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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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/*
 * @test
 * @bug     4858522
 * @summary Basic unit test of OperatingSystemMXBean.getTotalSwapSpaceSize()
 * @author  Steve Bohne
 * @author  Jaroslav Bachorik
 *
 * @library /test/lib
 *
 * @run main TestTotalSwap
 */

/*
 * This test tests the actual swap size on Linux and MacOS only.
 */

import com.sun.management.OperatingSystemMXBean;
import java.lang.management.*;

import jdk.test.lib.Platform;
import jdk.test.lib.process.ProcessTools;
import jdk.test.lib.process.OutputAnalyzer;

public class TestTotalSwap {

    private static final OperatingSystemMXBean mbean =
        (com.sun.management.OperatingSystemMXBean)
        ManagementFactory.getOperatingSystemMXBean();

    // Careful with these values.
    // Min size for pass dynamically determined below.
    // zero if no swap space is configured.
    private static long       min_size_for_pass = 0;
    private static final long MAX_SIZE_FOR_PASS = Long.MAX_VALUE;

    public static void main(String args[]) throws Throwable {

        // yocto might ignore the request to report swap size in bytes
        boolean swapInKB = mbean.getVersion().contains("yocto");

        long min_size = mbean.getFreeSwapSpaceSize();
        if (min_size > 0) {
            min_size_for_pass = min_size;
        }

        long expected_swap_size = getSwapSizeFromOs();
        long size = mbean.getTotalSwapSpaceSize();

        System.out.println("Total swap space size from OS in bytes: " + expected_swap_size);
        System.out.println("Total swap space size in MBean bytes: " + size);

        // if swap data from OS chnaged re-read OS and MBean data
        while (expected_swap_size != getSwapSizeFromOs()) {
            System.out.println("Total swap space reported by OS changed form " + expected_swap_size
                               + " current value = " + getSwapSizeFromOs());
            expected_swap_size = getSwapSizeFromOs();
            size = mbean.getTotalSwapSpaceSize();

            System.out.println("Re-read total swap space size from OS in bytes: " + expected_swap_size);
            System.out.println("Total swap space size in MBean bytes: " + size);
        }

        if (expected_swap_size > -1) {
            if (size != expected_swap_size) {
                // try the expected size in kiloBytes
                if (!(swapInKB && expected_swap_size * 1024 == size)) {
                    throw new RuntimeException("Expected total swap size      : " +
                                               expected_swap_size +
                                               " but getTotalSwapSpaceSize returned: " +
                                               size);
                }
            }
        }

        // sanity check
        if (size < min_size_for_pass || size > MAX_SIZE_FOR_PASS) {
            throw new RuntimeException("Total swap space size " +
                                       "illegal value: " + size + " bytes " +
                                       "(MIN = " + min_size_for_pass + "; " +
                                       "MAX = " + MAX_SIZE_FOR_PASS + ")");
        }

        System.out.println("Test passed.");
    }

    private static long getSwapSizeFromOs() throws Throwable {
        if (Platform.isLinux()) {
            // total       used       free     shared    buffers     cached
            // Mem:    16533540864 13638467584 2895073280  534040576 1630248960 6236909568
            // -/+ buffers/cache: 5771309056 10762231808
            // Swap:   15999168512          0 15999168512
            String swapSizeStr = ProcessTools.executeCommand("free", "-b")
                                             .firstMatch("Swap:\\s+([0-9]+)\\s+.*", 1);
            return Long.parseLong(swapSizeStr);
        } else if (Platform.isOSX()) {
            // total = 8192.00M used = 7471.11M free = 720.89M (encrypted)
            String swapSizeStr = ProcessTools.executeCommand(
                    "/usr/sbin/sysctl",
                    "-n",
                    "vm.swapusage"
            ).firstMatch("total\\s+=\\s+([0-9]+(\\.[0-9]+)?[Mm]?).*", 1);
            if (swapSizeStr.toLowerCase().endsWith("m")) {
                swapSizeStr = swapSizeStr.substring(0, swapSizeStr.length() - 1);
                return (long)(Double.parseDouble(swapSizeStr) * 1024 * 1024); // size in MB
            }
            return (long)(Double.parseDouble(swapSizeStr) * 1024 * 1024);
        } else {
            System.err.println("Unsupported operating system: " + Platform.getOsName());
        }

        return -1;
    }
}