it is more about memory accounting sake. At allocation time,
we make clear we re possibly reusing regions marked as reusable.
Noted also calls might not necessarily succeed at first so we do
only when necessary.
With this patch, TracePoint receives a `:fiber_switch` event for
_almost_ every fiber switch. Previously, it would not be sent when an
exception was going to be raised. Now the event should only be blockable
by an interrupt (including `Thread#raise`) or a fatal error.
Additionally, interrupts will now be checked on the return fiber
_before_ re-raising the terminating unhandled exception. And a fiber
that terminates with an unhandled exception no longer creates a pending
interrupt on its thread. The exception will be raised in the return
fiber the same way as `Fiber#raise`: using `cont.value` with `cont.argc
== -1`
I moved `rb_exc_raise` from `fiber_store` to the end of `fiber_switch`
after _all_ of the other cleanup code: `fiber_stack_release`,
`th->blocking` increment, `RUBY_VM_CHECK_INTS`, and `EXEC_EVENT_HOOK`.
It seems to me that skipping those other cleanup steps may have also
resulted in other bugs.
* Rename `rb_scheduler` to `rb_fiber_scheduler`.
* Use public interface if available.
* Use `rb_check_funcall` where possible.
* Don't use `unblock` unless the fiber was non-blocking.
* Document Fiber's method related to scheduling;
* Extend Fiber's class docs with concepts of non-blocking
fibers;
* Introduce "imaginary" (documentation-only) class
Fiber::SchedulerInterface to properly document how
scheduler's methods should look.
This automatically choosess whether to use transfer on a transferring
fiber or resume on a yielding fiber. If the fiber is resuming, it
raises a FiberError.
This has been a TODO since 79df14c04b. While adcf0316d1 covered the
root_fiber of the initial thread, it didn't cover root_fibers of other
threads. Now it's hooked properly in rb_threadptr_root_fiber_setup.
With regards to "XXX: Is this mjit_cont `mjit_cont_free`d?", when
rb_threadptr_root_fiber_release is called, although I'm not sure when
th->root_fiber is truthy, fiber_free seems to call cont_free and
mjit_cont_free. So mjit_conts of root_fibers seem to be freed properly.
To make some kind of Ractor related extensions, some functions
should be exposed.
* include/ruby/thread_native.h
* rb_native_mutex_*
* rb_native_cond_*
* include/ruby/ractor.h
* RB_OBJ_SHAREABLE_P(obj)
* rb_ractor_shareable_p(obj)
* rb_ractor_std*()
* rb_cRactor
and rm ractor_pub.h
and rename srcdir/ractor.h to srcdir/ractor_core.h
(to avoid conflict with include/ruby/ractor.h)
Using Fiber#transfer with Fiber#resume for a same Fiber is
limited (once Fiber#transfer is called for a fiber, the fiber
can not be resumed more). This restriction was introduced to
protect the resume/yield chain, but we realized that it is too much
to protect the chain. Instead of the current restriction, we
introduce some other protections.
(1) can not transfer to the resuming fiber.
(2) can not transfer to the yielding fiber.
(3) can not resume transferred fiber.
(4) can not yield from not-resumed fiber.
[Bug #17221]
Also at the end of a transferred fiber, it had continued on root fiber.
However, if the root fiber resumed a fiber (and that fiber can resumed
another fiber), this behavior also breaks the resume/yield chain.
So at the end of a transferred fiber, switch to the edge of resume
chain from root fiber.
For example, root fiber resumed f1 and f1 resumed f2, transferred to
f3 and f3 terminated, then continue from the fiber f2 (it was continued
from root fiber without this patch).
If a fiber and thread are collected at the same time, the thread might
get collected first and the pointer on the fiber will go bad. I don't
think we need to check whether or not this is the main fiber in order to
release its stack
* Enables Mutex to be used as synchronization between multiple Fibers
of the same Thread.
* With a Fiber scheduler we can yield to another Fiber on contended
Mutex#lock instead of blocking the entire thread.
* This also makes the behavior of Mutex consistent across CRuby, JRuby and TruffleRuby.
* [Feature #16792]
This commit introduces Ractor mechanism to run Ruby program in
parallel. See doc/ractor.md for more details about Ractor.
See ticket [Feature #17100] to see the implementation details
and discussions.
[Feature #17100]
This commit does not complete the implementation. You can find
many bugs on using Ractor. Also the specification will be changed
so that this feature is experimental. You will see a warning when
you make the first Ractor with `Ractor.new`.
I hope this feature can help programmers from thread-safety issues.