Remove 'clearStatus' option from container.Wait*PID()

clearStatus was added to allow detached execution to wait
on the exec'd process and retrieve its exit status. However,
it's not currently used. Both docker and gvisor-containerd-shim
wait on the "shim" process and retrieve the exit status from
there. We could change gvisor-containerd-shim to use waits, but
it will end up also consuming a process for the wait, which is
similar to having the shim process.

Closes #234

PiperOrigin-RevId: 251349490

2 files changed, 6 insertions, 13 deletions

diff --git a/runsc/boot/controller.go b/runsc/boot/controller.go
index 72ab9ef86..419cb79d3 100644
--- a/runsc/boot/controller.go
+++ b/runsc/boot/controller.go
@@ -420,16 +420,12 @@ type WaitPIDArgs struct {
 
 	// CID is the container ID.
 	CID string
-
-	// ClearStatus determines whether the exit status of the process should
-	// be cleared when WaitPID returns.
-	ClearStatus bool
 }
 
 // WaitPID waits for the process with PID 'pid' in the sandbox.
 func (cm *containerManager) WaitPID(args *WaitPIDArgs, waitStatus *uint32) error {
 	log.Debugf("containerManager.Wait")
-	return cm.l.waitPID(kernel.ThreadID(args.PID), args.CID, args.ClearStatus, waitStatus)
+	return cm.l.waitPID(kernel.ThreadID(args.PID), args.CID, waitStatus)
 }
 
 // SignalDeliveryMode enumerates different signal delivery modes.
diff --git a/runsc/boot/loader.go b/runsc/boot/loader.go
index b29cb334f..52dccc994 100644
--- a/runsc/boot/loader.go
+++ b/runsc/boot/loader.go
@@ -724,7 +724,7 @@ func (l *Loader) waitContainer(cid string, waitStatus *uint32) error {
 	return nil
 }
 
-func (l *Loader) waitPID(tgid kernel.ThreadID, cid string, clearStatus bool, waitStatus *uint32) error {
+func (l *Loader) waitPID(tgid kernel.ThreadID, cid string, waitStatus *uint32) error {
 	if tgid <= 0 {
 		return fmt.Errorf("PID (%d) must be positive", tgid)
 	}
@@ -736,13 +736,10 @@ func (l *Loader) waitPID(tgid kernel.ThreadID, cid string, clearStatus bool, wai
 		ws := l.wait(execTG)
 		*waitStatus = ws
 
-		// Remove tg from the cache if caller requested it.
-		if clearStatus {
-			l.mu.Lock()
-			delete(l.processes, eid)
-			log.Debugf("updated processes (removal): %v", l.processes)
-			l.mu.Unlock()
-		}
+		l.mu.Lock()
+		delete(l.processes, eid)
+		log.Debugf("updated processes (removal): %v", l.processes)
+		l.mu.Unlock()
 		return nil
 	}