diff options
| author | uwe <uwe@NetBSD.org> | 2019-12-16 22:22:11 +0000 |
|---|---|---|
| committer | uwe <uwe@NetBSD.org> | 2019-12-16 22:22:11 +0000 |
| commit | d6f7de49fc523d076f19562807c46fd1f3dda62e (patch) | |
| tree | d17154787ff5fbd65a1fc729f801023ee31314e9 /lib/libpthread | |
| parent | 362d0d0f7fd653f9c8b1f79256f530a4527eb4f6 (diff) | |
pthread__rwlock_spin - clarify the test.
It's more pedantically correct to check RW_WRITE_LOCKED before
obtaining the thread id of the owner. And since there must be an
owner annotate the guard NULL check as unlinkely.
No functional change intended. Ok ad@.
Diffstat (limited to 'lib/libpthread')
| -rw-r--r-- | lib/libpthread/pthread_rwlock.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/lib/libpthread/pthread_rwlock.c b/lib/libpthread/pthread_rwlock.c index d5427132ddf..e5eda990c5b 100644 --- a/lib/libpthread/pthread_rwlock.c +++ b/lib/libpthread/pthread_rwlock.c @@ -1,4 +1,4 @@ -/* $NetBSD: pthread_rwlock.c,v 1.35 2019/12/15 23:13:33 uwe Exp $ */ +/* $NetBSD: pthread_rwlock.c,v 1.36 2019/12/16 22:22:11 uwe Exp $ */ /*- * Copyright (c) 2002, 2006, 2007, 2008 The NetBSD Foundation, Inc. @@ -30,7 +30,7 @@ */ #include <sys/cdefs.h> -__RCSID("$NetBSD: pthread_rwlock.c,v 1.35 2019/12/15 23:13:33 uwe Exp $"); +__RCSID("$NetBSD: pthread_rwlock.c,v 1.36 2019/12/16 22:22:11 uwe Exp $"); #include <sys/types.h> #include <sys/lwpctl.h> @@ -134,12 +134,15 @@ pthread__rwlock_spin(uintptr_t owner) pthread_t thread; unsigned int i; - thread = (pthread_t)(owner & RW_THREAD); - if (thread == NULL || (owner & ~RW_THREAD) != RW_WRITE_LOCKED) + if ((owner & ~RW_THREAD) != RW_WRITE_LOCKED) return 0; - if (thread->pt_lwpctl->lc_curcpu == LWPCTL_CPU_NONE || + + thread = (pthread_t)(owner & RW_THREAD); + if (__predict_false(thread == NULL) || + thread->pt_lwpctl->lc_curcpu == LWPCTL_CPU_NONE || thread->pt_blocking) return 0; + for (i = 128; i != 0; i--) pthread__rwlock_pause(); return 1; |
