RFR: 8281511: java/net/ipv6tests/UdpTest.java fails with checkTime failed [v4]

[Daniel Fuchs]

On Fri, 28 Feb 2025 14:40:28 GMT, serhiysachkov <duke at openjdk.org> wrote:

>> switching to nanoTime as suggested in ticket comments
>
> serhiysachkov has updated the pull request incrementally with one additional commit since the last revision:
> 
>   8281511: update Copyright header

Additionally could you have a look at the superclass Tests.java? There is this code there:


    /* check the time got is within 50% of the time expected */
    public static void checkTime (long got, long expected) {
        checkTime(got, expected, expected);
    }

    /* check the time got is between start and end, given 50% tolerance */
    public static void checkTime(long got, long start, long end) {
        dprintln("checkTime: got = " + got + " start = " + start + " end = " + end);
        long upper = end + (end / 2);
        long lower = start - (start / 2);
        if (got > upper || got < lower) {
            throw new RuntimeException("checkTime failed: got " + got
                    + ", expected between " + start + " and " + end);
        }
    }

For the exception message, it would be better to use `lower` and `upper` instead of `start` and `end` - because when start == end the messsage lacks credibility.

test/jdk/java/net/ipv6tests/UdpTest.java line 149:

> 147:         }
> 148:         final long expectedTimeInNanos = TimeUnit.SECONDS.toNanos(4);
> 149:         checkTime (System.nanoTime() - t1, expectedTimeInNanos);

Actually, maybe it would be better to keep the expectedTime in milliseconds here, and convert `System.nanoTime() - t1` to milliseconds before calling checkTime. We obviously don't need the nano second precision, and milliseconds are more human readable than nanoseconds when looking at the log.

test/jdk/java/net/ipv6tests/UdpTest.java line 183:

> 181:         final long startTimeInNanos = TimeUnit.SECONDS.toNanos(2);
> 182:         final long endTimeInNanos = TimeUnit.SECONDS.toNanos(10);
> 183:         checkTime (System.nanoTime() - t1, startTimeInNanos, endTimeInNanos);

same remark here.

-------------

PR Review: https://git.openjdk.org/jdk/pull/23840#pullrequestreview-2651325490
PR Review Comment: https://git.openjdk.org/jdk/pull/23840#discussion_r1975746133
PR Review Comment: https://git.openjdk.org/jdk/pull/23840#discussion_r1975746875