On Wed, 11 Nov 2020 07:18:33 GMT, David Holmes <dhol...@openjdk.org> wrote:
>> Maurizio Cimadamore has updated the pull request incrementally with 10 >> additional commits since the last revision: >> >> - Merge pull request #7 from JornVernee/Additional_Review_Comments >> >> Additional review comments >> - Revert System.java changes >> - Set copyright year for added files to 2020 >> - Check result of AttachCurrentThread >> - Sort includes alphabetically >> - Relax ret_addr_offset() assert >> - Extra space after if >> - remove excessive asserts in ProgrammableInvoker::invoke_native >> - Remove os::is_MP() check >> - remove blank line in thread.hpp > > src/hotspot/share/prims/universalUpcallHandler.cpp line 55: > >> 53: JavaVM_ *vm = (JavaVM *)(&main_vm); >> 54: jint result = vm->functions->AttachCurrentThread(vm, (void**) >> &p_env, nullptr); >> 55: guarantee(result == JNI_OK, "Could not attach thread for upcall. JNI >> error code: %d", result); > > I'm assuming you don't have a mechanism for conveying an error back to the > original entry point used by the native thread? Attaching an existing thread > should only fail if we run out of C-Heap, so we're on the brink of aborting > anyway, but still the guarantee here is not ideal. Yeah, we have no idea where/how to report such and error. The native code might just call a function through a function pointer like `void(*)(void)` i.e. no place to return an error code. Also, since it's a previously non-attached thread, there is no JavaFrameAnchor that gives us a last Java frame we could jump back to and throw an exception. Is there's a more explicit way to exit with an error, other than a `guarantee` that you would prefer here? ------------- PR: https://git.openjdk.java.net/jdk/pull/634
