RFR: 8328630: Add logging when needed symbols in dll are missing. [v2]

[Robbin Ehn]

On Thu, 21 Mar 2024 10:38:34 GMT, David Holmes <dholmes at openjdk.org> wrote:

>> Robbin Ehn has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   clear errors, comment
>
> src/hotspot/os/posix/os_posix.cpp line 714:
> 
>> 712: 
>> 713: void* os::dll_lookup(void* handle, const char* name) {
>> 714:   ::dlerror(); // Clear any previous error
> 
> Uggghhh! It is awful that we need to do that. Now this needs to be guarded with `log_is_enabled(Debug, os)`. Otherwise we need to check for the performance hit of doing this, particularly during startup.

The result are stored in per thread struct, so that method just load that thread local and check that result is NULL and returns. IMHO that's fine.

If there is an error it must free it, so maybe considering all the libjsvml ~40-50 errors that must be freed ?

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PR Review Comment: https://git.openjdk.org/jdk/pull/18404#discussion_r1533645495