*** old/test/lib/jdk/test/lib/cds/CDSTestUtils.java	Wed Aug 22 09:26:45 2018
--- new/test/lib/jdk/test/lib/cds/CDSTestUtils.java	Wed Aug 22 09:26:45 2018

*** 193,207 ****
--- 193,215 ----
              output.shouldNotHaveExitValue(0);
              return this;
          }
      }
  
      // Specify this property to copy sdandard output of the child test process to
      // the parent/main stdout of the test.
      // By default such output is logged into a file, and is copied into the main stdout.
!     public static final boolean CopyChildStdoutToMainStdout =
!         Boolean.valueOf(System.getProperty("test.cds.copy.child.stdout", "true"));
+     // A number to be included in the filename of the stdout and the stderr output file.
+     static int count = 0;
+ 
!     private static int getNextCount() {
!         return count++;
+     }
+ 
+     // By default, stdout of child processes are logged in files such as
+     // <testname>-0000-exec.stdout. If you want to also include the stdout
+     // inside jtr files, you can override this in the jtreg command line like
+     // "jtreg -Dtest.cds.copy.child.stdout=true ...."
+     public static final boolean copyChildStdoutToMainStdout =
+         Boolean.getBoolean("test.cds.copy.child.stdout");
  
      // This property is passed to child test processes
      public static final String TestTimeoutFactor = System.getProperty("test.timeout.factor", "1.0");
  
      public static final String UnableToMapMsg =

*** 542,558 ****
--- 550,570 ----
  
      // ============================= Logging
      public static OutputAnalyzer executeAndLog(ProcessBuilder pb, String logName) throws Exception {
          long started = System.currentTimeMillis();
          OutputAnalyzer output = new OutputAnalyzer(pb.start());
+         String outputFileNamePrefix =
+             getTestName() + "-" + String.format("%04d", getNextCount()) + "-" + logName;
  
!         writeFile(getOutputFile(logName + ".stdout"), output.getStdout());
!         writeFile(getOutputFile(logName + ".stderr"), output.getStderr());
!         writeFile(getOutputFile(outputFileNamePrefix + ".stdout"), output.getStdout());
!         writeFile(getOutputFile(outputFileNamePrefix + ".stderr"), output.getStderr());
          System.out.println("[ELAPSED: " + (System.currentTimeMillis() - started) + " ms]");
+         System.out.println("[logging stdout to " + outputFileNamePrefix + ".stdout]");
+         System.out.println("[logging stderr to " + outputFileNamePrefix + ".stderr]");
          System.out.println("[STDERR]\n" + output.getStderr());
  
!         if (CopyChildStdoutToMainStdout)
!         if (copyChildStdoutToMainStdout)
              System.out.println("[STDOUT]\n" + output.getStdout());
  
          return output;
      }