port/threads/pthr_mutex.c

	pthr_mutex.c revision 7257d1b4d25bfac0c802847390e98a464fd787ac
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include "lint.h"
#include "thr_uberdata.h"
#include <pthread.h>

/*
 * pthread_mutexattr_init: allocates the mutex attribute object and
 * initializes it with the default values.
 */
#pragma weak _pthread_mutexattr_init = pthread_mutexattr_init
int
pthread_mutexattr_init(pthread_mutexattr_t *attr)
{
    mattr_t *ap;

    if ((ap = lmalloc(sizeof (mattr_t))) == NULL)
        return (ENOMEM);
    ap->pshared = DEFAULT_TYPE;
    ap->type = PTHREAD_MUTEX_DEFAULT;
    ap->protocol = PTHREAD_PRIO_NONE;
    ap->robustness = PTHREAD_MUTEX_STALL_NP;
    attr->__pthread_mutexattrp = ap;
    return (0);
}

/*
 * pthread_mutexattr_destroy: frees the mutex attribute object and
 * invalidates it with NULL value.
 */
int
pthread_mutexattr_destroy(pthread_mutexattr_t *attr)
{
    if (attr == NULL || attr->__pthread_mutexattrp == NULL)
        return (EINVAL);
    lfree(attr->__pthread_mutexattrp, sizeof (mattr_t));
    attr->__pthread_mutexattrp = NULL;
    return (0);
}

/*
 * pthread_mutexattr_setpshared: sets the shared attribute
 * to PTHREAD_PROCESS_PRIVATE or PTHREAD_PROCESS_SHARED.
 * This is equivalent to setting the USYNC_THREAD/USYNC_PROCESS
 * flag in mutex_init().
 */
int
pthread_mutexattr_setpshared(pthread_mutexattr_t *attr, int pshared)
{
    mattr_t *ap;

    if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
        (pshared != PTHREAD_PROCESS_PRIVATE &&
        pshared != PTHREAD_PROCESS_SHARED))
        return (EINVAL);
    ap->pshared = pshared;
    return (0);
}

/*
 * pthread_mutexattr_getpshared: gets the shared attribute.
 */
#pragma weak _pthread_mutexattr_getpshared = pthread_mutexattr_getpshared
int
pthread_mutexattr_getpshared(const pthread_mutexattr_t *attr, int *pshared)
{
    mattr_t *ap;

    if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
        pshared == NULL)
        return (EINVAL);
    *pshared = ap->pshared;
    return (0);
}

/*
 * pthread_mutexattr_setprioceiling: sets the prioceiling attribute.
 */
int
pthread_mutexattr_setprioceiling(pthread_mutexattr_t *attr, int prioceiling)
{
    const pcclass_t *pccp = get_info_by_policy(SCHED_FIFO);
    mattr_t *ap;

    if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
        prioceiling < pccp->pcc_primin || prioceiling > pccp->pcc_primax)
        return (EINVAL);
    ap->prioceiling = prioceiling;
    return (0);
}

/*
 * pthread_mutexattr_getprioceiling: gets the prioceiling attribute.
 */
#pragma weak _pthread_mutexattr_getprioceiling = \
            pthread_mutexattr_getprioceiling
int
pthread_mutexattr_getprioceiling(const pthread_mutexattr_t *attr, int *ceiling)
{
    mattr_t *ap;

    if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
        ceiling == NULL)
        return (EINVAL);
    *ceiling = ap->prioceiling;
    return (0);
}

/*
 * pthread_mutexattr_setprotocol: sets the protocol attribute.
 */
int
pthread_mutexattr_setprotocol(pthread_mutexattr_t *attr, int protocol)
{
    mattr_t *ap;

    if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL)
        return (EINVAL);
    if (protocol != PTHREAD_PRIO_NONE &&
        protocol != PTHREAD_PRIO_INHERIT &&
        protocol != PTHREAD_PRIO_PROTECT)
        return (ENOTSUP);
    ap->protocol = protocol;
    return (0);
}

/*
 * pthread_mutexattr_getprotocol: gets the protocol attribute.
 */
#pragma weak _pthread_mutexattr_getprotocol = pthread_mutexattr_getprotocol
int
pthread_mutexattr_getprotocol(const pthread_mutexattr_t *attr, int *protocol)
{
    mattr_t *ap;

    if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
        protocol == NULL)
        return (EINVAL);
    *protocol = ap->protocol;
    return (0);
}

/*
 * pthread_mutexattr_setrobust_np: sets the robustness attribute
 * to PTHREAD_MUTEX_ROBUST_NP or PTHREAD_MUTEX_STALL_NP.
 */
int
pthread_mutexattr_setrobust_np(pthread_mutexattr_t *attr, int robust)
{
    mattr_t *ap;

    if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
        (robust != PTHREAD_MUTEX_ROBUST_NP &&
        robust != PTHREAD_MUTEX_STALL_NP))
        return (EINVAL);
    ap->robustness = robust;
    return (0);
}

