freebsd-skq/lib/libthr/thread/thr_umtx.c
pfg 260ba0bff1 lib: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-26 02:00:33 +00:00

377 lines
8.8 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2005 David Xu <davidxu@freebsd.org>
* All rights reserved.
*
* 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 unmodified, 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 AUTHOR ``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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "thr_private.h"
#include "thr_umtx.h"
#ifndef HAS__UMTX_OP_ERR
int _umtx_op_err(void *obj, int op, u_long val, void *uaddr, void *uaddr2)
{
if (_umtx_op(obj, op, val, uaddr, uaddr2) == -1)
return (errno);
return (0);
}
#endif
void
_thr_umutex_init(struct umutex *mtx)
{
static const struct umutex default_mtx = DEFAULT_UMUTEX;
*mtx = default_mtx;
}
void
_thr_urwlock_init(struct urwlock *rwl)
{
static const struct urwlock default_rwl = DEFAULT_URWLOCK;
*rwl = default_rwl;
}
int
__thr_umutex_lock(struct umutex *mtx, uint32_t id)
{
uint32_t owner;
if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) != 0)
return (_umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, 0));
for (;;) {
owner = mtx->m_owner;
if ((owner & ~UMUTEX_CONTESTED) == 0 &&
atomic_cmpset_acq_32(&mtx->m_owner, owner, id | owner))
return (0);
if (owner == UMUTEX_RB_OWNERDEAD &&
atomic_cmpset_acq_32(&mtx->m_owner, owner,
id | UMUTEX_CONTESTED))
return (EOWNERDEAD);
if (owner == UMUTEX_RB_NOTRECOV)
return (ENOTRECOVERABLE);
/* wait in kernel */
_umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, 0);
}
}
#define SPINLOOPS 1000
int
__thr_umutex_lock_spin(struct umutex *mtx, uint32_t id)
{
uint32_t owner;
int count;
if (!_thr_is_smp)
return (__thr_umutex_lock(mtx, id));
if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) != 0)
return (_umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, 0));
for (;;) {
count = SPINLOOPS;
while (count--) {
owner = mtx->m_owner;
if ((owner & ~UMUTEX_CONTESTED) == 0 &&
atomic_cmpset_acq_32(&mtx->m_owner, owner,
id | owner))
return (0);
if (__predict_false(owner == UMUTEX_RB_OWNERDEAD) &&
atomic_cmpset_acq_32(&mtx->m_owner, owner,
id | UMUTEX_CONTESTED))
return (EOWNERDEAD);
if (__predict_false(owner == UMUTEX_RB_NOTRECOV))
return (ENOTRECOVERABLE);
CPU_SPINWAIT;
}
/* wait in kernel */
_umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, 0);
}
}
int
__thr_umutex_timedlock(struct umutex *mtx, uint32_t id,
const struct timespec *abstime)
{
struct _umtx_time *tm_p, timeout;
size_t tm_size;
uint32_t owner;
int ret;
if (abstime == NULL) {
tm_p = NULL;
tm_size = 0;
} else {
timeout._clockid = CLOCK_REALTIME;
timeout._flags = UMTX_ABSTIME;
timeout._timeout = *abstime;
tm_p = &timeout;
tm_size = sizeof(timeout);
}
for (;;) {
if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT |
UMUTEX_PRIO_INHERIT)) == 0) {
/* try to lock it */
owner = mtx->m_owner;
if ((owner & ~UMUTEX_CONTESTED) == 0 &&
atomic_cmpset_acq_32(&mtx->m_owner, owner,
id | owner))
return (0);
if (__predict_false(owner == UMUTEX_RB_OWNERDEAD) &&
atomic_cmpset_acq_32(&mtx->m_owner, owner,
id | UMUTEX_CONTESTED))
return (EOWNERDEAD);
if (__predict_false(owner == UMUTEX_RB_NOTRECOV))
return (ENOTRECOVERABLE);
/* wait in kernel */
ret = _umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0,
(void *)tm_size, __DECONST(void *, tm_p));
} else {
ret = _umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0,
(void *)tm_size, __DECONST(void *, tm_p));
if (ret == 0 || ret == EOWNERDEAD ||
ret == ENOTRECOVERABLE)
break;
}
if (ret == ETIMEDOUT)
break;
}
return (ret);
}
int
__thr_umutex_unlock(struct umutex *mtx)
{
return (_umtx_op_err(mtx, UMTX_OP_MUTEX_UNLOCK, 0, 0, 0));
}
int
__thr_umutex_trylock(struct umutex *mtx)
{
return (_umtx_op_err(mtx, UMTX_OP_MUTEX_TRYLOCK, 0, 0, 0));
}
int
__thr_umutex_set_ceiling(struct umutex *mtx, uint32_t ceiling,
uint32_t *oldceiling)
{
return (_umtx_op_err(mtx, UMTX_OP_SET_CEILING, ceiling, oldceiling, 0));
}
int
_thr_umtx_wait(volatile long *mtx, long id, const struct timespec *timeout)
{
if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
timeout->tv_nsec <= 0)))
return (ETIMEDOUT);
return (_umtx_op_err(__DEVOLATILE(void *, mtx), UMTX_OP_WAIT, id, 0,
__DECONST(void*, timeout)));
}
int
_thr_umtx_wait_uint(volatile u_int *mtx, u_int id,
const struct timespec *timeout, int shared)
{
if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
timeout->tv_nsec <= 0)))
return (ETIMEDOUT);
return (_umtx_op_err(__DEVOLATILE(void *, mtx), shared ?
