Jeremy Hylton | 92bb6e7 | 2002-08-14 19:25:42 +0000 | [diff] [blame] | 1 | """Thread module emulating a subset of Java's threading model.""" |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 2 | |
Antoine Pitrou | 4a8bcdf | 2017-05-28 14:02:26 +0200 | [diff] [blame] | 3 | import os as _os |
Fred Drake | a872595 | 2002-12-30 23:32:50 +0000 | [diff] [blame] | 4 | import sys as _sys |
Georg Brandl | 2067bfd | 2008-05-25 13:05:15 +0000 | [diff] [blame] | 5 | import _thread |
Fred Drake | a872595 | 2002-12-30 23:32:50 +0000 | [diff] [blame] | 6 | |
Victor Stinner | ae58649 | 2014-09-02 23:18:25 +0200 | [diff] [blame] | 7 | from time import monotonic as _time |
Antoine Pitrou | c081c0c | 2011-07-15 22:12:24 +0200 | [diff] [blame] | 8 | from _weakrefset import WeakSet |
R David Murray | b186f1df | 2014-10-04 17:43:54 -0400 | [diff] [blame] | 9 | from itertools import islice as _islice, count as _count |
Raymond Hettinger | ec4b174 | 2013-03-10 17:57:28 -0700 | [diff] [blame] | 10 | try: |
Raymond Hettinger | ec4b174 | 2013-03-10 17:57:28 -0700 | [diff] [blame] | 11 | from _collections import deque as _deque |
Brett Cannon | cd171c8 | 2013-07-04 17:43:24 -0400 | [diff] [blame] | 12 | except ImportError: |
Raymond Hettinger | ec4b174 | 2013-03-10 17:57:28 -0700 | [diff] [blame] | 13 | from collections import deque as _deque |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 14 | |
Benjamin Peterson | b3085c9 | 2008-09-01 23:09:31 +0000 | [diff] [blame] | 15 | # Note regarding PEP 8 compliant names |
| 16 | # This threading model was originally inspired by Java, and inherited |
| 17 | # the convention of camelCase function and method names from that |
Ezio Melotti | 30b9d5d | 2013-08-17 15:50:46 +0300 | [diff] [blame] | 18 | # language. Those original names are not in any imminent danger of |
Benjamin Peterson | b3085c9 | 2008-09-01 23:09:31 +0000 | [diff] [blame] | 19 | # being deprecated (even for Py3k),so this module provides them as an |
| 20 | # alias for the PEP 8 compliant names |
| 21 | # Note that using the new PEP 8 compliant names facilitates substitution |
| 22 | # with the multiprocessing module, which doesn't provide the old |
| 23 | # Java inspired names. |
| 24 | |
Victor Stinner | d12e757 | 2019-05-21 12:44:57 +0200 | [diff] [blame] | 25 | __all__ = ['get_ident', 'active_count', 'Condition', 'current_thread', |
| 26 | 'enumerate', 'main_thread', 'TIMEOUT_MAX', |
Martin Panter | 19e69c5 | 2015-11-14 12:46:42 +0000 | [diff] [blame] | 27 | 'Event', 'Lock', 'RLock', 'Semaphore', 'BoundedSemaphore', 'Thread', |
| 28 | 'Barrier', 'BrokenBarrierError', 'Timer', 'ThreadError', |
Victor Stinner | cd590a7 | 2019-05-28 00:39:52 +0200 | [diff] [blame^] | 29 | 'setprofile', 'settrace', 'local', 'stack_size', |
| 30 | 'excepthook', 'ExceptHookArgs'] |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 31 | |
Raymond Hettinger | 5cee47f | 2011-01-11 19:59:46 +0000 | [diff] [blame] | 32 | # Rename some stuff so "from threading import *" is safe |
Georg Brandl | 2067bfd | 2008-05-25 13:05:15 +0000 | [diff] [blame] | 33 | _start_new_thread = _thread.start_new_thread |
| 34 | _allocate_lock = _thread.allocate_lock |
Antoine Pitrou | 7b47699 | 2013-09-07 23:38:37 +0200 | [diff] [blame] | 35 | _set_sentinel = _thread._set_sentinel |
Victor Stinner | 2a12974 | 2011-05-30 23:02:52 +0200 | [diff] [blame] | 36 | get_ident = _thread.get_ident |
Jake Tesler | b121f63 | 2019-05-22 08:43:17 -0700 | [diff] [blame] | 37 | try: |
| 38 | get_native_id = _thread.get_native_id |
| 39 | _HAVE_THREAD_NATIVE_ID = True |
| 40 | __all__.append('get_native_id') |
| 41 | except AttributeError: |
| 42 | _HAVE_THREAD_NATIVE_ID = False |
Georg Brandl | 2067bfd | 2008-05-25 13:05:15 +0000 | [diff] [blame] | 43 | ThreadError = _thread.error |
Antoine Pitrou | 434736a | 2009-11-10 18:46:01 +0000 | [diff] [blame] | 44 | try: |
| 45 | _CRLock = _thread.RLock |
| 46 | except AttributeError: |
| 47 | _CRLock = None |
Antoine Pitrou | 7c3e577 | 2010-04-14 15:44:10 +0000 | [diff] [blame] | 48 | TIMEOUT_MAX = _thread.TIMEOUT_MAX |
Georg Brandl | 2067bfd | 2008-05-25 13:05:15 +0000 | [diff] [blame] | 49 | del _thread |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 50 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 51 | |
Jeremy Hylton | bfccb35 | 2003-06-29 16:58:41 +0000 | [diff] [blame] | 52 | # Support for profile and trace hooks |
| 53 | |
| 54 | _profile_hook = None |
| 55 | _trace_hook = None |
| 56 | |
| 57 | def setprofile(func): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 58 | """Set a profile function for all threads started from the threading module. |
| 59 | |
| 60 | The func will be passed to sys.setprofile() for each thread, before its |
| 61 | run() method is called. |
| 62 | |
| 63 | """ |
Jeremy Hylton | bfccb35 | 2003-06-29 16:58:41 +0000 | [diff] [blame] | 64 | global _profile_hook |
| 65 | _profile_hook = func |
Tim Peters | d1b108b | 2003-06-29 17:24:17 +0000 | [diff] [blame] | 66 | |
Jeremy Hylton | bfccb35 | 2003-06-29 16:58:41 +0000 | [diff] [blame] | 67 | def settrace(func): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 68 | """Set a trace function for all threads started from the threading module. |
| 69 | |
| 70 | The func will be passed to sys.settrace() for each thread, before its run() |
| 71 | method is called. |
| 72 | |
| 73 | """ |
Jeremy Hylton | bfccb35 | 2003-06-29 16:58:41 +0000 | [diff] [blame] | 74 | global _trace_hook |
| 75 | _trace_hook = func |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 76 | |
| 77 | # Synchronization classes |
| 78 | |
| 79 | Lock = _allocate_lock |
| 80 | |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 81 | def RLock(*args, **kwargs): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 82 | """Factory function that returns a new reentrant lock. |
| 83 | |
| 84 | A reentrant lock must be released by the thread that acquired it. Once a |
| 85 | thread has acquired a reentrant lock, the same thread may acquire it again |
| 86 | without blocking; the thread must release it once for each time it has |
| 87 | acquired it. |
| 88 | |
| 89 | """ |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 90 | if _CRLock is None: |
| 91 | return _PyRLock(*args, **kwargs) |
Antoine Pitrou | 434736a | 2009-11-10 18:46:01 +0000 | [diff] [blame] | 92 | return _CRLock(*args, **kwargs) |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 93 | |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 94 | class _RLock: |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 95 | """This class implements reentrant lock objects. |
| 96 | |
| 97 | A reentrant lock must be released by the thread that acquired it. Once a |
| 98 | thread has acquired a reentrant lock, the same thread may acquire it |
| 99 | again without blocking; the thread must release it once for each time it |
| 100 | has acquired it. |
| 101 | |
| 102 | """ |
Tim Peters | b90f89a | 2001-01-15 03:26:36 +0000 | [diff] [blame] | 103 | |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 104 | def __init__(self): |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 105 | self._block = _allocate_lock() |
| 106 | self._owner = None |
| 107 | self._count = 0 |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 108 | |
| 109 | def __repr__(self): |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 110 | owner = self._owner |
Antoine Pitrou | b087268 | 2009-11-09 16:08:16 +0000 | [diff] [blame] | 111 | try: |
| 112 | owner = _active[owner].name |
| 113 | except KeyError: |
| 114 | pass |
Raymond Hettinger | 62f4dad | 2014-05-25 18:22:35 -0700 | [diff] [blame] | 115 | return "<%s %s.%s object owner=%r count=%d at %s>" % ( |
| 116 | "locked" if self._block.locked() else "unlocked", |
| 117 | self.__class__.__module__, |
| 118 | self.__class__.__qualname__, |
| 119 | owner, |
| 120 | self._count, |
| 121 | hex(id(self)) |
| 122 | ) |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 123 | |
Antoine Pitrou | 7c3e577 | 2010-04-14 15:44:10 +0000 | [diff] [blame] | 124 | def acquire(self, blocking=True, timeout=-1): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 125 | """Acquire a lock, blocking or non-blocking. |
| 126 | |
| 127 | When invoked without arguments: if this thread already owns the lock, |
| 128 | increment the recursion level by one, and return immediately. Otherwise, |
| 129 | if another thread owns the lock, block until the lock is unlocked. Once |
| 130 | the lock is unlocked (not owned by any thread), then grab ownership, set |
| 131 | the recursion level to one, and return. If more than one thread is |
| 132 | blocked waiting until the lock is unlocked, only one at a time will be |
| 133 | able to grab ownership of the lock. There is no return value in this |
| 134 | case. |
| 135 | |
| 136 | When invoked with the blocking argument set to true, do the same thing |
| 137 | as when called without arguments, and return true. |
| 138 | |
| 139 | When invoked with the blocking argument set to false, do not block. If a |
| 140 | call without an argument would block, return false immediately; |
| 141 | otherwise, do the same thing as when called without arguments, and |
| 142 | return true. |
| 143 | |
| 144 | When invoked with the floating-point timeout argument set to a positive |
| 145 | value, block for at most the number of seconds specified by timeout |
| 146 | and as long as the lock cannot be acquired. Return true if the lock has |
| 147 | been acquired, false if the timeout has elapsed. |
| 148 | |
| 149 | """ |
Victor Stinner | 2a12974 | 2011-05-30 23:02:52 +0200 | [diff] [blame] | 150 | me = get_ident() |
Antoine Pitrou | b087268 | 2009-11-09 16:08:16 +0000 | [diff] [blame] | 151 | if self._owner == me: |
Raymond Hettinger | 720da57 | 2013-03-10 15:13:35 -0700 | [diff] [blame] | 152 | self._count += 1 |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 153 | return 1 |
Antoine Pitrou | 7c3e577 | 2010-04-14 15:44:10 +0000 | [diff] [blame] | 154 | rc = self._block.acquire(blocking, timeout) |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 155 | if rc: |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 156 | self._owner = me |
| 157 | self._count = 1 |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 158 | return rc |
| 159 | |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 160 | __enter__ = acquire |
| 161 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 162 | def release(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 163 | """Release a lock, decrementing the recursion level. |
| 164 | |
| 165 | If after the decrement it is zero, reset the lock to unlocked (not owned |
| 166 | by any thread), and if any other threads are blocked waiting for the |
| 167 | lock to become unlocked, allow exactly one of them to proceed. If after |
| 168 | the decrement the recursion level is still nonzero, the lock remains |
