Function _get_module_lock

Lib/importlib/_bootstrap.py:429–463

Get or create the module lock for a given module name. Acquire/release internally the global import lock to protect _module_locks.

(name)

# The following two functions are for consumption by Python/import.c.

def _get_module_lock(name):
    """Get or create the module lock for a given module name.

    Acquire/release internally the global import lock to protect
    _module_locks."""

    _imp.acquire_lock()
    try:
        try:
            lock = _module_locks[name]()
        except KeyError:
            lock = None

        if lock is None:
            if _thread is None:
                lock = _DummyModuleLock(name)
            else:
                lock = _ModuleLock(name)

            def cb(ref, name=name):
                _imp.acquire_lock()
                try:
                    # bpo-31070: Check if another thread created a new lock
                    # after the previous lock was destroyed
                    # but before the weakref callback was called.
                    if _module_locks.get(name) is ref:
                        del _module_locks[name]
                finally:
                    _imp.release_lock()

            _module_locks[name] = _weakref.ref(lock, cb)
    finally:
        _imp.release_lock()

    return lock


def _lock_unlock_module(name):