In a forked process from a fiber, the fiber becomes the only
fiber, `fiber_switch` does nothing as there is no other fibers,
`rb_fiber_terminate` does not terminate the fiber. In that case,
reaches the end of `fiber_entry` finaly, which is declared as
"COROUTINE" and should never return.
SunC
```
"cont.c", line 24: identifier redeclared: madvise
current : function(pointer to char, unsigned int, int) returning int
previous: function(pointer to void, unsigned int, int) returning int : "/usr/include/sys/mman.h", line 232
```
GCC
```
cont.c:24:12: error: conflicting types for 'madvise'
24 | extern int madvise(caddr_t, size_t, int);
| ^~~~~~~
In file included from cont.c:16:
/usr/include/sys/mman.h:232:12: note: previous declaration of 'madvise' was here
232 | extern int madvise(void *, size_t, int);
| ^~~~~~~
```
On Solaris, madvise(3C) is NOT defined for SUS (XPG4v2) or later,
but MADV_* macros are defined when __EXTENSIONS__ is defined.
This may cause compile error on Solaris 10 with GCC when
"-Werror=implicit-function-declaration" and "-D_XOPEN_SOURCE=600"
are added by configure.
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)
