Name: stC104175 Date: 08/09/2000


$ java -version
java version "1.3.0beta_refresh"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0beta_refresh-b09)
Java HotSpot(TM) Client VM (build 1.3.0beta-b07, mixed mode)


run the following code:
#include <stdio.h>
#include <signal.h>
#include <assert.h>
#include <jni.h>

void signalHandler(int sig, siginfo_t* info, void *vp) { }

int main(int argc, char **argv)
{
  JNIEnv *env = NULL;
  JavaVM *JVP_jvm;
  jint res;
  JavaVMInitArgs vm_args;
  JavaVMOption options[1];
  struct sigaction sigAct;
  int ret;

  /* install a signal handler for SEGV */
  sigfillset(&(sigAct.sa_mask));
  sigAct.sa_handler = SIG_DFL;
  sigAct.sa_sigaction = signalHandler;
  sigAct.sa_flags = SA_SIGINFO|SA_RESTART;
  ret = sigaction(SIGSEGV,&sigAct,NULL);
  assert(ret == 0);

  options[0].optionString = "" ;
  // this resolves the problem, but does not install JVM's signal handlers:
  // options[0].optionString = "-XX:+AllowUserSignalHandlers" ;

  vm_args.version = JNI_VERSION_1_2 ;
  vm_args.options = options;
  vm_args.nOptions = 1;
  vm_args.ignoreUnrecognized = 1;

  res = JNI_CreateJavaVM(&JVP_jvm, (void **) &env, &vm_args);
  printf("JVM %screated.\n", res < 0 ? "not ":"" );

  return(0);
}

compiled with:
cc -I/usr/java/include -I/usr/java/include/linux hotsig.c
-L/usr/java/jre/lib/i386 -ljava

$ ldd a.out
        libjava.so => /usr/java/jre/lib/i386/libjava.so (0x4001e000)
        libc.so.6 => /lib/libc.so.6 (0x40042000)
        libjvm.so => /usr/java/jre/lib/i386/hotspot/libjvm.so (0x4013d000)
        libverify.so => /usr/java/jre/lib/i386/libverify.so (0x40541000)
        libnsl.so.1 => /lib/libnsl.so.1 (0x40555000)
        libdl.so.2 => /lib/libdl.so.2 (0x4056b000)
        /lib/ld-linux.so.2 => /lib/ld-linux.so.2 (0x40000000)
        libpthread.so.0 => /lib/libpthread.so.0 (0x4056e000)
        libstdc++-libc6.1-1.so.2 => /usr/lib/libstdc++-libc6.1-1.so.2
(0x40580000)
        libm.so.6 => /lib/libm.so.6 (0x405c8000)


gives:
$ a.out
#
# HotSpot Virtual Machine Error, Internal Error
# Please report this error at
# http://java.sun.com/cgi-bin/bugreport.cgi
#
# Error ID: 4F533F4C494E55580E4350500549
#
# Problematic Thread: Segmentation fault


Is there a way to let the hotspot JVM install its own signal handlers
if there are already signal handlers installed before VM is brought up
thru JNI ?
(Review ID: 107898)
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