UMTX_OP_WAIT_UINT : UMTX_OP_WAIT_UINT_PRIVATE, id, 0,
__DECONST(void*, timeout)));
}
int
_thr_umtx_timedwait_uint(volatile u_int *mtx, u_int id, int clockid,
const struct timespec *abstime, int shared)
{
struct _umtx_time *tm_p, timeout;
size_t tm_size;
if (abstime == NULL) {
tm_p = NULL;
tm_size = 0;
} else {
timeout._clockid = clockid;
timeout._flags = UMTX_ABSTIME;
timeout._timeout = *abstime;
tm_p = &timeout;
tm_size = sizeof(timeout);
}
return (_umtx_op_err(__DEVOLATILE(void *, mtx), shared ?
UMTX_OP_WAIT_UINT : UMTX_OP_WAIT_UINT_PRIVATE, id,
(void *)tm_size, __DECONST(void *, tm_p)));
}
int
_thr_umtx_wake(volatile void *mtx, int nr_wakeup, int shared)
{
return (_umtx_op_err(__DEVOLATILE(void *, mtx), shared ?
UMTX_OP_WAKE : UMTX_OP_WAKE_PRIVATE, nr_wakeup, 0, 0));
}
void
_thr_ucond_init(struct ucond *cv)
{
bzero(cv, sizeof(struct ucond));
}
int
_thr_ucond_wait(struct ucond *cv, struct umutex *m,
const struct timespec *timeout, int flags)
{
struct pthread *curthread;
if (timeout && (timeout->tv_sec < 0 || (timeout->tv_sec == 0 &&
timeout->tv_nsec <= 0))) {
curthread = _get_curthread();
_thr_umutex_unlock(m, TID(curthread));
return (ETIMEDOUT);
}
return (_umtx_op_err(cv, UMTX_OP_CV_WAIT, flags, m,
__DECONST(void*, timeout)));
}
int
_thr_ucond_signal(struct ucond *cv)
{
if (!cv->c_has_waiters)
return (0);
return (_umtx_op_err(cv, UMTX_OP_CV_SIGNAL, 0, NULL, NULL));
}
int
_thr_ucond_broadcast(struct ucond *cv)
{
if (!cv->c_has_waiters)
return (0);
return (_umtx_op_err(cv, UMTX_OP_CV_BROADCAST, 0, NULL, NULL));
}
int
__thr_rwlock_rdlock(struct urwlock *rwlock, int flags,
const struct timespec *tsp)
{
struct _umtx_time timeout, *tm_p;
size_t tm_size;
if (tsp == NULL) {
tm_p = NULL;
tm_size = 0;
} else {
timeout._timeout = *tsp;
timeout._flags = UMTX_ABSTIME;
timeout._clockid = CLOCK_REALTIME;
tm_p = &timeout;
tm_size = sizeof(timeout);
}
return (_umtx_op_err(rwlock, UMTX_OP_RW_RDLOCK, flags,
(void *)tm_size, tm_p));
}
int
__thr_rwlock_wrlock(struct urwlock *rwlock, const struct timespec *tsp)
{
struct _umtx_time timeout, *tm_p;
size_t tm_size;
if (tsp == NULL) {
tm_p = NULL;
tm_size = 0;
} else {
timeout._timeout = *tsp;
timeout._flags = UMTX_ABSTIME;
timeout._clockid = CLOCK_REALTIME;
tm_p = &timeout;
tm_size = sizeof(timeout);
}
return (_umtx_op_err(rwlock, UMTX_OP_RW_WRLOCK, 0, (void *)tm_size,
tm_p));
}
int
__thr_rwlock_unlock(struct urwlock *rwlock)
{
return (_umtx_op_err(rwlock, UMTX_OP_RW_UNLOCK, 0, NULL, NULL));
}
void
_thr_rwl_rdlock(struct urwlock *rwlock)
{
int ret;
for (;;) {
if (_thr_rwlock_tryrdlock(rwlock, URWLOCK_PREFER_READER) == 0)
return;
ret = __thr_rwlock_rdlock(rwlock, URWLOCK_PREFER_READER, NULL);
if (ret == 0)
return;
if (ret != EINTR)
PANIC("rdlock error");
}
}
void
_thr_rwl_wrlock(struct urwlock *rwlock)
{
int ret;
for (;;) {
if (_thr_rwlock_trywrlock(rwlock) == 0)
return;
ret = __thr_rwlock_wrlock(rwlock, NULL);
if (ret == 0)
return;
if (ret != EINTR)
PANIC("wrlock error");
}
}
void
_thr_rwl_unlock(struct urwlock *rwlock)
{
if (_thr_rwlock_unlock(rwlock))
PANIC("unlock error");
}