netstack: update goroutine save / restore safety comments.

PiperOrigin-RevId: 204930314
Change-Id: Ifc4c41ed28616cd57fafbf7c92e87141a945c41f

2 files changed, 8 insertions, 2 deletions

diff --git a/pkg/tcpip/link/fdbased/endpoint.go b/pkg/tcpip/link/fdbased/endpoint.go
index 413f77dcc..8fc009160 100644
--- a/pkg/tcpip/link/fdbased/endpoint.go
+++ b/pkg/tcpip/link/fdbased/endpoint.go
@@ -108,7 +108,10 @@ func New(opts *Options) tcpip.LinkEndpointID {
 // dispatches them via the provided dispatcher.
 func (e *endpoint) Attach(dispatcher stack.NetworkDispatcher) {
 	e.attached = true
-	go e.dispatchLoop(dispatcher) // S/R-FIXME
+	// Link endpoints are not savable. When transportation endpoints are
+	// saved, they stop sending outgoing packets and all incoming packets
+	// are rejected.
+	go e.dispatchLoop(dispatcher) // S/R-SAFE: See above.
 }
 
 // IsAttached implements stack.LinkEndpoint.IsAttached.
diff --git a/pkg/tcpip/link/sharedmem/sharedmem.go b/pkg/tcpip/link/sharedmem/sharedmem.go
index 223eb3a1b..eabf35bd3 100644
--- a/pkg/tcpip/link/sharedmem/sharedmem.go
+++ b/pkg/tcpip/link/sharedmem/sharedmem.go
@@ -142,7 +142,10 @@ func (e *endpoint) Attach(dispatcher stack.NetworkDispatcher) {
 	if !e.workerStarted && atomic.LoadUint32(&e.stopRequested) == 0 {
 		e.workerStarted = true
 		e.completed.Add(1)
-		go e.dispatchLoop(dispatcher) // S/R-FIXME
+		// Link endpoints are not savable. When transportation endpoints
+		// are saved, they stop sending outgoing packets and all
+		// incoming packets are rejected.
+		go e.dispatchLoop(dispatcher) // S/R-SAFE: see above.
 	}
 	e.mu.Unlock()
 }