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/*
 * @test TestHeapDumpOnOutOfMemoryError
 * @summary Test verifies that -XX:HeapDumpOnOutOfMemoryError dump heap when OutOfMemory is thrown in heap
 * @library /test/lib
 * @run driver TestHeapDumpOnOutOfMemoryError run heap
 */

import jdk.test.lib.Asserts;
import jdk.test.lib.Platform;
import jdk.test.lib.classloader.GeneratingClassLoader;
import jdk.test.lib.hprof.HprofParser;
import jdk.test.lib.process.ProcessTools;
import jdk.test.lib.process.OutputAnalyzer;

import java.io.File;

public class TestHeapDumpOnOutOfMemoryError {

    public static final String HEAP_OOME = "heap";
    public static final String METASPACE_OOME = "metaspace";

    public static void main(String[] args) throws Exception {
        if (args.length == 1) {
             try {
                if (args[0].equals(HEAP_OOME)) {
                    Object[] oa = new Object[Integer.MAX_VALUE];
                    for(int i = 0; i < oa.length; i++) {
                        oa[i] = new Object[Integer.MAX_VALUE];
                    }
                } else {
                    GeneratingClassLoader loader = new GeneratingClassLoader();
                    for (int i = 0; ; i++) {
                        loader.loadClass(loader.getClassName(i));
                    }
                }
                throw new Error("OOME not triggered");
            } catch (OutOfMemoryError err) {
                return;
            }
        }
        test(args[1]);
    }

    static void test(String type) throws Exception {
        String heapdumpFilename = type + ".hprof";
        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder("-XX:+HeapDumpOnOutOfMemoryError",
                "-XX:HeapDumpPath=" + heapdumpFilename,
                // Note: When trying to provoke a metaspace OOM we may generate a lot of classes. In debug VMs this
                //  can cause considerable wait times since:
                // - Compiler Dependencies verification iterates the class tree
                // - Before exit, the CLDG is checked.
                // Both verifications show quadratic time or worse wrt to number of loaded classes. Therefore it
                //  makes sense to switch one or both off and limit the metaspace size to something sensible.
                // Example numbers on a slow ppc64 machine:
                //  MaxMetaspaceSize=64M - ~60-70K classes - ~20min runtime with all verifications
                //  MaxMetaspaceSize=16M - ~12-15K classes - ~12sec runtime with all verifications
                //  MaxMetaspaceSize=16M - ~12-15K classes - VerifyDependencies off - ~3seconds on ppc
                "-XX:MaxMetaspaceSize=16m",
                Platform.isDebugBuild() ? "-XX:-VerifyDependencies" : "-Dx",
                TestHeapDumpOnOutOfMemoryError.class.getName(), type);

        OutputAnalyzer output = new OutputAnalyzer(pb.start());
        output.stdoutShouldNotBeEmpty();
        output.shouldContain("Dumping heap to " + type + ".hprof");
        File dump = new File(heapdumpFilename);
        Asserts.assertTrue(dump.exists() && dump.isFile(),
                "Could not find dump file " + dump.getAbsolutePath());

        HprofParser.parse(new File(heapdumpFilename));
        System.out.println("PASSED");
    }

}
