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/*
* Project: S.Ha.R.K.
*
* Coordinators:
* Giorgio Buttazzo <giorgio@sssup.it>
* Paolo Gai <pj@gandalf.sssup.it>
*
* Authors :
* Paolo Gai <pj@gandalf.sssup.it>
* Massimiliano Giorgi <massy@gandalf.sssup.it>
* Luca Abeni <luca@gandalf.sssup.it>
* (see the web pages for full authors list)
*
* ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy)
*
* http://www.sssup.it
* http://retis.sssup.it
* http://shark.sssup.it
*/
/**
------------
CVS : $Id: nopm.c,v 1.3 2003-01-07 17:07:50 pj Exp $
File: $File$
Revision: $Revision: 1.3 $
Last update: $Date: 2003-01-07 17:07:50 $
------------
See modules/nopm.h.
This code is a copy of nop.c with minor modifications.
**/
/*
* Copyright (C) 2000 Massimiliano Giorgi
*
* This program 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; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <modules/nop.h>
#include <ll/ll.h>
#include <ll/stdio.h>
#include <ll/string.h>
#include <kernel/const.h>
#include <sys/types.h>
#include <kernel/descr.h>
#include <kernel/var.h>
#include <kernel/func.h>
/* The NOPM resource level descriptor */
typedef struct {
mutex_resource_des m; /*+ the mutex interface +*/
} NOPM_mutex_resource_des;
/* this is the structure normally pointed by the opt field in the
mutex_t structure */
typedef struct {
PID owner;
IQUEUE blocked;
int counter;
} NOPM_mutex_t;
#define MAXTABLE 4096
static mutex_t *table[MAXTABLE];
static int index=0;
static int register_nopm(mutex_t *p)
{
if (index>=MAXTABLE) return -1;
table[index++]=p;
return 0;
}
void dump_nopm_table(void)
{
NOPM_mutex_t *ptr;
SYS_FLAGS f;
PID j;
int i;
f=kern_fsave();
kern_printf("nopm_mutex module TABLE\n");
kern_printf("----------------------\n");
for(i=0;i<index;i++) {
ptr=table[i]->opt;
if (!iq_isempty(&ptr->blocked)) {
kern_printf("%i blocks on 0x%p: ",ptr->owner,table[i]);
j=iq_query_first(&ptr->blocked);
while (j!=NIL) {
kern_printf("%i ",(int)j);
j=iq_query_next(j, &ptr->blocked);
}
kern_printf("\n");
} else {
//kern_printf("0x%p no block\n",table[i]);
}
}
kern_frestore(f);
}
/* Wait status for this library */
#define NOPM_WAIT LIB_STATUS_BASE
static int NOPM_res_register(RLEVEL l, PID p, RES_MODEL *r)
{
return -1;
}
static void NOPM_res_detach(RLEVEL l, PID p)
{
}
static int NOPM_init(RLEVEL l, mutex_t *m, const mutexattr_t *a)
{
NOPM_mutex_t *p;
if (a->mclass != NOPM_MCLASS)
return -1;
p = (NOPM_mutex_t *) kern_alloc(sizeof(NOPM_mutex_t));
/* control if there is enough memory; no control on init on a
non- destroyed mutex */
if (!p)
return (ENOMEM);
p->owner = NIL;
iq_init(&p->blocked, &freedesc, 0);
p->counter=0;
m->mutexlevel = l;
m->opt = (void *)p;
/* MG */
register_nopm(m);
return 0;
}
static int NOPM_destroy(RLEVEL l, mutex_t *m)
{
// NOPM_mutex_resource_des *lev = (NOPM_mutex_resource_des *)(resource_table[l]);
if ( ((NOPM_mutex_t *)m->opt)->owner != NIL)
return (EBUSY);
kern_cli();
if (m->opt) {
kern_free(m->opt,sizeof(NOPM_mutex_t));
m->opt = NULL;
}
kern_sti();
return 0;
}
