Method Exit

src/task/exit.cpp:12–62

#include "task_messages.hpp"

auto TaskManager::Exit(int exit_code) -> void {
  auto& cpu_sched = GetCurrentCpuSched();
  auto* current = GetCurrentTask();
  assert(current != nullptr && "Exit: No current task to exit");
  assert(current->GetStatus() == TaskStatus::kRunning &&
         "Exit: current task status must be kRunning");

  ResourceId wait_resource_id{};
  bool should_wake_parent = false;

  {
    LockGuard<SpinLock> lock_guard(cpu_sched.lock);

    current->aux->exit_code = exit_code;
    bool is_group_leader = current->IsThreadGroupLeader();

    if (is_group_leader && current->GetThreadGroupSize() > 1) {
      klog::Warn(
          "Exit: Thread group leader (pid={}, tgid={}) exiting, but group "
          "still has {} threads",
          current->pid, current->aux->tgid, current->GetThreadGroupSize());
    }

    current->LeaveThreadGroup();

    if (current->aux->parent_pid != 0) {
      current->fsm.Receive(MsgExit{exit_code, true});
      wait_resource_id =
          ResourceId(ResourceType::kChildExit, current->aux->parent_pid);
      should_wake_parent = true;

      klog::Debug("Exit: pid={} entering zombie, will wake parent={}",
                  current->pid, current->aux->parent_pid);
    } else {
      current->fsm.Receive(MsgExit{exit_code, false});
    }

    if (is_group_leader) {
      ReparentChildren(current);
    }
  }

  if (should_wake_parent) {
    Wakeup(wait_resource_id);
  }

  Schedule();

  // UNREACHABLE
  __builtin_unreachable();
}