Date: Fri, 20 May 2005 06:40:07 GMT From: Jens A Nilsson <jnilsson@ludd.ltu.se> To: freebsd-threads@FreeBSD.org Subject: Re: threads/81258: Thread specific data is sometimes assigned to multiple keys and/or threads Message-ID: <200505200640.j4K6e7oc094400@freefall.freebsd.org>
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The following reply was made to PR threads/81258; it has been noted by GNATS. From: Jens A Nilsson <jnilsson@ludd.ltu.se> To: Daniel Eischen <deischen@freebsd.org> Cc: Jens Nilsson <jnilsson@ludd.luth.se>, freebsd-gnats-submit@freebsd.org, freebsd-threads@freebsd.org Subject: Re: threads/81258: Thread specific data is sometimes assigned to multiple keys and/or threads Date: Fri, 20 May 2005 06:10:51 +0200 On Thu, May 19, 2005 at 08:52:23AM -0400, Daniel Eischen wrote: > On Thu, 19 May 2005, Jens Nilsson wrote: > > Thread specific data is sometimes assinged to multiple keys > > and/or threads. In the attached test program two threads getting > > the same tsd for the same key seems to be the most usual. > > > > >How-To-Repeat: > > Run the attached test program a couple of times. One of the > > threads will wait for input, the bug is most likely to show up if > > enter is pressed in about half a second after the thread asked > > for data. > > > > I ran into the bug some time ago while developing a bit more > > complex application that involved a couple of threads all of them > > with TSD and some doing RPC-calls. In that application I had the > > same problem with any of the thread libs libpthread, libthr, and > > libc_r. This test program only seems to be able to repeat the > > problem with libpthread. > > Thread-specific data is destroyed when the thread exits. Your > TSD is allocated using malloc() and destroyed using free(). Your > test program does nothing to ensure that all threads have started > running and have all created/initialized their TSD before the > first thread exits. malloc() is probably reusing a prior > allocation that has been free()'d. > > Thread exiting != Thread being joined. I see, sorry to have bothered you. -- Regards Jens
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