mutex.h

/*
 * Written by Gilles Chanteperdrix <[email protected]>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#ifndef _POSIX_MUTEX_H
#define _POSIX_MUTEX_H

#include <asm/xenomai/atomic.h>
#include <pthread.h>

struct pse51_mutex;

union __xeno_mutex {
        pthread_mutex_t native_mutex;
        struct __shadow_mutex {
                unsigned magic;
                unsigned lockcnt;
                struct pse51_mutex *mutex;
                xnarch_atomic_t lock;
#ifdef CONFIG_XENO_FASTSYNCH
                union {
                        unsigned owner_offset;
                        xnarch_atomic_t *owner;
                };
                struct pse51_mutexattr attr;
#endif /* CONFIG_XENO_FASTSYNCH */
        } shadow_mutex;
};

#if defined(__KERNEL__) || defined(__XENO_SIM__)

#include <posix/internal.h>
#include <posix/thread.h>
#include <posix/cb_lock.h>

typedef struct pse51_mutex {
        unsigned magic;
        xnsynch_t synchbase;
        xnholder_t link;            /* Link in pse51_mutexq */

#define link2mutex(laddr)                                               \
        ((pse51_mutex_t *)(((char *)laddr) - offsetof(pse51_mutex_t, link)))

        pthread_mutexattr_t attr;
        pse51_kqueues_t *owningq;
} pse51_mutex_t;

extern pthread_mutexattr_t pse51_default_mutex_attr;

void pse51_mutexq_cleanup(pse51_kqueues_t *q);

void pse51_mutex_pkg_init(void);

void pse51_mutex_pkg_cleanup(void);

/* Internal mutex functions, exposed for use by syscall.c. */
int pse51_mutex_timedlock_break(struct __shadow_mutex *shadow,
                                int timed, xnticks_t to);

int pse51_mutex_check_init(struct __shadow_mutex *shadow,
                           const pthread_mutexattr_t *attr);

int pse51_mutex_init_internal(struct __shadow_mutex *shadow,
                              pse51_mutex_t *mutex,
                              xnarch_atomic_t *ownerp,
                              const pthread_mutexattr_t *attr);

void pse51_mutex_destroy_internal(pse51_mutex_t *mutex,
                                  pse51_kqueues_t *q);

/* must be called with nklock locked, interrupts off. */
static inline int pse51_mutex_timedlock_internal(xnthread_t *cur,
                                                 struct __shadow_mutex *shadow,
                                                 unsigned count,
                                                 int timed,
                                                 xnticks_t abs_to)

{
        pse51_mutex_t *mutex = shadow->mutex;

        if (xnpod_unblockable_p())
                return -EPERM;

        if (!pse51_obj_active(shadow, PSE51_MUTEX_MAGIC, struct __shadow_mutex)
            || !pse51_obj_active(mutex, PSE51_MUTEX_MAGIC, struct pse51_mutex))
                return -EINVAL;

#if XENO_DEBUG(POSIX)
        if (mutex->owningq != pse51_kqueues(mutex->attr.pshared))
                return -EPERM;
#endif /* XENO_DEBUG(POSIX) */

        if (xnsynch_owner_check(&mutex->synchbase, cur) == 0)
                return -EBUSY;

        if (timed)
                xnsynch_acquire(&mutex->synchbase, abs_to, XN_REALTIME);
        else
                xnsynch_acquire(&mutex->synchbase, XN_INFINITE, XN_RELATIVE);

        if (unlikely(xnthread_test_info(cur, XNBREAK | XNRMID | XNTIMEO))) {
                if (xnthread_test_info(cur, XNBREAK))
                        return -EINTR;
                else if (xnthread_test_info(cur, XNTIMEO))
                        return -ETIMEDOUT;
                else /* XNRMID */
                        return -EINVAL;
        }

        shadow->lockcnt = count;

        return 0;
}

#endif /* __KERNEL__ */

#endif /* !_POSIX_MUTEX_H */