freebsd-dev/lib/libkse/thread/thr_rtld.c
2005-08-29 13:47:42 +00:00

303 lines
6.6 KiB
C

/*
* Copyright (c) 2001 Alexander Kabaev
* 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, this list of conditions and the following disclaimer
* in this position and unchanged.
* 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 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.
*
* $FreeBSD$
*/
#include <sys/cdefs.h>
#include <stdlib.h>
#include "rtld_lock.h"
#include "thr_private.h"
static int _thr_rtld_clr_flag(int);
static void *_thr_rtld_lock_create(void);
static void _thr_rtld_lock_destroy(void *);
static void _thr_rtld_lock_release(void *);
static void _thr_rtld_rlock_acquire(void *);
static int _thr_rtld_set_flag(int);
static void _thr_rtld_wlock_acquire(void *);
#ifdef NOTYET
static void *
_thr_rtld_lock_create(void)
{
pthread_rwlock_t prwlock;
if (_pthread_rwlock_init(&prwlock, NULL))
return (NULL);
return (prwlock);
}
static void
_thr_rtld_lock_destroy(void *lock)
{
pthread_rwlock_t prwlock;
prwlock = (pthread_rwlock_t)lock;
if (prwlock != NULL)
_pthread_rwlock_destroy(&prwlock);
}
static void
_thr_rtld_rlock_acquire(void *lock)
{
pthread_rwlock_t prwlock;
prwlock = (pthread_rwlock_t)lock;
_thr_rwlock_rdlock(&prwlock);
}
static void
_thr_rtld_wlock_acquire(void *lock)
{
pthread_rwlock_t prwlock;
prwlock = (pthread_rwlock_t)lock;
_thr_rwlock_wrlock(&prwlock);
}
static void
_thr_rtld_lock_release(void *lock)
{
pthread_rwlock_t prwlock;
prwlock = (pthread_rwlock_t)lock;
_thr_rwlock_unlock(&prwlock);
}
static int
_thr_rtld_set_flag(int mask)
{
struct pthread *curthread;
int bits;
curthread = _get_curthread();
if (curthread != NULL) {
bits = curthread->rtld_bits;
curthread->rtld_bits |= mask;
} else {
bits = 0;
PANIC("No current thread in rtld call");
}
return (bits);
}
static int
_thr_rtld_clr_flag(int mask)
{
struct pthread *curthread;
int bits;
curthread = _get_curthread();
if (curthread != NULL) {
bits = curthread->rtld_bits;
curthread->rtld_bits &= ~mask;
} else {
bits = 0;
PANIC("No current thread in rtld call");
}
return (bits);
}
void
_thr_rtld_init(void)
{
struct RtldLockInfo li;
li.lock_create = _thr_rtld_lock_create;
li.lock_destroy = _thr_rtld_lock_destroy;
li.rlock_acquire = _thr_rtld_rlock_acquire;
li.wlock_acquire = _thr_rtld_wlock_acquire;
li.lock_release = _thr_rtld_lock_release;
li.thread_set_flag = _thr_rtld_set_flag;
li.thread_clr_flag = _thr_rtld_clr_flag;
li.at_fork = NULL;
_rtld_thread_init(&li);
}
void
_thr_rtld_fini(void)
{
_rtld_thread_init(NULL);
}
#endif
struct rtld_kse_lock {
struct lock lck;
struct kse *owner;
kse_critical_t crit;
int count;
int write;
};
static void *
_thr_rtld_lock_create(void)
{
struct rtld_kse_lock *l;
if ((l = malloc(sizeof(struct rtld_kse_lock))) != NULL) {
_lock_init(&l->lck, LCK_ADAPTIVE, _kse_lock_wait,
_kse_lock_wakeup);
l->owner = NULL;
l->count = 0;
l->write = 0;
}
return (l);
}
static void
_thr_rtld_lock_destroy(void *lock)
{
/* XXX We really can not free memory after a fork() */
#if 0
struct rtld_kse_lock *l;
l = (struct rtld_kse_lock *)lock;
_lock_destroy(&l->lck);
free(l);
#endif
return;
}
static void
_thr_rtld_rlock_acquire(void *lock)
{
struct rtld_kse_lock *l;
kse_critical_t crit;
struct kse *curkse;
l = (struct rtld_kse_lock *)lock;
crit = _kse_critical_enter();
curkse = _get_curkse();
if (l->owner == curkse) {
l->count++;
_kse_critical_leave(crit); /* probably not necessary */
} else {
KSE_LOCK_ACQUIRE(curkse, &l->lck);
l->crit = crit;
l->owner = curkse;
l->count = 1;
l->write = 0;
}
}
static void
_thr_rtld_wlock_acquire(void *lock)
{
struct rtld_kse_lock *l;
kse_critical_t crit;
struct kse *curkse;
l = (struct rtld_kse_lock *)lock;
crit = _kse_critical_enter();
curkse = _get_curkse();
if (l->owner == curkse) {
_kse_critical_leave(crit);
PANIC("Recursive write lock attempt on rtld lock");
} else {
KSE_LOCK_ACQUIRE(curkse, &l->lck);
l->crit = crit;
l->owner = curkse;
l->count = 1;
l->write = 1;
}
}
static void
_thr_rtld_lock_release(void *lock)
{
struct rtld_kse_lock *l;
kse_critical_t crit;
struct kse *curkse;
l = (struct rtld_kse_lock *)lock;
crit = _kse_critical_enter();
curkse = _get_curkse();
if (l->owner != curkse) {
/*
* We might want to forcibly unlock the rtld lock
* and/or disable threaded mode so there is better
* chance that the panic will work. Otherwise,
* we could end up trying to take the rtld lock
* again.
*/
_kse_critical_leave(crit);
PANIC("Attempt to unlock rtld lock when not owner.");
} else {
l->count--;
if (l->count == 0) {
/*
* If there ever is a count associated with
* _kse_critical_leave(), we'll need to add
* another call to it here with the crit
* value from above.
*/
crit = l->crit;
l->owner = NULL;
l->write = 0;
KSE_LOCK_RELEASE(curkse, &l->lck);
}
_kse_critical_leave(crit);
}
}
static int
_thr_rtld_set_flag(int mask)
{
return (0);
}
static int
_thr_rtld_clr_flag(int mask)
{
return (0);
}
void
_thr_rtld_init(void)
{
struct RtldLockInfo li;
li.lock_create = _thr_rtld_lock_create;
li.lock_destroy = _thr_rtld_lock_destroy;
li.rlock_acquire = _thr_rtld_rlock_acquire;
li.wlock_acquire = _thr_rtld_wlock_acquire;
li.lock_release = _thr_rtld_lock_release;
li.thread_set_flag = _thr_rtld_set_flag;
li.thread_clr_flag = _thr_rtld_clr_flag;
li.at_fork = NULL;
_rtld_thread_init(&li);
}
void
_thr_rtld_fini(void)
{
_rtld_thread_init(NULL);
}