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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * accompanied this code).
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package jdk.jfr.event.gc.collection;

import static jdk.testlibrary.Asserts.assertGreaterThan;
import static jdk.testlibrary.Asserts.assertTrue;

import java.io.File;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import jdk.jfr.consumer.RecordedEvent;
import jdk.jfr.consumer.RecordingFile;
import jdk.testlibrary.jfr.AppExecutorHelper;
import jdk.testlibrary.jfr.Events;
import jdk.testlibrary.OutputAnalyzer;


/**
 * Class to verify GarbageCollection event.
 * It starts the application provoking GCGarbageCollection with enabled JFR,
 * collects events and verify the 'name' and 'cause' fields to be expected.
 * It's supposed to be invoked from tests.
 */
public class GCGarbageCollectionUtil {
    private final static String EVENT_SETTINGS_FILE =
            System.getProperty("test.src", ".") + File.separator + "gc-testsettings.jfc";

    /**
     * Verifies the 'name' and 'cause' fields of received events to be expected.
     * @param testID - a string to identify test
     * @param testFlags - VM flags including GC to start the app
     * @param gcNames - expected values for the 'name' field
     * @param gcCauses - expected values for the 'cause' field
     * @throws Exception in case of any failure
     */
    public static void test(String testID, String[] testFlags,
            String[] gcNames, String... gcCauses) throws Exception {

        String jfrFile = testID + ".jfr";

        List<String> summaryFlags = new ArrayList<>();
        Collections.addAll(summaryFlags, testFlags);
        summaryFlags.add("-Xmx100m");
        summaryFlags.add("-XX:+UnlockExperimentalVMOptions");
        summaryFlags.add("-XX:-UseFastUnorderedTimeStamps");
        summaryFlags.add("-verbose:gc");


        String args[] = {};
        OutputAnalyzer analyzer = AppExecutorHelper.executeAndRecord(EVENT_SETTINGS_FILE, jfrFile,
                (String[])summaryFlags.toArray(new String[0]), AppGCProvoker.class.getName(), args);
        analyzer.shouldHaveExitValue(0);

        Set<String> gcValidNames = new HashSet<>();
        for (String n: gcNames) {
            gcValidNames.add(n);
        }
        Set<String> gcValidCauses = new HashSet<>();
        for (String n: gcCauses) {
            gcValidCauses.add(n);
        }

        int total = 0;
        for (RecordedEvent event : RecordingFile.readAllEvents(Paths.get(jfrFile))) {
            total++;
            System.out.println("Event: " + event);

            final String name = Events.assertField(event, "name").notEmpty().getValue();
            assertTrue(gcValidNames.contains(name), "GC name '" + name + "' not in the valid list" + gcValidNames);

            final String cause = Events.assertField(event, "cause").notEmpty().getValue();
            assertTrue(gcValidCauses.contains(cause), "GC cause '" + cause + "' not in the valid causes" + gcValidCauses);
        }
        assertGreaterThan(total, 0, "Expected at least one event");
    }
}