+ UnixRuntime prev = tasks[pid];
+ if(prev == null || prev == this || prev.pid != pid || prev.parent != parent)
+ throw new Error("should never happen");
+ synchronized(parent.children) {
+ int i = parent.activeChildren.indexOf(prev);
+ if(i == -1) throw new Error("should never happen");
+ parent.activeChildren.set(i,this);
+ }