avoid a double-lock of initproc->lock if child of init is reparenting

This commit is contained in:
Robert Morris 2019-07-07 07:03:28 -04:00
parent 7114bf43ed
commit c4f6a241cd

View file

@ -292,6 +292,7 @@ fork(void)
// are locked.
void reparent(struct proc *p, struct proc *parent) {
struct proc *pp;
int init_is_my_parent = (p->parent == initproc);
for(pp = ptable.proc; pp < &ptable.proc[NPROC]; pp++){
if (pp != p && pp != parent) {
@ -299,8 +300,10 @@ void reparent(struct proc *p, struct proc *parent) {
if(pp->parent == p){
pp->parent = initproc;
if(pp->state == ZOMBIE) {
if(!init_is_my_parent)
acquire(&initproc->lock);
wakeup1(initproc);
if(!init_is_my_parent)
release(&initproc->lock);
}
}