/*
 * Copyright (C) 2006 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */ 

#include <thread.h>
#include <libc.h>
#include <stdlib.h>
#include <arch/faddr.h>
#include <kernel/proc/uarg.h>

/** Main thread function.
 *
 * This function is called from __thread_entry() and is used
 * to call the thread's implementing function and perform cleanup
 * and exit when thread returns back. Do not call this function
 * directly.
 *
 * @param uarg Pointer to userspace argument structure.
 */
void thread_main(uspace_arg_t *uarg)
{
	uarg->uspace_thread_function(uarg->uspace_thread_arg);
	free(uarg->uspace_stack);
	free(uarg);
	thread_exit(0);
}

/** Create userspace thread.
 *
 * This function creates new userspace thread and allocates userspace
 * stack and userspace argument structure for it.
 *
 * @param function Function implementing the thread.
 * @param arg Argument to be passed to thread.
 * @param name Symbolic name of the thread.
 *
 * @param TID of the new thread on success or -1 on failure.
 */
int thread_create(void (* function)(void *), void *arg, char *name)
{
	char *stack;
	uspace_arg_t *uarg;

	stack = (char *) malloc(getpagesize());
	if (!stack)
		return -1;
		
	uarg = (uspace_arg_t *) malloc(sizeof(uspace_arg_t));
	if (!uarg) {
		free(stack);
		return -1;
	}
	
	uarg->uspace_entry = (void *) FADDR(__thread_entry);
	uarg->uspace_stack = (void *) stack;
	uarg->uspace_thread_function = function;
	uarg->uspace_thread_arg = arg;
	uarg->uspace_uarg = uarg;
	
	return __SYSCALL2(SYS_THREAD_CREATE, (sysarg_t) uarg, (sysarg_t) name);
}

/** Terminate current thread.
 *
 * @param stat Exit status. Currently not used.
 */
void thread_exit(int status)
{
	__SYSCALL1(SYS_THREAD_EXIT, (sysarg_t) status);
}