runsc: Enable waiting on exited processes.

This makes `runsc wait` behave more like waitpid()/wait4() in that:
- Once a process has run to completion, you can wait on it and get its exit
  code.
- Processes not waited on will consume memory (like a zombie process)

PiperOrigin-RevId: 213358916
Change-Id: I5b5eca41ce71eea68e447380df8c38361a4d1558

1 files changed, 4 insertions, 3 deletions

diff --git a/runsc/sandbox/sandbox.go b/runsc/sandbox/sandbox.go
index 8c4d0d495..3b10fd20e 100644
--- a/runsc/sandbox/sandbox.go
+++ b/runsc/sandbox/sandbox.go
@@ -522,7 +522,7 @@ func (s *Sandbox) Wait(cid string) (syscall.WaitStatus, error) {
 
 // WaitPID waits for process 'pid' in the container's sandbox and returns its
 // WaitStatus.
-func (s *Sandbox) WaitPID(pid int32, cid string) (syscall.WaitStatus, error) {
+func (s *Sandbox) WaitPID(cid string, pid int32, clearStatus bool) (syscall.WaitStatus, error) {
 	log.Debugf("Waiting for PID %d in sandbox %q", pid, s.ID)
 	var ws syscall.WaitStatus
 	conn, err := s.sandboxConnect()
@@ -532,8 +532,9 @@ func (s *Sandbox) WaitPID(pid int32, cid string) (syscall.WaitStatus, error) {
 	defer conn.Close()
 
 	args := &boot.WaitPIDArgs{
-		PID: pid,
-		CID: cid,
+		PID:         pid,
+		CID:         cid,
+		ClearStatus: clearStatus,
 	}
 	if err := conn.Call(boot.ContainerWaitPID, args, &ws); err != nil {
 		return ws, fmt.Errorf("error waiting on PID %d in sandbox %q: %v", pid, s.ID, err)