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*/
/*
* @bug 4858522
* @summary Basic unit test of UnixOperatingSystemMXBean.getOpenFileDescriptorCount()
* @author Steve Bohne
*/
/*
* This test is just a sanity check and does not check for the correct
* value. The correct value should be checked manually:
* Solaris/Linux:
* 1. Find the pid of the java process.
* 2. In a shell, enter the command: "ls -1 /proc/<pid>/fd | wc -l"
*/
import com.sun.management.UnixOperatingSystemMXBean;
import java.lang.management.*;
public class GetOpenFileDescriptorCount {
private static UnixOperatingSystemMXBean mbean =
(UnixOperatingSystemMXBean)ManagementFactory.getOperatingSystemMXBean();
// Careful with these values.
private static final long MIN_COUNT_FOR_PASS = 1;
// Max count for pass dynamically determined below
private static long max_count_for_pass = Long.MAX_VALUE;
private static boolean trace = false;
public static void main(String args[]) throws Exception {
if (args.length > 0 && args[0].equals("trace")) {
trace = true;
}
long max_count = mbean.getMaxFileDescriptorCount();
if (max_count > 0) {
max_count_for_pass = max_count;
}
long count = mbean.getOpenFileDescriptorCount();
if (trace) {
System.out.println("Open file descriptor count: " + count);
}
if (count < MIN_COUNT_FOR_PASS || count > max_count_for_pass) {
throw new RuntimeException("Open file descriptor count " +
"illegal value: " + count + " bytes " +
"(MIN = " + MIN_COUNT_FOR_PASS + "; " +
"MAX = " + max_count_for_pass + ")");
}
System.out.println("Test passed.");
}
}