New Java-style threading module. The doc strings are in a separate module.
diff --git a/Lib/threading.py b/Lib/threading.py
new file mode 100644
index 0000000..79319c1
--- /dev/null
+++ b/Lib/threading.py
@@ -0,0 +1,638 @@
+# threading.py:
+# Proposed new threading module, emulating a subset of Java's threading model
+
+import sys
+import time
+import thread
+import traceback
+import StringIO
+
+# Rename some stuff so "from threading import *" is safe
+
+_sys = sys
+del sys
+
+_time = time.time
+_sleep = time.sleep
+del time
+
+_start_new_thread = thread.start_new_thread
+_allocate_lock = thread.allocate_lock
+_get_ident = thread.get_ident
+del thread
+
+_print_exc = traceback.print_exc
+del traceback
+
+_StringIO = StringIO.StringIO
+del StringIO
+
+
+# Debug support (adapted from ihooks.py)
+
+_VERBOSE = 0
+
+if __debug__:
+
+ class _Verbose:
+
+ 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
+ format = "%s: %s\n" % (
+ currentThread().getName(), format)
+ _sys.stderr.write(format)
+
+else:
+ # Disable this when using "python -O"
+ class _Verbose:
+ def __init__(self, verbose=None):
+ pass
+ def _note(self, *args):
+ pass
+
+
+# Synchronization classes
+
+Lock = _allocate_lock
+
+def RLock(*args, **kwargs):
+ return apply(_RLock, args, kwargs)
+
+class _RLock(_Verbose):
+
+ def __init__(self, verbose=None):
+ _Verbose.__init__(self, verbose)
+ self.__block = _allocate_lock()
+ self.__owner = None
+ self.__count = 0
+
+ def __repr__(self):
+ return "<%s(%s, %d)>" % (
+ self.__class__.__name__,
+ self.__owner and self.__owner.getName(),
+ self.__count)
+
+ def acquire(self, blocking=1):
+ me = currentThread()
+ if self.__owner is me:
+ self.__count = self.__count + 1
+ if __debug__:
+ self._note("%s.acquire(%s): recursive success", self, blocking)
+ return 1
+ rc = self.__block.acquire(blocking)
+ if rc:
+ self.__owner = me
+ self.__count = 1
+ if __debug__:
+ self._note("%s.acquire(%s): initial succes", self, blocking)
+ else:
+ if __debug__:
+ self._note("%s.acquire(%s): failure", self, blocking)
+ return rc
+
+ def release(self):
+ me = currentThread()
+ assert self.__owner is me, "release() of un-acquire()d 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)
+
+ # Internal methods used by condition variables
+
+ def _acquire_restore(self, (count, owner)):
+ self.__block.acquire()
+ self.__count = count
+ self.__owner = owner
+ if __debug__:
+ self._note("%s._acquire_restore()", self)
+
+ def _release_save(self):
+ if __debug__:
+ self._note("%s._release_save()", self)
+ count = self.__count
+ self.__count = 0
+ owner = self.__owner
+ self.__owner = None
+ self.__block.release()
+ return (count, owner)
+
+ def _is_owned(self):
+ return self.__owner is currentThread()
+
+
+def Condition(*args, **kwargs):
+ return apply(_Condition, args, kwargs)
+
+class _Condition(_Verbose):
+
+ def __init__(self, lock=None, verbose=None):
+ _Verbose.__init__(self, verbose)
+ if lock is None:
+ lock = RLock()
+ self.__lock = lock
+ # Export the lock's acquire() and release() methods
+ self.acquire = lock.acquire
+ self.release = lock.release
+ # If the lock defines _release_save() and/or _acquire_restore(),
+ # these override the default implementations (which just call
+ # release() and acquire() on the lock). Ditto for _is_owned().
