On Wed, 24 Feb 2021 10:24:06 GMT, Conor Cleary <ccle...@openjdk.org> wrote:
> A number of net tests use a > **[HostsFileNameService](https://github.com/openjdk/jdk/blob/382e38dd246596ec94a1f1ce0e0f9e87f53366c7/src/java.base/share/classes/java/net/InetAddress.java#L955)** > to verify either the functionality of this type of Name Service or as a > complement to other tests (such as Caching, Address Format etc.). > > Intermittent failures of these tests can be caused by tools used during JVM > start-up accessing/initialising classes sooner than may be expected which can > cause unexpected behaviour. Most commonly, this unexpected behaviour takes > the form of the > **[PlatformNameService](https://github.com/openjdk/jdk/blob/382e38dd246596ec94a1f1ce0e0f9e87f53366c7/src/java.base/share/classes/java/net/InetAddress.java#L927)** > being used despite a call to `System.setProperty("jdk.net.hosts.file", ...)` > in the test file. Due to the fact that **InetAddress** initialises it's > Implementation and Name Service fields in a static class initialiser ([see > L1132 of > InetAddress.java](https://github.com/openjdk/jdk/blob/382e38dd246596ec94a1f1ce0e0f9e87f53366c7/src/java.base/share/classes/java/net/InetAddress.java#L1132)) > and that the default mode is to use the **Platform Name Service**, setting a > system property in the main method to specify the use of > **HostsFileNameService** (with the jdk.net.hosts.file property) has no affect if the class has been previously accessed during JVM start-up and **InetAddress** will default to the **PlatformNameService** which is unsuitable for this test. This explains the intermittent failures caused by the use of `System.setProperty("jdk.net.hosts.file", ...)`. > > This fix improves the robustness of this test by specifying the use of the > **HostsFileNameService** in the `@run` tag for this test via the previously > mentioned system property. This gives certainty that the property will be > properly set in time for the actual run of this test after the JVM has > booted. An example of one the fixes... > * @run main/othervm -Djdk.net.hosts.file=TestToNumericFormatHosts > textToNumericFormat Looks good to me. Good tidy-up. ------------- Marked as reviewed by michaelm (Reviewer). PR: https://git.openjdk.java.net/jdk/pull/2703
