/*************************************************************
 * File: lib/signal.c
 * Purpose: Part of C runtime library
 * Author: Phil Bunce (pjb@carmel.com)
 * Revision History:
 *	970304	Start of revision history
 *	971007	This has a prob because longjmp will xfer to inactive 
 *		context. It does work, but it also crashes (sometimes).
 */

#include <signal.h>
#include <termio.h>
#include <errno.h>

/*
 * This is a somewhat skeletal implementation of signal, it is
 * only intended to make the porting of benchmarks to the
 * LR33000 a little more straightforward.
 */

#ifdef TEST /*-------------------------------------------------------------*/
main()
{
char buf[100];
int gotsig();

if (signal(SIGINT,gotsig) == -1) {
        printf("signal: Bad return code\n");
        exit(-1);
        }
setjmp(sjbuf);
 
printf("Waiting for signal.\n");
for (;;) {
        printf("> ");
        gets(buf);
        if (buf[0] == '.') break;
        printf("%s\n",buf);
        }
}
 
gotsig()
{
 
printf("Got a signal\n");
if (signal(SIGINT,gotsig) == -1) {
        printf("signal: Bad return code\n");
        exit(-1); 
        } 
longjmp(sjbuf,0);
}
#endif /*-------------------------------------------------------------*/


vFunc *signal(op,func)
int op;
vFunc *func;
{
static vFunc *sigintfunc,*savedintr;
static jmp_buf sigintbuf;
vFunc *tmp;

if (op == SIGINT) {
	if (func == SIG_IGN) { /* ignore the SIGINT */
		ioctl(STDIN,GETINTR,&savedintr);
		ioctl(STDIN,SETINTR,0);	 /* ignore */
		return(savedintr);
		}
	else if (func == SIG_DFL) {
		if (!savedintr) return(SIG_ERR);
		ioctl(STDIN,GETINTR,&tmp);
		ioctl(STDIN,SETINTR,savedintr);
		return(tmp);
		}
	else {
		ioctl(STDIN,GETINTR,&savedintr);
		sigintfunc = func;
		if (setjmp(sigintbuf)) { /* when INTR occurs */
			ioctl(STDIN,SETINTR,savedintr);
			(*sigintfunc)();
			}
		else { /* when signal was called */
			ioctl(STDIN,SETINTR,sigintbuf);
			return(0);
			}
		}
	}

errno = EINVAL;
return((vFunc *)-1);
}