static int NOPM_lock(RLEVEL l, mutex_t *m)
{
NOPM_mutex_t *p;
kern_cli();
p = (NOPM_mutex_t *)m->opt;
if (!p) {
/* if the mutex is not initialized, initialize it! */
NOPM_mutexattr_t a;
NOPM_mutexattr_default(a);
NOPM_init(l, m, &a);
}
if (p->owner == exec_shadow) {
/* the task already owns the mutex */
p->counter++;
kern_sti();
return 0;
}
if (p->owner != NIL) { /* We must block exec task */
LEVEL l; /* for readableness only */
proc_table[exec_shadow].context = kern_context_save();
kern_epilogue_macro();
l = proc_table[exec_shadow].task_level;
level_table[l]->public_block(l,exec_shadow);
/* we insert the task in the semaphore queue */
proc_table[exec_shadow].status = NOPM_WAIT;
iq_insertlast(exec_shadow,&p->blocked);
/* and finally we reschedule */
exec = exec_shadow = -1;
scheduler();
kern_context_load(proc_table[exec_shadow].context);
}
else {
/* the mutex is free, We can lock it! */
p->owner = exec_shadow;
p->counter++;
kern_sti();
}
return 0;
}
static int NOPM_trylock(RLEVEL l, mutex_t *m)
{
NOPM_mutex_t *p;
kern_cli();
p = (NOPM_mutex_t *)m->opt;
if (!p) {
/* if the mutex is not initialized, initialize it! */
NOPM_mutexattr_t a;
NOPM_mutexattr_default(a);
NOPM_init(l, m, &a);
}
if (p->owner != NIL) {
/* a task already owns the mutex */
kern_sti();
return (EBUSY);
}
else {
/* the mutex is free, We can lock it! */
p->owner = exec_shadow;
p->counter++;
kern_sti();
}
return 0;
}
static int NOPM_unlock(RLEVEL l, mutex_t *m)
{
NOPM_mutex_t *p;
PID e;
p = (NOPM_mutex_t *)m->opt;
if (!p)
return (EINVAL);
if (p->owner != exec_shadow) {
/* the mutex is owned by another task!!! */
kern_printf("wrongunlock<owner=%i,unlocker=%i>",p->owner,exec_shadow);
kern_sti();
return (EPERM);
}
p->counter--;
if (p->counter!=0) {
/* we have multiple lock on this mutex */
kern_sti();
return 0;
}
proc_table[exec_shadow].context = kern_context_save();
/* the mutex is mine, pop the firsttask to extract */
for (;;) {
e = iq_getfirst(&p->blocked);
if (e == NIL) {
p->owner = NIL;
break;
} else if (proc_table[e].status == NOPM_WAIT) {
l = proc_table[e].task_level;
level_table[l]->public_unblock(l,e);
p->counter++;
break;
}
}
/* MG!!! */
p->owner = e;
scheduler();
kern_context_load(proc_table[exec_shadow].context);
return 0;
}
RLEVEL NOPM_register_module(void)
{
RLEVEL l; /* the level that we register */
NOPM_mutex_resource_des *m; /* for readableness only */
printk("NOPM_register_module\n");
/* request an entry in the level_table */
l = resource_alloc_descriptor();
/* alloc the space needed for the EDF_level_des */
m = (NOPM_mutex_resource_des *)kern_alloc(sizeof(NOPM_mutex_resource_des));
/* update the level_table with the new entry */
resource_table[l] = (resource_des *)m;
/* fill the resource_des descriptor */
m->m.r.rtype = MUTEX_RTYPE;
m->m.r.res_register = NOPM_res_register;
m->m.r.res_detach = NOPM_res_detach;
/* fill the mutex_resource_des descriptor */
m->m.init = NOPM_init;
m->m.destroy = NOPM_destroy;
m->m.lock = NOPM_lock;
m->m.trylock = NOPM_trylock;
m->m.unlock = NOPM_unlock;
return l;
}