Date: Tue, 17 Apr 2012 09:18:06 +0000 (UTC) From: David Xu <davidxu@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-8@freebsd.org Subject: svn commit: r234373 - stable/8/lib/libthr/thread Message-ID: <201204170918.q3H9I6YL074845@svn.freebsd.org>
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Author: davidxu Date: Tue Apr 17 09:18:06 2012 New Revision: 234373 URL: http://svn.freebsd.org/changeset/base/234373 Log: Merge 233103 from head: Some software think a mutex can be destroyed after it owned it, for example, it uses a serialization point like following: pthread_mutex_lock(&mutex); pthread_mutex_unlock(&mutex); pthread_mutex_destroy(&muetx); They think a previous lock holder should have already left the mutex and is no longer referencing it, so they destroy it. To be maximum compatible with such code, we use IA64 version to unlock the mutex in kernel, remove the two steps unlocking code. Modified: stable/8/lib/libthr/thread/thr_umtx.c Directory Properties: stable/8/lib/libthr/ (props changed) Modified: stable/8/lib/libthr/thread/thr_umtx.c ============================================================================== --- stable/8/lib/libthr/thread/thr_umtx.c Tue Apr 17 09:09:14 2012 (r234372) +++ stable/8/lib/libthr/thread/thr_umtx.c Tue Apr 17 09:18:06 2012 (r234373) @@ -112,13 +112,6 @@ __thr_umutex_timedlock(struct umutex *mt int __thr_umutex_unlock(struct umutex *mtx, uint32_t id) { -#ifndef __ia64__ - /* XXX this logic has a race-condition on ia64. */ - if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) { - atomic_cmpset_rel_32(&mtx->m_owner, id | UMUTEX_CONTESTED, UMUTEX_CONTESTED); - return _umtx_op_err(mtx, UMTX_OP_MUTEX_WAKE, 0, 0, 0); - } -#endif /* __ia64__ */ return _umtx_op_err(mtx, UMTX_OP_MUTEX_UNLOCK, 0, 0, 0); }
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