/*
 * kern/sys_ps.c - show kernel active processes and threads
 * 
 * Copyright (c) 2008,2009,2010,2011,2012 Ghassan Almaless
 * Copyright (c) 2011,2012,2013,2014,2015 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 <task.h>
#include <pid.h>
#include <thread.h>
#include <vmm.h>
#include <errno.h>
#include <utils.h>
#include <rpc.h>
#include <cluster.h>

extern error_t ps_func(void *param);

/* TODO: add remote support. */
static error_t sys_ps_check_thread(pid_t pid, uint_t tid, struct thread_s **th_ptr)
{
	struct task_s *task;
	struct thread_s *thread;
        cid_t  location;

	if(pid == PID_MIN_LOCAL)
		return EINVAL;

        location = task_whereis(pid);

        tasks_manager_lock();
        if ( location == current_cid )
        {
                task = task_lookup(pid)->task;

                if((task == NULL) || (tid > task->max_order))
                        return EINVAL;

                thread = task->th_tbl[tid];

                if((thread == NULL)                 ||
                   (thread->signature != THREAD_ID) ||
                   (thread->info.attr.key != tid))
                {
                        return ESRCH;
                }

                *th_ptr = thread;
                return 0;
        }
        else
        {
                printk(WARNING, "%s: cluster %u can't execute this function on remote task (pid %u on cluster %u)\n",   \
                                __FUNCTION__, current_cid, pid, location);
                return ENOSYS;
        }
        tasks_manager_unlock();
}

/*TODO: use RPC_ARG_NULL instead of sending a useless variable.
 * It's not urgent, it's a minor change.
 */
RPC_DECLARE(__ps_func,                                  \
                RPC_RET( RPC_RET_PTR(error_t, err) ),   \
                RPC_ARG( RPC_ARG_PTR(error_t, foo) )    \
           )
{
        *err = ps_func(NULL);
}

int sys_ps(uint_t cmd, pid_t pid, uint_t tid)
{
        cid_t next;
	error_t err;
	struct thread_s *thread;
        struct kernel_iter_s *kernel_iter;

        err = 0;

	switch(cmd)
	{
	case TASK_PS_TRACE_OFF:
		err = sys_ps_check_thread(pid, tid, &thread);
		if(err) goto fail_trace_off;
		thread->info.isTraced = false;
		cpu_wbflush();
		printk(INFO,"INFO: pid %d, tid %x, tracing is turned [OFF]\n", pid, tid);
		break;

	case TASK_PS_TRACE_ON:
		err = sys_ps_check_thread(pid, tid, &thread);
		if(err) goto fail_trace_on;
		thread->info.isTraced = true;
		cpu_wbflush();
		printk(INFO,"INFO: pid %d, tid %x, tracing is turned [ON]\n", pid, tid);
		break;

	case TASK_PS_SHOW:
                kernel_foreach_backward(kernel_iter, next)
                {
                        RCPC( next, RPC_PRIO_PS, __ps_func,
                              RPC_RECV( RPC_RECV_OBJ(err) ),
                              RPC_SEND( RPC_SEND_OBJ(err) )
                           );
                }
		break;
	}

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