From e3ab8bda604dbafb6c69f4c42979e92ead445138 Mon Sep 17 00:00:00 2001
From: zyu <yuzhihong@gmail.com>
Date: Fri, 6 Mar 2020 09:51:26 -0800
Subject: [PATCH] Avoid allocating slice for finding Process

Signed-off-by: zyu <yuzhihong@gmail.com>
---
 runtime/v1/shim/service.go | 57 +++++++++++++++++---------------------
 1 file changed, 26 insertions(+), 31 deletions(-)

diff --git a/runtime/v1/shim/service.go b/runtime/v1/shim/service.go
index c0ec03931..6bd6aefa2 100644
--- a/runtime/v1/shim/service.go
+++ b/runtime/v1/shim/service.go
@@ -503,42 +503,37 @@ func (s *Service) processExits() {
 	}
 }
 
-func (s *Service) allProcesses() []process.Process {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-
-	res := make([]process.Process, 0, len(s.processes))
-	for _, p := range s.processes {
-		res = append(res, p)
-	}
-	return res
-}
-
 func (s *Service) checkProcesses(e runc.Exit) {
-	for _, p := range s.allProcesses() {
-		if p.Pid() != e.Pid {
-			continue
+	var p process.Process
+	s.mu.Lock()
+	for _, proc := range s.processes {
+		if proc.Pid() == e.Pid {
+			p = proc
+			break
 		}
-
-		if ip, ok := p.(*process.Init); ok {
-			// Ensure all children are killed
-			if shouldKillAllOnExit(s.context, s.bundle) {
-				if err := ip.KillAll(s.context); err != nil {
-					log.G(s.context).WithError(err).WithField("id", ip.ID()).
-						Error("failed to kill init's children")
-				}
+	}
+	s.mu.Unlock()
+	if p == nil {
+		log.G(s.context).Infof("process with id:%d wasn't found", e.Pid)
+		return
+	}
+	if ip, ok := p.(*process.Init); ok {
+		// Ensure all children are killed
+		if shouldKillAllOnExit(s.context, s.bundle) {
+			if err := ip.KillAll(s.context); err != nil {
+				log.G(s.context).WithError(err).WithField("id", ip.ID()).
+					Error("failed to kill init's children")
 			}
 		}
+	}
 
-		p.SetExited(e.Status)
-		s.events <- &eventstypes.TaskExit{
-			ContainerID: s.id,
-			ID:          p.ID(),
-			Pid:         uint32(e.Pid),
-			ExitStatus:  uint32(e.Status),
-			ExitedAt:    p.ExitedAt(),
-		}
-		return
+	p.SetExited(e.Status)
+	s.events <- &eventstypes.TaskExit{
+		ContainerID: s.id,
+		ID:          p.ID(),
+		Pid:         uint32(e.Pid),
+		ExitStatus:  uint32(e.Status),
+		ExitedAt:    p.ExitedAt(),
 	}
 }