int main(int argc, char *argv[])
{
int nproc;
/*
* For each of argv[1] to argv[argc - 1],
* create a new child process, add it to the process list.
*/
nproc = 0; /* number of proccesses goes here */
/* Wait for all children to raise SIGSTOP before exec()ing. */
wait_for_ready_children(nproc);
/* Install SIGALRM and SIGCHLD handlers. */
install_signal_handlers();
if (nproc == 0) {
fprintf(stderr, "Scheduler: No tasks. Exiting...\n");
exit(1);
}
/* loop forever until we exit from inside a signal handler. */
while (pause())
;
/* Unreachable */
fprintf(stderr, "Internal error: Reached unreachable point\n");
return 1;
}
int main(int argc, char *argv[])
{
pid_t pid;
int status;
struct tree_node *root;
if (argc != 2) {
fprintf(stderr, "Usage: %s <input_tree_file>\n\n", argv[0]);
exit(1);
}
root = get_tree_from_file(argv[1]);
print_tree(root);
pid=fork();
if(pid<0){
perror("main: fork");
exit(1);
}
else if(pid==0){
fork_procs(root);
exit(1);
}
wait_for_ready_children(1);
show_pstree(pid);
kill(pid,SIGCONT);
pid=wait(&status);
explain_wait_status(pid,status);
return 0;
}
//--ENTRY POINT--
int main (int argc, char *argv[]) {
if (argc!=2) {
fprintf(stderr, "Invalild number of arguments.\n");
return 1;
}
node_type *root;
root=get_tree_from_file(argv[1]);
pid_t FIRST;
int status;
FIRST=fork();
if (FIRST<0) {
fork_err(getpid());
exit(EXIT_FAILURE);
}
if (FIRST==0) { //Process Tree R00T:
create_ptree(root, 0);
exit(EXIT_SUCCESS);
} else { //MAIN:
wait_for_ready_children(1);
//All children are in slumber!
show_pstree(FIRST);
kill(FIRST, SIGCONT);
if ((wait(&status))==-1) {
sign_err(FIRST, "main");
exit(EXIT_FAILURE);
} else {
explain_wait_status(FIRST, status);
}
}
return 0;
}
//--FUNCTIONS--
void create_ptree(node_type *cur, size_t lvl) {
int status;
pid_t *CHILDREN=NULL; //Children PID array.
if (cur->nr_children>0) { //Allocation of children PID array memory.
CHILDREN=(pid_t *)malloc((cur->nr_children)*sizeof(pid_t));
if (CHILDREN==NULL) {
alloc_err;
exit(EXIT_FAILURE);
}
}
pid_t par=getpid(), child=0, retv=0;
change_pname(cur->name); //Change name.
// proc_enter(par); //Enter message.
size_t i=0;
for (i=0; i<cur->nr_children; i++) { //Create heirs.
// fprintf(stderr, "FORK LV: %u - IT: %u\n", lvl, i); //DEBUG
child=fork();
if (child<0) { //Sanity.
fork_err(cur);
exit(EXIT_FAILURE);
}
if (child==0) { //Recursion for child:
create_ptree(&cur->children[i], lvl+1);
//...
} else { //Rest of parent:
CHILDREN[i]=child;
continue;
}
}
if (cur->nr_children>0) { //Node: //Wait for heirs to sleep.
wait_for_ready_children(cur->nr_children);
} //else //Leaf: Fall-through.
if (raise(SIGSTOP)) { //Sleep yourself.
sign_err(par, "0");
exit(EXIT_FAILURE);
}
actual_msg(par, cur->name); //Wake-up and print awake message.
// fprintf(stderr, "i=%u, child=%ld, CHILDREN[i]=%ld\n", i, (long)child, (long)CHILDREN[i]);
if (cur->nr_children>0) {
for (i=0; i<cur->nr_children; i++) {//Parents continue and bury their children 1 by 1.
cont_msg(cur->name, CHILDREN[i]);
if ((kill(CHILDREN[i], SIGCONT))==-1) {
sign_err(par, "1");
exit(EXIT_FAILURE);
}
// wait_for_ready_children(1); //NEEDs DEBUGGING: Doesn't work with this instead of the 2 next commands.
retv=wait(&status); //Wait the just awoken child to terminate before you wake up the next (condition for the depth first traversal).
bury_msg(cur->name, retv); //Bury message.
}
} //else //Fall-through.
// proc_exit(par); //Exit message.
