[plt-scheme] concurrency bug in tcp-connect

From: Matthew Flatt (mflatt at cs.utah.edu)
Date: Fri Jun 6 17:58:49 EDT 2003

At Thu, 5 Jun 2003 13:38:53 -0400, "Anton van Straaten" wrote:
> A bit of investigation shows that the problem seems to be in the function
> MZ_GETHOSTBYNAME in mzscheme/src/network.c.  There's a static buffer,
> ghbn_hostname, which is being written to without any kind of synchronization
> check.  Moving this code down into the synchronized section, after
> "ghbn_lock = 1", fixes this problem, and has worked so far in my tests.
> I've appended a diff.

Thanks for tracking down this bug. As the variable names suggest, that
particular lock is indeed supposed to protect that particular buffer!

I modified your patch, slightly: I moved the strlen() test back to the
top of the function (since one branch of the test escapes), but I kept
the strcpy() under the lock.


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