+ try:
+ self._release_save = lock._release_save
+ except AttributeError:
+ pass
+ try:
+ self._acquire_restore = lock._acquire_restore
+ except AttributeError:
+ pass
+ try:
+ self._is_owned = lock._is_owned
+ except AttributeError:
+ pass
+ self.__waiters = []
+
+ def __repr__(self):
+ return "<Condition(%s, %d)>" % (self.__lock, len(self.__waiters))
+
+ def _release_save(self):
+ self.__lock.release() # No state to save
+
+ def _acquire_restore(self, x):
+ self.__lock.acquire() # Ignore saved state
+
+ def _is_owned(self):
+ if self.__lock.acquire(0):
+ self.__lock.release()
+ return 0
+ else:
+ return 1
+
+ def wait(self, timeout=None):
+ me = currentThread()
+ assert self._is_owned(), "wait() of un-acquire()d lock"
+ waiter = _allocate_lock()
+ waiter.acquire()
+ self.__waiters.append(waiter)
+ saved_state = self._release_save()
+ if timeout is None:
+ waiter.acquire()
+ if __debug__:
+ self._note("%s.wait(): got it", self)
+ else:
+ endtime = _time() + timeout
+ delay = 0.000001 # 1 usec
+ while 1:
+ gotit = waiter.acquire(0)
+ if gotit or _time() >= endtime:
+ break
+ _sleep(delay)
+ if delay < 1.0:
+ delay = delay * 2.0
+ 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)
+ self._acquire_restore(saved_state)
+
+ def notify(self, n=1):
+ me = currentThread()
+ assert self._is_owned(), "notify() of un-acquire()d lock"
+ __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:
+ __waiters.remove(waiter)
+ except ValueError:
+ pass
+
+ def notifyAll(self):
+ self.notify(len(self.__waiters))
+
+
+def Semaphore(*args, **kwargs):
+ return apply(_Semaphore, args, kwargs)
+
+class _Semaphore(_Verbose):
+
+ # After Tim Peters' semaphore class, but bnot quite the same (no maximum)
+
+ def __init__(self, value=1, verbose=None):
+ assert value >= 0, "Semaphore initial value must be >= 0"
+ _Verbose.__init__(self, verbose)
+ self.__cond = Condition(Lock())
+ self.__value = value
+
+ def acquire(self, blocking=1):
+ rc = 0
+ self.__cond.acquire()
+ while self.__value == 0:
+ if not blocking:
+ break
+ self.__cond.wait()
+ else:
+ self.__value = self.__value - 1
+ rc = 1
+ self.__cond.release()
+ return rc
+
+ def release(self):
+ self.__cond.acquire()
+ self.__value = self.__value + 1
+ self.__cond.notify()
+ self.__cond.release()
+
+
+def Event(*args, **kwargs):
+ return apply(_Event, args, kwargs)
+
+class _Event(_Verbose):
+
+ # After Tim Peters' event class (without is_posted())
+
+ def __init__(self, verbose=None):
+ _Verbose.__init__(self, verbose)
+ self.__cond = Condition(Lock())
+ self.__flag = 0
+
+ def isSet(self):
+ return self.__flag
+
+ def set(self):
+ self.__cond.acquire()
+ self.__flag = 1
+ self.__cond.notifyAll()
+ self.__cond.release()
+
+ def clear(self):
+ self.__cond.acquire()
+ self.__flag = 0
+ self.__cond.release()
+
+ def wait(self, timeout=None):
+ self.__cond.acquire()
+ if not self.__flag:
+ self.__cond.wait(timeout)
+ self.__cond.release()
+
+
+# Helper to generate new thread names
+_counter = 0
+def _newname(template="Thread-%d"):
+ global _counter
+ _counter = _counter + 1
+ return template % _counter
+
+# Active thread administration
+_active_limbo_lock = _allocate_lock()
+_active = {}
+_limbo = {}
+
+
+# Main class for threads
+
+class Thread(_Verbose):
+
+ __initialized = 0
+
+ def __init__(self, group=None, target=None, name=None,
+ args=(), kwargs={}, verbose=None):
+ assert group is None, "group argument must be None for now"
+ _Verbose.__init__(self, verbose)
+ self.__target = target
+ self.__name = str(name or _newname())
+ self.__args = args
+ self.__kwargs = kwargs
+ self.__daemonic = self._set_daemon()
+ self.__started = 0
+ self.__stopped = 0
+ self.__block = Condition(Lock())
+ self.__initialized = 1
+
+ def _set_daemon(self):
+ # Overridden in _MainThread and _DummyThread
+ return currentThread().isDaemon()
+
+ def __repr__(self):
+ assert self.__initialized, "Thread.__init__() was not called"
+ status = "initial"
+ if self.__started:
+ status = "started"
+ if self.__stopped:
