jdk-24/test/hotspot/jtreg/compiler/escapeAnalysis/TestNestedRelockAtDeopt.java

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/*
 * @test
 * @bug 8324174
 * @summary During deoptimization locking and unlocking for nested locks are executed in incorrect order.
 * @requires vm.compMode != "Xint"
 * @run main/othervm -XX:-TieredCompilation -XX:-BackgroundCompilation -Xmx128M
 *                   -XX:CompileCommand=exclude,TestNestedRelockAtDeopt::main TestNestedRelockAtDeopt
 */

import java.util.ArrayList;
public class TestNestedRelockAtDeopt {

    static final int CHUNK = 1000;
    static ArrayList<Object> arr = null;

    public static void main(String[] args) {
        arr = new ArrayList<>();
        try {
            while (true) {
                test1();
            }
        } catch (OutOfMemoryError oom) {
            arr = null; // Free memory
            System.out.println("OOM caught in test1");
        }
        arr = new ArrayList<>();
        try {
            while (true) {
                test2();
            }
        } catch (OutOfMemoryError oom) {
            arr = null; // Free memory
            System.out.println("OOM caught in test2");
        }
        arr = new ArrayList<>();
        TestNestedRelockAtDeopt obj = new TestNestedRelockAtDeopt();
        try {
            while (true) {
                test3(obj);
            }
        } catch (OutOfMemoryError oom) {
            arr = null; // Free memory
            System.out.println("OOM caught in test3");
        }
        arr = new ArrayList<>();
        try {
            while (true) {
                test4(obj);
            }
        } catch (OutOfMemoryError oom) {
            arr = null; // Free memory
            System.out.println("OOM caught in test4");
        }
    }

    // Nested locks in one method
    static void test1() { // Nested lock in one method
        synchronized (TestNestedRelockAtDeopt.class) {
            synchronized (new TestNestedRelockAtDeopt()) { // lock eliminated - not escaped allocation
                synchronized (TestNestedRelockAtDeopt.class) { // nested lock eliminated
                    synchronized (new TestNestedRelockAtDeopt()) { // lock eliminated - not escaped allocation
                        synchronized (TestNestedRelockAtDeopt.class) { // nested lock eliminated
                            arr.add(new byte[CHUNK]);
                        }
                    }
                }
            }
        }
    }

    // Nested locks in inlined method
    static void foo() {
        synchronized (new TestNestedRelockAtDeopt()) {  // lock eliminated - not escaped allocation
            synchronized (TestNestedRelockAtDeopt.class) {  // nested lock eliminated when inlined
                arr.add(new byte[CHUNK]);
            }
        }
    }

    static void test2() {
        synchronized (TestNestedRelockAtDeopt.class) {
            synchronized (new TestNestedRelockAtDeopt()) {  // lock eliminated - not escaped allocation
                synchronized (TestNestedRelockAtDeopt.class) { // nested lock eliminated
                    foo(); // Inline
                }
            }
        }
    }

    // Nested locks in one method
    static void test3(TestNestedRelockAtDeopt obj) {
        synchronized (TestNestedRelockAtDeopt.class) {
            synchronized (obj) { // lock not eliminated - external object
                synchronized (TestNestedRelockAtDeopt.class) { // nested lock eliminated
                    synchronized (obj) { // nested lock eliminated
                        synchronized (TestNestedRelockAtDeopt.class) { // nested lock eliminated
                            arr.add(new byte[CHUNK]);
                        }
                    }
                }
            }
        }
    }

    // Nested locks with different objects in inlined method
    static void bar(TestNestedRelockAtDeopt obj) {
        synchronized (obj) {  // nested lock eliminated when inlined
            synchronized (TestNestedRelockAtDeopt.class) {  // nested lock eliminated when inlined
                arr.add(new byte[CHUNK]);
            }
        }
    }

    static void test4(TestNestedRelockAtDeopt obj) {
        synchronized (TestNestedRelockAtDeopt.class) {
            synchronized (obj) {  // lock not eliminated - external object
                synchronized (TestNestedRelockAtDeopt.class) { // nested lock eliminated
                    bar(obj); // Inline
                }
            }
        }
    }
}