RFR: JDK-8265362 java/net/Socket/UdpSocket.java fails with "java.net.BindException: Address already in use" (macos-aarch64) [v2]

[zoulasc]

On Mon, 24 May 2021 12:30:38 GMT, Mark Sheppard <msheppar at openjdk.org> wrote:

>> The test java/net/Socket/UdpSocket.java has been seen to fail with a BindException, in the testMaxSockets test, on a regular basis on macOS-aarch64 platform. testMaxSockets tests the maximum number of UDP Sockets that may be created as defined by a system property sun.net.maxDatagramSockets. It invokes the Socket constructor Socket(InetAddress host, int port, boolean stream) with stream set to false to create a UDP Socket. This instantiation is a compound operation, consisting of the creation of a socket, the explicit binding of wildcard address and ephemeral port, and a connect to the socket end point specified in the constructor parameters.  Analysis has shown that during the test that the OS intermittently allocates the same ephemeral port multiple times during the bind system call, such that two separate sockets end up bound to the same port. Then on the connect invocation a BindException is thrown for the second socket. This has been determined to be a transient condition dur
 ing heavy loads and where a significant number of ephemeral ports are being allocated.
>> 
>> As this is deemed an OS issues, and in order to increase test stability, it has been found that for the BindException condition a retry of the Socket creation mitigates the issues and tests the max creation property.
>
> Mark Sheppard has updated the pull request incrementally with one additional commit since the last revision:
> 
>   JDK-8265362 java/net/Socket/UdpSocket.java fails with "java.net.BindException: Address already in use" (macos-aarch64)
>   update as per request by AB

Changes requested by zoulasc at github.com (no known OpenJDK username).

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PR: https://git.openjdk.java.net/jdk/pull/4103