locks/os2/locks.c

/* ====================================================================
 * The Apache Software License, Version 1.1
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 *       "This product includes software developed by the
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#include "apr_general.h"
#include "apr_lib.h"
#include "apr_strings.h"
#include "locks.h"
#include "fileio.h"
#include <string.h>
#define INCL_DOS
#include <os2.h>

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


void setup_lock()
{
}



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



apr_status_t apr_create_lock(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_register_cleanup(cont, new, lock_cleanup, apr_null_cleanup);

    return APR_OS2_STATUS(rc);
}



apr_status_t apr_child_init_lock(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_register_cleanup(cont, *lock, lock_cleanup, apr_null_cleanup);

    return APR_OS2_STATUS(rc);
}



apr_status_t apr_lock(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_unlock(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_destroy_lock(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_unlock(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);
}