All normal Ruby IO methods (IO#read, IO#gets, IO#write, ...) are
all capable of appearing to be "blocking" when presented with a
file description with the O_NONBLOCK flag set; so there is
little risk of incompatibility within Ruby-using programs.
The biggest compatibility risk is when spawning external
programs. As a result, stdin, stdout, and stderr are now always
made blocking before exec-family calls.
This change will make an event-oriented MJIT usable if it is
waiting on pipes on POSIX_like platforms.
It is ALSO necessary to take advantage of (proposed lightweight
concurrency (aka "auto-Fiber") or any similar proposal for
network concurrency: https://bugs.ruby-lang.org/issues/13618
Named-pipe (FIFO) are NOT yet non-blocking by default since
they are rarely-used and may introduce compatibility problems
and extra syscall overhead for a common path.
Please revert this commit if there are problems and if I am afk
since I am afk a lot, lately.
[ruby-core:89950] [Bug #14968]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65922 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Let me silence this until I have time to work on them, and make the CI
usable for testing other features.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65893 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
The behaviour of IO#ungetbyte has been depending on the width of
Fixnums. Fixnums should be invisible nowadays. It must be a
bug. Fix [Bug #14359]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65802 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Under pipe page memory pressure on Linux, a pipe may only be
created with a single buffer[1]. And as of Linux v4.18, the
fs/pipe.c::pipe_poll callback does not account for merging
done in fs/pipe::pipe_write; only the number of usable buffers
in the pipe. Thus it is possible for a pipe to be writable
(if only by a small amount) despite IO.select saying it is not.
With the default 16384 /proc/sys/fs/pipe-user-pages-soft value
and the pipe having 16 pages of buffers, this issue is trivially
reproducible by creating 1024 pipes in a background process
before running the spec:
$ ulimit -n 2053 # or something higher
$ ./miniruby -e '1024.times.map { IO.pipe }; sleep' &
$ make test-spec MSPECOPT=spec/ruby/core/io/select_spec.rb
So, we create a new pipe we never write to for testing
writability of IO.select. This may cause the test to fail with
ENFILE on an overloaded system, but at least that's an obvious
failure (unlike having a test get stuck). This should reduce
failures on our overloaded CI machines:
http://ci.rvm.jp/results/trunk-nopara@silicon-docker/1239426
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/fs/pipe.c?h=v4.18#n642
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64478 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* io.c (rb_io_puts): write a newline together at once for each
argument. based on the patch by rohitpaulk (Rohit Kuruvilla) at
[ruby-core:83508]. [Feature #14042]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60417 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* Other ruby implementations use the spec/ruby directory.
[Misc #13792] [ruby-core:82287]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59979 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
