RFR: JDK-8318736: com/sun/jdi/JdwpOnThrowTest.java failed with "transport error 202: bind failed: Address already in use"

[Alex Menkov]

On Wed, 25 Oct 2023 11:27:18 GMT, Johannes Bechberger <jbechberger at openjdk.org> wrote:

> Fix race condition in debugger port selection, introduced with [JDK-8317920](https://bugs.openjdk.org/browse/JDK-8317920).
> 
> Tested on my Mac M1, but it doesn't contain platform-dependent code.

test/jdk/com/sun/jdi/lib/jdb/Debuggee.java line 106:

> 104: 
> 105:         // required to pass non null port with address and emit string before the throw
> 106:         public Launcher enableOnThrow(String value, String expectedOutputBeforeThrow) {

Suggestion:

        public Launcher enableOnThrow(String exceptionClassName) {

expectedOutputBeforeThrow is not needed.
Comment for the method is obsolete

test/jdk/com/sun/jdi/lib/jdb/Debuggee.java line 136:

> 134: 
> 135:     // starts the process, waits for "Listening for transport" output and detects transport/address
> 136:     private Debuggee(ProcessBuilder pb, String name, boolean hasOnThrow, String expectedOutputBeforeThrow) {

expectedOutputBeforeThrow is not used/not neded

test/jdk/com/sun/jdi/lib/jdb/Debuggee.java line 136:

> 134: 
> 135:     // starts the process, waits for "Listening for transport" output and detects transport/address
> 136:     private Debuggee(ProcessBuilder pb, String name, boolean hasOnThrow, String expectedOutputBeforeThrow) {

Launcher prepares command line and address detection logic depends on on the command line, so I think it would be better to make
Suggestion:

    private Debuggee(ProcessBuilder pb, String name, Function<String, JDWP.ListenAddress> addressDetector) {

then warm-up predicate in the ctor uses `listenAddress[0] = addressDetector.apply(s)`

Launcher.launch() can pass JDWP::parseListenAddress for usual cases and implement the detector for onthrow case

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PR Review Comment: https://git.openjdk.org/jdk/pull/16358#discussion_r1372415102
PR Review Comment: https://git.openjdk.org/jdk/pull/16358#discussion_r1372403856
PR Review Comment: https://git.openjdk.org/jdk/pull/16358#discussion_r1372413049