/*
 * pthread_mutexattr_getrobust_np: gets the robustness attribute.
 */
int
pthread_mutexattr_getrobust_np(const pthread_mutexattr_t *attr, int *robust)
{
    mattr_t *ap;

    if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
        robust == NULL)
        return (EINVAL);
    *robust = ap->robustness;
    return (0);
}

/*
 * pthread_mutex_init: Initializes the mutex object.  It copies the
 * various attributes into one type argument and calls mutex_init().
 */
#pragma weak _pthread_mutex_init = pthread_mutex_init
int
pthread_mutex_init(pthread_mutex_t *_RESTRICT_KYWD mutex,
    const pthread_mutexattr_t *_RESTRICT_KYWD attr)
{
    mattr_t *ap;
    int type;
    int prioceiling = 0;

    /*
     * All of the pshared, type, protocol, robust attributes
     * translate to bits in the mutex_type field.
     */
    if (attr != NULL) {
        if ((ap = attr->__pthread_mutexattrp) == NULL)
            return (EINVAL);
        type = ap->pshared | ap->type | ap->protocol | ap->robustness;
        if (ap->protocol == PTHREAD_PRIO_PROTECT)
            prioceiling = ap->prioceiling;
    } else {
        type = DEFAULT_TYPE | PTHREAD_MUTEX_DEFAULT |
            PTHREAD_PRIO_NONE | PTHREAD_MUTEX_STALL_NP;
    }

    return (mutex_init((mutex_t *)mutex, type, &prioceiling));
}

/*
 * pthread_mutex_setprioceiling: sets the prioceiling.
 * From the SUSv3 (POSIX) specification for pthread_mutex_setprioceiling():
 *  The process of locking the mutex need not
 *  adhere to the priority protect protocol.
 * We pass the MUTEX_NOCEIL flag to mutex_lock_internal() so that
 * a non-realtime thread can successfully execute this operation.
 */
int
pthread_mutex_setprioceiling(pthread_mutex_t *mutex, int ceil, int *oceil)
{
    mutex_t *mp = (mutex_t *)mutex;
    const pcclass_t *pccp = get_info_by_policy(SCHED_FIFO);
    int error;

    if (!(mp->mutex_type & PTHREAD_PRIO_PROTECT) ||
        ceil < pccp->pcc_primin || ceil > pccp->pcc_primax)
        return (EINVAL);
    error = mutex_lock_internal(mp, NULL, MUTEX_LOCK | MUTEX_NOCEIL);
    if (error == 0) {
        if (oceil)
            *oceil = mp->mutex_ceiling;
        mp->mutex_ceiling = ceil;
        error = mutex_unlock_internal(mp, 0);
    }
    return (error);
}

/*
 * pthread_mutex_getprioceiling: gets the prioceiling.
 */
#pragma weak _pthread_mutex_getprioceiling = pthread_mutex_getprioceiling
int
pthread_mutex_getprioceiling(const pthread_mutex_t *mp, int *ceiling)
{
    *ceiling = ((mutex_t *)mp)->mutex_ceiling;
    return (0);
}

/*
 * UNIX98
 * pthread_mutexattr_settype: sets the type attribute
 */
int
pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type)
{
    mattr_t *ap;

    if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL)
        return (EINVAL);
    switch (type) {
    case PTHREAD_MUTEX_NORMAL:
        type = LOCK_NORMAL;
        break;
    case PTHREAD_MUTEX_ERRORCHECK:
        type = LOCK_ERRORCHECK;
        break;
    case PTHREAD_MUTEX_RECURSIVE:
        type = LOCK_RECURSIVE | LOCK_ERRORCHECK;
        break;
    default:
        return (EINVAL);
    }
    ap->type = type;
    return (0);
}

/*
 * UNIX98
 * pthread_mutexattr_gettype: gets the type attribute.
 */
int
pthread_mutexattr_gettype(const pthread_mutexattr_t *attr, int *typep)
{
    mattr_t *ap;
    int type;

    if (attr == NULL || (ap = attr->__pthread_mutexattrp) == NULL ||
        typep == NULL)
        return (EINVAL);
    switch (ap->type) {
    case LOCK_NORMAL:
        type = PTHREAD_MUTEX_NORMAL;
        break;
    case LOCK_ERRORCHECK:
        type = PTHREAD_MUTEX_ERRORCHECK;
        break;
    case LOCK_RECURSIVE | LOCK_ERRORCHECK:
        type = PTHREAD_MUTEX_RECURSIVE;
        break;
    default:
        return (EINVAL);
    }
    *typep = type;
    return (0);
}