[ruby-core:95147] [Ruby master Bug#16186] Calling Net::HTTP from within an #inspect implementation hang when invoked from p

[nobu@ruby-lang.org]

Issue #16186 has been updated by nobu (Nobuyoshi Nakada).

Assignee set to kosaki (Motohiro KOSAKI)

Current implementation is since r38225 (fe6b2e20e9f17ed2c2900aa72994e075ffdc7124).
I think this was discussed in the mailing list (probably ruby-dev), but I can't find it now.
And I think which should be uninterruptible is only printing the argument and a newline.

https://github.com/nobu/ruby/pull/new/bug/16186-allow-interrupts-during-inspect-in-p


----------------------------------------
Bug #16186: Calling Net::HTTP from within an #inspect implementation hang when invoked from p
https://bugs.ruby-lang.org/issues/16186#change-81786

* Author: byteit101 (Patrick Plenefisch)
* Status: Open
* Priority: Normal
* Assignee: kosaki (Motohiro KOSAKI)
* Target version: 
* ruby -v: ruby 2.7.0dev (2019-09-27T18:22:21Z trunk d53cf85474) [x86_64-linux]
* Backport: 2.5: UNKNOWN, 2.6: UNKNOWN
----------------------------------------
Using this script:
``` ruby
require 'net/http'
class Victim
	def inspect
		puts "before"
		Net::HTTP.get('example.com', '/index.html') # this hangs. I haven't tried other network libraries
		puts "After"
		return "success"
	end
end
puts Victim.new.inspect # for some reason this doesn't hang
puts "now we hang"
p Victim.new  # but this implicit invocation of inspect does hang. Independent of ordering, and works on JRuby
puts "It worked!"
```

Expected:
```
$ rvm use jruby
$ ruby bug.rb
before
After
success
now we hang
before
After
success
It worked!
$
```

Actual:
```
$ rvm use ruby-head 
$ ruby bug.rb
before
After
success
now we hang
before
^C^C^Z
[1]  + 13423 suspended  ruby bug.rb
$ kill %1
$ (time passes)
Traceback (most recent call last):
	11: from bug.rb:12:in `<main>'
	10: from bug.rb:12:in `p'
	 9: from bug.rb:5:in `inspect'
	 8: from /home/byteit101/.rvm/rubies/ruby-head/lib/ruby/2.7.0/net/http.rb:458:in `get'
	 7: from /home/byteit101/.rvm/rubies/ruby-head/lib/ruby/2.7.0/net/http.rb:476:in `get_response'
	 6: from /home/byteit101/.rvm/rubies/ruby-head/lib/ruby/2.7.0/net/http.rb:919:in `start'
	 5: from /home/byteit101/.rvm/rubies/ruby-head/lib/ruby/2.7.0/net/http.rb:930:in `do_start'
	 4: from /home/byteit101/.rvm/rubies/ruby-head/lib/ruby/2.7.0/net/http.rb:945:in `connect'
	 3: from /home/byteit101/.rvm/rubies/ruby-head/lib/ruby/2.7.0/timeout.rb:105:in `timeout'
	 2: from /home/byteit101/.rvm/rubies/ruby-head/lib/ruby/2.7.0/timeout.rb:99:in `block in timeout'
	 1: from /home/byteit101/.rvm/rubies/ruby-head/lib/ruby/2.7.0/timeout.rb:99:in `ensure in block in timeout'
/home/byteit101/.rvm/rubies/ruby-head/lib/ruby/2.7.0/timeout.rb:99:in `join': Interrupt

[1]  + 13423 interrupt  ruby bug.rb
$
```
The thing that is surprising to me is the explicit `print` + `inspect` works, whereas a straight `p` hangs.





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