test/hotspot/jtreg/runtime/8176717/TestInheritFD.java

changes after first review

*** 3,17 ****
--- 3,22 ----
  import static java.lang.System.getProperty;
  import static java.lang.management.ManagementFactory.getOperatingSystemMXBean;
  import static java.nio.file.Files.readAllBytes;
  import static java.nio.file.Files.readSymbolicLink;
  import static java.util.Arrays.stream;
+ import static java.util.Optional.empty;
+ import static java.util.Optional.of;
  import static java.util.stream.Collectors.joining;
  import static jdk.test.lib.process.ProcessTools.createJavaProcessBuilder;
  
  import java.io.File;
+ import java.io.FileNotFoundException;
+ import java.io.FileOutputStream;
  import java.io.IOException;
+ import java.util.Optional;
  
  import com.sun.management.UnixOperatingSystemMXBean;
  
  /*
   * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
***************
*** 122,140 ****
          public static void main(String[] args) throws InterruptedException {
              File logFile = new File(args[0]);
              long parentPid = parseLong(args[1]);
              long parentFDCount = parseLong(args[2]);
  
              if(supportsUnixMXBean()){
                  long thisFDCount = unixNrFD();
                  System.out.println("This VM FD-count ("
                          + thisFDCount
                          + ") should be strictly less than parent VM FD-count ("
                          + parentFDCount
                          + ") as log file should have been closed, HOWEVER, THIS CAN NOT BE RELIED"
!                         + " ON as files in /proc and /sys is opened by the JVM");
!                 System.out.println(findOpenLogFile()?LEAKS_FD:RETAINS_FD);
              } else if (getProperty("os.name").toLowerCase().contains("win")) {
                  windows(logFile, parentPid);
              } else {
                  System.out.println(LEAKS_FD); // default fail on unknown configuration
              }
--- 127,147 ----
          public static void main(String[] args) throws InterruptedException {
              File logFile = new File(args[0]);
              long parentPid = parseLong(args[1]);
              long parentFDCount = parseLong(args[2]);
  
+             fakeLeakyJVM(false);
+ 
              if(supportsUnixMXBean()){
                  long thisFDCount = unixNrFD();
                  System.out.println("This VM FD-count ("
                          + thisFDCount
                          + ") should be strictly less than parent VM FD-count ("
                          + parentFDCount
                          + ") as log file should have been closed, HOWEVER, THIS CAN NOT BE RELIED"
!                         + " ON as files in /proc and /sys are opened by the JVM");
!                 System.out.println(findOpenLogFile() ? LEAKS_FD : RETAINS_FD);
              } else if (getProperty("os.name").toLowerCase().contains("win")) {
                  windows(logFile, parentPid);
              } else {
                  System.out.println(LEAKS_FD); // default fail on unknown configuration
              }
***************
*** 149,181 ****
      static long unixNrFD() {
          UnixOperatingSystemMXBean osBean = (UnixOperatingSystemMXBean) getOperatingSystemMXBean();
          return osBean.getOpenFileDescriptorCount();
      }
  
!     static File linkTarget(File f) {
          try {
!             return readSymbolicLink(f.toPath()).toFile();
          } catch (IOException e) {
!             return new File("Error: could not read symbolic link (last link can not be read as it points to the /proc/self/fd directory that has been closed): " + e.toString());
          }
      }
  
      static boolean findOpenLogFile() {
          File dir = new File("/proc/self/fd");
  
          System.out.println("Open file descriptors:\n" + stream(dir.listFiles())
!             .map(f -> "###" + f.getAbsolutePath() + " -> " + linkTarget(f))
              .collect(joining("\n")));
  
          return stream(dir.listFiles())
!             .map(TestInheritFD::linkTarget)
!             .filter(f -> f.getName().endsWith(LOG_SUFFIX))
              .findAny()
              .isPresent();
      }
  
      static void windows(File f, long parentPid) throws InterruptedException {
          System.out.println("waiting for pid: " + parentPid);
          ProcessHandle.of(parentPid).ifPresent(handle -> handle.onExit().join());
          System.out.println("trying to rename file to the same name: " + f);
!         System.out.println(f.renameTo(f)?RETAINS_FD:LEAKS_FD); // this parts communicates a closed file descriptor by printing "VM RESULT => RETAINS FD"
      }
--- 156,199 ----
      static long unixNrFD() {
          UnixOperatingSystemMXBean osBean = (UnixOperatingSystemMXBean) getOperatingSystemMXBean();
          return osBean.getOpenFileDescriptorCount();
      }
  
!     static Optional<String> linkTargetName(File f) {
          try {
!             return of(readSymbolicLink(f.toPath()).toFile().getName());
          } catch (IOException e) {
!             return empty();
!         }
!     }
! 
!     @SuppressWarnings("resource")
!     static void fakeLeakyJVM(boolean fake) {
!         if (fake) {
!             try {
!                 new FileOutputStream("fakeLeakyJVM" + LOG_SUFFIX, false);
!             } catch (FileNotFoundException e) {
!             }
          }
      }
  
      static boolean findOpenLogFile() {
          File dir = new File("/proc/self/fd");
  
          System.out.println("Open file descriptors:\n" + stream(dir.listFiles())
!             .map(f -> f.getAbsolutePath() + " maps to: " + linkTargetName(f).orElse("?"))
              .collect(joining("\n")));
  
          return stream(dir.listFiles())
!             .map(TestInheritFD::linkTargetName)
!             .flatMap(Optional::stream)
!             .filter(fileName -> fileName.endsWith(LOG_SUFFIX))
              .findAny()
              .isPresent();
      }
  
      static void windows(File f, long parentPid) throws InterruptedException {
          System.out.println("waiting for pid: " + parentPid);
          ProcessHandle.of(parentPid).ifPresent(handle -> handle.onExit().join());
          System.out.println("trying to rename file to the same name: " + f);
!         System.out.println(f.renameTo(f) ? RETAINS_FD : LEAKS_FD); // this parts communicates a closed file descriptor by printing "VM RESULT => RETAINS FD"
      }