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    Length: 2465 (0x9a1)
    Types: TextFile
    Notes: UNIX file
    Names: »job.c«

└─⟦f27320a65⟧ Bits:30001972 Commodore 900 hard disk image with partial source code
    └─⟦2d53db1df⟧ UNIX V7 Filesystem
        └─ ⟦this⟧ »hr/src/jlib/job.c« 

TextFile

#include	<stdio.h>
#include	<job.h>


#define	SINC	16			/* stack growth increment */

struct	jqueue	runq;

static struct jqueue	idleq;
static jmp_buf		newstate;
static			*estack;

extern char	*malloc( ),
		*realloc( );


jmain( )
{
	int	v,
		jidle( );

	estack = &v;
	if (setjmp( newstate)) {
		(*my->j_startf)( );
		jdone( );
	}
	jstart( jidle);
	longjmp( newstate, not 0);
}


static
jidle( )
{

	loop{
		jdoze( &idleq);
	}
}


struct job	*
jstart( f)
int	(*f)( );
{
	struct job	*jp;


	jp = malloc( sizeof *jp);
	if (not jp)
		nomem( );
	jp->j_startf = f;
	jp->j_stack = 0;
	if (runq.jq_head)
		runq.jq_tail->j_next = jp;
	else
		runq.jq_head = jp;
	runq.jq_tail = jp;
	jp->j_next = 0;
	return (jp);
}


jdoze( jq)
struct jqueue	*jq;
{
	register struct job	*jp0,
				*jp1;
	uint	n;
	int	*sp;

	jalert( &idleq);
	jp0 = me;
	while (not jp0->j_next)
		readmesg( );
	jp1 = jp0->j_next;
	if (jq->jq_head)
		jq->jq_tail->j_next = jp0;
	else
		jq->jq_head = jp0;
	jq->jq_tail = jp0;
	me = jp1;
	jp0->j_next = 0;

	if (setjmp( jp0->j_env))
		return;
	sp = ((int **)jp0->j_env)[5];	/* not portable */
	n = estack - sp;
	if (not jp0->j_stack) {
		jp0->j_smax = roundup( n, SINC);
		jp0->j_stack = malloc( jp0->j_smax*sizeof( *jp0->j_stack));
		if (not jp0->j_stack)
			nomem( );
	}
	else if (n > jp0->j_smax) {
		jp0->j_smax = roundup( n, SINC);
		jp0->j_stack = realloc( jp0->j_stack,
			jp0->j_smax*sizeof( *jp0->j_stack));
		if (not jp0->j_stack)
			nomem( );
	}
	copy( sp, n, jp0->j_stack);
	jp0->j_slength = n;
	if (not jp1->j_stack)
		longjmp( newstate, not 0);
	copygo( jp1->j_stack, jp1->j_slength, estack-jp1->j_slength);
}


jalert( jq)
struct jqueue	*jq;
{
	struct job	*jp;

	if (jp = jq->jq_head) {
		jq->jq_head = jp->j_next;
		if (runq.jq_head)
			runq.jq_tail->j_next = jp;
		else
			runq.jq_head = jp;
		runq.jq_tail = jp;
		jp->j_next = 0;
		return ~0;
	}
	return 0;
}


jdone( )
{
	struct job	*jp;

	jalert( &idleq);
	while (not my->j_next)
		readmesg( );
	jp = me;
	me = jp->j_next;
	if (jp->j_stack)
		free( (char *)jp->j_stack);
	free( (char *)jp);
	if (not my->j_stack)
		longjmp( newstate, not 0);
	copygo( my->j_stack, my->j_slength, estack-my->j_slength);
}


static
copy( from, n, to)
int	*from,
	*to;
uint	n;
{

	if (n)
		do {
			*to++ = *from++;
		} while (--n);
}


static
copygo( from, n, to)
int	*from,
	*to;
uint	n;
{
	char	baggage[128];

	if (baggage < to) {
		copy( from, n, to);
		longjmp( my->j_env, not 0);
	}
	copygo( from, n, to);
}