From: "Avdi B. Grimm" <avdi@...>
Date: 2001-09-24T12:18:30+09:00
Subject: [ruby-talk:21616] opening a named pipe?

I'm having trouble reading from a named pipe in linux. basicly, I'm
creating a pipe for another program (diald) to write status information
to, opening the pipe, and then telling the external program to start
writing to the named pipe. A simplified version of the code follows:

`mkfifo #{$STATUS_FIFO_NAME}`
File.open($STATUS_FIFO_NAME, 'r') {|status_fifo|
  sendCmdToDiald 'monitor', $STATUS_FIFO_NAME
  timeout(2.0) {  # ensure this doesn't read indefinitely
    # ... read and store data from the pipe 
  }
}

Except on rare occasions, this code never gets past the call to
File#open. It just hangs on the open indefinitely. I can't even put a
timeout on the 'open' call; presumably because it's an IO issue and Ruby
threads all halt for IO.  Every now and then, with no predictability,
the code works perfectly, but it usually hangs.

1. Can anyone tell me what I'm doing wrong?

2. Has anyone created a Ruby wrapper for mkfifo or any of the other more
obscure *NIX calls? 'ftools' seems to only contain cross-platform file
commands.

3. Is anyone working on native threads for Ruby yet?  Having threads
that may block unpredictably is incredibly annoying for someone used to
coding fully-multithreaded apps in C++. Couldn't we just wrap the
excellent ACE middleware? No need to reinvent the wheel...