Implement process-shared spinlocks.
Sponsored by: The FreeBSD Foundation
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parent
e13c604596
commit
6eced731e8
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=297138
@ -1,7 +1,11 @@
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/*-
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* Copyright (c) 2003 David Xu <davidxu@freebsd.org>
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* Copyright (c) 2016 The FreeBSD Foundation
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* All rights reserved.
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*
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* Portions of this software were developed by Konstantin Belousov
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* under sponsorship from the FreeBSD Foundation.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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@ -46,93 +50,100 @@ int
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_pthread_spin_init(pthread_spinlock_t *lock, int pshared)
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{
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struct pthread_spinlock *lck;
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int ret;
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if (lock == NULL || pshared != PTHREAD_PROCESS_PRIVATE)
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ret = EINVAL;
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else if ((lck = malloc(sizeof(struct pthread_spinlock))) == NULL)
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ret = ENOMEM;
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else {
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_thr_umutex_init(&lck->s_lock);
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if (lock == NULL)
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return (EINVAL);
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if (pshared == PTHREAD_PROCESS_PRIVATE) {
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lck = malloc(sizeof(struct pthread_spinlock));
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if (lck == NULL)
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return (ENOMEM);
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*lock = lck;
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ret = 0;
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} else if (pshared == PTHREAD_PROCESS_SHARED) {
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lck = __thr_pshared_offpage(lock, 1);
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if (lck == NULL)
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return (EFAULT);
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*lock = THR_PSHARED_PTR;
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} else {
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return (EINVAL);
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}
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return (ret);
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_thr_umutex_init(&lck->s_lock);
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return (0);
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}
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int
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_pthread_spin_destroy(pthread_spinlock_t *lock)
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{
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void *l;
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int ret;
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if (lock == NULL || *lock == NULL)
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if (lock == NULL || *lock == NULL) {
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ret = EINVAL;
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else {
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} else if (*lock == THR_PSHARED_PTR) {
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l = __thr_pshared_offpage(lock, 0);
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if (l != NULL)
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__thr_pshared_destroy(l);
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ret = 0;
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} else {
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free(*lock);
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*lock = NULL;
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ret = 0;
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}
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return (ret);
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}
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int
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_pthread_spin_trylock(pthread_spinlock_t *lock)
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{
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struct pthread *curthread = _get_curthread();
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struct pthread_spinlock *lck;
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int ret;
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if (lock == NULL || (lck = *lock) == NULL)
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ret = EINVAL;
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else
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ret = THR_UMUTEX_TRYLOCK(curthread, &lck->s_lock);
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return (ret);
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if (lock == NULL || *lock == NULL)
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return (EINVAL);
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lck = *lock == THR_PSHARED_PTR ? __thr_pshared_offpage(lock, 0) : *lock;
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if (lck == NULL)
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return (EINVAL);
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return (THR_UMUTEX_TRYLOCK(_get_curthread(), &lck->s_lock));
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}
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int
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_pthread_spin_lock(pthread_spinlock_t *lock)
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{
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struct pthread *curthread = _get_curthread();
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struct pthread *curthread;
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struct pthread_spinlock *lck;
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int ret, count;
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int count;
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if (lock == NULL || (lck = *lock) == NULL)
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ret = EINVAL;
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else {
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count = SPIN_COUNT;
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while ((ret = THR_UMUTEX_TRYLOCK(curthread, &lck->s_lock)) != 0) {
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while (lck->s_lock.m_owner) {
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if (!_thr_is_smp) {
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if (lock == NULL)
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return (EINVAL);
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lck = *lock == THR_PSHARED_PTR ? __thr_pshared_offpage(lock, 0) : *lock;
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if (lck == NULL)
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return (EINVAL);
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curthread = _get_curthread();
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count = SPIN_COUNT;
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while (THR_UMUTEX_TRYLOCK(curthread, &lck->s_lock) != 0) {
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while (lck->s_lock.m_owner) {
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if (!_thr_is_smp) {
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_pthread_yield();
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} else {
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CPU_SPINWAIT;
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if (--count <= 0) {
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count = SPIN_COUNT;
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_pthread_yield();
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} else {
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CPU_SPINWAIT;
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if (--count <= 0) {
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count = SPIN_COUNT;
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_pthread_yield();
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}
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}
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}
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}
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ret = 0;
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}
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return (ret);
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return (0);
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}
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int
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_pthread_spin_unlock(pthread_spinlock_t *lock)
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{
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struct pthread *curthread = _get_curthread();
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struct pthread_spinlock *lck;
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int ret;
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if (lock == NULL || (lck = *lock) == NULL)
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ret = EINVAL;
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else {
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ret = THR_UMUTEX_UNLOCK(curthread, &lck->s_lock);
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}
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return (ret);
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if (lock == NULL)
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return (EINVAL);
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lck = *lock == THR_PSHARED_PTR ? __thr_pshared_offpage(lock, 0) : *lock;
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if (lck == NULL)
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return (EINVAL);
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return (THR_UMUTEX_UNLOCK(_get_curthread(), &lck->s_lock));
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}
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