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[netbsd-mini2440.git] / external / bsd / openldap / dist / libraries / libldap_r / thr_lwp.c

/* thr_lwp.c - wrappers around SunOS LWP threads */
/* $OpenLDAP: pkg/ldap/libraries/libldap_r/thr_lwp.c,v 1.20.2.3 2008/02/11 23:26:42 kurt Exp $ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
 *
 * Copyright 1998-2008 The OpenLDAP Foundation.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted only as authorized by the OpenLDAP
 * Public License.
 *
 * A copy of this license is available in file LICENSE in the
 * top-level directory of the distribution or, alternatively, at
 * <http://www.OpenLDAP.org/license.html>.
 */

/* BUGS:
 * - slurpd calls the get_stack/free_stack functions. Should be fixed, so
 *   they can become static.
 */

#include "portable.h"

#if defined( HAVE_LWP )

/*************
 *           *
 * SunOS LWP *
 *           *
 *************/

/* This implementation NEEDS WORK.   It currently does not compile */

#include <stdio.h>

#include <ac/time.h>
#include <ac/socket.h>

#include "ldap-int.h"

#include "ldap_pvt_thread.h" /* Get the thread interface */
#define LDAP_THREAD_IMPLEMENTATION
#include "ldap_thr_debug.h"      /* May rename the symbols defined below */

#include <lwp/lwp.h>
#include <lwp/stackdep.h>

#define MAX_STACK       51200
#define MAX_THREADS     20

/*
 * Initialize LWP by spinning of a schedular
 */
int
ldap_int_thread_initialize( void )
{
        thread_t                tid;
        stkalign_t              *stack;
        int                     stackno;

        if (( stack = get_stack( &stackno )) == NULL ) {
                return -1;
        }

        lwp_create( &tid, lwp_scheduler, MINPRIO, 0, stack, 1, stackno );
        return 0;
}

int
ldap_int_thread_destroy( void )
{
        /* need to destroy lwp_scheduler thread and clean up private
                variables */
        return 0;
}

struct stackinfo {
        int             stk_inuse;
        stkalign_t      *stk_stack;
};

static struct stackinfo *stacks;

static stkalign_t * ldap_int_thread_get_stack( int *stacknop )
{
        int     i;

        if ( stacks == NULL ) {
                stacks = (struct stackinfo *) LDAP_CALLOC( 1, MAX_THREADS *
                    sizeof(struct stackinfo) );

                if( stacks == NULL ) {
                        Debug( LDAP_DEBUG_ANY, "stacks allocation failed",
                                0, 0, 0 );
                        return NULL;
                }
        }

        for ( i = 0; i < MAX_THREADS; i++ ) {
                if ( stacks[i].stk_inuse == 0 ) {
                        break;
                }
        }

        if ( i == MAX_THREADS ) {
                Debug( LDAP_DEBUG_ANY,
                    "no more stacks (max %d) - increase MAX_THREADS for more",
                    MAX_THREADS, 0, 0 );
                return( NULL );
        }

        if ( stacks[i].stk_stack == NULL ) {
                stacks[i].stk_stack = (stkalign_t *) LDAP_MALLOC(
                    (MAX_STACK / sizeof(stkalign_t) + 1 )
                    * sizeof(stkalign_t) );

                if( stacks[i].stk_stack == NULL ) {
                        Debug( LDAP_DEBUG_ANY, "stack allocation failed",
                                0, 0, 0 );
                        return( NULL );
                }
        }

        *stacknop = i;
        stacks[i].stk_inuse = 1;
        return( stacks[i].stk_stack + MAX_STACK / sizeof(stkalign_t) );
}

static void
ldap_int_thread_free_stack( int stackno )
{
        if ( stackno < 0 || stackno > MAX_THREADS ) {
                Debug( LDAP_DEBUG_ANY, "free_stack of bogus stack %d\n",
                    stackno, 0, 0 );
        }

        stacks[stackno].stk_inuse = 0;
}

static void
lwp_create_stack( void *(*func)(), void *arg, int stackno )
{
        (*func)( arg );

        ldap_int_thread_free_stack( stackno );
}

int 
ldap_pvt_thread_create( ldap_pvt_thread_t * thread, 
        int detach,
        void *(*start_routine)( void *),
        void *arg)
{
        stkalign_t      *stack;
        int             stackno;

        if ( (stack = ldap_int_thread_get_stack( &stackno )) == NULL ) {
                return( -1 );
        }
        return( lwp_create( thread, lwp_create_stack, MINPRIO, 0, 
                           stack, 3, start_routine, arg, stackno ) );
}

void 
ldap_pvt_thread_exit( void *retval )
{
        lwp_destroy( SELF );
}

unsigned int
ldap_pvt_thread_sleep(
        unsigned int interval
)
{
        thread_t                mylwp;
        tl_t            *t, *nt;
        time_t          now;


        if ( lwp_self( &mylwp ) < 0 ) {
                return -1;
        }

        time( &now );

        mon_enter( &sglob->tsl_mon );