+ status = "stopped"
+ if self.__daemonic:
+ status = status + " daemon"
+ return "<%s(%s, %s)>" % (self.__class__.__name__, self.__name, status)
+
+ def start(self):
+ assert self.__initialized, "Thread.__init__() not called"
+ assert not self.__started, "thread already started"
+ if __debug__:
+ self._note("%s.start(): starting thread", self)
+ _active_limbo_lock.acquire()
+ _limbo[self] = self
+ _active_limbo_lock.release()
+ _start_new_thread(self.__bootstrap, ())
+ self.__started = 1
+ _sleep(0.000001) # 1 usec, to let the thread run (Solaris hack)
+
+ def run(self):
+ if self.__target:
+ apply(self.__target, self.__args, self.__kwargs)
+
+ def __bootstrap(self):
+ try:
+ self.__started = 1
+ _active_limbo_lock.acquire()
+ _active[_get_ident()] = self
+ del _limbo[self]
+ _active_limbo_lock.release()
+ if __debug__:
+ self._note("%s.__bootstrap(): thread started", self)
+ try:
+ self.run()
+ except SystemExit:
+ if __debug__:
+ self._note("%s.__bootstrap(): raised SystemExit", self)
+ except:
+ if __debug__:
+ self._note("%s.__bootstrap(): unhandled exception", self)
+ s = _StringIO()
+ _print_exc(file=s)
+ _sys.stderr.write("Exception in thread %s:\n%s\n" %
+ (self.getName(), s.getvalue()))
+ else:
+ if __debug__:
+ self._note("%s.__bootstrap(): normal return", self)
+ finally:
+ self.__stop()
+ self.__delete()
+
+ def __stop(self):
+ self.__block.acquire()
+ self.__stopped = 1
+ self.__block.notifyAll()
+ self.__block.release()
+
+ def __delete(self):
+ _active_limbo_lock.acquire()
+ del _active[_get_ident()]
+ _active_limbo_lock.release()
+
+ def join(self, timeout=None):
+ assert self.__initialized, "Thread.__init__() not called"
+ assert self.__started, "cannot join thread before it is started"
+ assert self is not currentThread(), "cannot join current thread"
+ if __debug__:
+ if not self.__stopped:
+ self._note("%s.join(): waiting until thread stops", self)
+ self.__block.acquire()
+ if timeout is None:
+ while not self.__stopped:
+ self.__block.wait()
+ if __debug__:
+ self._note("%s.join(): thread stopped", self)
+ else:
+ deadline = time.time() + timeout
+ while not self.__stopped:
+ delay = deadline - time.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)
+ self.__block.release()
+
+ def getName(self):
+ assert self.__initialized, "Thread.__init__() not called"
+ return self.__name
+
+ def setName(self, name):
+ assert self.__initialized, "Thread.__init__() not called"
+ self.__name = str(name)
+
+ def isAlive(self):
+ assert self.__initialized, "Thread.__init__() not called"
+ return self.__started and not self.__stopped
+
+ def isDaemon(self):
+ assert self.__initialized, "Thread.__init__() not called"
+ return self.__daemonic
+
+ def setDaemon(self, daemonic):
+ assert self.__initialized, "Thread.__init__() not called"
+ assert not self.__started, "cannot set daemon status of active thread"
+ self.__daemonic = daemonic
+
+
+# Special thread class to represent the main thread
+# This is garbage collected through an exit handler
+
+class _MainThread(Thread):
+
+ def __init__(self):
+ Thread.__init__(self, name="MainThread")
+ self._Thread__started = 1
+ _active_limbo_lock.acquire()
+ _active[_get_ident()] = self
+ _active_limbo_lock.release()
+ try:
+ self.__oldexitfunc = _sys.exitfunc
+ except AttributeError:
+ self.__oldexitfunc = None
+ _sys.exitfunc = self.__exitfunc
+
+ def _set_daemon(self):
+ return 0
+
+ def __exitfunc(self):
+ self._Thread__stop()
+ t = _pickSomeNonDaemonThread()
+ if t:
+ if __debug__:
+ self._note("%s: waiting for other threads", self)
+ while t:
+ t.join()
+ t = _pickSomeNonDaemonThread()
+ if self.__oldexitfunc:
+ if __debug__:
+ self._note("%s: calling exit handler", self)
+ self.__oldexitfunc()
+ if __debug__:
+ self._note("%s: exiting", self)
+ self._Thread__delete()
+
+def _pickSomeNonDaemonThread():
+ for t in enumerate():
+ if not t.isDaemon() and t.isAlive():
+ return t
+ return None
+
+
+# Dummy thread class to represent threads not started here.
