
|
372 is_set = isSet |
|
373 |
|
374 def set(self): |
|
375 self.__cond.acquire() |
|
376 try: |
|
377 self.__flag = True |
|
378 self.__cond.notify_all() |
|
379 finally: |
|
380 self.__cond.release() |
|
381 |
|
382 def clear(self): |
|
383 self.__cond.acquire() |
|
384 try: |
|
385 self.__flag = False |
|
386 finally: |
|
387 self.__cond.release() |
|
388 |
|
389 def wait(self, timeout=None): |
|
390 self.__cond.acquire() |
|
391 try: |
|
392 if not self.__flag: |
|
393 self.__cond.wait(timeout) |
|
394 finally: |
|
395 self.__cond.release() |
|
396 |
|
397 # Helper to generate new thread names |
|
398 _counter = 0 |
|
399 def _newname(template="Thread-%d"): |
|
400 global _counter |
|
401 _counter = _counter + 1 |
|
402 return template % _counter |
|
403 |
|
404 # Active thread administration |
|
405 _active_limbo_lock = _allocate_lock() |
|
406 _active = {} # maps thread id to Thread object |
|
407 _limbo = {} |
|
408 |
|
409 |
|
410 # Main class for threads |
|
411 |
|
412 class Thread(_Verbose): |
|
413 |
|
414 __initialized = False |
|
415 # Need to store a reference to sys.exc_info for printing |
|
416 # out exceptions when a thread tries to use a global var. during interp. |
|
417 # shutdown and thus raises an exception about trying to perform some |
|
418 # operation on/with a NoneType |
|
419 __exc_info = _sys.exc_info |
|
420 # Keep sys.exc_clear too to clear the exception just before |
|
421 # allowing .join() to return. |
|
422 __exc_clear = _sys.exc_clear |
|
423 |
|
424 def __init__(self, group=None, target=None, name=None, |
|
425 args=(), kwargs=None, verbose=None): |
|
426 assert group is None, "group argument must be None for now" |
|
427 _Verbose.__init__(self, verbose) |
|
428 if kwargs is None: |
|
429 kwargs = {} |
|
430 self.__target = target |
|
431 self.__name = str(name or _newname()) |
|
432 self.__args = args |
|
433 self.__kwargs = kwargs |
|
434 self.__daemonic = self._set_daemon() |
|
435 self.__ident = None |
|
436 self.__started = Event() |
|
437 self.__stopped = False |
|
438 self.__block = Condition(Lock()) |
|
439 self.__initialized = True |
|
440 # sys.stderr is not stored in the class like |
|
441 # sys.exc_info since it can be changed between instances |
|
442 self.__stderr = _sys.stderr |
|
443 |
|
444 def _set_daemon(self): |
|
445 # Overridden in _MainThread and _DummyThread |
|
446 return current_thread().daemon |
|
447 |
|
448 def __repr__(self): |
|
449 assert self.__initialized, "Thread.__init__() was not called" |
|
450 status = "initial" |
|
451 if self.__started.is_set(): |
|
452 status = "started" |
|
453 if self.__stopped: |
|
454 status = "stopped" |
|
455 if self.__daemonic: |
|
456 status += " daemon" |
|
457 if self.__ident is not None: |
|
458 status += " %s" % self.__ident |
|
459 return "<%s(%s, %s)>" % (self.__class__.__name__, self.__name, status) |
|
460 |
|
461 def start(self): |
|
462 if not self.__initialized: |
|
463 raise RuntimeError("thread.__init__() not called") |
|
464 if self.__started.is_set(): |
|
465 raise RuntimeError("thread already started") |
|
466 if __debug__: |
|
467 self._note("%s.start(): starting thread", self) |
|
468 _active_limbo_lock.acquire() |
|
469 _limbo[self] = self |
|
470 _active_limbo_lock.release() |
|
471 _start_new_thread(self.__bootstrap, ()) |
|
472 self.__started.wait() |
|
473 |
|
474 def run(self): |
|
475 try: |
|
476 if self.__target: |
|
477 self.__target(*self.__args, **self.__kwargs) |
|
478 finally: |
|
479 # Avoid a refcycle if the thread is running a function with |
|
480 # an argument that has a member that points to the thread. |
|
481 del self.__target, self.__args, self.__kwargs |
|
482 |
|
483 def __bootstrap(self): |
|
484 # Wrapper around the real bootstrap code that ignores |
|
485 # exceptions during interpreter cleanup. Those typically |
|
486 # happen when a daemon thread wakes up at an unfortunate |
|
487 # moment, finds the world around it destroyed, and raises some |
