From 267c6f2ac71f92999e969232431ba04678e7437e Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Mon, 15 Apr 2024 07:54:39 +0200
Subject: Adding upstream version 4:24.2.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 .../sun/star/lib/util/AsynchronousFinalizer.java   | 117 +++++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 ridljar/com/sun/star/lib/util/AsynchronousFinalizer.java

(limited to 'ridljar/com/sun/star/lib/util/AsynchronousFinalizer.java')

diff --git a/ridljar/com/sun/star/lib/util/AsynchronousFinalizer.java b/ridljar/com/sun/star/lib/util/AsynchronousFinalizer.java
new file mode 100644
index 0000000000..588b8fe388
--- /dev/null
+++ b/ridljar/com/sun/star/lib/util/AsynchronousFinalizer.java
@@ -0,0 +1,117 @@
+/* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+package com.sun.star.lib.util;
+
+import java.util.LinkedList;
+
+/**
+ * Helper class to asynchronously execute finalize methods.
+ *
+ * <p>Current JVMs seem not to be robust against long-running finalize methods,
+ * in that such long-running finalize methods may lead to OutOfMemoryErrors.
+ * This class mitigates the problem by asynchronously shifting the bodies of
+ * potentially long-running finalize methods into an extra thread.  Classes that
+ * make use of this in their finalize methods are the proxies used in the
+ * intra-process JNI UNO bridge and the inter-process Java URP UNO bridge (where
+ * in both cases finalizers lead to synchronous UNO release calls).</p>
+ *
+ * <p>Irrespective whether JVMs are getting more mature and should no longer
+ * have problems with long-running finalize methods, at least the JNI UNO bridge
+ * needs some way to stop finalization of proxies (to C++ objects) well before
+ * process exit, as provided by drain().</p>
+ */
+public final class AsynchronousFinalizer {
+    public AsynchronousFinalizer() {
+        thread = new Thread("AsynchronousFinalizer") {
+                @Override
+                public void run() {
+                    for (;;) {
+                        Job j;
+                        synchronized (queue) {
+                            for (;;) {
+                                if (done) {
+                                    return;
+                                }
+                                if (!queue.isEmpty()) {
+                                    break;
+                                }
+                                try {
+                                    queue.wait();
+                                } catch (InterruptedException e) {
+                                    return;
+                                }
+                            }
+                            j = queue.remove(0);
+                        }
+                        try {
+                            j.run();
+                        } catch (Throwable e) {}
+                    }
+                }
+            };
+        thread.start();
+    }
+
+    /**
+     * Add a job to be executed asynchronously.
+     *
+     * <p>The run method of the given job is called exactly once. If it terminates
+     * abnormally by throwing any Throwable, that is ignored.</p>
+     *
+     * @param job represents the body of some finalize method; must not be null.
+     */
+    public void add(Job job) {
+        synchronized (queue) {
+            boolean first = queue.isEmpty();
+            queue.add(job);
+            if (first) {
+                queue.notify();
+            }
+        }
+    }
+
+    public void drain() throws InterruptedException {
+        synchronized (queue) {
+            done = true;
+            queue.notify();
+        }
+        // tdf#123481 Only join if we are not in our own thread, else we have a deadlock
+        if (Thread.currentThread() != thread)
+            thread.join();
+    }
+
+    /**
+     * An interface to represent bodies of finalize methods.
+     *
+     * Similar to <code>Runnable</code>, except that the run method may throw any
+     * <code>Throwable</code> (which is effectively ignored by
+     * <code>AsynchronousFinalizer.add</code>, similar to any <code>Throwables</code>
+     * raised by finalize being ignored).
+    */
+    public interface Job {
+        void run() throws Throwable;
+    }
+
+    private final LinkedList<Job> queue = new LinkedList<Job>();
+    private final Thread thread;
+    private boolean done = false;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
-- 
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