Commit 4f24255 introduced a bug which allows a length to be passed to
rb_ary_new4 which is too large, resulting in invalid memory access.
For example:
(1..1000).to_a.slice!(-2, 1000)
Force recycled objects could create a freelist for the page. At the
start of sweeping we should append to the freelist to avoid
permanently losing the slots on the freelist.
There were two issues:
1. When an IO object is waiting for writablility only (as in test_tcp_accept) the selected hash is empty.
Therefore selected[fiber] returns nil but needs to default to 0 in order to be or'ed with IO::WRITABLE.
2. When an IO object is waiting for read- or writability (as in test_tcp_connect), but only one of these
two events arrive, the Fiber and IO object need to be removed from the other `@readable` or `@writable` list.
We don't need to increment/decrement iteration level for frozen Hash
because frozen Hash can't be modified. We can assume that nobody
changes the target Hash while calling #each family.
How to reproduce:
a = {}
100.times do |i|
a[i] = true
end
Ractor.make_shareable(a)
4.times.collect do
Ractor.new(a) do |b|
100.times do
b.each_value do
end
end
end
end.each(&:take)
Example output:
internal:ractor>:267: warning: Ractor is experimental, and the behavior may change in future versions of Ruby! Also there are many implementation issues.
#<Thread:0x00007fcfb087bb30 run> terminated with exception (report_on_exception is true):
#<Thread:0x00007fcfb087b8d8 run> terminated with exception (report_on_exception is true):
#<Thread:0x00007fcfb088d678 run> terminated with exception (report_on_exception is true):
#<Thread:0x00007fcfb087bd88 run> terminated with exception (report_on_exception is true):
/tmp/h.rb:10:in `each_value'/tmp/h.rb:10:in `each_value': : /tmp/h.rb:10:in `each_value'no implicit conversion from nil to integer/tmp/h.rb:10:in `each_value'no implicit conversion from nil to integer (: : (TypeErrorTypeError)no implicit conversion from nil to integer)no implicit conversion from nil to integer (
(TypeErrorTypeError from /tmp/h.rb:10:in `block (3 levels) in <main>'
from /tmp/h.rb:10:in `block (3 levels) in <main>'
)) from /tmp/h.rb:9:in `times'
from /tmp/h.rb:9:in `times'
from /tmp/h.rb:9:in `block (2 levels) in <main>'
from /tmp/h.rb:10:in `block (3 levels) in <main>'
from /tmp/h.rb:10:in `block (3 levels) in <main>'
from /tmp/h.rb:9:in `block (2 levels) in <main>'
from /tmp/h.rb:9:in `times'
from /tmp/h.rb:9:in `times'
from /tmp/h.rb:9:in `block (2 levels) in <main>'
from /tmp/h.rb:9:in `block (2 levels) in <main>'
<internal:ractor>:694:in `take': thrown by remote Ractor. (Ractor::RemoteError)
from /tmp/h.rb:14:in `each'
from /tmp/h.rb:14:in `<main>'
/tmp/h.rb:10:in `each_value': no implicit conversion from nil to integer (TypeError)
from /tmp/h.rb:10:in `block (3 levels) in <main>'
from /tmp/h.rb:9:in `times'
from /tmp/h.rb:9:in `block (2 levels) in <main>'
