Common Ruby additions to benefit Fibers

gistfile1.md

Currently the Thread APIs behave in a way which obscures the root Fiber from access. There have been several new APIs added to support accessing the root Thread local data.

If you consider that each Thread has a root Fiber, then accessing locals and the backtrace on that Fiber object could return locals and the backtrace for the Thread.

I have a WIP branch on top of Rubinius.

Thread#root_fiber or Fiber.root ➞ fiber

This returns a Fiber wrapping the structures for the original Thread. Instead of using the new Thread APIs, it would be possible to simply call methods on this object.

Thread#fibers ➞ array

This returns an Array of Fiber objects currently owned by the Thread. If a Fiber is moved to another Thread, the Fiber would no longer be returned in the previous Thread#fibers call.

Fiber.list ➞ array

This returns an Array of all executing or suspended Fibers.

Fiber#[key] ➞ obj or nil

This returns the value associated with this key on the Fiber independent of which Fiber is executing on the Thread currently.

thread.thread_variable_get(key) should be equivalent to thread.root_fiber[key].

Fiber#[key] = obj ➞ obj

This sets the value associated with this key on the Fiber independent of which Fiber is executing on the Thread currently.

thread.thread_variable_set(key, value) should be equivalent to thread.root_fiber[key] = value.

Fiber#keys ➞ keys

This returns the keys associated with this Fiber independent of which Fiber is executing on the Thread currently.

thread.thread_variables should be equivalent to thread.root_fiber.keys.

Fiber#backtrace ➞ array

This returns the backtrace of this Fiber independent of which Fiber is executing on the Thread currently.

Fiber#backtrace_locations(*args) ➞ array or nil

This returns the execution stack of this Fiber independent of which Fiber is executing on the Thread currently. See Thread::Backtrace::Location for more information.

Fiber#alive? ➞ bool

This returns whether the Fiber is still alive.

Fiber#status ➞ string

This returns the status of the Fiber, whether it is executing or suspended.

Fiber#raise(exception)

This raises an exception inside the Fiber when the Fiber is next resumed.

Filed feature requests

• http://bugs.ruby-lang.org/issues/8215
• http://bugs.ruby-lang.org/issues/8263
• http://bugs.ruby-lang.org/issues/8291

I got a good example of the @celluloid use-case: https://gist.github.com/halorgium/c770d3cf27f6279e5e43

rubinius/rubinius#2200