diff options
Diffstat (limited to 'Lib/threading.py')
| -rw-r--r-- | Lib/threading.py | 221 |
1 files changed, 44 insertions, 177 deletions
diff --git a/Lib/threading.py b/Lib/threading.py index 58ffa7ebc2..6c34d49782 100644 --- a/Lib/threading.py +++ b/Lib/threading.py @@ -3,7 +3,11 @@ import sys as _sys import _thread -from time import time as _time, sleep as _sleep +from time import sleep as _sleep +try: + from time import monotonic as _time +except ImportError: + from time import time as _time from traceback import format_exc as _format_exc from _weakrefset import WeakSet @@ -19,12 +23,12 @@ from _weakrefset import WeakSet __all__ = ['active_count', 'Condition', 'current_thread', 'enumerate', 'Event', 'Lock', 'RLock', 'Semaphore', 'BoundedSemaphore', 'Thread', 'Barrier', - 'Timer', 'setprofile', 'settrace', 'local', 'stack_size'] + 'Timer', 'ThreadError', 'setprofile', 'settrace', 'local', 'stack_size'] # Rename some stuff so "from threading import *" is safe _start_new_thread = _thread.start_new_thread _allocate_lock = _thread.allocate_lock -_get_ident = _thread.get_ident +get_ident = _thread.get_ident ThreadError = _thread.error try: _CRLock = _thread.RLock @@ -34,40 +38,6 @@ TIMEOUT_MAX = _thread.TIMEOUT_MAX del _thread -# Debug support (adapted from ihooks.py). - -_VERBOSE = False - -if __debug__: - - class _Verbose(object): - - def __init__(self, verbose=None): - if verbose is None: - verbose = _VERBOSE - self._verbose = verbose - - def _note(self, format, *args): - if self._verbose: - format = format % args - # Issue #4188: calling current_thread() can incur an infinite - # recursion if it has to create a DummyThread on the fly. - ident = _get_ident() - try: - name = _active[ident].name - except KeyError: - name = "<OS thread %d>" % ident - format = "%s: %s\n" % (name, format) - _sys.stderr.write(format) - -else: - # Disable this when using "python -O" - class _Verbose(object): - def __init__(self, verbose=None): - pass - def _note(self, *args): - pass - # Support for profile and trace hooks _profile_hook = None @@ -85,17 +55,14 @@ def settrace(func): Lock = _allocate_lock -def RLock(verbose=None, *args, **kwargs): - if verbose is None: - verbose = _VERBOSE - if (__debug__ and verbose) or _CRLock is None: - return _PyRLock(verbose, *args, **kwargs) +def RLock(*args, **kwargs): + if _CRLock is None: + return _PyRLock(*args, **kwargs) return _CRLock(*args, **kwargs) -class _RLock(_Verbose): +class _RLock: - def __init__(self, verbose=None): - _Verbose.__init__(self, verbose) + def __init__(self): self._block = _allocate_lock() self._owner = None self._count = 0 @@ -110,37 +77,25 @@ class _RLock(_Verbose): self.__class__.__name__, owner, self._count) def acquire(self, blocking=True, timeout=-1): - me = _get_ident() + me = get_ident() if self._owner == me: self._count = self._count + 1 - if __debug__: - self._note("%s.acquire(%s): recursive success", self, blocking) return 1 rc = self._block.acquire(blocking, timeout) if rc: self._owner = me self._count = 1 - if __debug__: - self._note("%s.acquire(%s): initial success", self, blocking) - else: - if __debug__: - self._note("%s.acquire(%s): failure", self, blocking) return rc __enter__ = acquire def release(self): - if self._owner != _get_ident(): + if self._owner != get_ident(): raise RuntimeError("cannot release un-acquired lock") self._count = count = self._count - 1 if not count: self._owner = None self._block.release() - if __debug__: - self._note("%s.release(): final release", self) - else: - if __debug__: - self._note("%s.release(): non-final release", self) def __exit__(self, t, v, tb): self.release() @@ -150,12 +105,10 @@ class _RLock(_Verbose): def _acquire_restore(self, state): self._block.acquire() self._count, self._owner = state - if __debug__: - self._note("%s._acquire_restore()", self) def _release_save(self): - if __debug__: - self._note("%s._release_save()", self) + if self._count == 0: + raise RuntimeError("cannot release un-acquired lock") count = self._count self._count = 0 owner = self._owner @@ -164,18 +117,14 @@ class _RLock(_Verbose): return (count, owner) def _is_owned(self): - return self._owner == _get_ident() + return self._owner == get_ident() _PyRLock = _RLock -def Condition(*args, **kwargs): - return _Condition(*args, **kwargs) +class Condition: -class _Condition(_Verbose): - - def __init__(self, lock=None, verbose=None): - _Verbose.__init__(self, verbose) + def __init__(self, lock=None): if lock is None: lock = RLock() self._lock = lock @@ -234,23 +183,16 @@ class _Condition(_Verbose): if timeout is None: waiter.acquire() gotit = True - if __debug__: - self._note("%s.wait(): got it", self) else: if timeout > 0: gotit = waiter.acquire(True, timeout) else: gotit = waiter.acquire(False) if not gotit: - if __debug__: - self._note("%s.wait(%s): timed out", self, timeout) try: self._waiters.remove(waiter) except ValueError: pass - else: - if __debug__: - self._note("%s.wait(%s): got it", self, timeout) return gotit finally: self._acquire_restore(saved_state) @@ -266,19 +208,9 @@ class _Condition(_Verbose): else: waittime = endtime - _time() if waittime <= 0: - if __debug__: - self._note("%s.wait_for(%r, %r): Timed out.", - self, predicate, timeout) break - if __debug__: - self._note("%s.wait_for(%r, %r): Waiting with timeout=%s.", - self, predicate, timeout, waittime) self.wait(waittime) result = predicate() - else: - if __debug__: - self._note("%s.wait_for(%r, %r): Success.", - self, predicate, timeout) return result def notify(self, n=1): @@ -287,11 +219,7 @@ class _Condition(_Verbose): __waiters = self._waiters waiters = __waiters[:n] if not waiters: - if __debug__: - self._note("%s.notify(): no waiters", self) return - self._note("%s.notify(): notifying %d waiter%s", self, n, - n!=1 and "s" or "") for waiter in waiters: waiter.release() try: @@ -305,17 +233,13 @@ class _Condition(_Verbose): notifyAll = notify_all -def Semaphore(*args, **kwargs): - return _Semaphore(*args, **kwargs) - -class _Semaphore(_Verbose): +class Semaphore: # After Tim Peters' semaphore class, but not quite the same (no maximum) - def __init__(self, value=1, verbose=None): + def __init__(self, value=1): if value < 0: raise ValueError("semaphore initial value must be >= 0") - _Verbose.__init__(self, verbose) self._cond = Condition(Lock()) self._value = value @@ -328,9 +252,6 @@ class _Semaphore(_Verbose): while self._value == 0: if not blocking: break - if __debug__: - self._note("%s.acquire(%s): blocked waiting, value=%s", - self, blocking, self._value) if timeout is not None: if endtime is None: endtime = _time() + timeout @@ -341,9 +262,6 @@ class _Semaphore(_Verbose): self._cond.wait(timeout) else: self._value = self._value - 1 - if __debug__: - self._note("%s.acquire: success, value=%s", - self, self._value) rc = True self._cond.release() return rc @@ -353,9 +271,6 @@ class _Semaphore(_Verbose): def release(self): self._cond.acquire() self._value = self._value + 1 - if __debug__: - self._note("%s.release: success, value=%s", - self, self._value) self._cond.notify() self._cond.release() @@ -363,30 +278,23 @@ class _Semaphore(_Verbose): self.release() -def BoundedSemaphore(*args, **kwargs): - return _BoundedSemaphore(*args, **kwargs) - -class _BoundedSemaphore(_Semaphore): +class BoundedSemaphore(Semaphore): """Semaphore that checks that # releases is <= # acquires""" - def __init__(self, value=1, verbose=None): - _Semaphore.