| 169 | locked and owned by the calling thread. |
| 170 | |
| 171 | Only call this method when the calling thread owns the lock. A |
| 172 | RuntimeError is raised if this method is called when the lock is |
| 173 | unlocked. |
| 174 | |
| 175 | There is no return value. |
| 176 | |
| 177 | """ |
Victor Stinner | 2a12974 | 2011-05-30 23:02:52 +0200 | [diff] [blame] | 178 | if self._owner != get_ident(): |
Georg Brandl | 495f7b5 | 2009-10-27 15:28:25 +0000 | [diff] [blame] | 179 | raise RuntimeError("cannot release un-acquired lock") |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 180 | self._count = count = self._count - 1 |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 181 | if not count: |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 182 | self._owner = None |
| 183 | self._block.release() |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 184 | |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 185 | def __exit__(self, t, v, tb): |
| 186 | self.release() |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 187 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 188 | # Internal methods used by condition variables |
| 189 | |
Guido van Rossum | 1bc535d | 2007-05-15 18:46:22 +0000 | [diff] [blame] | 190 | def _acquire_restore(self, state): |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 191 | self._block.acquire() |
| 192 | self._count, self._owner = state |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 193 | |
| 194 | def _release_save(self): |
Victor Stinner | c2824d4 | 2011-04-24 23:41:33 +0200 | [diff] [blame] | 195 | if self._count == 0: |
| 196 | raise RuntimeError("cannot release un-acquired lock") |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 197 | count = self._count |
| 198 | self._count = 0 |
| 199 | owner = self._owner |
| 200 | self._owner = None |
| 201 | self._block.release() |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 202 | return (count, owner) |
| 203 | |
| 204 | def _is_owned(self): |
Victor Stinner | 2a12974 | 2011-05-30 23:02:52 +0200 | [diff] [blame] | 205 | return self._owner == get_ident() |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 206 | |
Antoine Pitrou | 434736a | 2009-11-10 18:46:01 +0000 | [diff] [blame] | 207 | _PyRLock = _RLock |
| 208 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 209 | |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 210 | class Condition: |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 211 | """Class that implements a condition variable. |
| 212 | |
| 213 | A condition variable allows one or more threads to wait until they are |
| 214 | notified by another thread. |
| 215 | |
| 216 | If the lock argument is given and not None, it must be a Lock or RLock |
| 217 | object, and it is used as the underlying lock. Otherwise, a new RLock object |
| 218 | is created and used as the underlying lock. |
| 219 | |
| 220 | """ |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 221 | |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 222 | def __init__(self, lock=None): |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 223 | if lock is None: |
| 224 | lock = RLock() |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 225 | self._lock = lock |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 226 | # Export the lock's acquire() and release() methods |
| 227 | self.acquire = lock.acquire |
| 228 | self.release = lock.release |
| 229 | # If the lock defines _release_save() and/or _acquire_restore(), |
| 230 | # these override the default implementations (which just call |
| 231 | # release() and acquire() on the lock). Ditto for _is_owned(). |
| 232 | try: |
| 233 | self._release_save = lock._release_save |
| 234 | except AttributeError: |
| 235 | pass |
| 236 | try: |
| 237 | self._acquire_restore = lock._acquire_restore |
| 238 | except AttributeError: |
| 239 | pass |
| 240 | try: |
| 241 | self._is_owned = lock._is_owned |
| 242 | except AttributeError: |
| 243 | pass |
Raymond Hettinger | ec4b174 | 2013-03-10 17:57:28 -0700 | [diff] [blame] | 244 | self._waiters = _deque() |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 245 | |
Thomas Wouters | 477c8d5 | 2006-05-27 19:21:47 +0000 | [diff] [blame] | 246 | def __enter__(self): |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 247 | return self._lock.__enter__() |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 248 | |
Thomas Wouters | 477c8d5 | 2006-05-27 19:21:47 +0000 | [diff] [blame] | 249 | def __exit__(self, *args): |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 250 | return self._lock.__exit__(*args) |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 251 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 252 | def __repr__(self): |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 253 | return "<Condition(%s, %d)>" % (self._lock, len(self._waiters)) |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 254 | |
| 255 | def _release_save(self): |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 256 | self._lock.release() # No state to save |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 257 | |
| 258 | def _acquire_restore(self, x): |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 259 | self._lock.acquire() # Ignore saved state |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 260 | |
| 261 | def _is_owned(self): |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 262 | # Return True if lock is owned by current_thread. |
Serhiy Storchaka | 52005c2 | 2014-09-21 22:08:13 +0300 | [diff] [blame] | 263 | # This method is called only if _lock doesn't have _is_owned(). |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 264 | if self._lock.acquire(0): |
| 265 | self._lock.release() |
Tim Peters | bc0e910 | 2002-04-04 22:55:58 +0000 | [diff] [blame] | 266 | return False |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 267 | else: |
Tim Peters | bc0e910 | 2002-04-04 22:55:58 +0000 | [diff] [blame] | 268 | return True |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 269 | |
| 270 | def wait(self, timeout=None): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 271 | """Wait until notified or until a timeout occurs. |
| 272 | |
| 273 | If the calling thread has not acquired the lock when this method is |
| 274 | called, a RuntimeError is raised. |
| 275 | |
| 276 | This method releases the underlying lock, and then blocks until it is |
| 277 | awakened by a notify() or notify_all() call for the same condition |
| 278 | variable in another thread, or until the optional timeout occurs. Once |
| 279 | awakened or timed out, it re-acquires the lock and returns. |
| 280 | |
| 281 | When the timeout argument is present and not None, it should be a |
| 282 | floating point number specifying a timeout for the operation in seconds |
| 283 | (or fractions thereof). |
| 284 | |
| 285 | When the underlying lock is an RLock, it is not released using its |
| 286 | release() method, since this may not actually unlock the lock when it |
| 287 | was acquired multiple times recursively. Instead, an internal interface |
| 288 | of the RLock class is used, which really unlocks it even when it has |
| 289 | been recursively acquired several times. Another internal interface is |
| 290 | then used to restore the recursion level when the lock is reacquired. |
| 291 | |
| 292 | """ |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 293 | if not self._is_owned(): |
Georg Brandl | 495f7b5 | 2009-10-27 15:28:25 +0000 | [diff] [blame] | 294 | raise RuntimeError("cannot wait on un-acquired lock") |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 295 | waiter = _allocate_lock() |
| 296 | waiter.acquire() |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 297 | self._waiters.append(waiter) |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 298 | saved_state = self._release_save() |
Antoine Pitrou | a64b92e | 2014-08-29 23:26:36 +0200 | [diff] [blame] | 299 | gotit = False |
Tim Peters | c951bf9 | 2001-04-02 20:15:57 +0000 | [diff] [blame] | 300 | try: # restore state no matter what (e.g., KeyboardInterrupt) |
| 301 | if timeout is None: |
| 302 | waiter.acquire() |
Georg Brandl | b9a4391 | 2010-10-28 09:03:20 +0000 | [diff] [blame] | 303 | gotit = True |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 304 | else: |
Antoine Pitrou | 7c3e577 | 2010-04-14 15:44:10 +0000 | [diff] [blame] | 305 | if timeout > 0: |
| 306 | gotit = waiter.acquire(True, timeout) |
| 307 | else: |
| 308 | gotit = waiter.acquire(False) |
Georg Brandl | b9a4391 | 2010-10-28 09:03:20 +0000 | [diff] [blame] | 309 | return gotit |
Tim Peters | c951bf9 | 2001-04-02 20:15:57 +0000 | [diff] [blame] | 310 | finally: |
| 311 | self._acquire_restore(saved_state) |
Antoine Pitrou | a64b92e | 2014-08-29 23:26:36 +0200 | [diff] [blame] | 312 | if not gotit: |
| 313 | try: |
| 314 | self._waiters.remove(waiter) |
| 315 | except ValueError: |
| 316 | pass |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 317 | |
Kristján Valur Jónsson | 6331520 | 2010-11-18 12:46:39 +0000 | [diff] [blame] | 318 | def wait_for(self, predicate, timeout=None): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 319 | """Wait until a condition evaluates to True. |
| 320 | |
| 321 | predicate should be a callable which result will be interpreted as a |
| 322 | boolean value. A timeout may be provided giving the maximum time to |
| 323 | wait. |
| 324 | |
| 325 | """ |
Kristján Valur Jónsson | 6331520 | 2010-11-18 12:46:39 +0000 | [diff] [blame] | 326 | endtime = None |
| 327 | waittime = timeout |
| 328 | result = predicate() |
| 329 | while not result: |
| 330 | if waittime is not None: |
| 331 | if endtime is None: |
| 332 | endtime = _time() + waittime |
| 333 | else: |
| 334 | waittime = endtime - _time() |
| 335 | if waittime <= 0: |
Kristján Valur Jónsson | 6331520 | 2010-11-18 12:46:39 +0000 | [diff] [blame] | 336 | break |
Kristján Valur Jónsson | 6331520 | 2010-11-18 12:46:39 +0000 | [diff] [blame] | 337 | self.wait(waittime) |
| 338 | result = predicate() |
Kristján Valur Jónsson | 6331520 | 2010-11-18 12:46:39 +0000 | [diff] [blame] | 339 | return result |
| 340 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 341 | def notify(self, n=1): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 342 | """Wake up one or more threads waiting on this condition, if any. |
| 343 | |
| 344 | If the calling thread has not acquired the lock when this method is |
| 345 | called, a RuntimeError is raised. |
| 346 | |
| 347 | This method wakes up at most n of the threads waiting for the condition |
| 348 | variable; it is a no-op if no threads are waiting. |
| 349 | |
| 350 | """ |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 351 | if not self._is_owned(): |
Georg Brandl | 495f7b5 | 2009-10-27 15:28:25 +0000 | [diff] [blame] | 352 | raise RuntimeError("cannot notify on un-acquired lock") |
