Hi All, Problem: Several of Java's "c" files call exit(0) if you pass certain command-line options to JNI_CreateJavaVM, which can terminate the C++ code JNI users use to initialise the JVM.
Example: If you write some C++ code that calls JNI_CreateJavaVM, and uses the option "-agentlib:jdwp=help", Java's c files will print the needed help output and call exit(0). Result: Your C++ code is terminated on this line, and a return code of 0 is produced. Issues: Issue 1: The exit(0) prevents your code from doing anything useful after the JNI_CreateJavaVM call. Issue 2: The exit(0) indicates to anything monitoring your C++ code that your code exited normally, even though it was terminated mid-way-through. Issue 3: This return code is useless to us, as a 0 can indicate the VM started correctly, or it can indicate the VM was terminated due to one or more of these command-line options. Issue 4: Of the other JNI return values (JNI_OK, JNI_ERR, etc) none of them appear to cover this scenario. Proposed solutions: PS1: We should amend the JNI specification to include a "JNI_SILENT_EXIT" return code, so the C++ code knows a VM was not created, but that it isn't an error. PS2: We should identify a list of the command-line options that produce this behaviour via the JNI. (not all of the "help" options are recognised by the JNI interface. E.g. -version and -help produce a JNI_ERR and an "Option not recognised" message) PS3: We should replace these annoying exit(0) calls with code that returns "JNI_SILENT_EXIT", so the C++ code has a chance to finish. Best Regards Adam Farley Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU
