Integrated: JDK-8325530: Vague error message when com.sun.tools.attach.VirtualMachine fails to load agent library

[Alex Menkov]

On Wed, 21 Feb 2024 21:13:36 GMT, Alex Menkov <amenkov at openjdk.org> wrote:

> VirtualMachine.loadAgentPath/loadAgentLibrary can fail with AgentLoadException in 2 cases:
> - attach listener returns error; in the case the exception is thrown from HotSpotVirtualMachine.processCompletionStatus (called from HotSpotVirtualMachine.execute);
> - attach listener returns success, but reply does not contain Agent_onAttach return code ("return code: %d" message).
> 
> before jdk21 if attach listener fails to load required library, it returned error (case 1)
> from jdk21 attach listener always returns success (case 2)
> Both cases are ok, but for 2nd case HotSpotVirtualMachine.loadAgentLibrary read only single line of the response message, so exception message didn't contain error details.
> 
> The fix updates HotSpotVirtualMachine.loadAgentLibrary to read the whole response message.
> Walking through the code, fixed some other minor things in attach listener and attach API implementation (commented in the code)
> 
> Testing:
>   - test/jdk/com/sun/tools;
>   - tier1,tier2,tier5-svc

This pull request has now been integrated.

Changeset: fc67c2b4
Author:    Alex Menkov <amenkov at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/fc67c2b4f17216d4adcc0825d0f378ae4f150025
Stats:     150 lines in 6 files changed: 109 ins; 16 del; 25 mod

8325530: Vague error message when com.sun.tools.attach.VirtualMachine fails to load agent library

Reviewed-by: sspitsyn, cjplummer

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PR: https://git.openjdk.org/jdk/pull/17954