Raymond Hettinger | b65e579 | 2013-03-10 20:34:16 -0700 | [diff] [blame] | 353 | all_waiters = self._waiters |
| 354 | waiters_to_notify = _deque(_islice(all_waiters, n)) |
| 355 | if not waiters_to_notify: |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 356 | return |
Raymond Hettinger | b65e579 | 2013-03-10 20:34:16 -0700 | [diff] [blame] | 357 | for waiter in waiters_to_notify: |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 358 | waiter.release() |
| 359 | try: |
Raymond Hettinger | b65e579 | 2013-03-10 20:34:16 -0700 | [diff] [blame] | 360 | all_waiters.remove(waiter) |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 361 | except ValueError: |
| 362 | pass |
| 363 | |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 364 | def notify_all(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 365 | """Wake up all threads waiting on this condition. |
| 366 | |
| 367 | If the calling thread has not acquired the lock when this method |
| 368 | is called, a RuntimeError is raised. |
| 369 | |
| 370 | """ |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 371 | self.notify(len(self._waiters)) |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 372 | |
Benjamin Peterson | b3085c9 | 2008-09-01 23:09:31 +0000 | [diff] [blame] | 373 | notifyAll = notify_all |
| 374 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 375 | |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 376 | class Semaphore: |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 377 | """This class implements semaphore objects. |
| 378 | |
| 379 | Semaphores manage a counter representing the number of release() calls minus |
| 380 | the number of acquire() calls, plus an initial value. The acquire() method |
| 381 | blocks if necessary until it can return without making the counter |
| 382 | negative. If not given, value defaults to 1. |
| 383 | |
| 384 | """ |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 385 | |
Andrew M. Kuchling | 39d3bfc | 2000-02-29 00:10:24 +0000 | [diff] [blame] | 386 | # After Tim Peters' semaphore class, but not quite the same (no maximum) |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 387 | |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 388 | def __init__(self, value=1): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 389 | if value < 0: |
| 390 | raise ValueError("semaphore initial value must be >= 0") |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 391 | self._cond = Condition(Lock()) |
| 392 | self._value = value |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 393 | |
Antoine Pitrou | 0454af9 | 2010-04-17 23:51:58 +0000 | [diff] [blame] | 394 | def acquire(self, blocking=True, timeout=None): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 395 | """Acquire a semaphore, decrementing the internal counter by one. |
| 396 | |
| 397 | When invoked without arguments: if the internal counter is larger than |
| 398 | zero on entry, decrement it by one and return immediately. If it is zero |
| 399 | on entry, block, waiting until some other thread has called release() to |
| 400 | make it larger than zero. This is done with proper interlocking so that |
| 401 | if multiple acquire() calls are blocked, release() will wake exactly one |
| 402 | of them up. The implementation may pick one at random, so the order in |
| 403 | which blocked threads are awakened should not be relied on. There is no |
| 404 | return value in this case. |
| 405 | |
| 406 | When invoked with blocking set to true, do the same thing as when called |
| 407 | without arguments, and return true. |
| 408 | |
| 409 | When invoked with blocking set to false, do not block. If a call without |
| 410 | an argument would block, return false immediately; otherwise, do the |
| 411 | same thing as when called without arguments, and return true. |
| 412 | |
| 413 | When invoked with a timeout other than None, it will block for at |
| 414 | most timeout seconds. If acquire does not complete successfully in |
| 415 | that interval, return false. Return true otherwise. |
| 416 | |
| 417 | """ |
Antoine Pitrou | 0454af9 | 2010-04-17 23:51:58 +0000 | [diff] [blame] | 418 | if not blocking and timeout is not None: |
| 419 | raise ValueError("can't specify timeout for non-blocking acquire") |
Guido van Rossum | 8ca162f | 2002-04-07 06:36:23 +0000 | [diff] [blame] | 420 | rc = False |
Antoine Pitrou | 0454af9 | 2010-04-17 23:51:58 +0000 | [diff] [blame] | 421 | endtime = None |
Serhiy Storchaka | 81a5855 | 2013-04-22 22:51:43 +0300 | [diff] [blame] | 422 | with self._cond: |
| 423 | while self._value == 0: |
| 424 | if not blocking: |
| 425 | break |
| 426 | if timeout is not None: |
| 427 | if endtime is None: |
| 428 | endtime = _time() + timeout |
| 429 | else: |
| 430 | timeout = endtime - _time() |
| 431 | if timeout <= 0: |
| 432 | break |
| 433 | self._cond.wait(timeout) |
| 434 | else: |
Serhiy Storchaka | b00b596 | 2013-04-22 22:54:16 +0300 | [diff] [blame] | 435 | self._value -= 1 |
Serhiy Storchaka | 81a5855 | 2013-04-22 22:51:43 +0300 | [diff] [blame] | 436 | rc = True |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 437 | return rc |
| 438 | |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 439 | __enter__ = acquire |
| 440 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 441 | def release(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 442 | """Release a semaphore, incrementing the internal counter by one. |
| 443 | |
| 444 | When the counter is zero on entry and another thread is waiting for it |
| 445 | to become larger than zero again, wake up that thread. |
| 446 | |
| 447 | """ |
Serhiy Storchaka | 81a5855 | 2013-04-22 22:51:43 +0300 | [diff] [blame] | 448 | with self._cond: |
Serhiy Storchaka | b00b596 | 2013-04-22 22:54:16 +0300 | [diff] [blame] | 449 | self._value += 1 |
Serhiy Storchaka | 81a5855 | 2013-04-22 22:51:43 +0300 | [diff] [blame] | 450 | self._cond.notify() |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 451 | |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 452 | def __exit__(self, t, v, tb): |
| 453 | self.release() |
Guido van Rossum | 1a5e21e | 2006-02-28 21:57:43 +0000 | [diff] [blame] | 454 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 455 | |
Éric Araujo | 0cdd445 | 2011-07-28 00:28:28 +0200 | [diff] [blame] | 456 | class BoundedSemaphore(Semaphore): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 457 | """Implements a bounded semaphore. |
| 458 | |
| 459 | A bounded semaphore checks to make sure its current value doesn't exceed its |
| 460 | initial value. If it does, ValueError is raised. In most situations |
| 461 | semaphores are used to guard resources with limited capacity. |
| 462 | |
| 463 | If the semaphore is released too many times it's a sign of a bug. If not |
| 464 | given, value defaults to 1. |
| 465 | |
| 466 | Like regular semaphores, bounded semaphores manage a counter representing |
| 467 | the number of release() calls minus the number of acquire() calls, plus an |
| 468 | initial value. The acquire() method blocks if necessary until it can return |
| 469 | without making the counter negative. If not given, value defaults to 1. |
| 470 | |
| 471 | """ |
| 472 | |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 473 | def __init__(self, value=1): |
| 474 | Semaphore.__init__(self, value) |
Skip Montanaro | e428bb7 | 2001-08-20 20:27:58 +0000 | [diff] [blame] | 475 | self._initial_value = value |
| 476 | |
| 477 | def release(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 478 | """Release a semaphore, incrementing the internal counter by one. |
| 479 | |
| 480 | When the counter is zero on entry and another thread is waiting for it |
| 481 | to become larger than zero again, wake up that thread. |
| 482 | |
| 483 | If the number of releases exceeds the number of acquires, |
| 484 | raise a ValueError. |
| 485 | |
| 486 | """ |
Tim Peters | 7634e1c | 2013-10-08 20:55:51 -0500 | [diff] [blame] | 487 | with self._cond: |
| 488 | if self._value >= self._initial_value: |
| 489 | raise ValueError("Semaphore released too many times") |
| 490 | self._value += 1 |
| 491 | self._cond.notify() |
Skip Montanaro | e428bb7 | 2001-08-20 20:27:58 +0000 | [diff] [blame] | 492 | |
| 493 | |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 494 | class Event: |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 495 | """Class implementing event objects. |
| 496 | |
| 497 | Events manage a flag that can be set to true with the set() method and reset |
| 498 | to false with the clear() method. The wait() method blocks until the flag is |
| 499 | true. The flag is initially false. |
| 500 | |
| 501 | """ |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 502 | |
| 503 | # After Tim Peters' event class (without is_posted()) |
| 504 | |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 505 | def __init__(self): |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 506 | self._cond = Condition(Lock()) |
| 507 | self._flag = False |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 508 | |
Gregory P. Smith | 9bd4a24 | 2011-01-04 18:33:38 +0000 | [diff] [blame] | 509 | def _reset_internal_locks(self): |
| 510 | # private! called by Thread._reset_internal_locks by _after_fork() |
Benjamin Peterson | 15982aa | 2015-10-05 21:56:22 -0700 | [diff] [blame] | 511 | self._cond.__init__(Lock()) |
Gregory P. Smith | 9bd4a24 | 2011-01-04 18:33:38 +0000 | [diff] [blame] | 512 | |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 513 | def is_set(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 514 | """Return true if and only if the internal flag is true.""" |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 515 | return self._flag |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 516 | |
Benjamin Peterson | b3085c9 | 2008-09-01 23:09:31 +0000 | [diff] [blame] | 517 | isSet = is_set |
Benjamin Peterson | f0923f5 | 2008-08-18 22:10:13 +0000 | [diff] [blame] | 518 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 519 | def set(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 520 | """Set the internal flag to true. |
| 521 | |
| 522 | All threads waiting for it to become true are awakened. Threads |
| 523 | that call wait() once the flag is true will not block at all. |
| 524 | |
| 525 | """ |
Benjamin Peterson | 414918a | 2015-10-10 19:34:46 -0700 | [diff] [blame] | 526 | with self._cond: |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 527 | self._flag = True |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 528 | self._cond.notify_all() |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 529 | |
| 530 | def clear(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 531 | """Reset the internal flag to false. |
| 532 | |
| 533 | Subsequently, threads calling wait() will block until set() is called to |
