test/java/lang/ProcessBuilder/CloseRace.java

@@ -31,20 +31,24 @@
  */
 
 import java.io.*;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.CountDownLatch;
 
 public class CloseRace {
     private static final String BIG_FILE = "bigfile";
 
     private static final int[] procFDs = new int[6];
 
     /** default value sufficient to repro bug 8024521. */
     private static final int testDurationSeconds
         = Integer.getInteger("test.duration", 600);
 
+    private static final CountDownLatch startedSignal
+        = new CountDownLatch(2);
+
     static boolean fdInUse(int i) {
         return new File("/proc/self/fd/" + i).exists();
     }
 
     static boolean[] procFDsInUse() {

@@ -82,20 +86,22 @@
             new Thread(new ExecLoop()),
         };
         for (Thread thread : threads)
             thread.start();
 
+        startedSignal.await();
         Thread.sleep(testDurationSeconds * 1000);
 
         for (Thread thread : threads)
             thread.interrupt();
         for (Thread thread : threads)
             thread.join();
     }
 
     static class OpenLoop implements Runnable {
         public void run() {
+            startedSignal.countDown();
             while (!Thread.interrupted()) {
                 try {
                     // wait for ExecLoop to finish creating process
                     do {} while (count(procFDsInUse()) != 3);
                     List<InputStream> iss = new ArrayList<>(4);

@@ -118,10 +124,11 @@
         }
     }
 
     static class ExecLoop implements Runnable {
         public void run() {
+            startedSignal.countDown();
             ProcessBuilder builder = new ProcessBuilder("/bin/true");
             while (!Thread.interrupted()) {
                 try {
                     // wait for OpenLoop to finish
                     do {} while (count(procFDsInUse()) > 0);