Fiber#transfer prevents calling Fiber#resume on the receiver of the
transfer method, not the fiber calling transfer.
Transfering back to a fiber does not allow later calling resume on
the fiber. Once transfer has been called on a fiber, you can never
call resume on the fiber.
Calling resume on a transferred fiber is not a double resume error,
it is a different FiberError (cannot resume transferred Fiber).
For details on the differences between transferred fibers and
regular fibers, see Sasada-san's RubyKaigi 2017 presentation (in
short, Fiber#transfer is for coroutine, Fiber#resume is for
semi-coroutine).
Added by jeremyevans (Jeremy Evans) over 5 years ago
Fix documentation for Fiber#transfer [ci skip]
Fiber#transfer prevents calling Fiber#resume on the receiver of the
transfer method, not the fiber calling transfer.
Transfering back to a fiber does not allow later calling resume on
the fiber. Once transfer has been called on a fiber, you can never
call resume on the fiber.
Calling resume on a transferred fiber is not a double resume error,
it is a different FiberError (cannot resume transferred Fiber).
For details on the differences between transferred fibers and
regular fibers, see Sasada-san's RubyKaigi 2017 presentation (in
short, Fiber#transfer is for coroutine, Fiber#resume is for
semi-coroutine).