On 2/1/19 9:22 AM, Nick Gasson (Arm Technology China) wrote:
> On AArch64, if you use "jhsdb clhsdb --pid=..." to attach a debugger to
> a Java process, and then run "jstack -v" while any thread is executing a
> native method, you will get a NullPointerException like this:
This does not happen for me. I have a test case which runs a native
method; the native method does not return. I then run jstack -v
and get a clean stack trace, regardless of whether it's interpreted or compiled:
"main" #1 prio=5 tid=0x0000ffff7001a000 nid=0x596c runnable [0x0000ffff7624e000]
java.lang.Thread.State: RUNNABLE
JavaThread state: _thread_in_native
- Spinner.main(java.lang.String[]) @bci=0, line=9, pc=0x0000ffff6d6954d8,
Method*=0x0000ffff2321e380 (Compiled frame; information may be imprecise)
Locked ownable synchronizers:
- None
I tries various combinations of Xcomp and tiered compilation. What did you do?
--
Andrew Haley
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671
#include <jni.h>
#include <stdio.h>
/*
* Class: Spinner
* Method: run
* Signature: ()V
*/
JNIEXPORT void JNICALL Java_Spinner_run
(JNIEnv *env, jclass k) {
printf("Spinning...\n");
for(;;);
}
/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class Spinner */
#ifndef _Included_Spinner
#define _Included_Spinner
#ifdef __cplusplus
extern "C" {
#endif
/*
* Class: Spinner
* Method: run
* Signature: ()V
*/
JNIEXPORT void JNICALL Java_Spinner_run
(JNIEnv *, jclass);
#ifdef __cplusplus
}
#endif
#endif
public class Spinner {
static native void run();
static {
System.loadLibrary("Spinner");
}
public static void main(String[] args) {
run();
}
}
