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From: jon@walt.cc.utexas.edu (Jon Boede)
Newsgroups: comp.lang.c
Subject: Does O_NDELAY shred read(2)?
Keywords: O_NDELAY, read, pipes
Message-ID: <20764@ut-emx.UUCP>
Date: 10 Nov 89 19:52:50 GMT
Sender: news@ut-emx.UUCP
Reply-To: jon@walt.cc.utexas.edu (Jon Boede)
Organization: The People's Republic of Austin, Texas
Lines: 20

If I have two processes communicating through a named pipe, and if the process
that is read(2)ing has O_NDELAY set on the file descriptor so that it will
return if nothing is on the pipe...

If a write(fd,buf,X) is made, will a read(fd2,buf2,X) == X?  In other words, I
know that the write will be atomic... will the read also be?  Is there a
certain buffer size past which I'll start running into trouble?  I'm thinking
of using a buffer that's about 2,000 bytes in length.

Also, with a named pipe, how much (byte-wise) can be written before the writer
will be suspended?  Does setting O_NDELAY on the write end do anything?

Thanks,
Jon
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Jon Boede					jon@bodedo.ucm.org
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