|
488 # random exception *** while trying to report the exception in |
|
489 # __bootstrap_inner() below ***. Those random exceptions |
|
490 # don't help anybody, and they confuse users, so we suppress |
|
491 # them. We suppress them only when it appears that the world |
|
492 # indeed has already been destroyed, so that exceptions in |
|
493 # __bootstrap_inner() during normal business hours are properly |
|
494 # reported. Also, we only suppress them for daemonic threads; |
|
495 # if a non-daemonic encounters this, something else is wrong. |
|
496 try: |
|
497 self.__bootstrap_inner() |
|
498 except: |
|
499 if self.__daemonic and _sys is None: |
|
500 return |
|
501 raise |
|
502 |
|
503 def __bootstrap_inner(self): |
|
504 try: |
|
505 self.__ident = _get_ident() |
|
506 self.__started.set() |
|
507 _active_limbo_lock.acquire() |
|
508 _active[self.__ident] = self |
|
509 del _limbo[self] |
|
510 _active_limbo_lock.release() |
|
511 if __debug__: |
|
512 self._note("%s.__bootstrap(): thread started", self) |
|
513 |
|
514 if _trace_hook: |
|
515 self._note("%s.__bootstrap(): registering trace hook", self) |
|
516 _sys.settrace(_trace_hook) |
|
517 if _profile_hook: |
|
518 self._note("%s.__bootstrap(): registering profile hook", self) |
|
519 _sys.setprofile(_profile_hook) |
|
520 |
|
521 try: |
|
522 self.run() |
|
523 except SystemExit: |
|
524 if __debug__: |
|
525 self._note("%s.__bootstrap(): raised SystemExit", self) |
|
526 except: |
|
527 if __debug__: |
|
528 self._note("%s.__bootstrap(): unhandled exception", self) |
|
529 # If sys.stderr is no more (most likely from interpreter |
|
530 # shutdown) use self.__stderr. Otherwise still use sys (as in |
|
531 # _sys) in case sys.stderr was redefined since the creation of |
|
532 # self. |
|
533 if _sys: |
|
534 _sys.stderr.write("Exception in thread %s:\n%s\n" % |
|
535 (self.name, _format_exc())) |
|
536 else: |
|
537 # Do the best job possible w/o a huge amt. of code to |
|
538 # approximate a traceback (code ideas from |
|
539 # Lib/traceback.py) |
|
540 exc_type, exc_value, exc_tb = self.__exc_info() |
|
541 try: |
|
542 print>>self.__stderr, ( |
|
543 "Exception in thread " + self.name + |
|
544 " (most likely raised during interpreter shutdown):") |
|
545 print>>self.__stderr, ( |
|
546 "Traceback (most recent call last):") |
|
547 while exc_tb: |
|
548 print>>self.__stderr, ( |
|
549 ' File "%s", line %s, in %s' % |
|
550 (exc_tb.tb_frame.f_code.co_filename, |
|
551 exc_tb.tb_lineno, |
|
552 exc_tb.tb_frame.f_code.co_name)) |
|
553 exc_tb = exc_tb.tb_next |
|
554 print>>self.__stderr, ("%s: %s" % (exc_type, exc_value)) |
|
555 # Make sure that exc_tb gets deleted since it is a memory |
|
556 # hog; deleting everything else is just for thoroughness |
|
557 finally: |
|
558 del exc_type, exc_value, exc_tb |
|
559 else: |
|
560 if __debug__: |
|
561 self._note("%s.__bootstrap(): normal return", self) |
|
562 finally: |
|
563 # Prevent a race in |
|
564 # test_threading.test_no_refcycle_through_target when |
|
565 # the exception keeps the target alive past when we |
|
566 # assert that it's dead. |
|
567 self.__exc_clear() |
|
568 finally: |
|
569 with _active_limbo_lock: |
|
570 self.__stop() |
|
571 try: |
|
572 # We don't call self.__delete() because it also |
|
573 # grabs _active_limbo_lock. |
|
574 del _active[_get_ident()] |
|
575 except: |
|
576 pass |
|
577 |
|
578 def __stop(self): |
|
579 self.__block.acquire() |
|
580 self.__stopped = True |
|
581 self.__block.notify_all() |
|
582 self.__block.release() |
|
583 |
|
584 def __delete(self): |
|
585 "Remove current thread from the dict of currently running threads." |
|
586 |
|
587 # Notes about running with dummy_thread: |
|
588 # |
|
589 # Must take care to not raise an exception if dummy_thread is being |
|
590 # used (and thus this module is being used as an instance of |
|
591 # dummy_threading). dummy_thread.get_ident() always returns -1 since |