        if ( sglob->tsl_list != NULL ) {
                for ( t = sglob->tsl_list; t != NULL; t = t->tl_next ) {
                        if ( SAMETHREAD( t->tl_tid, mylwp )) {
                                /* We're already sleeping? */
                                t->tl_wake = now + interval;
                                mon_exit( &sglob->tsl_mon );
                                lwp_suspend( mylwp );
                                return 0;
                        }
                }
        }

        nt = (tl_t *) LDAP_MALLOC( sizeof( tl_t ));

        if( nt == NULL ) return -1;

        nt->tl_next = sglob->tsl_list;
        nt->tl_wake = now + interval;
        nt->tl_tid = mylwp;
        sglob->tsl_list = nt;

        mon_exit( &sglob->tsl_mon );

        lwp_suspend( mylwp );
        return 0;
}

/*
 * The lwp_scheduler thread periodically checks to see if any threads
 * are due to be resumed.  If there are, it resumes them.  Otherwise,
 * it computes the lesser of ( 1 second ) or ( the minimum time until
 * a thread need to be resumed ) and puts itself to sleep for that amount
 * of time.
 */
static void
lwp_scheduler(
        int             stackno
)
{
        time_t                  now, min;
        struct timeval          interval;
        tl_t                    *t;

        while ( !sglob->slurpd_shutdown ) {
                mon_enter( &sglob->tsl_mon );

                time( &now );
                min = 0L;
                if ( sglob->tsl_list != NULL ) {
                        for ( t = sglob->tsl_list; t != NULL; t = t->tl_next ) {
                                if (( t->tl_wake  > 0L ) && ( t->tl_wake < now )) {
                                        lwp_resume( t->tl_tid );
                                        t->tl_wake = 0L;
                                }

                                if (( t->tl_wake > now ) && ( t->tl_wake < min )) {
                                        min =  t->tl_wake;
                                }
                        }
                }

                mon_exit( &sglob->tsl_mon );

                interval.tv_usec = 0L;
                if ( min == 0L ) {
                        interval.tv_sec = 1L;
                } else {
                        interval.tv_sec = min;
                }

                lwp_sleep( &interval );
        }

        mon_enter( &sglob->tsl_mon );

        for ( t = sglob->tsl_list; t != NULL; t = t->tl_next ) {
                lwp_resume( t->tl_tid );
        }

        mon_exit( &sglob->tsl_mon );

        free_stack( stackno );
}

int 
ldap_pvt_thread_join( ldap_pvt_thread_t thread, void **thread_return )
{
        lwp_join( thread );
        return 0;
}

int 
ldap_pvt_thread_kill( ldap_pvt_thread_t thread, int signo )
{
        return 0;
}

int 
ldap_pvt_thread_yield( void )
{
        lwp_yield( SELF );
        return 0;
}

int 
ldap_pvt_thread_cond_init( ldap_pvt_thread_cond_t *cond )
{
        /*
         * lwp cv_create requires the monitor id be passed in
         * when the cv is created, pthreads passes it when the
         * condition is waited for.  so, we fake the creation
         * here and actually do it when the cv is waited for
         * later.
         */

        cond->lcv_created = 0;

        return( 0 );
}

int 
ldap_pvt_thread_cond_signal( ldap_pvt_thread_cond_t *cond )
{
        return( cond->lcv_created ? cv_notify( cv->lcv_cv ) : 0 );
}

int 
ldap_pvt_thread_cond_wait( ldap_pvt_thread_cond_t *cond, 
        ldap_pvt_thread_mutex_t *mutex )
{
        if ( ! cond->lcv_created ) {
                cv_create( &cond->lcv_cv, *mutex );
                cond->lcv_created = 1;
        }

        return( cv_wait( cond->lcv_cv ) );      
}

int 
ldap_pvt_thread_mutex_init( ldap_pvt_thread_mutex_t *mutex )
{
        return( mon_create( mutex ) );
}

int 
ldap_pvt_thread_mutex_destroy( ldap_pvt_thread_mutex_t *mutex )
{
        return( mon_destroy( *mutex ) );
}

int 
ldap_pvt_thread_mutex_lock( ldap_pvt_thread_mutex_t *mutex )
{
        return( mon_enter( *mutex ) );
}

int 
ldap_pvt_thread_mutex_unlock( ldap_pvt_thread_mutex_t *mutex )
{
        return( mon_exit( *mutex ) );
}

int
ldap_pvt_thread_mutex_trylock( ldap_pvt_thread_mutex_t *mp )
{
        return( mon_cond_enter( *mp ) );
}

int
ldap_pvt_thread_cond_destroy( ldap_pvt_thread_cond_t *cv )
{
        return( cv->lcv_created ? cv_destroy( cv->lcv_cv ) : 0 );
}

int
ldap_pvt_thread_cond_broadcast( ldap_pvt_thread_cond_t *cv )
{
        return( cv->lcv_created ? cv_broadcast( cv->lcv_cv ) : 0 );
}

ldap_pvt_thread_t
ldap_pvt_thread_self( void )
{
        thread_t                mylwp;

        lwp_self( &mylwp );

        return mylwp;
}

#endif /* HAVE_LWP */