Method instance

zmq/sugar/context.py:207–241

Returns a global Context instance. Most single-process applications have a single, global Context. Use this method instead of passing around Context instances throughout your code. A common pattern for classes that depend on Contexts is to use a default argu

(cls: type[_ContextType], io_threads: int = 1)

    # static method copied from tornado IOLoop.instance
    @classmethod
    def instance(cls: type[_ContextType], io_threads: int = 1) -> _ContextType:
        """Returns a global Context instance.

        Most single-process applications have a single, global Context.
        Use this method instead of passing around Context instances
        throughout your code.

        A common pattern for classes that depend on Contexts is to use
        a default argument to enable programs with multiple Contexts
        but not require the argument for simpler applications::

            class MyClass(object):
                def __init__(self, context=None):
                    self.context = context or Context.instance()

        .. versionchanged:: 18.1

            When called in a subprocess after forking,
            a new global instance is created instead of inheriting
            a Context that won't work from the parent process.
        """
        if (
            cls._instance is None
            or cls._instance_pid != os.getpid()
            or cls._instance.closed
        ):
            with cls._instance_lock:
                if (
                    cls._instance is None
                    or cls._instance_pid != os.getpid()
                    or cls._instance.closed
                ):
                    cls._instance = cls(io_threads=io_threads)
                    cls._instance_pid = os.getpid()
        return cls._instance

    def term(self) -> None:
        """Close or terminate the context.