Ruby » Ruby master

Bug #13632

Updated by ko1 (Koichi Sasada) over 7 years ago

In the bugfix for https://bugs.ruby-lang.org/issues/13076 has been introduced another bug, caused by a busy waiting in rb_notify_fd_close method, while the FD is being released. During this waiting, it pumps huge amounts of the ruby_error_stream_closed errors into thread's interrupt queue, which almost all stay there unprocessed. It can be up for several hundred of exceptions in the queue, depending on circumstances. 

 
 ``` 
   a = [] 
   t = [] 
   10.times do 
     r,w = IO.pipe 
     a << [r,w] 
     t << Thread.new do 
       while r.gets 
       end rescue IOError 
       # Interrupt queue is full and all IO is broken 
      Thread.current.pending_interrupt? # Expected to be false, because it's already rescued 
       IO.sysopen ("/dev/tty")                     # Expected not to throw an error. On each such call, it dequeues the next item from interrupt queue until there's none 
     end 
   end 
   a.each do |r,w| 
     w.puts "test" 
     w.close 
     r.close 
   end 
   t.each do |th| 
     th.join 
   end 
 ``` 

 
 Output: 

 
 ``` text 
 Traceback (most recent call last): 
	 1: from test2.rb:9:in `block (2 levels) in <main>' 
 test2.rb:9:in `sysopen': stream closed in another thread (IOError) 
 ``` 
 

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