locks.c

Apache V2.0.15 Alpha For Linuxhttpd-2_0_15-alpha.tar.Z

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000-2001 The Apache Software Foundation.  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.
 *
 * 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 end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

#include "apr_general.h"
#include "apr_lib.h"
#include "apr_strings.h"
#include "apr_portable.h"
#include "locks.h"
#include "fileio.h"
#include <string.h>

#define CurrentTid (lock->tib->tib_ptib2->tib2_ultid)


static apr_status_t lock_cleanup(void *thelock)
{
    apr_lock_t *lock = thelock;
    return apr_lock_destroy(lock);
}



apr_status_t apr_lock_create(apr_lock_t **lock, apr_locktype_e type, apr_lockscope_e scope, 
			   const char *fname, apr_pool_t *cont)
{
    apr_lock_t *new;
    ULONG rc;
    char *semname;
    PIB *ppib;

    new = (apr_lock_t *)apr_palloc(cont, sizeof(apr_lock_t));
    new->cntxt = cont;
    new->type  = type;
    new->scope = scope;
    new->owner = 0;
    new->lock_count = 0;
    new->fname = apr_pstrdup(cont, fname);
    DosGetInfoBlocks(&(new->tib), &ppib);

    if (fname == NULL)
        semname = NULL;
    else
        semname = apr_pstrcat(cont, "/SEM32/", fname, NULL);

    rc = DosCreateMutexSem(semname, &(new->hMutex), scope == APR_CROSS_PROCESS ? DC_SEM_SHARED : 0, FALSE);
    *lock = new;

    if (!rc)
        apr_pool_cleanup_register(cont, new, lock_cleanup, apr_pool_cleanup_null);

    return APR_OS2_STATUS(rc);
}



apr_status_t apr_lock_child_init(apr_lock_t **lock, const char *fname,
			       apr_pool_t *cont)
{
    int rc;
    PIB *ppib;

    *lock = (apr_lock_t *)apr_palloc(cont, sizeof(apr_lock_t));

    if (lock == NULL)
        return APR_ENOMEM;

    DosGetInfoBlocks(&((*lock)->tib), &ppib);
    (*lock)->owner = 0;
    (*lock)->lock_count = 0;
    rc = DosOpenMutexSem( (char *)fname, &(*lock)->hMutex );

    if (!rc)
        apr_pool_cleanup_register(cont, *lock, lock_cleanup, apr_pool_cleanup_null);

    return APR_OS2_STATUS(rc);
}



apr_status_t apr_lock_acquire(apr_lock_t *lock)
{
    ULONG rc;
    
    rc = DosRequestMutexSem(lock->hMutex, SEM_INDEFINITE_WAIT);

    if (rc == 0) {
        lock->owner = CurrentTid;
        lock->lock_count++;
    }

    return APR_OS2_STATUS(rc);
}



apr_status_t apr_lock_release(apr_lock_t *lock)
{
    ULONG rc;
    
    if (lock->owner == CurrentTid && lock->lock_count > 0) {
        lock->lock_count--;
        rc = DosReleaseMutexSem(lock->hMutex);
        return APR_OS2_STATUS(rc);
    }
    
    return APR_SUCCESS;
}



apr_status_t apr_lock_destroy(apr_lock_t *lock)
{
    ULONG rc;
    apr_status_t stat = APR_SUCCESS;

    if (lock->owner == CurrentTid) {
        while (lock->lock_count > 0 && stat == APR_SUCCESS)
            stat = apr_lock_release(lock);
    }

    if (stat != APR_SUCCESS)
        return stat;
        
    if (lock->hMutex == 0)
        return APR_SUCCESS;

    rc = DosCloseMutexSem(lock->hMutex);
    
    if (!rc)
        lock->hMutex = 0;
        
    return APR_OS2_STATUS(rc);
}



apr_status_t apr_os_lock_get(apr_os_lock_t *oslock, apr_lock_t *lock)
{
    *oslock = lock->hMutex;
    return APR_SUCCESS;
}



apr_status_t apr_os_lock_put(apr_lock_t **lock, apr_os_lock_t *thelock, 
                           apr_pool_t *cont)
{
    if (cont == NULL) {
        return APR_ENOPOOL;
    }
    if ((*lock) == NULL) {
        (*lock) = (apr_lock_t *)apr_pcalloc(cont, sizeof(apr_lock_t));
        (*lock)->cntxt = cont;
    }
    (*lock)->hMutex = *thelock;
    return APR_SUCCESS;
}



apr_status_t apr_lock_data_get(apr_lock_t *lock, const char *key, void *data)
{
    return apr_pool_userdata_get(data, key, lock->cntxt);
}



apr_status_t apr_lock_data_set(apr_lock_t *lock, void *data, const char *key,
                            apr_status_t (*cleanup) (void *))
{
    return apr_pool_userdata_set(data, key, cleanup, lock->cntxt);
}