Make blocking channel for StartTransientUnit buffered

filbranden · filbranden · commit e2b796e3a32f · 2018-04-13T23:35:52.000-07:00
So that, if a timeout happens and we decide to stop blocking on the operation, the writer will not block when they try to report the result of the operation. This should address Issue opencontainers#1780 and it's a follow up for PR opencontainers#1683, PR opencontainers#1754 and PR opencontainers#1772.
diff --git a/libcontainer/cgroups/systemd/apply_systemd.go b/libcontainer/cgroups/systemd/apply_systemd.go
@@ -320,7 +320,7 @@ func (m *Manager) Apply(pid int) error {
 		}
 	}
 
-	statusChan := make(chan string)
+	statusChan := make(chan string, 1)
 	if _, err := theConn.StartTransientUnit(unitName, "replace", properties, statusChan); err == nil {
 		select {
 		case <-statusChan:

Original file line number	Diff line number	Diff line change
`@@ -320,7 +320,7 @@ func (m *Manager) Apply(pid int) error {`
`320`	`320`	`}`
`321`	`321`	`}`
`322`	`322`
`323`		`- statusChan := make(chan string)`
	`323`	`+ statusChan := make(chan string, 1)`
`324`	`324`	`if _, err := theConn.StartTransientUnit(unitName, "replace", properties, statusChan); err == nil {`
`325`	`325`	`select {`
`326`	`326`	`case <-statusChan:`