RFR: 8339725: Concurrent GC crashed due to GetMethodDeclaringClass [v5]

[Denghui Dong]

On Tue, 10 Sep 2024 22:20:10 GMT, Leonid Mesnik <lmesnik at openjdk.org> wrote:

>> Liang Mao has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Exclude libagent8339725.cpp compiling for windows
>
> test/hotspot/jtreg/runtime/8339725/libagent8339725.cpp line 36:
> 
>> 34: 
>> 35: #define BUFFER_SIZE 100000
>> 36: static size_t ring_buffer[BUFFER_SIZE] = {0};
> 
> The rung_buffer is shared between threads without any locks, not safe.

`jmethodID` is a pointer according to the implementation.
IIUC, the read operation and write operation are both atomic, which means the read thread will never read an illegal jmethodID value.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/20907#discussion_r1753679313