source: trunk/kernel/syscalls/sys_cond_var.c @ 8

/*
 * sys_cond_var: interface to access condition vraibles service
 * 
 * Copyright (c) 2008,2009,2010,2011,2012 Ghassan Almaless
 * Copyright (c) 2011,2012 UPMC Sorbonne Universites
 *
 * This file is part of ALMOS-kernel.
 *
 * ALMOS-kernel 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; version 2.0 of the License.
 *
 * ALMOS-kernel 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 ALMOS-kernel; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <types.h>
#include <errno.h>
#include <thread.h>
#include <kmem.h>
#include <task.h>
#include <vmm.h>
#include <kmagics.h>
#include <semaphore.h>
#include <cond_var.h>

static inline bool_t isBadSem(struct semaphore_s *sem)
{ 
        return vmm_check_object(sem, struct semaphore_s, SEMAPHORE_ID);
}

static inline bool_t isBadCV(struct cv_s *cv)
{ 
        return vmm_check_object(cv, struct cv_s, COND_VAR_ID);
}

int sys_cond_var(struct cv_s **cv, uint_t operation, struct semaphore_s **sem)
{
        kmem_req_t req;
        struct cv_s *icv;
        struct semaphore_s *isem;
        error_t err = EINVAL;
 
        if((err = vmm_check_address("usr cv ptr", current_task,cv,sizeof(struct cv_s*))))
                goto SYS_COND_END;

        if((err = cpu_copy_from_uspace(&icv, cv, sizeof(struct cv_s *))))
                goto SYS_COND_END;

        switch(operation)
        {
        case CV_INIT:
                req.type  = KMEM_CV;
                req.size  = sizeof(*icv);
                req.flags = AF_USER;
    
                if((icv = kmem_alloc(&req)) == NULL)
                {
                        err = ENOMEM;
                        break;
                }
    
                if((err = cv_init(icv)))
                        break;
    
                if((err = cpu_copy_to_uspace(cv, &icv, sizeof(struct cv_s *))))
                {
                        req.ptr = icv;
                        kmem_free(&req);
                }

                break;

        case CV_WAIT:
                err = vmm_check_address("usr sem ptr", 
                                        current_task, 
                                        sem, sizeof(struct semaphore_s*));

                if(err) break;

                if((err = cpu_copy_from_uspace(&isem, sem, sizeof(struct semaphore_s *))))
                        break;

                if(isBadSem(isem))
                        break;

                if(isBadCV(icv))
                        break;
    
                return cv_wait(icv, isem);

        case CV_SIGNAL:
                if(isBadCV(icv))
                        break;
    
                return cv_signal(icv);

        case CV_BROADCAST:
                if(isBadCV(icv))
                        break;
    
                return cv_broadcast(icv);

        case CV_DESTROY:
                if(isBadCV(icv))
                        break;
    
                if((err = cv_destroy(icv)))
                        break;
    
                req.type = KMEM_CV;
                req.ptr  = icv;
                kmem_free(&req);
                return 0;

        default:
                err = EINVAL;
        }

SYS_COND_END:
        current_thread->info.errno = err;
        return err;
}

KMEM_OBJATTR_INIT(cv_kmem_init)
{
        attr->type   = KMEM_CV;
        attr->name   = "KCM Condition Variable";
        attr->size   = sizeof(struct cv_s);
        attr->aligne = 0;
        attr->min    = CONFIG_CONDTION_VAR_MIN;
        attr->max    = CONFIG_CONDTION_VAR_MAX;
        attr->ctor   = NULL;
        attr->dtor   = NULL;
  
        return 0;
}