int kwait(int *status) // wait for ZOMBIE child
{
PROC *p; int i, hasChild = 0;
while(1){ // search PROCs for a child
for (i=1; i<NPROC; i++){ // exclude P0
p = &proc[i];
if (p->status != FREE && p->ppid == running->pid){
hasChild = 1; // has child flag
if (p->status == ZOMBIE){ // lay the dead child to rest
*status = p->exitCode; // collect its exitCode
p->status = FREE; // free its PROC
put_proc(&freeList, p); // to freeList
nproc--; // once less processes
return(p->pid); // return its pid
}
}
}
if (!hasChild)
return -1; // no child, return ERROR
ksleep(running); // still has kids alive: sleep on PROC address
}
}
int kwait(int *status) {
PROC *p;
int i, hasChild = 0;
while(1) {
for(i = 1; i < NPROC; i++) {
p = &proc[i];
if(p->status != FREE && p->ppid == running->pid) {
hasChild = 1;
if(p->status == ZOMBIE) {
*status = p->exitCode;
p->status = FREE;
put_proc(&freeList, p);
nproc--;
return(p->pid);
}
}
}
if(!hasChild) return -1; //no children return ERROR
ksleep(running); //stil had kids alive: sleep on PROC address
}
}
static void
port_put(port *p,
char *data,
int length)
{
char *(*put_proc)(port *, char *, int);
char *error;
if (p->status & OUTPUT_CLOSED) {
var_set_variable("error",
"Attempt to write to a port whose output has been closed");
return;
}
put_proc = p->put;
if (!put_proc) {
var_set_variable("error",
"Attempt to write to a port which does not support writing");
return;
}
error = put_proc(p, data, length);
if (error)
var_set_variable("error", error);
}
int kwait(int *status)
{
PROC *p;
int i, found = 0;
while(1){
//found = 0;
for (i=0; i<NPROC; i++){
p = &proc[i];
if (p->ppid == running->pid && p->status != FREE){
found = 1;
/* lay the dead child to rest */
if (p->status == ZOMBIE){
*status = p->exitCode;
p->status = FREE; /* free its PROC */
put_proc(p);
nproc--;
return(p->pid); /* return its pid */
}
}
}
if (!found) /* no child */
return(-1);
ksleep(running); /* has kids still alive */
}
}
//free's up a zombies resources and puts it back in the ready queue
int kwait(int *status) // wait for ZOMBIE child
{
PROC *p;
int i, found = 0;
while(1)
{
for (i = 0; i < NPROC; i++)
{
p = &proc[i];
if (p->ppid == running->pid && p->status != FREE)
{
found = 1;
//lay the dead child to rest
if(p->status == ZOMBIE)
{
*status = p->exitCode;
p->status = FREE;//free its PROC
put_proc(&freeList, p);
nproc--;
return (p->pid);//return its pid
}
}
}
if (!found)//no child
return -1;
ksleep(running);//has kids still alive
}
}
int ksleep(int event)
{
//printf("ksleep():\n\r");
running->event = event; // record event in PROC.event
running->status = SLEEP; // change status to SLEEP
//add proc to sleepList
put_proc(&sleepList, running);
//printf("after put_proc: pid %d status %d \n\r", running->pid, running->status);
// give up CPU
tswitch();
}
// resurrects all zombie processes.
resurrect()
{
int i, counter = 0;
PROC *p;
for (i=0; i < NPROC; i++)
{
p = &proc[i]; // make it easier to access this proc :)
// if the process is a zombie, make it free of its plague and stick it back on the free processes list.
if (p->status == ZOMBIE)
{
p->status = FREE;
put_proc(p);
counter++;
}
}
printf("%d processes resurrected!\n", counter);
}
int body()
{
char c;
printf("proc %d resumes to body()\n", running->pid);
while(1){
color = running->pid + 7;
printf("proc %d running : enter a key : ", running->pid);
c = getc();
switch(c){
case 'f' : do_kfork(); break;
case 's' : tswitch(); break;
case 'q':
running->status = ZOMBIE;
running->priority = 0;
put_proc(&freeList, running);
tswitch();
break;
case 'p':
printf("*****readyQueue: ");
printQueue(readyQueue);
printf("\n");
printf("*****freeList: ");
printQueue(freeList);
printf("\n");
break;
default: printf("ERROR: invalid key\n"); break;
}
}
}
