Author: kib
Date: Mon Mar 21 06:40:54 2016
New Revision: 297138
URL: https://svnweb.freebsd.org/changeset/base/297138
Log:
Implement process-shared spinlocks.
Sponsored by: The FreeBSD Foundation
Modified:
head/lib/libthr/thread/thr_pspinlock.c
Modified: head/lib/libthr/thread/thr_pspinlock.c
==============================================================================
--- head/lib/libthr/thread/thr_pspinlock.c Mon Mar 21 05:59:05 2016
(r297137)
+++ head/lib/libthr/thread/thr_pspinlock.c Mon Mar 21 06:40:54 2016
(r297138)
@@ -1,7 +1,11 @@
/*-
* Copyright (c) 2003 David Xu <davi...@freebsd.org>
+ * Copyright (c) 2016 The FreeBSD Foundation
* All rights reserved.
*
+ * Portions of this software were developed by Konstantin Belousov
+ * under sponsorship from the FreeBSD Foundation.
+ *
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
@@ -46,93 +50,100 @@ int
_pthread_spin_init(pthread_spinlock_t *lock, int pshared)
{
struct pthread_spinlock *lck;
- int ret;
- if (lock == NULL || pshared != PTHREAD_PROCESS_PRIVATE)
- ret = EINVAL;
- else if ((lck = malloc(sizeof(struct pthread_spinlock))) == NULL)
- ret = ENOMEM;
- else {
- _thr_umutex_init(&lck->s_lock);
+ if (lock == NULL)
+ return (EINVAL);
+ if (pshared == PTHREAD_PROCESS_PRIVATE) {
+ lck = malloc(sizeof(struct pthread_spinlock));
+ if (lck == NULL)
+ return (ENOMEM);
*lock = lck;
- ret = 0;
+ } else if (pshared == PTHREAD_PROCESS_SHARED) {
+ lck = __thr_pshared_offpage(lock, 1);
+ if (lck == NULL)
+ return (EFAULT);
+ *lock = THR_PSHARED_PTR;
+ } else {
+ return (EINVAL);
}
-
- return (ret);
+ _thr_umutex_init(&lck->s_lock);
+ return (0);
}
int
_pthread_spin_destroy(pthread_spinlock_t *lock)
{
+ void *l;
int ret;
- if (lock == NULL || *lock == NULL)
+ if (lock == NULL || *lock == NULL) {
ret = EINVAL;
- else {
+ } else if (*lock == THR_PSHARED_PTR) {
+ l = __thr_pshared_offpage(lock, 0);
+ if (l != NULL)
+ __thr_pshared_destroy(l);
+ ret = 0;
+ } else {
free(*lock);
*lock = NULL;
ret = 0;
}
-
return (ret);
}
int
_pthread_spin_trylock(pthread_spinlock_t *lock)
{
- struct pthread *curthread = _get_curthread();
struct pthread_spinlock *lck;
- int ret;
- if (lock == NULL || (lck = *lock) == NULL)
- ret = EINVAL;
- else
- ret = THR_UMUTEX_TRYLOCK(curthread, &lck->s_lock);
- return (ret);
+ if (lock == NULL || *lock == NULL)
+ return (EINVAL);
+ lck = *lock == THR_PSHARED_PTR ? __thr_pshared_offpage(lock, 0) : *lock;
+ if (lck == NULL)
+ return (EINVAL);
+ return (THR_UMUTEX_TRYLOCK(_get_curthread(), &lck->s_lock));
}
int
_pthread_spin_lock(pthread_spinlock_t *lock)
{
- struct pthread *curthread = _get_curthread();
+ struct pthread *curthread;
struct pthread_spinlock *lck;
- int ret, count;
+ int count;
- if (lock == NULL || (lck = *lock) == NULL)
- ret = EINVAL;
- else {
- count = SPIN_COUNT;
- while ((ret = THR_UMUTEX_TRYLOCK(curthread, &lck->s_lock)) !=
0) {
- while (lck->s_lock.m_owner) {
- if (!_thr_is_smp) {
+ if (lock == NULL)
+ return (EINVAL);
+ lck = *lock == THR_PSHARED_PTR ? __thr_pshared_offpage(lock, 0) : *lock;
+ if (lck == NULL)
+ return (EINVAL);
+
+ curthread = _get_curthread();
+ count = SPIN_COUNT;
+ while (THR_UMUTEX_TRYLOCK(curthread, &lck->s_lock) != 0) {
+ while (lck->s_lock.m_owner) {
+ if (!_thr_is_smp) {
+ _pthread_yield();
+ } else {
+ CPU_SPINWAIT;
+ if (--count <= 0) {
+ count = SPIN_COUNT;
_pthread_yield();
- } else {
- CPU_SPINWAIT;
-
- if (--count <= 0) {
- count = SPIN_COUNT;
- _pthread_yield();
- }
}
}
}
- ret = 0;
}
-
- return (ret);
+ return (0);
}
int
_pthread_spin_unlock(pthread_spinlock_t *lock)
{
- struct pthread *curthread = _get_curthread();
struct pthread_spinlock *lck;
- int ret;
- if (lock == NULL || (lck = *lock) == NULL)
- ret = EINVAL;
- else {
- ret = THR_UMUTEX_UNLOCK(curthread, &lck->s_lock);
- }
- return (ret);
+ if (lock == NULL)
+ return (EINVAL);
+ lck = *lock == THR_PSHARED_PTR ? __thr_pshared_offpage(lock, 0) : *lock;
+ if (lck == NULL)
+ return (EINVAL);
+ return (THR_UMUTEX_UNLOCK(_get_curthread(), &lck->s_lock));
}
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