From 0ce132eb8ff6c9b1e357a8a153552c4f958378a6 Mon Sep 17 00:00:00 2001
From: Dominic Wong <domwongemail@googlemail.com>
Date: Wed, 10 Jun 2020 09:36:41 +0100
Subject: [PATCH] Fix race condition when updating process being waited on
 (#1694)

---
 runtime/service.go | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/runtime/service.go b/runtime/service.go
index 5c6ba621..8e28de1f 100644
--- a/runtime/service.go
+++ b/runtime/service.go
@@ -197,11 +197,20 @@ func (s *service) Error() error {
 // Wait waits for the service to finish running
 func (s *service) Wait() {
 	// wait for process to exit
-	err := s.Process.Wait(s.PID)
+	s.RLock()
+	thisPID := s.PID
+	s.RUnlock()
+	err := s.Process.Wait(thisPID)
 
 	s.Lock()
 	defer s.Unlock()
 
+	if s.PID.ID != thisPID.ID {
+		// trying to update when it's already been switched out, ignore
+		logger.Warnf("Trying to update a process status but PID doesn't match. Old %s, New %s. Skipping update.", thisPID.ID, s.PID.ID)
+		return
+	}
+
 	// save the error
 	if err != nil {
 		if logger.V(logger.ErrorLevel, logger.DefaultLogger) {