// kill(par, SIGKILL);
exit(EXIT_SUCCESS); //Children and parents who buried theirs, just roll off and die.
}
int main(int argc, char *argv[])
{
pid_t p;
int i;
/*
* For each of argv[1] to argv[argc - 1],
* create a new child process, add it to the process list.
*/
current = 0; /* current proccess number goes here */
nprog = argc - 1; /* number of proccesses goes here */
childid = malloc((nprog)*sizeof(int));
alive = malloc((nprog)*sizeof(int));
for (i=0; i < nprog; i++){
printf("forking..%d %d\n", argc, i);
p = fork();
//if (p<0)...
if (p == 0){
do_child(argv[i+1]);
}
else{
childid[i] = (int) p;
alive[i] = 1;
}
}
/* Wait for all children to raise SIGSTOP before exec()ing. */
wait_for_ready_children(nprog);
/* Install SIGALRM and SIGCHLD handlers. */
install_signal_handlers();
if (nprog == 0) {
fprintf(stderr, "Scheduler: No tasks. Exiting...\n");
exit(1);
}
else{
alarm(SCHED_TQ_SEC);
kill(childid[0], SIGCONT);
}
/* loop forever until we exit from inside a signal handler. */
while (pause())
;
/* Unreachable */
fprintf(stderr, "Internal error: Reached unreachable point\n");
return 1;
}
void fork_procs(struct tree_node *root)
{
pid_t child ;
int i,status ;
pid_t* children;
children = (pid_t*)malloc((sizeof(pid_t)*root->nr_children));
if (children == NULL){
fprintf(stderr, "allocate children failed\n");
exit(1);
}
printf("PID = %ld, name %s, starting...\n",(long)getpid(), root->name);
change_pname(root->name);
for (i = 0 ; i < root->nr_children; i++){
printf("%s:Creating child %s...\n",root->name,root->children[i].name);
child = fork();
if (child < 0) {
perror("child fork");
exit(1);
}
if (child == 0) {
/* Child */
fork_procs(&root->children[i]);
}
/* Father saves child's pid ! */
children[i] = child;
}
wait_for_ready_children(root->nr_children);
printf("%s: All children ready ! Suspending with SIGSTOP...\n",root->name);
/*
* Suspend Self
*/
raise(SIGSTOP);
printf("PID = %ld, name = %s is awake\n",(long)getpid(), root->name);
for (i = 0 ; i < root->nr_children;i++){
printf("%s: Activating child %s...\n",root->name,root->children[i].name);
kill(children[i],SIGCONT);
children[i] = wait(&status);
explain_wait_status(children[i],status);
}
printf("%s: Exiting...\n",root->name);
free(children);
exit(0);
}
int main(int argc, char *argv[])
{
pid_t pid;
int status;
struct tree_node *root;
if (argc < 2){
fprintf(stderr, "Usage: %s <tree_file>\n", argv[0]);
exit(1);
}
/* Read tree into memory */
root = get_tree_from_file(argv[1]);
/* Fork root of process tree */
pid = fork();
if (pid < 0) {
perror("main: fork");
exit(1);
}
if (pid == 0) {
/* Child */
fork_procs(root);
exit(1);
}
/*
* Father
*/
/* for ask2-signals */
wait_for_ready_children(1);
/* Print the process tree root at pid */
show_pstree(pid);
/* for ask2-signals */
kill(pid, SIGCONT);
/* Wait for the root of the process tree to terminate */
pid = wait(&status);
explain_wait_status(pid, status);
return 0;
}
void fork_procs(struct tree_node *current){
pid_t p_new[20];
int status;
int i;
struct tree_node *temp;
change_pname(current->name);
printf("%s:Starting..\n",current->name);
for(i=0;i<current->nr_children;i++){
p_new[i]=fork();
if(p_new[i]<0){
perror("fork");
exit(2);
}
else if(p_new[i]==0){
fork_procs(current->children+i);
}
}
wait_for_ready_children(current->nr_children);
printf("%s:I gave birth to %d childs and then suspended myself..\n",current->name,current->nr_children);
raise(SIGSTOP);
printf("%s:Before you know,awake!..\n",current->name);
for(i=0;i<current->nr_children;i++){
temp=current->children+i;
printf("I, %s , am your father %s,and i say wake!\n",current->name,temp->name);
kill(p_new[i],SIGCONT);
p_new[i]=wait(&status);
explain_wait_status(p_new[i],status);
}
printf("%s:Exiting..\n",current->name);
exit(3);
}
