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From: Jens Eichendorff <jexo@online.de>
To: musl@lists.openwall.com
Subject: What does this code do?
Date: Sat, 22 Feb 2014 15:35:43 +0100	[thread overview]
Message-ID: <20140222143536.GA5438@diogenes.samsung.router> (raw)

While skimming some parts of the musl libc I have come across the
following weird line in `src/thread/__wait.c':

  if (priv) priv = 128; priv=0;

whereby `priv' is then bitwise OR-ed to the FUTEX_WAIT operation
constant to a futex syscall.  Does this code exist to avoid
optimizations, do optimizations, or just add waiting time?  What does it
do and what is the `priv' parameter of __wait() for?  Excuse me if this
is a really stupid question, I'm not very familiar with somewhat
low-level code.

Looking through the git logs this is part of the initial import commit,
so I could not find any comments to why this was done.

MfG
Jens


             reply	other threads:[~2014-02-22 14:35 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-02-22 14:35 Jens Eichendorff [this message]
2014-02-22 14:59 ` Rich Felker
2014-02-23  5:31   ` Rich Felker

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