|
592 # there is only one thread if dummy_thread is being used. Thus |
|
593 # len(_active) is always <= 1 here, and any Thread instance created |
|
594 # overwrites the (if any) thread currently registered in _active. |
|
595 # |
|
596 # An instance of _MainThread is always created by 'threading'. This |
|
597 # gets overwritten the instant an instance of Thread is created; both |
|
598 # threads return -1 from dummy_thread.get_ident() and thus have the |
|
599 # same key in the dict. So when the _MainThread instance created by |
|
600 # 'threading' tries to clean itself up when atexit calls this method |
|
601 # it gets a KeyError if another Thread instance was created. |
|
602 # |
|
603 # This all means that KeyError from trying to delete something from |
|
604 # _active if dummy_threading is being used is a red herring. But |
|
605 # since it isn't if dummy_threading is *not* being used then don't |
|
606 # hide the exception. |
|
607 |
|
608 try: |
|
609 with _active_limbo_lock: |
|
610 del _active[_get_ident()] |
|
611 # There must not be any python code between the previous line |
|
612 # and after the lock is released. Otherwise a tracing function |
|
613 # could try to acquire the lock again in the same thread, (in |
|
614 # current_thread()), and would block. |
|
615 except KeyError: |
|
616 if 'dummy_threading' not in _sys.modules: |
|
617 raise |
|
618 |
|
619 def join(self, timeout=None): |
|
620 if not self.__initialized: |
|
621 raise RuntimeError("Thread.__init__() not called") |
|
622 if not self.__started.is_set(): |
|
623 raise RuntimeError("cannot join thread before it is started") |
|
624 if self is current_thread(): |
|
625 raise RuntimeError("cannot join current thread") |
|
626 |
|
627 if __debug__: |
|
628 if not self.__stopped: |
|
629 self._note("%s.join(): waiting until thread stops", self) |
|
630 self.__block.acquire() |
|
631 try: |
|
632 if timeout is None: |
|
633 while not self.__stopped: |
|
634 self.__block.wait() |
|
635 if __debug__: |
|
636 self._note("%s.join(): thread stopped", self) |
|
637 else: |
|
638 deadline = _time() + timeout |
|
639 while not self.__stopped: |
|
640 delay = deadline - _time() |
|
641 if delay <= 0: |
|
642 if __debug__: |
|
643 self._note("%s.join(): timed out", self) |
|
644 break |
|
645 self.__block.wait(delay) |
|
646 else: |
|
647 if __debug__: |
|
648 self._note("%s.join(): thread stopped", self) |
|
649 finally: |
|
650 self.__block.release() |
|
651 |
|
652 @property |
|
653 def name(self): |
|
654 assert self.__initialized, "Thread.__init__() not called" |
|
655 return self.__name |
|
656 |
|
657 @name.setter |
|
658 def name(self, name): |
|
659 assert self.__initialized, "Thread.__init__() not called" |
|
660 self.__name = str(name) |
|
661 |
|
662 @property |
|
663 def ident(self): |
|
664 assert self.__initialized, "Thread.__init__() not called" |
|
665 return self.__ident |
|
666 |
|
667 def isAlive(self): |
|
668 assert self.__initialized, "Thread.__init__() not called" |
|
669 return self.__started.is_set() and not self.__stopped |
|
670 |
|
671 is_alive = isAlive |
|
672 |
|
673 @property |
|
674 def daemon(self): |
|
675 assert self.__initialized, "Thread.__init__() not called" |
|
676 return self.__daemonic |
|
677 |
|
678 @daemon.setter |
|
679 def daemon(self, daemonic): |
|
680 if not self.__initialized: |
|
681 raise RuntimeError("Thread.__init__() not called") |
|
682 if self.__started.is_set(): |
|
683 raise RuntimeError("cannot set daemon status of active thread"); |
|
684 self.__daemonic = daemonic |
|
685 |
|
686 def isDaemon(self): |
|
687 return self.daemon |
|
688 |
|
689 def setDaemon(self, daemonic): |
|
690 self.daemon = daemonic |
|
691 |
|
692 def getName(self): |
|
693 return self.name |
|
694 |
|
695 def setName(self, name): |
|
696 self.name = name |
|
697 |
|
698 # The timer class was contributed by Itamar Shtull-Trauring |
|
699 |
|
