# gevent

# 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)
        else:
            greenlet = Greenlet.spawn(function, *args)
        return get_ident(greenlet)

    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

        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()