| 534 | set the internal flag to true again. |
| 535 | |
| 536 | """ |
Benjamin Peterson | 414918a | 2015-10-10 19:34:46 -0700 | [diff] [blame] | 537 | with self._cond: |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 538 | self._flag = False |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 539 | |
| 540 | def wait(self, timeout=None): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 541 | """Block until the internal flag is true. |
| 542 | |
| 543 | If the internal flag is true on entry, return immediately. Otherwise, |
| 544 | block until another thread calls set() to set the flag to true, or until |
| 545 | the optional timeout occurs. |
| 546 | |
| 547 | When the timeout argument is present and not None, it should be a |
| 548 | floating point number specifying a timeout for the operation in seconds |
| 549 | (or fractions thereof). |
| 550 | |
| 551 | This method returns the internal flag on exit, so it will always return |
| 552 | True except if a timeout is given and the operation times out. |
| 553 | |
| 554 | """ |
Benjamin Peterson | 414918a | 2015-10-10 19:34:46 -0700 | [diff] [blame] | 555 | with self._cond: |
Charles-François Natali | ded0348 | 2012-01-07 18:24:56 +0100 | [diff] [blame] | 556 | signaled = self._flag |
| 557 | if not signaled: |
| 558 | signaled = self._cond.wait(timeout) |
| 559 | return signaled |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 560 | |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 561 | |
| 562 | # A barrier class. Inspired in part by the pthread_barrier_* api and |
| 563 | # the CyclicBarrier class from Java. See |
| 564 | # http://sourceware.org/pthreads-win32/manual/pthread_barrier_init.html and |
| 565 | # http://java.sun.com/j2se/1.5.0/docs/api/java/util/concurrent/ |
| 566 | # CyclicBarrier.html |
| 567 | # for information. |
| 568 | # We maintain two main states, 'filling' and 'draining' enabling the barrier |
| 569 | # to be cyclic. Threads are not allowed into it until it has fully drained |
| 570 | # since the previous cycle. In addition, a 'resetting' state exists which is |
| 571 | # similar to 'draining' except that threads leave with a BrokenBarrierError, |
Ezio Melotti | e130a52 | 2011-10-19 10:58:56 +0300 | [diff] [blame] | 572 | # and a 'broken' state in which all threads get the exception. |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 573 | class Barrier: |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 574 | """Implements a Barrier. |
| 575 | |
| 576 | Useful for synchronizing a fixed number of threads at known synchronization |
Carl Bordum Hansen | 62fa51f | 2019-03-09 18:38:05 +0100 | [diff] [blame] | 577 | points. Threads block on 'wait()' and are simultaneously awoken once they |
| 578 | have all made that call. |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 579 | |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 580 | """ |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 581 | |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 582 | def __init__(self, parties, action=None, timeout=None): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 583 | """Create a barrier, initialised to 'parties' threads. |
| 584 | |
| 585 | 'action' is a callable which, when supplied, will be called by one of |
| 586 | the threads after they have all entered the barrier and just prior to |
Carl Bordum Hansen | 62fa51f | 2019-03-09 18:38:05 +0100 | [diff] [blame] | 587 | releasing them all. If a 'timeout' is provided, it is used as the |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 588 | default for all subsequent 'wait()' calls. |
| 589 | |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 590 | """ |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 591 | self._cond = Condition(Lock()) |
| 592 | self._action = action |
| 593 | self._timeout = timeout |
| 594 | self._parties = parties |
| 595 | self._state = 0 #0 filling, 1, draining, -1 resetting, -2 broken |
| 596 | self._count = 0 |
| 597 | |
| 598 | def wait(self, timeout=None): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 599 | """Wait for the barrier. |
| 600 | |
| 601 | When the specified number of threads have started waiting, they are all |
| 602 | simultaneously awoken. If an 'action' was provided for the barrier, one |
| 603 | of the threads will have executed that callback prior to returning. |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 604 | Returns an individual index number from 0 to 'parties-1'. |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 605 | |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 606 | """ |
| 607 | if timeout is None: |
| 608 | timeout = self._timeout |
| 609 | with self._cond: |
| 610 | self._enter() # Block while the barrier drains. |
| 611 | index = self._count |
| 612 | self._count += 1 |
| 613 | try: |
| 614 | if index + 1 == self._parties: |
| 615 | # We release the barrier |
| 616 | self._release() |
| 617 | else: |
| 618 | # We wait until someone releases us |
| 619 | self._wait(timeout) |
| 620 | return index |
| 621 | finally: |
| 622 | self._count -= 1 |
| 623 | # Wake up any threads waiting for barrier to drain. |
| 624 | self._exit() |
| 625 | |
| 626 | # Block until the barrier is ready for us, or raise an exception |
| 627 | # if it is broken. |
| 628 | def _enter(self): |
| 629 | while self._state in (-1, 1): |
| 630 | # It is draining or resetting, wait until done |
| 631 | self._cond.wait() |
| 632 | #see if the barrier is in a broken state |
| 633 | if self._state < 0: |
| 634 | raise BrokenBarrierError |
| 635 | assert self._state == 0 |
| 636 | |
| 637 | # Optionally run the 'action' and release the threads waiting |
| 638 | # in the barrier. |
| 639 | def _release(self): |
| 640 | try: |
| 641 | if self._action: |
| 642 | self._action() |
| 643 | # enter draining state |
| 644 | self._state = 1 |
| 645 | self._cond.notify_all() |
| 646 | except: |
| 647 | #an exception during the _action handler. Break and reraise |
| 648 | self._break() |
| 649 | raise |
| 650 | |
Martin Panter | 69332c1 | 2016-08-04 13:07:31 +0000 | [diff] [blame] | 651 | # Wait in the barrier until we are released. Raise an exception |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 652 | # if the barrier is reset or broken. |
| 653 | def _wait(self, timeout): |
Kristján Valur Jónsson | 6331520 | 2010-11-18 12:46:39 +0000 | [diff] [blame] | 654 | if not self._cond.wait_for(lambda : self._state != 0, timeout): |
| 655 | #timed out. Break the barrier |
| 656 | self._break() |
| 657 | raise BrokenBarrierError |
| 658 | if self._state < 0: |
| 659 | raise BrokenBarrierError |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 660 | assert self._state == 1 |
| 661 | |
| 662 | # If we are the last thread to exit the barrier, signal any threads |
| 663 | # waiting for the barrier to drain. |
| 664 | def _exit(self): |
| 665 | if self._count == 0: |
| 666 | if self._state in (-1, 1): |
| 667 | #resetting or draining |
| 668 | self._state = 0 |
| 669 | self._cond.notify_all() |
| 670 | |
| 671 | def reset(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 672 | """Reset the barrier to the initial state. |
| 673 | |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 674 | Any threads currently waiting will get the BrokenBarrier exception |
| 675 | raised. |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 676 | |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 677 | """ |
| 678 | with self._cond: |
| 679 | if self._count > 0: |
| 680 | if self._state == 0: |
| 681 | #reset the barrier, waking up threads |
| 682 | self._state = -1 |
| 683 | elif self._state == -2: |
| 684 | #was broken, set it to reset state |
| 685 | #which clears when the last thread exits |
| 686 | self._state = -1 |
| 687 | else: |
| 688 | self._state = 0 |
| 689 | self._cond.notify_all() |
| 690 | |
| 691 | def abort(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 692 | """Place the barrier into a 'broken' state. |
| 693 | |
| 694 | Useful in case of error. Any currently waiting threads and threads |
| 695 | attempting to 'wait()' will have BrokenBarrierError raised. |
| 696 | |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 697 | """ |
| 698 | with self._cond: |
| 699 | self._break() |
| 700 | |
| 701 | def _break(self): |
| 702 | # An internal error was detected. The barrier is set to |
| 703 | # a broken state all parties awakened. |
| 704 | self._state = -2 |
| 705 | self._cond.notify_all() |
| 706 | |
| 707 | @property |
| 708 | def parties(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 709 | """Return the number of threads required to trip the barrier.""" |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 710 | return self._parties |
| 711 | |
| 712 | @property |
| 713 | def n_waiting(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 714 | """Return the number of threads currently waiting at the barrier.""" |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 715 | # We don't need synchronization here since this is an ephemeral result |
| 716 | # anyway. It returns the correct value in the steady state. |
| 717 | if self._state == 0: |
| 718 | return self._count |
| 719 | return 0 |
| 720 | |
| 721 | @property |
| 722 | def broken(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 723 | """Return True if the barrier is in a broken state.""" |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 724 | return self._state == -2 |
| 725 | |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 726 | # exception raised by the Barrier class |
| 727 | class BrokenBarrierError(RuntimeError): |
| 728 | pass |
Kristján Valur Jónsson | 3be0003 | 2010-10-28 09:43:10 +0000 | [diff] [blame] | 729 | |
| 730 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 731 | # Helper to generate new thread names |
R David Murray | b186f1df | 2014-10-04 17:43:54 -0400 | [diff] [blame] | 732 | _counter = _count().__next__ |
| 733 | _counter() # Consume 0 so first non-main thread has id 1. |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 734 | def _newname(template="Thread-%d"): |
R David Murray | b186f1df | 2014-10-04 17:43:54 -0400 | [diff] [blame] | 735 | return template % _counter() |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 736 | |
| 737 | # Active thread administration |
| 738 | _active_limbo_lock = _allocate_lock() |
Tim Peters | 711906e | 2005-01-08 07:30:42 +0000 | [diff] [blame] | 739 | _active = {} # maps thread id to Thread object |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 740 | _limbo = {} |
Antoine Pitrou | c081c0c | 2011-07-15 22:12:24 +0200 | [diff] [blame] | 741 | _dangling = WeakSet() |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 742 | |
| 743 | # Main class for threads |
| 744 | |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 745 | class Thread: |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 746 | """A class that represents a thread of control. |
