test/runner: interrupt S/R loop if the test has been signalled

When a test exceed a specified timeout and receives SIGTERM and then it has 15
seconds to complete all operations and collect all logs. If it doesn't exit in
15 seconds, it will be killed by SIGKILL.

PiperOrigin-RevId: 721504425

test/runner/main.go

@@ -27,6 +27,7 @@ import (
 	"os/signal"
 	"path/filepath"
 	"strings"
+	"sync/atomic"
 	"syscall"
 	"testing"
 	"time"
@@ -495,13 +496,15 @@ func runRunsc(tc *gtest.TestCase, spec *specs.Spec) error {
 	cmd.Stderr = os.Stderr
 	sig := make(chan os.Signal, 1)
 	defer close(sig)
+	signalled := atomic.Bool{}
 	signal.Notify(sig, unix.SIGTERM)
 	defer signal.Stop(sig)
 	go func() {
 		s, ok := <-sig
 		if !ok {
 			return
 		}
+		signalled.Store(true)
 		log.Warningf("%s: Got signal: %v", name, s)
 		done := make(chan bool, 1)
 		dArgs := append([]string{}, args...)
@@ -541,6 +544,9 @@ func runRunsc(tc *gtest.TestCase, spec *specs.Spec) error {
 
 		// Restore the sandbox with the previous state file.
 		for i := 1; ; i++ {
+			if signalled.Load() {
+				return fmt.Errorf("timeout")
+			}
 			// Check if the latest state file is valid. If the file
 			// is empty, delete it and exit the loop.
 			isEmpty, err := deleteIfEmptyFile(dirs[i-1])