Fatal Error Detected by the Java Runtime Environment

Question

I am trying to run a simple Java program using C++ and wrote the following code-

1 #include <jni.h>
2 #include <stdio.h>
3
4 JNIEnv * create_vm() {
5     JavaVM *jvm;
6     JNIEnv *env;
7     JavaVMInitArgs vm_args;
8
9     JavaVMOption options[1];
10
11     options[0].optionString = "-Djava.class.path=~/openbr/java/JavainC";
12     vm_args.version = JNI_VERSION_1_6;
13     vm_args.nOptions = 1;
14     vm_args.options = options;
15     vm_args.ignoreUnrecognized = JNI_FALSE;
16
17     int res = JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args);
18     return env;
19 }
20
21 void run_java(JNIEnv* env) {
22     jclass cls;
23     jmethodID mid;
24     jint square;
25
26     cls = env->FindClass("javaTest");
27     mid = env->GetStaticMethodID(cls, "square", "(I)I");
28     square = env->CallStaticIntMethod(cls, mid, 5);
29     printf("Result of square: %d\n", square);
30 }
31
32 int main() {
33     JNIEnv* env = create_vm();
34     run_java(env);
35     printf("running some code");
36     //jvm->DestroyJavaVM();
37     return 0;
38 }

My Java Code looks like-

1 public class javaTest {
2     public static int square(int n) {
3         return n*n;
4     }
5 }
6

My code compiled fine but when I tried to run it I got this error message-

# A fatal error has been detected by the Java Runtime Environment: 
#
#  SIGSEGV (0xb) at pc=0x00007fc3038f984f, pid=12689, tid=140475565049664
#
# JRE version: 7.0_21-b02
# Java VM: OpenJDK 64-Bit Server VM (23.7-b01 mixed mode linux-amd64 compressed oops)
# Problematic frame:
# V  [libjvm.so+0x53284f]  jni_CallStaticIntMethodV+0x4f
#
# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -    c unlimited" before starting Java again
#
# An error report file with more information is saved as:
# /home/jcheney/openbr/java/JavainC/hs_err_pid12689.log
#
# If you would like to submit a bug report, please include
# instructions on how to reproduce the bug and visit:
#   https://bugs.launchpad.net/ubuntu/+source/openjdk-7/
#
Aborted

The error printout it gave me said-

---------------  T H R E A D  ---------------

Current thread (0x00000000011be800):  JavaThread "main" [_thread_in_vm, id=12689, stack
(0x00007fff54814000,0x00007fff54914000)]

siginfo:si_signo=SIGSEGV: si_errno=0, si_code=1 (SEGV_MAPERR), si_addr=0x0000000000000000

Registers:
RAX=0x00007fc303c4a138, RBX=0x00000000011be800, RCX=0x00007fff549127c0, RDX=0x00000000011bf318
RSP=0x00007fff549126e0, RBP=0x00007fff54912790, RSI=0x00000000011be800, RDI=0x00000000011be800
R8 =0x00007fc3038f9800, R9 =0x746f7073746f682f, R10=0x6168732f6372732f, R11=0x0000000000000246
R12=0x00000000011be9d8, R13=0x0000000000000000, R14=0x00007fff549127c0, R15=0x0000000000000000
RIP=0x00007fc3038f984f, EFLAGS=0x0000000000010287, CSGSFS=0x0000000000000033,    
ERR=0x0000000000000004
TRAPNO=0x000000000000000e

Top of Stack: (sp=0x00007fff549126e0)
0x00007fff549126e0:   00007fff549126c8 0000000800000002
0x00007fff549126f0:   00007fff54912701 0000000000000000
0x00007fff54912700:   00007fff54912730 00007fc3038125ac
0x00007fff54912710:   00000000011be800 00000000011be800
0x00007fff54912720:   00000000011be800 00000000011bf310
0x00007fff54912730:   00007fff0000063d 00007fc303c4a138
0x00007fff54912740:   0000000000000000 0000000000400901
0x00007fff54912750:   00000000011be800 0000000000000000
0x00007fff54912760:   00000000011be800 0000000000400906
0x00007fff54912770:   0000000000000000 00000000004004d0
0x00007fff54912780:   00007fff549129d0 0000000000000000
0x00007fff54912790:   00007fff54912890 00000000004007cd
0x00007fff549127a0:   0000000000000000 0000000000000000
0x00007fff549127b0:   0000000000000000 00000000011be9d8
0x00007fff549127c0:   0000003000000018 00007fff549128a0
0x00007fff549127d0:   00007fff549127e0 0000000000400901
0x00007fff549127e0:   0000000000000000 0000000000000000
0x00007fff549127f0:   00007fff54912860 0000000000000005
0x00007fff54912800:   00007fc303c3ae8f 746f7073746f682f
0x00007fff54912810:   00007fff000000a8 00007fc303c68e68
0x00007fff54912820:   00000000011be800 00007fff549128c0
0x00007fff54912830:   00000000011be800 00007fc303903233
0x00007fff54912840:   0000000000000000 00000000004004d0
0x00007fff54912850:   00007fff549129d0 0000000000000000
0x00007fff54912860:   00007fff54912890 0000000000400712
0x00007fff54912870:   0000000000400901 0000000000400906
0x00007fff54912880:   0000000000000000 00000000011be9d8
0x00007fff54912890:   00007fff549128d0 000000000040065b
0x00007fff549128a0:   00000000004008d0 00000000011be9d8
0x00007fff549128b0:   00007fff54912930 0000000000000000
0x00007fff549128c0:   0000000000000000 00000000004007e0
0x00007fff549128d0:   00007fff549128f0 0000000000400691

Any ideas on what is going on?

Thanks

Answer 1

My guess -- and it's only a guess at this point -- is that one of the methods FindClass or GetStaticMethodId is not succeeding for some reason, and since you're not checking for errors, your program eventually crashes trying to call a method through a bad method pointer. Minimally, check the return values of both of these methods against NULL , and fail if that's what they return.

At @TimBender's urging, I looked at your code again, and I agree -- it's probably FindClass . You definitely can't include a ~ in your classpath -- only the shell knows how to interpret that, and that parameter won't go through a shell before the JVM sees it. Use a full, absolute path to the location of the class -- the root of the package hierarchy, actually.

Answer 2

Based on limited research, I'm 99% sure that the problem is with the FindClass declaration. FindClass accepts as the second argument a fully qualified class name. Fully qualified meaning the package name must be included before the class name. I'm assuming that javaTest is not in the default package, or if it is that there is still some convention for referencing it.