+# These aren't garbage collected when they die,
+# nor can they be waited for.
+# Their purpose is to return *something* from currentThread().
+# They are marked as daemon threads so we won't wait for them
+# when we exit (conform previous semantics).
+
+class _DummyThread(Thread):
+
+ def __init__(self):
+ Thread.__init__(self, name=_newname("Dummy-%d"))
+ self.__Thread_started = 1
+ _active_limbo_lock.acquire()
+ _active[_get_ident()] = self
+ _active_limbo_lock.release()
+
+ def _set_daemon(self):
+ return 1
+
+ def join(self):
+ assert 0, "cannot join a dummy thread"
+
+
+# Global API functions
+
+def currentThread():
+ try:
+ return _active[_get_ident()]
+ except KeyError:
+ print "currentThread(): no current thread for", _get_ident()
+ return _DummyThread()
+
+def activeCount():
+ _active_limbo_lock.acquire()
+ count = len(_active) + len(_limbo)
+ _active_limbo_lock.release()
+ return count
+
+def enumerate():
+ _active_limbo_lock.acquire()
+ active = _active.values() + _limbo.values()
+ _active_limbo_lock.release()
+ return active
+
+
+# Create the main thread object
+
+_MainThread()
+
+
+# Self-test code
+
+def _test():
+
+ import whrandom
+
+ class BoundedQueue(_Verbose):
+
+ def __init__(self, limit):
+ _Verbose.__init__(self)
+ self.mon = RLock()
+ self.rc = Condition(self.mon)
+ self.wc = Condition(self.mon)
+ self.limit = limit
+ self.queue = []
+
+ def put(self, item):
+ self.mon.acquire()
+ while len(self.queue) >= self.limit:
+ self._note("put(%s): queue full", item)
+ self.wc.wait()
+ self.queue.append(item)
+ self._note("put(%s): appended, length now %d",
+ item, len(self.queue))
+ self.rc.notify()
+ self.mon.release()
+
+ def get(self):
+ self.mon.acquire()
+ while not self.queue:
+ self._note("get(): queue empty")
+ self.rc.wait()
+ item = self.queue[0]
+ del self.queue[0]
+ self._note("get(): got %s, %d left", item, len(self.queue))
+ self.wc.notify()
+ self.mon.release()
+ return item
+
+ class ProducerThread(Thread):
+
+ def __init__(self, queue, quota):
+ Thread.__init__(self, name="Producer")
+ self.queue = queue
+ self.quota = quota
+
+ def run(self):
+ from whrandom import random
+ counter = 0
+ while counter < self.quota:
+ counter = counter + 1
+ self.queue.put("%s.%d" % (self.getName(), counter))
+ _sleep(random() * 0.00001)
+
+
+ class ConsumerThread(Thread):
+
+ def __init__(self, queue, count):
+ Thread.__init__(self, name="Consumer")
+ self.queue = queue
+ self.count = count
+
+ def run(self):
+ while self.count > 0:
+ item = self.queue.get()
+ print item
+ self.count = self.count - 1
+
+ import time
+
+ NP = 3
+ QL = 4
+ NI = 5
+
+ Q = BoundedQueue(QL)
+ P = []
+ for i in range(NP):
+ t = ProducerThread(Q, NI)
+ t.setName("Producer-%d" % (i+1))
+ P.append(t)
+ C = ConsumerThread(Q, NI*NP)
+ for t in P:
+ t.start()
+ _sleep(0.000001)
+ C.start()
+ for t in P:
+ t.join()
+ C.join()
+
+if __name__ == '__main__':
+ _test()