PR feedback

Check if there's running processes in the job object before promoting to
a silo

Signed-off-by: Daniel Canter <dcanter@microsoft.com>

internal/jobobject/jobobject.go

@@ -28,8 +28,8 @@ import (
 // of the job and a mutex for synchronized handle access.
 type JobObject struct {
  handle windows.Handle
- // All accesses to this MUST be done atomically. 1 signifies that this job
- // is currently a silo.
+ // All accesses to this MUST be done atomically. 1 signifies that this
+ // job is currently a silo.
  isAppSilo uint32
  mq *queue.MessageQueue
  handleLock sync.RWMutex
@@ -522,7 +522,16 @@ func (job *JobObject) PromoteToSilo() error {
  return nil
  }
 
- _, err := windows.SetInformationJobObject(
+ pids, err := job.Pids()
+ if err != nil {
+ return err
+ }
+
+ if len(pids) != 0 {
+ return fmt.Errorf("job cannot have running processes to be promoted to a silo, found %d running processes", len(pids))
+ }
+
+ _, err = windows.SetInformationJobObject(
  job.handle,
  winapi.JobObjectCreateSilo,
  0,