"""Source code from dask.utils.

GitHub:
https://github.com/dask/dask

Licence:
Copyright (c) 2014-2018, Anaconda, Inc. and contributors
All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.

Neither the name of Anaconda nor the names of any contributors may be used to
endorse or promote products derived from this software without specific prior
written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
THE POSSIBILITY OF SUCH DAMAGE.
"""

import threading
import uuid
import weakref


class SerializableLock:
    """ A Serializable per-process Lock

    This wraps a normal ``threading.Lock`` object and satisfies the same
    interface.  However, this lock can also be serialized and sent to different
    processes.  It will not block concurrent operations between processes (for
    this you should look at ``multiprocessing.Lock`` or ``locket.lock_file``
    but will consistently deserialize into the same lock.

    So if we make a lock in one process::

        lock = SerializableLock()

    And then send it over to another process multiple times::

        bytes = pickle.dumps(lock)
        a = pickle.loads(bytes)
        b = pickle.loads(bytes)

    Then the deserialized objects will operate as though they were the same
    lock, and collide as appropriate.

    This is useful for consistently protecting resources on a per-process
    level.

    The creation of locks is itself not threadsafe.
    """
    _locks = weakref.WeakValueDictionary()

    def __init__(self, token=None):
        self.token = token or str(uuid.uuid4())
        if self.token in SerializableLock._locks:
            self.lock = SerializableLock._locks[self.token]
        else:
            self.lock = threading.Lock()
            SerializableLock._locks[self.token] = self.lock

    def acquire(self, *args, **kwargs):
        return self.lock.acquire(*args, **kwargs)

    def release(self, *args, **kwargs):
        return self.lock.release(*args, **kwargs)

    def __enter__(self):
        self.lock.__enter__()

    def __exit__(self, *args):
        self.lock.__exit__(*args)

    def locked(self):
        return self.lock.locked()

    def __getstate__(self):
        return self.token

    def __setstate__(self, token):
        self.__init__(token)

    def __str__(self):
        return '<%s: %s>' % (self.__class__.__name__, self.token)

    __repr__ = __str__

"""Source code from dask.utils.

GitHub:
https://github.com/dask/dask

Licence:
Copyright (c) 2014-2018, Anaconda, Inc. and contributors
All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.

Neither the name of Anaconda nor the names of any contributors may be used to
endorse or promote products derived from this software without specific prior
written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
THE POSSIBILITY OF SUCH DAMAGE.
"""

import threading
import uuid
import weakref


class SerializableLock:
    """ A Serializable per-process Lock

    This wraps a normal ``threading.Lock`` object and satisfies the same
    interface.  However, this lock can also be serialized and sent to different
    processes.  It will not block concurrent operations between processes (for
    this you should look at ``multiprocessing.Lock`` or ``locket.lock_file``
    but will consistently deserialize into the same lock.

    So if we make a lock in one process::

        lock = SerializableLock()

    And then send it over to another process multiple times::

        bytes = pickle.dumps(lock)
        a = pickle.loads(bytes)
        b = pickle.loads(bytes)

    Then the deserialized objects will operate as though they were the same
    lock, and collide as appropriate.

    This is useful for consistently protecting resources on a per-process
    level.

    The creation of locks is itself not threadsafe.
    """
    _locks = weakref.WeakValueDictionary()

    def __init__(self, token=None):
        self.token = token or str(uuid.uuid4())
        if self.token in SerializableLock._locks:
            self.lock = SerializableLock._locks[self.token]
        else:
            self.lock = threading.Lock()
            SerializableLock._locks[self.token] = self.lock

    def acquire(self, *args, **kwargs):
        return self.lock.acquire(*args, **kwargs)

    def release(self, *args, **kwargs):
        return self.lock.release(*args, **kwargs)

    def __enter__(self):
        self.lock.__enter__()

    def __exit__(self, *args):
        self.lock.__exit__(*args)

    def locked(self):
        return self.lock.locked()

    def __getstate__(self):
        return self.token

    def __setstate__(self, token):
        self.__init__(token)

    def __str__(self):
        return '<%s: %s>' % (self.__class__.__name__, self.token)

    __repr__ = __str__

Source code from dask.utils.  GitHub: https://github.com/dask/dask  Licence: Copyright (c) 2014-2018, Anaconda, Inc. and contributors All rights reserved.  Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:  Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.  Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.  Neither the name of Anaconda nor the names of any contributors may be used to endorse or promote products derived from this software without specific prior written permission.  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. A Serializable per-process Lock      This wraps a normal ``threading.Lock`` object and satisfies the same     interface.  However, this lock can also be serialized and sent to different     processes.  It will not block concurrent operations between processes (for     this you should look at ``multiprocessing.Lock`` or ``locket.lock_file``     but will consistently deserialize into the same lock.      So if we make a lock in one process::          lock = SerializableLock()      And then send it over to another process multiple times::          bytes = pickle.dumps(lock)         a = pickle.loads(bytes)         b = pickle.loads(bytes)      Then the deserialized objects will operate as though they were the same     lock, and collide as appropriate.      This is useful for consistently protecting resources on a per-process     level.      The creation of locks is itself not threadsafe.