/* $NetBSD: pthread_spin.c,v 1.6.34.1 2023/08/04 13:04:03 martin Exp $ */ /*- * Copyright (c) 2001, 2006, 2007 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Nathan J. Williams and Andrew Doran. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * Public (POSIX-specified) spinlocks. */ #include __RCSID("$NetBSD: pthread_spin.c,v 1.6.34.1 2023/08/04 13:04:03 martin Exp $"); #include #include #include #include #include #include #include #include "pthread.h" #include "pthread_int.h" int pthread_spin_init(pthread_spinlock_t *lock, int pshared) { #ifdef ERRORCHECK if (lock == NULL || (pshared != PTHREAD_PROCESS_PRIVATE && pshared != PTHREAD_PROCESS_SHARED)) return EINVAL; #endif lock->pts_magic = _PT_SPINLOCK_MAGIC; /* * We don't actually use the pshared flag for anything; * CPU simple locks have all the process-shared properties * that we want anyway. */ lock->pts_flags = pshared; pthread_lockinit(&lock->pts_spin); return 0; } int pthread_spin_destroy(pthread_spinlock_t *lock) { #ifdef ERRORCHECK if (lock == NULL || lock->pts_magic != _PT_SPINLOCK_MAGIC) return EINVAL; if (!__SIMPLELOCK_UNLOCKED_P(&lock->pts_spin)) return EBUSY; #endif lock->pts_magic = _PT_SPINLOCK_DEAD; return 0; } int pthread_spin_lock(pthread_spinlock_t *lock) { pthread_t self; #ifdef ERRORCHECK if (lock == NULL || lock->pts_magic != _PT_SPINLOCK_MAGIC) return EINVAL; #endif self = pthread__self(); while (pthread__spintrylock(self, &lock->pts_spin) == 0) { pthread__smt_wait(); } return 0; } int pthread_spin_trylock(pthread_spinlock_t *lock) { pthread_t self; #ifdef ERRORCHECK if (lock == NULL || lock->pts_magic != _PT_SPINLOCK_MAGIC) return EINVAL; #endif self = pthread__self(); if (pthread__spintrylock(self, &lock->pts_spin) == 0) return EBUSY; return 0; } int pthread_spin_unlock(pthread_spinlock_t *lock) { pthread_t self; #ifdef ERRORCHECK if (lock == NULL || lock->pts_magic != _PT_SPINLOCK_MAGIC) return EINVAL; #endif self = pthread__self(); pthread__spinunlock(self, &lock->pts_spin); pthread__smt_wake(); return 0; }