| 747 | |
| 748 | This class can be safely subclassed in a limited fashion. There are two ways |
| 749 | to specify the activity: by passing a callable object to the constructor, or |
| 750 | by overriding the run() method in a subclass. |
| 751 | |
| 752 | """ |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 753 | |
Serhiy Storchaka | 52005c2 | 2014-09-21 22:08:13 +0300 | [diff] [blame] | 754 | _initialized = False |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 755 | |
| 756 | def __init__(self, group=None, target=None, name=None, |
Victor Stinner | 135b6d8 | 2012-03-03 01:32:57 +0100 | [diff] [blame] | 757 | args=(), kwargs=None, *, daemon=None): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 758 | """This constructor should always be called with keyword arguments. Arguments are: |
| 759 | |
| 760 | *group* should be None; reserved for future extension when a ThreadGroup |
| 761 | class is implemented. |
| 762 | |
| 763 | *target* is the callable object to be invoked by the run() |
| 764 | method. Defaults to None, meaning nothing is called. |
| 765 | |
| 766 | *name* is the thread name. By default, a unique name is constructed of |
| 767 | the form "Thread-N" where N is a small decimal number. |
| 768 | |
| 769 | *args* is the argument tuple for the target invocation. Defaults to (). |
| 770 | |
| 771 | *kwargs* is a dictionary of keyword arguments for the target |
| 772 | invocation. Defaults to {}. |
| 773 | |
| 774 | If a subclass overrides the constructor, it must make sure to invoke |
| 775 | the base class constructor (Thread.__init__()) before doing anything |
| 776 | else to the thread. |
| 777 | |
| 778 | """ |
Guido van Rossum | 5a43e1a | 1998-06-09 19:04:26 +0000 | [diff] [blame] | 779 | assert group is None, "group argument must be None for now" |
Georg Brandl | a4a8b82 | 2005-07-15 09:13:21 +0000 | [diff] [blame] | 780 | if kwargs is None: |
| 781 | kwargs = {} |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 782 | self._target = target |
| 783 | self._name = str(name or _newname()) |
| 784 | self._args = args |
| 785 | self._kwargs = kwargs |
Antoine Pitrou | 0bd4deb | 2011-02-25 22:07:43 +0000 | [diff] [blame] | 786 | if daemon is not None: |
| 787 | self._daemonic = daemon |
| 788 | else: |
| 789 | self._daemonic = current_thread().daemon |
Georg Brandl | 0c77a82 | 2008-06-10 16:37:50 +0000 | [diff] [blame] | 790 | self._ident = None |
Jake Tesler | b121f63 | 2019-05-22 08:43:17 -0700 | [diff] [blame] | 791 | if _HAVE_THREAD_NATIVE_ID: |
| 792 | self._native_id = None |
Antoine Pitrou | 7b47699 | 2013-09-07 23:38:37 +0200 | [diff] [blame] | 793 | self._tstate_lock = None |
Christian Heimes | 9e7f1d2 | 2008-02-28 12:27:11 +0000 | [diff] [blame] | 794 | self._started = Event() |
Tim Peters | c363a23 | 2013-09-08 18:44:40 -0500 | [diff] [blame] | 795 | self._is_stopped = False |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 796 | self._initialized = True |
Victor Stinner | cd590a7 | 2019-05-28 00:39:52 +0200 | [diff] [blame^] | 797 | # Copy of sys.stderr used by self._invoke_excepthook() |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 798 | self._stderr = _sys.stderr |
Victor Stinner | cd590a7 | 2019-05-28 00:39:52 +0200 | [diff] [blame^] | 799 | self._invoke_excepthook = _make_invoke_excepthook() |
Antoine Pitrou | 5da7e79 | 2013-09-08 13:19:06 +0200 | [diff] [blame] | 800 | # For debugging and _after_fork() |
Antoine Pitrou | c081c0c | 2011-07-15 22:12:24 +0200 | [diff] [blame] | 801 | _dangling.add(self) |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 802 | |
Antoine Pitrou | 7b47699 | 2013-09-07 23:38:37 +0200 | [diff] [blame] | 803 | def _reset_internal_locks(self, is_alive): |
Gregory P. Smith | 9bd4a24 | 2011-01-04 18:33:38 +0000 | [diff] [blame] | 804 | # private! Called by _after_fork() to reset our internal locks as |
| 805 | # they may be in an invalid state leading to a deadlock or crash. |
Gregory P. Smith | 9bd4a24 | 2011-01-04 18:33:38 +0000 | [diff] [blame] | 806 | self._started._reset_internal_locks() |
Antoine Pitrou | 7b47699 | 2013-09-07 23:38:37 +0200 | [diff] [blame] | 807 | if is_alive: |
| 808 | self._set_tstate_lock() |
| 809 | else: |
| 810 | # The thread isn't alive after fork: it doesn't have a tstate |
| 811 | # anymore. |
Tim Peters | b5e9ac9 | 2013-09-09 14:41:50 -0500 | [diff] [blame] | 812 | self._is_stopped = True |
Antoine Pitrou | 7b47699 | 2013-09-07 23:38:37 +0200 | [diff] [blame] | 813 | self._tstate_lock = None |
Gregory P. Smith | 9bd4a24 | 2011-01-04 18:33:38 +0000 | [diff] [blame] | 814 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 815 | def __repr__(self): |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 816 | assert self._initialized, "Thread.__init__() was not called" |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 817 | status = "initial" |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 818 | if self._started.is_set(): |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 819 | status = "started" |
Tim Peters | 72460fa | 2013-09-09 18:48:24 -0500 | [diff] [blame] | 820 | self.is_alive() # easy way to get ._is_stopped set when appropriate |
Tim Peters | c363a23 | 2013-09-08 18:44:40 -0500 | [diff] [blame] | 821 | if self._is_stopped: |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 822 | status = "stopped" |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 823 | if self._daemonic: |
Georg Brandl | 0c77a82 | 2008-06-10 16:37:50 +0000 | [diff] [blame] | 824 | status += " daemon" |
| 825 | if self._ident is not None: |
| 826 | status += " %s" % self._ident |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 827 | return "<%s(%s, %s)>" % (self.__class__.__name__, self._name, status) |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 828 | |
| 829 | def start(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 830 | """Start the thread's activity. |
| 831 | |
| 832 | It must be called at most once per thread object. It arranges for the |
| 833 | object's run() method to be invoked in a separate thread of control. |
| 834 | |
| 835 | This method will raise a RuntimeError if called more than once on the |
| 836 | same thread object. |
| 837 | |
| 838 | """ |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 839 | if not self._initialized: |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 840 | raise RuntimeError("thread.__init__() not called") |
Christian Heimes | 9e7f1d2 | 2008-02-28 12:27:11 +0000 | [diff] [blame] | 841 | |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 842 | if self._started.is_set(): |
Senthil Kumaran | fdd4d0f | 2010-04-06 03:30:18 +0000 | [diff] [blame] | 843 | raise RuntimeError("threads can only be started once") |
Benjamin Peterson | d23f822 | 2009-04-05 19:13:16 +0000 | [diff] [blame] | 844 | with _active_limbo_lock: |
| 845 | _limbo[self] = self |
Gregory P. Smith | 3fdd964 | 2010-02-28 18:57:46 +0000 | [diff] [blame] | 846 | try: |
| 847 | _start_new_thread(self._bootstrap, ()) |
| 848 | except Exception: |
| 849 | with _active_limbo_lock: |
| 850 | del _limbo[self] |
| 851 | raise |
Christian Heimes | 9e7f1d2 | 2008-02-28 12:27:11 +0000 | [diff] [blame] | 852 | self._started.wait() |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 853 | |
| 854 | def run(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 855 | """Method representing the thread's activity. |
| 856 | |
| 857 | You may override this method in a subclass. The standard run() method |
| 858 | invokes the callable object passed to the object's constructor as the |
| 859 | target argument, if any, with sequential and keyword arguments taken |
| 860 | from the args and kwargs arguments, respectively. |
| 861 | |
| 862 | """ |
Christian Heimes | d3eb5a15 | 2008-02-24 00:38:49 +0000 | [diff] [blame] | 863 | try: |
| 864 | if self._target: |
| 865 | self._target(*self._args, **self._kwargs) |
| 866 | finally: |
| 867 | # Avoid a refcycle if the thread is running a function with |
| 868 | # an argument that has a member that points to the thread. |
| 869 | del self._target, self._args, self._kwargs |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 870 | |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 871 | def _bootstrap(self): |
Guido van Rossum | 61e21b5 | 2007-08-20 19:06:03 +0000 | [diff] [blame] | 872 | # Wrapper around the real bootstrap code that ignores |
| 873 | # exceptions during interpreter cleanup. Those typically |
| 874 | # happen when a daemon thread wakes up at an unfortunate |
| 875 | # moment, finds the world around it destroyed, and raises some |
| 876 | # random exception *** while trying to report the exception in |
Christian Heimes | 9e7f1d2 | 2008-02-28 12:27:11 +0000 | [diff] [blame] | 877 | # _bootstrap_inner() below ***. Those random exceptions |
Guido van Rossum | 61e21b5 | 2007-08-20 19:06:03 +0000 | [diff] [blame] | 878 | # don't help anybody, and they confuse users, so we suppress |
| 879 | # them. We suppress them only when it appears that the world |
| 880 | # indeed has already been destroyed, so that exceptions in |
Christian Heimes | 9e7f1d2 | 2008-02-28 12:27:11 +0000 | [diff] [blame] | 881 | # _bootstrap_inner() during normal business hours are properly |
Guido van Rossum | 61e21b5 | 2007-08-20 19:06:03 +0000 | [diff] [blame] | 882 | # reported. Also, we only suppress them for daemonic threads; |
| 883 | # if a non-daemonic encounters this, something else is wrong. |
| 884 | try: |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 885 | self._bootstrap_inner() |
Guido van Rossum | 61e21b5 | 2007-08-20 19:06:03 +0000 | [diff] [blame] | 886 | except: |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 887 | if self._daemonic and _sys is None: |
Guido van Rossum | 61e21b5 | 2007-08-20 19:06:03 +0000 | [diff] [blame] | 888 | return |
| 889 | raise |
| 890 | |
Benjamin Peterson | d23f822 | 2009-04-05 19:13:16 +0000 | [diff] [blame] | 891 | def _set_ident(self): |
Victor Stinner | 2a12974 | 2011-05-30 23:02:52 +0200 | [diff] [blame] | 892 | self._ident = get_ident() |
Benjamin Peterson | d23f822 | 2009-04-05 19:13:16 +0000 | [diff] [blame] | 893 | |
Jake Tesler | b121f63 | 2019-05-22 08:43:17 -0700 | [diff] [blame] | 894 | if _HAVE_THREAD_NATIVE_ID: |
| 895 | def _set_native_id(self): |
| 896 | self._native_id = get_native_id() |
| 897 | |
Antoine Pitrou | 7b47699 | 2013-09-07 23:38:37 +0200 | [diff] [blame] | 898 | def _set_tstate_lock(self): |
| 899 | """ |
| 900 | Set a lock object which will be released by the interpreter when |
| 901 | the underlying thread state (see pystate.h) gets deleted. |
| 902 | """ |
| 903 | self._tstate_lock = _set_sentinel() |
| 904 | self._tstate_lock.acquire() |
| 905 | |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 906 | def _bootstrap_inner(self): |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 907 | try: |
