#include <stdio.h>
#include <stdlib.h>
#include "minithread_md.h"
#include "minithread.h"
#include "minithread_public.h"


int
atomic_test_and_set(tas_lock_t *l)
{
    int k;

    disable_interrupts();
    
    k = *l;
    *l = 1;
    
    enable_interrupts();
    
    return k;
}

void
atomic_clear(tas_lock_t *l)
{
    *l = 0;
}

/*
 * Internal routine to allocate a stack.
 */

#ifndef STACKALIGN
#define STACKALIGN 03
#endif

void
minithread_allocate_stack(stackbase, stacktop)
    stack_pointer_t *stackbase;
    stack_pointer_t *stacktop;
{
    *stackbase = (stack_pointer_t)malloc(STACKSIZE);
    if (!*stackbase)  {
	return;
    }
    if (STACK_GROWS_DOWN)  {
	/* Stacks grow down, but malloc grows up. Compensate and word align
	   (turn off low 2 bits by anding with ~3). */
	*stacktop = (stack_pointer_t)
	     ((ADDR_TO_INT(*stackbase) + STACKSIZE - 1)&~STACKALIGN);
    } else  {
	/* Word align (turn off low 2 bits by anding with ~3) */
	*stacktop = (stack_pointer_t)(( ADDR_TO_INT(*stackbase) + 3)&~STACKALIGN);
    }
}

void
minithread_free_stack(stackbase)
    stack_pointer_t stackbase;
{
    free(stackbase);
}

/*
 * See the architecture assembly file.
 */
extern int minithread_root();

/*
 * Initialize a stack.
 *	Stack frame is set up so that thread calls:
 *		initial_proc(initial_arg);
 *		body_proc(body_arg);
 *		finally_proc(finally_arg);
 */
void
minithread_initialize_stack(stacktop,
			    initial_proc, initial_arg,
			    body_proc, body_arg,
			    finally_proc, finally_arg)
    stack_pointer_t *stacktop;
    proc_t initial_proc;
    arg_t  initial_arg;
    proc_t body_proc;
    arg_t body_arg;
    proc_t finally_proc;
    arg_t finally_arg;

{
    initial_stack_state_t ss;

    /*
     * Configure initial machine state so that this thread starts
     * running inside a wrapper procedure named minithread_root.
     * minithread_root will invoke the procedures in order, and
     * then halt.
     */
    *((char **) stacktop) -= sizeof (struct initial_stack_state);
    ss = (initial_stack_state_t) *stacktop;

    ss->initial_proc = (void *) initial_proc;
    ss->initial_arg = (void *) initial_arg;
    ss->body_proc = (void *) body_proc;
    ss->body_arg = (void *) body_arg;
    ss->finally_proc = (void *) finally_proc;
    ss->finally_arg = (void *) finally_arg;

    ss->root_proc = (void *) MINITHREAD_ROOT;
}