src/java.base/share/classes/java/io/DeleteOnExitHook.java

*** 1,7 ****
  /*
!  * Copyright (c) 2005, 2018, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
--- 1,7 ----
  /*
!  * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
*** 33,43 ****
   * A set is used both to prevent double-insertion of the same file as well as offer
   * quick removal.
   */
  
  class DeleteOnExitHook {
!     private static LinkedHashSet<String> files = new LinkedHashSet<>();
      static {
          // DeleteOnExitHook must be the last shutdown hook to be invoked.
          // Application shutdown hooks may add the first file to the
          // delete on exit list and cause the DeleteOnExitHook to be
          // registered during shutdown in progress. So set the
--- 33,48 ----
   * A set is used both to prevent double-insertion of the same file as well as offer
   * quick removal.
   */
  
  class DeleteOnExitHook {
!     private static class OrderCount {
!         long order;
!         int count;
!     }
!     private static long nextOrder;
!     private static HashMap<String, OrderCount> files = new HashMap<>();
      static {
          // DeleteOnExitHook must be the last shutdown hook to be invoked.
          // Application shutdown hooks may add the first file to the
          // delete on exit list and cause the DeleteOnExitHook to be
          // registered during shutdown in progress. So set the
*** 53,84 ****
          );
      }
  
      private DeleteOnExitHook() {}
  
!     static synchronized void add(String file) {
          if(files == null) {
              // DeleteOnExitHook is running. Too late to add a file
              throw new IllegalStateException("Shutdown in progress");
          }
  
!         files.add(file);
      }
  
      static void runHooks() {
!         LinkedHashSet<String> theFiles;
  
          synchronized (DeleteOnExitHook.class) {
              theFiles = files;
              files = null;
          }
  
!         ArrayList<String> toBeDeleted = new ArrayList<>(theFiles);
! 
!         // reverse the list to maintain previous jdk deletion order.
!         // Last in first deleted.
!         Collections.reverse(toBeDeleted);
!         for (String filename : toBeDeleted) {
!             (new File(filename)).delete();
!         }
      }
  }
--- 58,102 ----
          );
      }
  
      private DeleteOnExitHook() {}
  
!     static synchronized void deleteOnExit(String file) {
          if(files == null) {
              // DeleteOnExitHook is running. Too late to add a file
              throw new IllegalStateException("Shutdown in progress");
          }
  
!         OrderCount oc = files.computeIfAbsent(file, f -> new OrderCount());
!         oc.order = nextOrder++;
!         oc.count++;
!     }
! 
!     static synchronized void cancelDeleteOnExit(String file) {
!         if(files != null) {
!             files.compute(file, (f, oc) -> {
!                 if (oc == null) {
!                     throw new IllegalStateException(
!                         "Unbalanced cancelDeleteOnExit for missing deleteOnExit");
!                 }
!                 return --oc.count <= 0 ? null : oc;
!             });
!         }
      }
  
      static void runHooks() {
!         HashMap<String, OrderCount> theFiles;
  
          synchronized (DeleteOnExitHook.class) {
              theFiles = files;
              files = null;
          }
  
!         theFiles
!             .entrySet()
!             .stream()
!             // last registered -> first deleted
!             .sorted(Comparator.comparing(e -> -e.getValue().order))
!             .map(e -> new File(e.getKey()))
!             .forEach(File::delete);
      }
  }