Benjamin Peterson | d23f822 | 2009-04-05 19:13:16 +0000 | [diff] [blame] | 908 | self._set_ident() |
Antoine Pitrou | 7b47699 | 2013-09-07 23:38:37 +0200 | [diff] [blame] | 909 | self._set_tstate_lock() |
Jake Tesler | b121f63 | 2019-05-22 08:43:17 -0700 | [diff] [blame] | 910 | if _HAVE_THREAD_NATIVE_ID: |
| 911 | self._set_native_id() |
Christian Heimes | 9e7f1d2 | 2008-02-28 12:27:11 +0000 | [diff] [blame] | 912 | self._started.set() |
Benjamin Peterson | d23f822 | 2009-04-05 19:13:16 +0000 | [diff] [blame] | 913 | with _active_limbo_lock: |
| 914 | _active[self._ident] = self |
| 915 | del _limbo[self] |
Jeremy Hylton | bfccb35 | 2003-06-29 16:58:41 +0000 | [diff] [blame] | 916 | |
| 917 | if _trace_hook: |
Jeremy Hylton | bfccb35 | 2003-06-29 16:58:41 +0000 | [diff] [blame] | 918 | _sys.settrace(_trace_hook) |
| 919 | if _profile_hook: |
Jeremy Hylton | bfccb35 | 2003-06-29 16:58:41 +0000 | [diff] [blame] | 920 | _sys.setprofile(_profile_hook) |
Tim Peters | d1b108b | 2003-06-29 17:24:17 +0000 | [diff] [blame] | 921 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 922 | try: |
| 923 | self.run() |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 924 | except: |
Victor Stinner | cd590a7 | 2019-05-28 00:39:52 +0200 | [diff] [blame^] | 925 | self._invoke_excepthook(self) |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 926 | finally: |
Christian Heimes | 1af737c | 2008-01-23 08:24:23 +0000 | [diff] [blame] | 927 | with _active_limbo_lock: |
Christian Heimes | 1af737c | 2008-01-23 08:24:23 +0000 | [diff] [blame] | 928 | try: |
Georg Brandl | 0c77a82 | 2008-06-10 16:37:50 +0000 | [diff] [blame] | 929 | # We don't call self._delete() because it also |
Christian Heimes | 1af737c | 2008-01-23 08:24:23 +0000 | [diff] [blame] | 930 | # grabs _active_limbo_lock. |
Victor Stinner | 2a12974 | 2011-05-30 23:02:52 +0200 | [diff] [blame] | 931 | del _active[get_ident()] |
Christian Heimes | 1af737c | 2008-01-23 08:24:23 +0000 | [diff] [blame] | 932 | except: |
| 933 | pass |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 934 | |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 935 | def _stop(self): |
Tim Peters | b5e9ac9 | 2013-09-09 14:41:50 -0500 | [diff] [blame] | 936 | # After calling ._stop(), .is_alive() returns False and .join() returns |
| 937 | # immediately. ._tstate_lock must be released before calling ._stop(). |
| 938 | # |
| 939 | # Normal case: C code at the end of the thread's life |
| 940 | # (release_sentinel in _threadmodule.c) releases ._tstate_lock, and |
| 941 | # that's detected by our ._wait_for_tstate_lock(), called by .join() |
| 942 | # and .is_alive(). Any number of threads _may_ call ._stop() |
| 943 | # simultaneously (for example, if multiple threads are blocked in |
| 944 | # .join() calls), and they're not serialized. That's harmless - |
| 945 | # they'll just make redundant rebindings of ._is_stopped and |
| 946 | # ._tstate_lock. Obscure: we rebind ._tstate_lock last so that the |
| 947 | # "assert self._is_stopped" in ._wait_for_tstate_lock() always works |
| 948 | # (the assert is executed only if ._tstate_lock is None). |
| 949 | # |
| 950 | # Special case: _main_thread releases ._tstate_lock via this |
| 951 | # module's _shutdown() function. |
| 952 | lock = self._tstate_lock |
| 953 | if lock is not None: |
| 954 | assert not lock.locked() |
Tim Peters | 7875523 | 2013-09-09 13:47:16 -0500 | [diff] [blame] | 955 | self._is_stopped = True |
| 956 | self._tstate_lock = None |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 957 | |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 958 | def _delete(self): |
Tim Peters | 2142993 | 2004-07-21 03:36:52 +0000 | [diff] [blame] | 959 | "Remove current thread from the dict of currently running threads." |
Antoine Pitrou | a6a4dc8 | 2017-09-07 18:56:24 +0200 | [diff] [blame] | 960 | with _active_limbo_lock: |
| 961 | del _active[get_ident()] |
| 962 | # There must not be any python code between the previous line |
| 963 | # and after the lock is released. Otherwise a tracing function |
| 964 | # could try to acquire the lock again in the same thread, (in |
| 965 | # current_thread()), and would block. |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 966 | |
| 967 | def join(self, timeout=None): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 968 | """Wait until the thread terminates. |
| 969 | |
| 970 | This blocks the calling thread until the thread whose join() method is |
| 971 | called terminates -- either normally or through an unhandled exception |
| 972 | or until the optional timeout occurs. |
| 973 | |
| 974 | When the timeout argument is present and not None, it should be a |
| 975 | floating point number specifying a timeout for the operation in seconds |
| 976 | (or fractions thereof). As join() always returns None, you must call |
Dong-hee Na | 36d9e9a | 2019-01-18 18:50:47 +0900 | [diff] [blame] | 977 | is_alive() after join() to decide whether a timeout happened -- if the |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 978 | thread is still alive, the join() call timed out. |
| 979 | |
| 980 | When the timeout argument is not present or None, the operation will |
| 981 | block until the thread terminates. |
| 982 | |
| 983 | A thread can be join()ed many times. |
| 984 | |
| 985 | join() raises a RuntimeError if an attempt is made to join the current |
| 986 | thread as that would cause a deadlock. It is also an error to join() a |
| 987 | thread before it has been started and attempts to do so raises the same |
| 988 | exception. |
| 989 | |
| 990 | """ |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 991 | if not self._initialized: |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 992 | raise RuntimeError("Thread.__init__() not called") |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 993 | if not self._started.is_set(): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 994 | raise RuntimeError("cannot join thread before it is started") |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 995 | if self is current_thread(): |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 996 | raise RuntimeError("cannot join current thread") |
Tim Peters | e5bb0bf | 2013-10-25 20:46:51 -0500 | [diff] [blame] | 997 | |
Tim Peters | c363a23 | 2013-09-08 18:44:40 -0500 | [diff] [blame] | 998 | if timeout is None: |
| 999 | self._wait_for_tstate_lock() |
Tim Peters | 7bad39f | 2013-10-25 22:33:52 -0500 | [diff] [blame] | 1000 | else: |
| 1001 | # the behavior of a negative timeout isn't documented, but |
Tim Peters | a577f1e | 2013-10-26 11:56:16 -0500 | [diff] [blame] | 1002 | # historically .join(timeout=x) for x<0 has acted as if timeout=0 |
Tim Peters | 7bad39f | 2013-10-25 22:33:52 -0500 | [diff] [blame] | 1003 | self._wait_for_tstate_lock(timeout=max(timeout, 0)) |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 1004 | |
Tim Peters | c363a23 | 2013-09-08 18:44:40 -0500 | [diff] [blame] | 1005 | def _wait_for_tstate_lock(self, block=True, timeout=-1): |
Antoine Pitrou | 7b47699 | 2013-09-07 23:38:37 +0200 | [diff] [blame] | 1006 | # Issue #18808: wait for the thread state to be gone. |
Tim Peters | c363a23 | 2013-09-08 18:44:40 -0500 | [diff] [blame] | 1007 | # At the end of the thread's life, after all knowledge of the thread |
| 1008 | # is removed from C data structures, C code releases our _tstate_lock. |
Martin Panter | 46f5072 | 2016-05-26 05:35:26 +0000 | [diff] [blame] | 1009 | # This method passes its arguments to _tstate_lock.acquire(). |
Tim Peters | c363a23 | 2013-09-08 18:44:40 -0500 | [diff] [blame] | 1010 | # If the lock is acquired, the C code is done, and self._stop() is |
| 1011 | # called. That sets ._is_stopped to True, and ._tstate_lock to None. |
Antoine Pitrou | 7b47699 | 2013-09-07 23:38:37 +0200 | [diff] [blame] | 1012 | lock = self._tstate_lock |
Tim Peters | c363a23 | 2013-09-08 18:44:40 -0500 | [diff] [blame] | 1013 | if lock is None: # already determined that the C code is done |
| 1014 | assert self._is_stopped |
| 1015 | elif lock.acquire(block, timeout): |
Antoine Pitrou | 7b47699 | 2013-09-07 23:38:37 +0200 | [diff] [blame] | 1016 | lock.release() |
Tim Peters | c363a23 | 2013-09-08 18:44:40 -0500 | [diff] [blame] | 1017 | self._stop() |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1018 | |
Benjamin Peterson | fdbea96 | 2008-08-18 17:33:47 +0000 | [diff] [blame] | 1019 | @property |
| 1020 | def name(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 1021 | """A string used for identification purposes only. |
| 1022 | |
| 1023 | It has no semantics. Multiple threads may be given the same name. The |
| 1024 | initial name is set by the constructor. |
| 1025 | |
| 1026 | """ |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 1027 | assert self._initialized, "Thread.__init__() not called" |
| 1028 | return self._name |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1029 | |
Benjamin Peterson | fdbea96 | 2008-08-18 17:33:47 +0000 | [diff] [blame] | 1030 | @name.setter |
| 1031 | def name(self, name): |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 1032 | assert self._initialized, "Thread.__init__() not called" |
| 1033 | self._name = str(name) |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1034 | |
Benjamin Peterson | 773c17b | 2008-08-18 16:45:31 +0000 | [diff] [blame] | 1035 | @property |
| 1036 | def ident(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 1037 | """Thread identifier of this thread or None if it has not been started. |
| 1038 | |
Skip Montanaro | 5634331 | 2018-05-18 13:38:36 -0500 | [diff] [blame] | 1039 | This is a nonzero integer. See the get_ident() function. Thread |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 1040 | identifiers may be recycled when a thread exits and another thread is |
| 1041 | created. The identifier is available even after the thread has exited. |
| 1042 | |
| 1043 | """ |
Georg Brandl | 0c77a82 | 2008-06-10 16:37:50 +0000 | [diff] [blame] | 1044 | assert self._initialized, "Thread.__init__() not called" |
| 1045 | return self._ident |
| 1046 | |
Jake Tesler | b121f63 | 2019-05-22 08:43:17 -0700 | [diff] [blame] | 1047 | if _HAVE_THREAD_NATIVE_ID: |
| 1048 | @property |
| 1049 | def native_id(self): |
| 1050 | """Native integral thread ID of this thread, or None if it has not been started. |
| 1051 | |
| 1052 | This is a non-negative integer. See the get_native_id() function. |
| 1053 | This represents the Thread ID as reported by the kernel. |
| 1054 | |
| 1055 | """ |
| 1056 | assert self._initialized, "Thread.__init__() not called" |
| 1057 | return self._native_id |
| 1058 | |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 1059 | def is_alive(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 1060 | """Return whether the thread is alive. |
| 1061 | |
| 1062 | This method returns True just before the run() method starts until just |
