test/hotspot/jtreg/runtime/handshake/HandshakeDirectTest.java

@@ -22,11 +22,11 @@
  *
  */
 
 /*
  * @test HandshakeDirectTest
- * @summary This test tries to stress direct handshakes between threads.
+ * @summary This test tries to stress direct handshakes between threads while suspending them.
  * @library /testlibrary /test/lib
  * @build HandshakeDirectTest
  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+SafepointALot -XX:BiasedLockingDecayTime=100000000 -XX:BiasedLockingBulkRebiasThreshold=1000000 -XX:BiasedLockingBulkRevokeThreshold=1000000 HandshakeDirectTest
  */
 

@@ -101,9 +101,30 @@
             workingThreads[i] = new Thread(test, Integer.toString(i));
             workingThreads[i].setDaemon(true);
             workingThreads[i].start();
         }
 
+        // Fire-up suspend-resume thread
+        Thread suspendResumeThread = new Thread() {
+            @Override
+            public void run() {
+                while (true) {
+                    int i = ThreadLocalRandom.current().nextInt(0, WORKING_THREADS-1);
+                    workingThreads[i].suspend();
+                    try {
+                        Thread.sleep(1); // sleep for 1 ms
+                    } catch(InterruptedException ie) {
+                    }
+                    workingThreads[i].resume();
+                }
+            }
+        };
+        suspendResumeThread.setDaemon(true);
+        suspendResumeThread.start();
+
         // Wait until the desired number of direct handshakes is reached
-        workingThreads[0].join();
+        // and check that all workers exited
+        for (int i = 0; i < WORKING_THREADS; i++) {
+            workingThreads[i].join();
+        }
     }
 }