__init__(self, value, verbose) + def __init__(self, value=1): + Semaphore.__init__(self, value) self._initial_value = value def release(self): if self._value >= self._initial_value: raise ValueError("Semaphore released too many times") - return _Semaphore.release(self) - + return Semaphore.release(self) -def Event(*args, **kwargs): - return _Event(*args, **kwargs) -class _Event(_Verbose): +class Event: # After Tim Peters' event class (without is_posted()) - def __init__(self, verbose=None): - _Verbose.__init__(self, verbose) + def __init__(self): self._cond = Condition(Lock()) self._flag = False @@ -436,13 +344,13 @@ class _Event(_Verbose): # since the previous cycle. In addition, a 'resetting' state exists which is # similar to 'draining' except that threads leave with a BrokenBarrierError, # and a 'broken' state in which all threads get the exception. -class Barrier(_Verbose): +class Barrier: """ Barrier. Useful for synchronizing a fixed number of threads at known synchronization points. Threads block on 'wait()' and are simultaneously once they have all made that call. """ - def __init__(self, parties, action=None, timeout=None, verbose=None): + def __init__(self, parties, action=None, timeout=None): """ Create a barrier, initialised to 'parties' threads. 'action' is a callable which, when supplied, will be called @@ -451,7 +359,6 @@ class Barrier(_Verbose): If a 'timeout' is provided, it is uses as the default for all subsequent 'wait()' calls. """ - _Verbose.__init__(self, verbose) self._cond = Condition(Lock()) self._action = action self._timeout = timeout @@ -612,7 +519,7 @@ _dangling = WeakSet() # Main class for threads -class Thread(_Verbose): +class Thread: __initialized = False # Need to store a reference to sys.exc_info for printing @@ -625,16 +532,18 @@ class Thread(_Verbose): #XXX __exc_clear = _sys.exc_clear def __init__(self, group=None, target=None, name=None, - args=(), kwargs=None, verbose=None): + args=(), kwargs=None, *, daemon=None): assert group is None, "group argument must be None for now" - _Verbose.__init__(self, verbose) if kwargs is None: kwargs = {} self._target = target self._name = str(name or _newname()) self._args = args self._kwargs = kwargs - self._daemonic = self._set_daemon() + if daemon is not None: + self._daemonic = daemon + else: + self._daemonic = current_thread().daemon self._ident = None self._started = Event() self._stopped = False @@ -652,10 +561,6 @@ class Thread(_Verbose): self._block.__init__() self._started._reset_internal_locks() - def _set_daemon(self): - # Overridden in _MainThread and _DummyThread - return current_thread().daemon - def __repr__(self): assert self._initialized, "Thread.__init__() was not called" status = "initial" @@ -675,8 +580,6 @@ class Thread(_Verbose): if self._started.is_set(): raise RuntimeError("threads can only be started once") - if __debug__: - self._note("%s.start(): starting thread", self) with _active_limbo_lock: _limbo[self] = self try: @@ -717,7 +620,7 @@ class Thread(_Verbose): raise def _set_ident(self): - self._ident = _get_ident() + self._ident = get_ident() def _bootstrap_inner(self): try: @@ -726,24 +629,17 @@ class Thread(_Verbose): with _active_limbo_lock: _active[self._ident] = self del _limbo[self] - if __debug__: - self._note("%s._bootstrap(): thread started", self) if _trace_hook: - self._note("%s._bootstrap(): registering trace hook", self) _sys.settrace(_trace_hook) if _profile_hook: - self._note("%s._bootstrap(): registering profile hook", self) _sys.setprofile(_profile_hook) try: self.run() except SystemExit: - if __debug__: - self._note("%s._bootstrap(): raised SystemExit", self) + pass except: - if __debug__: - self._note("%s._bootstrap(): unhandled exception", self) # If sys.stderr is no more (most likely from interpreter # shutdown) use self._stderr. Otherwise still use sys (as in # _sys) in case sys.stderr was redefined since the creation of @@ -774,9 +670,6 @@ class Thread(_Verbose): # hog; deleting everything else is just for thoroughness finally: del exc_type, exc_value, exc_tb - else: - if __debug__: - self._note("%s._bootstrap(): normal return", self) finally: # Prevent a race in # test_threading.test_no_refcycle_through_target when @@ -790,7 +683,7 @@ class Thread(_Verbose): try: # We don't call self._delete() because it also # grabs _active_limbo_lock. - del _active[_get_ident()] + del _active[get_ident()] except: pass @@ -826,7 +719,7 @@ class Thread(_Verbose): try: with _active_limbo_lock: - del _active[_get_ident()] + del _active[get_ident()] # There must not be any python code between the previous line # and after the lock is released. Otherwise a tracing function # could try to acquire the lock again in the same thread, (in @@ -843,29 +736,18 @@ class Thread(_Verbose): if self is current_thread(): raise RuntimeError("cannot join current thread") - if __debug__: - if not self._stopped: - self._note("%s.join(): waiting until thread stops", self) - self._block.acquire() try: if timeout is None: while not self._stopped: self._block.wait() - if __debug__: - self._note("%s.join(): thread stopped", self) else: deadline = _time() + timeout while not self._stopped: delay = deadline - _time() if delay <= 0: - if __debug__: - self._note("%s.join(): timed out", self) break self._block.wait(delay) - else: - if __debug__: - self._note("%s.join(): thread stopped", self) finally: self._block.release() @@ -917,10 +799,7 @@ class Thread(_Verbose): # The timer class was contributed by Itamar Shtull-Trauring -def Timer(*args, **kwargs): - return _Timer(*args, **kwargs) - -class _Timer(Thread): +class Timer(Thread): """Call a function after a specified number of seconds: t = Timer(30.0, f, args=[], kwargs={}) @@ -952,26 +831,18 @@ class _Timer(Thread): class _MainThread(Thread): def __init__(self): - Thread.__init__(self, name="MainThread") + Thread.__init__(self, name="MainThread", daemon=False) self._started.set() self._set_ident() with _active_limbo_lock: _active[self._ident] = self - def _set_daemon(self): - return False - def _exitfunc(self): self._stop() t = _pickSomeNonDaemonThread() - if t: - if __debug__: - self._note("%s: waiting for other threads", self) while t: t.join() t = _pickSomeNonDaemonThread() - if __debug__: - self._note("%s: exiting", self) self._delete() def _pickSomeNonDaemonThread(): @@ -992,7 +863,7 @@ def _pickSomeNonDaemonThread(): class _DummyThread(Thread): def __init__(self): - Thread.__init__(self, name=_newname("Dummy-%d")) + Thread.__init__(self, name=_newname("Dummy-%d"), daemon=True) # Thread._block consumes an OS-level locking primitive, which # can never be used by a _DummyThread. Since a _DummyThread @@ -1004,9 +875,6 @@ class _DummyThread(Thread): with _active_limbo_lock: _active[self._ident] = self - def _set_daemon(self): - return True - def _stop(self): pass @@ -1018,9 +886,8 @@ class _DummyThread(Thread): def current_thread(): try: - return _active[_get_ident()] + return _active[get_ident()] except KeyError: - ##print "current_thread(): no current thread for", _get_ident() return _DummyThread() currentThread = current_thread @@ -1077,7 +944,7 @@ def _after_fork(): if thread is current: # There is only one active thread. We reset the ident to # its new value since it can have changed. - ident = _get_ident() + ident = get_ident() thread._ident = ident new_active[ident] = thread else: |