| 1063 | after the run() method terminates. The module function enumerate() |
| 1064 | returns a list of all alive threads. |
| 1065 | |
| 1066 | """ |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 1067 | assert self._initialized, "Thread.__init__() not called" |
Tim Peters | c363a23 | 2013-09-08 18:44:40 -0500 | [diff] [blame] | 1068 | if self._is_stopped or not self._started.is_set(): |
Antoine Pitrou | 7b47699 | 2013-09-07 23:38:37 +0200 | [diff] [blame] | 1069 | return False |
Antoine Pitrou | 7b47699 | 2013-09-07 23:38:37 +0200 | [diff] [blame] | 1070 | self._wait_for_tstate_lock(False) |
Tim Peters | c363a23 | 2013-09-08 18:44:40 -0500 | [diff] [blame] | 1071 | return not self._is_stopped |
Tim Peters | b90f89a | 2001-01-15 03:26:36 +0000 | [diff] [blame] | 1072 | |
Dong-hee Na | 89669ff | 2019-01-17 21:14:45 +0900 | [diff] [blame] | 1073 | def isAlive(self): |
| 1074 | """Return whether the thread is alive. |
| 1075 | |
| 1076 | This method is deprecated, use is_alive() instead. |
| 1077 | """ |
| 1078 | import warnings |
| 1079 | warnings.warn('isAlive() is deprecated, use is_alive() instead', |
| 1080 | DeprecationWarning, stacklevel=2) |
| 1081 | return self.is_alive() |
Benjamin Peterson | f0923f5 | 2008-08-18 22:10:13 +0000 | [diff] [blame] | 1082 | |
Benjamin Peterson | fdbea96 | 2008-08-18 17:33:47 +0000 | [diff] [blame] | 1083 | @property |
| 1084 | def daemon(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 1085 | """A boolean value indicating whether this thread is a daemon thread. |
| 1086 | |
| 1087 | This must be set before start() is called, otherwise RuntimeError is |
| 1088 | raised. Its initial value is inherited from the creating thread; the |
| 1089 | main thread is not a daemon thread and therefore all threads created in |
| 1090 | the main thread default to daemon = False. |
| 1091 | |
| 1092 | The entire Python program exits when no alive non-daemon threads are |
| 1093 | left. |
| 1094 | |
| 1095 | """ |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 1096 | assert self._initialized, "Thread.__init__() not called" |
| 1097 | return self._daemonic |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1098 | |
Benjamin Peterson | fdbea96 | 2008-08-18 17:33:47 +0000 | [diff] [blame] | 1099 | @daemon.setter |
| 1100 | def daemon(self, daemonic): |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 1101 | if not self._initialized: |
Guido van Rossum | cd16bf6 | 2007-06-13 18:07:49 +0000 | [diff] [blame] | 1102 | raise RuntimeError("Thread.__init__() not called") |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 1103 | if self._started.is_set(): |
Antoine Pitrou | 1095907 | 2014-03-17 18:22:41 +0100 | [diff] [blame] | 1104 | raise RuntimeError("cannot set daemon status of active thread") |
Guido van Rossum | d064899 | 2007-08-20 19:25:41 +0000 | [diff] [blame] | 1105 | self._daemonic = daemonic |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1106 | |
Benjamin Peterson | 6640d72 | 2008-08-18 18:16:46 +0000 | [diff] [blame] | 1107 | def isDaemon(self): |
| 1108 | return self.daemon |
| 1109 | |
| 1110 | def setDaemon(self, daemonic): |
| 1111 | self.daemon = daemonic |
| 1112 | |
| 1113 | def getName(self): |
| 1114 | return self.name |
| 1115 | |
| 1116 | def setName(self, name): |
| 1117 | self.name = name |
| 1118 | |
Victor Stinner | cd590a7 | 2019-05-28 00:39:52 +0200 | [diff] [blame^] | 1119 | |
| 1120 | try: |
| 1121 | from _thread import (_excepthook as excepthook, |
| 1122 | _ExceptHookArgs as ExceptHookArgs) |
| 1123 | except ImportError: |
| 1124 | # Simple Python implementation if _thread._excepthook() is not available |
| 1125 | from traceback import print_exception as _print_exception |
| 1126 | from collections import namedtuple |
| 1127 | |
| 1128 | _ExceptHookArgs = namedtuple( |
| 1129 | 'ExceptHookArgs', |
| 1130 | 'exc_type exc_value exc_traceback thread') |
| 1131 | |
| 1132 | def ExceptHookArgs(args): |
| 1133 | return _ExceptHookArgs(*args) |
| 1134 | |
| 1135 | def excepthook(args, /): |
| 1136 | """ |
| 1137 | Handle uncaught Thread.run() exception. |
| 1138 | """ |
| 1139 | if args.exc_type == SystemExit: |
| 1140 | # silently ignore SystemExit |
| 1141 | return |
| 1142 | |
| 1143 | if _sys is not None and _sys.stderr is not None: |
| 1144 | stderr = _sys.stderr |
| 1145 | elif args.thread is not None: |
| 1146 | stderr = args.thread._stderr |
| 1147 | if stderr is None: |
| 1148 | # do nothing if sys.stderr is None and sys.stderr was None |
| 1149 | # when the thread was created |
| 1150 | return |
| 1151 | else: |
| 1152 | # do nothing if sys.stderr is None and args.thread is None |
| 1153 | return |
| 1154 | |
| 1155 | if args.thread is not None: |
| 1156 | name = args.thread.name |
| 1157 | else: |
| 1158 | name = get_ident() |
| 1159 | print(f"Exception in thread {name}:", |
| 1160 | file=stderr, flush=True) |
| 1161 | _print_exception(args.exc_type, args.exc_value, args.exc_traceback, |
| 1162 | file=stderr) |
| 1163 | stderr.flush() |
| 1164 | |
| 1165 | |
| 1166 | def _make_invoke_excepthook(): |
| 1167 | # Create a local namespace to ensure that variables remain alive |
| 1168 | # when _invoke_excepthook() is called, even if it is called late during |
| 1169 | # Python shutdown. It is mostly needed for daemon threads. |
| 1170 | |
| 1171 | old_excepthook = excepthook |
| 1172 | old_sys_excepthook = _sys.excepthook |
| 1173 | if old_excepthook is None: |
| 1174 | raise RuntimeError("threading.excepthook is None") |
| 1175 | if old_sys_excepthook is None: |
| 1176 | raise RuntimeError("sys.excepthook is None") |
| 1177 | |
| 1178 | sys_exc_info = _sys.exc_info |
| 1179 | local_print = print |
| 1180 | local_sys = _sys |
| 1181 | |
| 1182 | def invoke_excepthook(thread): |
| 1183 | global excepthook |
| 1184 | try: |
| 1185 | hook = excepthook |
| 1186 | if hook is None: |
| 1187 | hook = old_excepthook |
| 1188 | |
| 1189 | args = ExceptHookArgs([*sys_exc_info(), thread]) |
| 1190 | |
| 1191 | hook(args) |
| 1192 | except Exception as exc: |
| 1193 | exc.__suppress_context__ = True |
| 1194 | del exc |
| 1195 | |
| 1196 | if local_sys is not None and local_sys.stderr is not None: |
| 1197 | stderr = local_sys.stderr |
| 1198 | else: |
| 1199 | stderr = thread._stderr |
| 1200 | |
| 1201 | local_print("Exception in threading.excepthook:", |
| 1202 | file=stderr, flush=True) |
| 1203 | |
| 1204 | if local_sys is not None and local_sys.excepthook is not None: |
| 1205 | sys_excepthook = local_sys.excepthook |
| 1206 | else: |
| 1207 | sys_excepthook = old_sys_excepthook |
| 1208 | |
| 1209 | sys_excepthook(*sys_exc_info()) |
| 1210 | finally: |
| 1211 | # Break reference cycle (exception stored in a variable) |
| 1212 | args = None |
| 1213 | |
| 1214 | return invoke_excepthook |
| 1215 | |
| 1216 | |
Martin v. Löwis | 44f8696 | 2001-09-05 13:44:54 +0000 | [diff] [blame] | 1217 | # The timer class was contributed by Itamar Shtull-Trauring |
| 1218 | |
Éric Araujo | 0cdd445 | 2011-07-28 00:28:28 +0200 | [diff] [blame] | 1219 | class Timer(Thread): |
Martin v. Löwis | 44f8696 | 2001-09-05 13:44:54 +0000 | [diff] [blame] | 1220 | """Call a function after a specified number of seconds: |
Tim Peters | b64bec3 | 2001-09-18 02:26:39 +0000 | [diff] [blame] | 1221 | |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 1222 | t = Timer(30.0, f, args=None, kwargs=None) |
| 1223 | t.start() |
| 1224 | t.cancel() # stop the timer's action if it's still waiting |
| 1225 | |
Martin v. Löwis | 44f8696 | 2001-09-05 13:44:54 +0000 | [diff] [blame] | 1226 | """ |
Tim Peters | b64bec3 | 2001-09-18 02:26:39 +0000 | [diff] [blame] | 1227 | |
R David Murray | 19aeb43 | 2013-03-30 17:19:38 -0400 | [diff] [blame] | 1228 | def __init__(self, interval, function, args=None, kwargs=None): |
Martin v. Löwis | 44f8696 | 2001-09-05 13:44:54 +0000 | [diff] [blame] | 1229 | Thread.__init__(self) |
| 1230 | self.interval = interval |
| 1231 | self.function = function |
R David Murray | 19aeb43 | 2013-03-30 17:19:38 -0400 | [diff] [blame] | 1232 | self.args = args if args is not None else [] |
| 1233 | self.kwargs = kwargs if kwargs is not None else {} |
Martin v. Löwis | 44f8696 | 2001-09-05 13:44:54 +0000 | [diff] [blame] | 1234 | self.finished = Event() |
Tim Peters | b64bec3 | 2001-09-18 02:26:39 +0000 | [diff] [blame] | 1235 | |
Martin v. Löwis | 44f8696 | 2001-09-05 13:44:54 +0000 | [diff] [blame] | 1236 | def cancel(self): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 1237 | """Stop the timer if it hasn't finished yet.""" |
Martin v. Löwis | 44f8696 | 2001-09-05 13:44:54 +0000 | [diff] [blame] | 1238 | self.finished.set() |
Tim Peters | b64bec3 | 2001-09-18 02:26:39 +0000 | [diff] [blame] | 1239 | |
Martin v. Löwis | 44f8696 | 2001-09-05 13:44:54 +0000 | [diff] [blame] | 1240 | def run(self): |
| 1241 | self.finished.wait(self.interval) |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 1242 | if not self.finished.is_set(): |
Martin v. Löwis | 44f8696 | 2001-09-05 13:44:54 +0000 | [diff] [blame] | 1243 | self.function(*self.args, **self.kwargs) |
| 1244 | self.finished.set() |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1245 | |
Antoine Pitrou | 1023dbb | 2017-10-02 16:42:15 +0200 | [diff] [blame] | 1246 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1247 | # Special thread class to represent the main thread |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1248 | |
| 1249 | class _MainThread(Thread): |
| 1250 | |
| 1251 | def __init__(self): |
Antoine Pitrou | 0bd4deb | 2011-02-25 22:07:43 +0000 | [diff] [blame] | 1252 | Thread.__init__(self, name="MainThread", daemon=False) |
Tim Peters | c363a23 | 2013-09-08 18:44:40 -0500 | [diff] [blame] | 1253 | self._set_tstate_lock() |
Christian Heimes | 9e7f1d2 | 2008-02-28 12:27:11 +0000 | [diff] [blame] | 1254 | self._started.set() |
Benjamin Peterson | d23f822 | 2009-04-05 19:13:16 +0000 | [diff] [blame] | 1255 | self._set_ident() |
Jake Tesler | b121f63 | 2019-05-22 08:43:17 -0700 | [diff] [blame] | 1256 | if _HAVE_THREAD_NATIVE_ID: |
| 1257 | self._set_native_id() |
Benjamin Peterson | d23f822 | 2009-04-05 19:13:16 +0000 | [diff] [blame] | 1258 | with _active_limbo_lock: |
| 1259 | _active[self._ident] = self |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1260 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1261 | |
| 1262 | # Dummy thread class to represent threads not started here. |
Tim Peters | 711906e | 2005-01-08 07:30:42 +0000 | [diff] [blame] | 1263 | # These aren't garbage collected when they die, nor can they be waited for. |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 1264 | # If they invoke anything in threading.py that calls current_thread(), they |