700 def Timer(*args, **kwargs): |
|
701 return _Timer(*args, **kwargs) |
|
702 |
|
703 class _Timer(Thread): |
|
704 """Call a function after a specified number of seconds: |
|
705 |
|
706 t = Timer(30.0, f, args=[], kwargs={}) |
|
707 t.start() |
|
708 t.cancel() # stop the timer's action if it's still waiting |
|
709 """ |
|
710 |
|
711 def __init__(self, interval, function, args=[], kwargs={}): |
|
712 Thread.__init__(self) |
|
713 self.interval = interval |
|
714 self.function = function |
|
715 self.args = args |
|
716 self.kwargs = kwargs |
|
717 self.finished = Event() |
|
718 |
|
719 def cancel(self): |
|
720 """Stop the timer if it hasn't finished yet""" |
|
721 self.finished.set() |
|
722 |
|
723 def run(self): |
|
724 self.finished.wait(self.interval) |
|
725 if not self.finished.is_set(): |
|
726 self.function(*self.args, **self.kwargs) |
|
727 self.finished.set() |
|
728 |
|
729 # Special thread class to represent the main thread |
|
730 # This is garbage collected through an exit handler |
|
731 |
|
732 class _MainThread(Thread): |
|
733 |
|
734 def __init__(self): |
|
735 Thread.__init__(self, name="MainThread") |
|
736 self._Thread__started.set() |
|
737 _active_limbo_lock.acquire() |
|
738 _active[_get_ident()] = self |
|
739 _active_limbo_lock.release() |
|
740 |
|
741 def _set_daemon(self): |
|
742 return False |
|
743 |
|
744 def _exitfunc(self): |
|
745 self._Thread__stop() |
|
746 t = _pickSomeNonDaemonThread() |
|
747 if t: |
|
748 if __debug__: |
|
749 self._note("%s: waiting for other threads", self) |
|
750 while t: |
|
751 t.join() |
|
752 t = _pickSomeNonDaemonThread() |
|
753 if __debug__: |
|
754 self._note("%s: exiting", self) |
|
755 self._Thread__delete() |
|
756 |
|
757 def _pickSomeNonDaemonThread(): |
|
758 for t in enumerate(): |
|
759 if not t.daemon and t.is_alive(): |
|
760 return t |
|
761 return None |
|
762 |
|
763 |
|
764 # Dummy thread class to represent threads not started here. |
|
765 # These aren't garbage collected when they die, nor can they be waited for. |
|
766 # If they invoke anything in threading.py that calls current_thread(), they |
|
767 # leave an entry in the _active dict forever after. |
|
768 # Their purpose is to return *something* from current_thread(). |
|
769 # They are marked as daemon threads so we won't wait for them |
|
770 # when we exit (conform previous semantics). |
|
771 |
|
772 class _DummyThread(Thread): |
|
773 |
|
774 def __init__(self): |
|
775 Thread.__init__(self, name=_newname("Dummy-%d")) |
|
776 |
|
777 # Thread.__block consumes an OS-level locking primitive, which |
|
778 # can never be used by a _DummyThread. Since a _DummyThread |
|
779 # instance is immortal, that's bad, so release this resource. |
|
780 del self._Thread__block |
|
781 |
|
782 self._Thread__started.set() |
|
783 _active_limbo_lock.acquire() |
|
784 _active[_get_ident()] = self |
|
785 _active_limbo_lock.release() |
|
786 |
|
787 def _set_daemon(self): |
|
788 return True |
|
789 |
|
790 def join(self, timeout=None): |
|
791 assert False, "cannot join a dummy thread" |
|
792 |
|
793 |
|
794 # Global API functions |
|
795 |
|
796 def currentThread(): |
|
797 try: |
|
798 return _active[_get_ident()] |
|
799 except KeyError: |
|
800 ##print "current_thread(): no current thread for", _get_ident() |
|
801 return _DummyThread() |
|
802 |
|
803 current_thread = currentThread |
|
804 |
|
805 def activeCount(): |
|
806 _active_limbo_lock.acquire() |
|
807 count = len(_active) + len(_limbo) |
|
808 _active_limbo_lock.release() |
|
809 return count |
|
810 |
|
811 active_count = activeCount |
|
812 |
|
813 def enumerate(): |
|
814 _active_limbo_lock.acquire() |
|
815 active = _active.values() + _limbo.values() |
|
816 _active_limbo_lock.release() |
|
817 return active |
|
818 |
|
819 from thread import stack_size |
|
820 |
|
821 # Create the main thread object, |
|
822 # and make it available for the interpreter |
|
