Source code for gevent.thread

"""
Implementation of the standard :mod:`thread` module that spawns greenlets.

.. note::

    This module is a helper for :mod:`gevent.monkey` and is not
    intended to be used directly. For spawning greenlets in your
    applications, prefer higher level constructs like
    :class:`gevent.Greenlet` class or :func:`gevent.spawn`.
"""
from __future__ import absolute_import
import sys

__implements__ = [
    'allocate_lock',
    'get_ident',
    'exit',
    'LockType',
    'stack_size',
    'start_new_thread',
    '_local',
]

__imports__ = ['error']
if sys.version_info[0] == 2:
    import thread as __thread__ # pylint:disable=import-error
    PY2 = True
    PY3 = False
    # Name the `future` backport that might already have been imported;
    # Importing `pkg_resources` imports this, for example.
    __alternate_targets__ = ('_thread',)
else:
    import _thread as __thread__ # pylint:disable=import-error
    PY2 = False
    PY3 = True
    __target__ = '_thread'
    __imports__ += [
        'TIMEOUT_MAX',
        'allocate',
        'exit_thread',
        'interrupt_main',
        'start_new'
    ]
    if sys.version_info[:2] >= (3, 8):
        # We can't actually produce a value that "may be used
        # to identify this particular thread system-wide", right?
        # Even if we could, I imagine people will want to pass this to
        # non-Python (native) APIs, so we shouldn't mess with it.
        __imports__.append('get_native_id')


error = __thread__.error

from gevent._compat import PYPY
from gevent._util import copy_globals
from gevent.hub import getcurrent
from gevent.hub import GreenletExit
from gevent.hub import sleep
from gevent._hub_local import get_hub_if_exists
from gevent.greenlet import Greenlet
from gevent.lock import BoundedSemaphore
from gevent.local import local as _local
from gevent.exceptions import LoopExit

if hasattr(__thread__, 'RLock'):
    assert PY3 or PYPY
    # Added in Python 3.4, backported to PyPy 2.7-7.0
    __imports__.append("RLock")



def get_ident(gr=None):
    if gr is None:
        gr = getcurrent()
    return id(gr)


def start_new_thread(function, args=(), kwargs=None):
    if kwargs is not None:
        greenlet = Greenlet.spawn(function, *args, **kwargs) # pylint:disable=not-a-mapping
    else:
        greenlet = Greenlet.spawn(function, *args)
    return get_ident(greenlet)


[docs]class LockType(BoundedSemaphore): # Change the ValueError into the appropriate thread error # and any other API changes we need to make to match behaviour _OVER_RELEASE_ERROR = __thread__.error if PYPY and PY3: _OVER_RELEASE_ERROR = RuntimeError if PY3: _TIMEOUT_MAX = __thread__.TIMEOUT_MAX # python 2: pylint:disable=no-member else: _TIMEOUT_MAX = 9223372036.0
[docs] def acquire(self, blocking=True, timeout=-1): # This is the Python 3 signature. # On Python 2, Lock.acquire has the signature `Lock.acquire([wait])` # where `wait` is a boolean that cannot be passed by name, only position. # so we're fine to use the Python 3 signature. # Transform the default -1 argument into the None that our # semaphore implementation expects, and raise the same error # the stdlib implementation does. if timeout == -1: timeout = None if not blocking and timeout is not None: raise ValueError("can't specify a timeout for a non-blocking call") if timeout is not None: if timeout < 0: # in C: if(timeout < 0 && timeout != -1) raise ValueError("timeout value must be strictly positive") if timeout > self._TIMEOUT_MAX: raise OverflowError('timeout value is too large') try: acquired = BoundedSemaphore.acquire(self, blocking, timeout) except LoopExit: # Raised when the semaphore was not trivially ours, and we needed # to block. Some other thread presumably owns the semaphore, and there are no greenlets # running in this thread to switch to. So the best we can do is # release the GIL and try again later. if blocking: # pragma: no cover raise acquired = False if not acquired and not blocking and getcurrent() is not get_hub_if_exists(): # Run other callbacks. This makes spin locks works. # We can't do this if we're in the hub, which we could easily be: # printing the repr of a thread checks its tstate_lock, and sometimes we # print reprs in the hub. # See https://github.com/gevent/gevent/issues/1464 # By using sleep() instead of self.wait(0), we don't force a trip # around the event loop *unless* we've been running callbacks for # longer than our switch interval. sleep() return acquired
# Should we implement _is_owned, at least for Python 2? See notes in # monkey.py's patch_existing_locks. allocate_lock = LockType def exit(): raise GreenletExit if hasattr(__thread__, 'stack_size'): _original_stack_size = __thread__.stack_size def stack_size(size=None): if size is None: return _original_stack_size() if size > _original_stack_size(): return _original_stack_size(size) # not going to decrease stack_size, because otherwise other # greenlets in this thread will suffer else: __implements__.remove('stack_size') __imports__ = copy_globals(__thread__, globals(), only_names=__imports__, ignore_missing_names=True) __all__ = __implements__ + __imports__ __all__.remove('_local') # XXX interrupt_main # XXX _count()