/* $Id: parse.c,v 1.9 2004/03/23 04:50:13 jmuelmen Exp $ */

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <pthread.h>

#include "parse.h"
#include "scheduler.h"

/* create a parse action */
parse_action_t *parse_action_create (void (*func) (value_t *, value_t **, int),
				     value_t **argv, int argc)
{
     int i;
     parse_action_t *p = malloc(sizeof(parse_action_t));
     
     p->type = func_s;
     p->statement.func = func;
     for (i = 0; i < argc; p->args[i] = argv[i++]);
     p->n_args = argc;

     /* initialize the return */
     value_init(&p->ret);

     return p;
}

/* process a parse action */
void parse_action_process (parse_action_t *a)
{
     int i;
     value_t ret;

     /* check for no-op-ness */
     if (!a->statement.func) {
	  pthread_mutex_lock(&a->ret.mut);
	  a->ret.returned = 1;
	  pthread_mutex_unlock(&a->ret.mut);
	  pthread_cond_signal(&a->ret.has_returned);
	  return;
     }
     
     /* lock the return value */
     pthread_mutex_lock(&a->ret.mut);

/*       printf("Locking arguments... ");    */
/*       fflush(stdout);   */
     
     /* lock the arguments */
     for (i = 0; i < a->n_args; ++i) {
     	  pthread_mutex_lock(&a->args[i]->mut);
	  /* if the argument hasn't returned yet, we have to wait */
	  while (!a->args[i]->returned) {
#ifdef WINDOWS_IS_DOGSHIT
	       if (usleep(WINDOWS_IS_DOGSHIT))
		    perror("Sleeping on argument eval");
#endif 
	       pthread_cond_wait(&a->args[i]->has_returned, &a->args[i]->mut);
	  }
     }
/*       printf("arguments locked.\n");   */
/*       fflush(stdout);  */

     /*  printf("Locking return value... ");  */
     /*  printf("return value locked.\n");  */

     /* evaluate the action */
     a->statement.func(&a->ret, a->args, a->n_args);
     a->ret.returned = 1;
     
     /* unlock the arguments */
     i = 0;
     while (i < a->n_args) {
	  pthread_mutex_unlock(&a->args[i]->mut);
	  ++i;
     }

     /* unlock the return value */
     pthread_mutex_unlock(&a->ret.mut);
     
     /* signal that we've returned */
     pthread_cond_signal(&a->ret.has_returned);
     
}