823 # (Py_Main) as threading._shutdown. |
|
824 |
|
825 _shutdown = _MainThread()._exitfunc |
|
826 |
|
827 # get thread-local implementation, either from the thread |
|
828 # module, or from the python fallback |
|
829 |
|
830 try: |
|
831 from thread import _local as local |
|
832 except ImportError: |
|
833 from _threading_local import local |
|
834 |
|
835 |
|
836 def _after_fork(): |
|
837 # This function is called by Python/ceval.c:PyEval_ReInitThreads which |
|
838 # is called from PyOS_AfterFork. Here we cleanup threading module state |
|
839 # that should not exist after a fork. |
|
840 |
|
841 # Reset _active_limbo_lock, in case we forked while the lock was held |
|
842 # by another (non-forked) thread. http://bugs.python.org/issue874900 |
|
843 global _active_limbo_lock |
|
844 _active_limbo_lock = _allocate_lock() |
|
845 |
|
846 # fork() only copied the current thread; clear references to others. |
|
847 new_active = {} |
|
848 current = current_thread() |
|
849 with _active_limbo_lock: |
|
850 for thread in _active.itervalues(): |
|
851 if thread is current: |
|
852 # There is only one active thread. We reset the ident to |
|
853 # its new value since it can have changed. |
|
854 ident = _get_ident() |
|
855 thread._Thread__ident = ident |
|
856 new_active[ident] = thread |
|
857 else: |
|
858 # All the others are already stopped. |
|
859 # We don't call _Thread__stop() because it tries to acquire |
|
860 # thread._Thread__block which could also have been held while |
|
861 # we forked. |
|
862 thread._Thread__stopped = True |
|
863 |
|
864 _limbo.clear() |
|
865 _active.clear() |
|
866 _active.update(new_active) |
|
867 assert len(_active) == 1 |
|
868 |
|
869 |
|
870 # Self-test code |
|
871 |
|
872 def _test(): |
|
873 |
|
874 class BoundedQueue(_Verbose): |
|
875 |
|
876 def __init__(self, limit): |
|
877 _Verbose.__init__(self) |
|
878 self.mon = RLock() |
|
879 self.rc = Condition(self.mon) |
|
880 self.wc = Condition(self.mon) |
|
881 self.limit = limit |
|
882 self.queue = deque() |
|
883 |
|
884 def put(self, item): |
|
885 self.mon.acquire() |
|
886 while len(self.queue) >= self.limit: |
|
887 self._note("put(%s): queue full", item) |
|
888 self.wc.wait() |
|
889 self.queue.append(item) |
|
890 self._note("put(%s): appended, length now %d", |
|
891 item, len(self.queue)) |
|
892 self.rc.notify() |
|
893 self.mon.release() |
|
894 |
|
895 def get(self): |
|
896 self.mon.acquire() |
|
897 while not self.queue: |
|
898 self._note("get(): queue empty") |
|
899 self.rc.wait() |
|
900 item = self.queue.popleft() |
|
901 self._note("get(): got %s, %d left", item, len(self.queue)) |
|
902 self.wc.notify() |
|
903 self.mon.release() |
|
904 return item |
|
905 |
|
906 class ProducerThread(Thread): |
|
907 |
|
908 def __init__(self, queue, quota): |
|
909 Thread.__init__(self, name="Producer") |
|
910 self.queue = queue |
|
911 self.quota = quota |
|
912 |
|
913 def run(self): |
|
914 from random import random |
|
915 counter = 0 |
|
916 while counter < self.quota: |
|
917 counter = counter + 1 |
|
918 self.queue.put("%s.%d" % (self.name, counter)) |
|
919 _sleep(random() * 0.00001) |
|
920 |
|
921 |
|
922 class ConsumerThread(Thread): |
|
923 |
|
924 def __init__(self, queue, count): |
|
925 Thread.__init__(self, name="Consumer") |
|
926 self.queue = queue |
|
927 self.count = count |
|
928 |
|
929 def run(self): |
|
930 while self.count > 0: |
|
931 item = self.queue.get() |
|
932 print item |
|
933 self.count = self.count - 1 |
|
934 |
|
935 NP = 3 |
|
936 QL = 4 |
|
937 NI = 5 |
|
938 |
|
939 Q = BoundedQueue(QL) |
|
940 P = [] |
|
941 for i in range(NP): |
|
942 t = ProducerThread(Q, NI) |
|
943 t.name = ("Producer-%d" % (i+1)) |
|
944 P.append(t) |
|
945 C = ConsumerThread(Q, NI*NP) |
|
946 for t in P: |
|
947 t.start() |
|
948 _sleep(0.000001) |
|
949 C.start() |
|
950 for t in P: |
|
951 t.join() |
|
952 C.join() |
|
953 |
|
954 if __name__ == '__main__': |
|
955 _test() |