Tim Peters | 711906e | 2005-01-08 07:30:42 +0000 | [diff] [blame] | 1265 | # leave an entry in the _active dict forever after. |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 1266 | # Their purpose is to return *something* from current_thread(). |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1267 | # They are marked as daemon threads so we won't wait for them |
| 1268 | # when we exit (conform previous semantics). |
| 1269 | |
| 1270 | class _DummyThread(Thread): |
Tim Peters | b90f89a | 2001-01-15 03:26:36 +0000 | [diff] [blame] | 1271 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1272 | def __init__(self): |
Antoine Pitrou | 0bd4deb | 2011-02-25 22:07:43 +0000 | [diff] [blame] | 1273 | Thread.__init__(self, name=_newname("Dummy-%d"), daemon=True) |
Tim Peters | 711906e | 2005-01-08 07:30:42 +0000 | [diff] [blame] | 1274 | |
Christian Heimes | 9e7f1d2 | 2008-02-28 12:27:11 +0000 | [diff] [blame] | 1275 | self._started.set() |
Benjamin Peterson | d23f822 | 2009-04-05 19:13:16 +0000 | [diff] [blame] | 1276 | self._set_ident() |
Jake Tesler | b121f63 | 2019-05-22 08:43:17 -0700 | [diff] [blame] | 1277 | if _HAVE_THREAD_NATIVE_ID: |
| 1278 | self._set_native_id() |
Benjamin Peterson | d23f822 | 2009-04-05 19:13:16 +0000 | [diff] [blame] | 1279 | with _active_limbo_lock: |
| 1280 | _active[self._ident] = self |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1281 | |
Antoine Pitrou | 8e6e0fd | 2012-04-19 23:55:01 +0200 | [diff] [blame] | 1282 | def _stop(self): |
| 1283 | pass |
| 1284 | |
Xiang Zhang | f3a9fab | 2017-02-27 11:01:30 +0800 | [diff] [blame] | 1285 | def is_alive(self): |
| 1286 | assert not self._is_stopped and self._started.is_set() |
| 1287 | return True |
| 1288 | |
Neal Norwitz | 45bec8c | 2002-02-19 03:01:36 +0000 | [diff] [blame] | 1289 | def join(self, timeout=None): |
Guido van Rossum | 8ca162f | 2002-04-07 06:36:23 +0000 | [diff] [blame] | 1290 | assert False, "cannot join a dummy thread" |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1291 | |
| 1292 | |
| 1293 | # Global API functions |
| 1294 | |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 1295 | def current_thread(): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 1296 | """Return the current Thread object, corresponding to the caller's thread of control. |
| 1297 | |
| 1298 | If the caller's thread of control was not created through the threading |
| 1299 | module, a dummy thread object with limited functionality is returned. |
| 1300 | |
| 1301 | """ |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1302 | try: |
Victor Stinner | 2a12974 | 2011-05-30 23:02:52 +0200 | [diff] [blame] | 1303 | return _active[get_ident()] |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1304 | except KeyError: |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1305 | return _DummyThread() |
| 1306 | |
Benjamin Peterson | b3085c9 | 2008-09-01 23:09:31 +0000 | [diff] [blame] | 1307 | currentThread = current_thread |
Benjamin Peterson | f0923f5 | 2008-08-18 22:10:13 +0000 | [diff] [blame] | 1308 | |
Benjamin Peterson | 672b803 | 2008-06-11 19:14:14 +0000 | [diff] [blame] | 1309 | def active_count(): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 1310 | """Return the number of Thread objects currently alive. |
| 1311 | |
| 1312 | The returned count is equal to the length of the list returned by |
| 1313 | enumerate(). |
| 1314 | |
| 1315 | """ |
Benjamin Peterson | d23f822 | 2009-04-05 19:13:16 +0000 | [diff] [blame] | 1316 | with _active_limbo_lock: |
| 1317 | return len(_active) + len(_limbo) |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1318 | |
Benjamin Peterson | b3085c9 | 2008-09-01 23:09:31 +0000 | [diff] [blame] | 1319 | activeCount = active_count |
Benjamin Peterson | f0923f5 | 2008-08-18 22:10:13 +0000 | [diff] [blame] | 1320 | |
Antoine Pitrou | bdec11f | 2009-11-05 13:49:14 +0000 | [diff] [blame] | 1321 | def _enumerate(): |
| 1322 | # Same as enumerate(), but without the lock. Internal use only. |
| 1323 | return list(_active.values()) + list(_limbo.values()) |
| 1324 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1325 | def enumerate(): |
Georg Brandl | c30b59f | 2013-10-13 10:43:59 +0200 | [diff] [blame] | 1326 | """Return a list of all Thread objects currently alive. |
| 1327 | |
| 1328 | The list includes daemonic threads, dummy thread objects created by |
| 1329 | current_thread(), and the main thread. It excludes terminated threads and |
| 1330 | threads that have not yet been started. |
| 1331 | |
| 1332 | """ |
Benjamin Peterson | d23f822 | 2009-04-05 19:13:16 +0000 | [diff] [blame] | 1333 | with _active_limbo_lock: |
| 1334 | return list(_active.values()) + list(_limbo.values()) |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1335 | |
Georg Brandl | 2067bfd | 2008-05-25 13:05:15 +0000 | [diff] [blame] | 1336 | from _thread import stack_size |
Thomas Wouters | 0e3f591 | 2006-08-11 14:57:12 +0000 | [diff] [blame] | 1337 | |
Thomas Wouters | 902d6eb | 2007-01-09 23:18:33 +0000 | [diff] [blame] | 1338 | # Create the main thread object, |
| 1339 | # and make it available for the interpreter |
| 1340 | # (Py_Main) as threading._shutdown. |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1341 | |
Andrew Svetlov | 58b5c5a | 2013-09-04 07:01:07 +0300 | [diff] [blame] | 1342 | _main_thread = _MainThread() |
| 1343 | |
| 1344 | def _shutdown(): |
Tim Peters | c363a23 | 2013-09-08 18:44:40 -0500 | [diff] [blame] | 1345 | # Obscure: other threads may be waiting to join _main_thread. That's |
| 1346 | # dubious, but some code does it. We can't wait for C code to release |
| 1347 | # the main thread's tstate_lock - that won't happen until the interpreter |
| 1348 | # is nearly dead. So we release it here. Note that just calling _stop() |
| 1349 | # isn't enough: other threads may already be waiting on _tstate_lock. |
Antoine Pitrou | ee84a60 | 2017-08-16 20:53:28 +0200 | [diff] [blame] | 1350 | if _main_thread._is_stopped: |
| 1351 | # _shutdown() was already called |
| 1352 | return |
Tim Peters | b5e9ac9 | 2013-09-09 14:41:50 -0500 | [diff] [blame] | 1353 | tlock = _main_thread._tstate_lock |
| 1354 | # The main thread isn't finished yet, so its thread state lock can't have |
| 1355 | # been released. |
| 1356 | assert tlock is not None |
| 1357 | assert tlock.locked() |
| 1358 | tlock.release() |
Andrew Svetlov | 58b5c5a | 2013-09-04 07:01:07 +0300 | [diff] [blame] | 1359 | _main_thread._stop() |
| 1360 | t = _pickSomeNonDaemonThread() |
| 1361 | while t: |
| 1362 | t.join() |
| 1363 | t = _pickSomeNonDaemonThread() |
Andrew Svetlov | 58b5c5a | 2013-09-04 07:01:07 +0300 | [diff] [blame] | 1364 | |
| 1365 | def _pickSomeNonDaemonThread(): |
| 1366 | for t in enumerate(): |
| 1367 | if not t.daemon and t.is_alive(): |
| 1368 | return t |
| 1369 | return None |
| 1370 | |
| 1371 | def main_thread(): |
Andrew Svetlov | b1dd557 | 2013-09-04 10:33:11 +0300 | [diff] [blame] | 1372 | """Return the main thread object. |
| 1373 | |
| 1374 | In normal conditions, the main thread is the thread from which the |
| 1375 | Python interpreter was started. |
| 1376 | """ |
Andrew Svetlov | 58b5c5a | 2013-09-04 07:01:07 +0300 | [diff] [blame] | 1377 | return _main_thread |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1378 | |
Jim Fulton | d15dc06 | 2004-07-14 19:11:50 +0000 | [diff] [blame] | 1379 | # get thread-local implementation, either from the thread |
| 1380 | # module, or from the python fallback |
| 1381 | |
| 1382 | try: |
Georg Brandl | 2067bfd | 2008-05-25 13:05:15 +0000 | [diff] [blame] | 1383 | from _thread import _local as local |
Brett Cannon | cd171c8 | 2013-07-04 17:43:24 -0400 | [diff] [blame] | 1384 | except ImportError: |
Jim Fulton | d15dc06 | 2004-07-14 19:11:50 +0000 | [diff] [blame] | 1385 | from _threading_local import local |
| 1386 | |
Guido van Rossum | 7f5013a | 1998-04-09 22:01:42 +0000 | [diff] [blame] | 1387 | |
Jesse Noller | a851397 | 2008-07-17 16:49:17 +0000 | [diff] [blame] | 1388 | def _after_fork(): |
Antoine Pitrou | 4a8bcdf | 2017-05-28 14:02:26 +0200 | [diff] [blame] | 1389 | """ |
| 1390 | Cleanup threading module state that should not exist after a fork. |
| 1391 | """ |
Jesse Noller | a851397 | 2008-07-17 16:49:17 +0000 | [diff] [blame] | 1392 | # Reset _active_limbo_lock, in case we forked while the lock was held |
| 1393 | # by another (non-forked) thread. http://bugs.python.org/issue874900 |
Andrew Svetlov | 58b5c5a | 2013-09-04 07:01:07 +0300 | [diff] [blame] | 1394 | global _active_limbo_lock, _main_thread |
Jesse Noller | a851397 | 2008-07-17 16:49:17 +0000 | [diff] [blame] | 1395 | _active_limbo_lock = _allocate_lock() |
| 1396 | |
| 1397 | # fork() only copied the current thread; clear references to others. |
| 1398 | new_active = {} |
| 1399 | current = current_thread() |
Andrew Svetlov | 58b5c5a | 2013-09-04 07:01:07 +0300 | [diff] [blame] | 1400 | _main_thread = current |
Jesse Noller | a851397 | 2008-07-17 16:49:17 +0000 | [diff] [blame] | 1401 | with _active_limbo_lock: |
Antoine Pitrou | 5da7e79 | 2013-09-08 13:19:06 +0200 | [diff] [blame] | 1402 | # Dangling thread instances must still have their locks reset, |
| 1403 | # because someone may join() them. |
| 1404 | threads = set(_enumerate()) |
| 1405 | threads.update(_dangling) |
| 1406 | for thread in threads: |
Charles-François Natali | b055bf6 | 2011-12-18 18:45:16 +0100 | [diff] [blame] | 1407 | # Any lock/condition variable may be currently locked or in an |
| 1408 | # invalid state, so we reinitialize them. |
Jesse Noller | a851397 | 2008-07-17 16:49:17 +0000 | [diff] [blame] | 1409 | if thread is current: |
Antoine Pitrou | 5fe291f | 2008-09-06 23:00:03 +0000 | [diff] [blame] | 1410 | # There is only one active thread. We reset the ident to |
| 1411 | # its new value since it can have changed. |
Antoine Pitrou | 7b47699 | 2013-09-07 23:38:37 +0200 | [diff] [blame] | 1412 | thread._reset_internal_locks(True) |
Victor Stinner | 2a12974 | 2011-05-30 23:02:52 +0200 | [diff] [blame] | 1413 | ident = get_ident() |
Antoine Pitrou | 5fe291f | 2008-09-06 23:00:03 +0000 | [diff] [blame] | 1414 | thread._ident = ident |
Jesse Noller | a851397 | 2008-07-17 16:49:17 +0000 | [diff] [blame] | 1415 | new_active[ident] = thread |
| 1416 | else: |
| 1417 | # All the others are already stopped. |
Antoine Pitrou | 7b47699 | 2013-09-07 23:38:37 +0200 | [diff] [blame] | 1418 | thread._reset_internal_locks(False) |
Charles-François Natali | b055bf6 | 2011-12-18 18:45:16 +0100 | [diff] [blame] | 1419 | thread._stop() |
Jesse Noller | a851397 | 2008-07-17 16:49:17 +0000 | [diff] [blame] | 1420 | |
| 1421 | _limbo.clear() |
| 1422 | _active.clear() |
| 1423 | _active.update(new_active) |
| 1424 | assert len(_active) == 1 |
Antoine Pitrou | 4a8bcdf | 2017-05-28 14:02:26 +0200 | [diff] [blame] | 1425 | |
| 1426 | |
Gregory P. Smith | 163468a | 2017-05-29 10:03:41 -0700 | [diff] [blame] | 1427 | if hasattr(_os, "register_at_fork"): |
| 1428 | _os.register_at_fork(after_in_child=_after_fork) |