Name: saC57035 Date: 01/16/98


java.lang.ClassLoader.loadClass call of custom created class loader
results in JVM crash on all platforms.
(Core dumped on Solaris, unhandled exception on WinNT etc.)
The bug is introduced in JDK-1.2beta3-C build whereas previous build is okay.

This bug causes the following JCK tests to fail:

JCK-1.0.2b .. JCK-1.2ea2:
api/java_lang/Class/EquivClass.html#Class0603
api/java_lang/Class/EquivClass.html#Class0604
api/java_lang/Class/BoundValue.html#Class1605

JCK-1.2beta2:
api/java_lang/Class/manual.html#GetClassloader


Below is the minimized test demonstrating the bug:
----------- ClassTest.java--------------------
public class ClassTest {

  public static void main (String argv[]){
    String fname = null;
    if (argv.length == 1)
      fname = argv[0];
    else {
      System.out.println("Incorrect number of arguments passed");
      System.exit(1);
    }
    Class c = null;
    TestLoader tl = null;
    try {
      tl = new TestLoader();
    } catch(SecurityException s) {
// code checking forSecurityManager removed for clarity
    } catch (Throwable e) {
      System.out.println("Failed: Unexpected exception thrown: "+e);
    }
    try {
      c = tl.loadClass(fname);
    } catch (ClassNotFoundException e) {
      System.out.println("Failed: "+e.toString());
    }
    System.out.println("Passed: class loaded successfully");
  }

}

class TestLoader extends ClassLoader {

  TestLoader() {
  }

  protected Class loadClass(String name, boolean resolve) throws ClassNotFoundException {
    try {
      return findSystemClass(name);
    } catch (Throwable e) {
    }
    byte data[];
    try {
      java.io.InputStream in = (new java.net.URL(name)).openStream();
      java.io.ByteArrayOutputStream buf=new java.io.ByteArrayOutputStream();
      while (true) {
        int d=in.read();
        if (d==-1) break;
        buf.write(d);
      }
      data=buf.toByteArray();
  
      in.close();
    } catch(java.net.MalformedURLException e) {
      throw new ClassNotFoundException(e.toString());
    } catch(java.io.IOException e) {
      throw new RuntimeException(e.toString());
    }
Class cl = defineClass(null, data, 0, data.length);
    if (resolve)
      resolveClass(cl);
    return cl;
  }

}

class TestClass { int i; }

------ Output of the test under Solaris JDK-1.2beta3-C --------
83% javac ClassTest.java
84% java ClassTest file://`pwd`/TestClass.class
SIGSEGV 11* segmentation violation
    si_signo [11]: SIGSEGV 11* segmentation violation
    si_errno [0]: Error 0
    si_code [1]: SEGV_MAPERR [addr: 0x0]

stackbase=F0000000, stackpointer=EFFFD058

Full thread dump:
    "CachedReference sweeper" (TID:0xee300f28, sys_thread_t:0x76e68, state:CW) prio=9
at java.lang.Object.wait(Native Method)
at java.lang.Object.wait(Object.java:315)
at java.lang.Runtime.waitForMemoryAdvice(Runtime.java:569)
at java.lang.ref.CachedReference$Sweeper.run(CachedReference.java:342)
at java.lang.Thread.run(Thread.java:490)
    "Finalizer" (TID:0xee300318, sys_thread_t:0x5ce20, state:CW) prio=8
at java.lang.Object.wait(Native Method)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:86)
at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:99)
at java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:131)
    "Reference handler" (TID:0xee3003c8, sys_thread_t:0x552f0, state:CW) prio=10
at java.lang.Object.wait(Native Method)
at java.lang.Object.wait(Object.java:315)
at java.lang.ref.Reference$ReferenceHandler.run(Reference.java:198)
    "Async Garbage Collector" (TID:0xee3001b0, sys_thread_t:0x56678, state:R) prio=1
    "Idle thread" (TID:0xee3001f8, sys_thread_t:0x4d8f0, state:R) prio=0
    "Clock" (TID:0xee3002d0, sys_thread_t:0x4d7d0, state:CW) prio=12
    "main" (TID:0xee300038, sys_thread_t:0x20a08, state:R) prio=5 *current thread*
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:326)
at TestLoader.loadClass(ClassTest.java:57)
at java.lang.ClassLoader.loadClass(ClassLoader.java:172)
at ClassTest.main(ClassTest.java:21)
Monitor Cache Dump:
Registered Monitor Dump:
    utf8 hash table: <unowned>
    JNI pinning lock: <unowned>
    JNI global reference lock: <unowned>
    BinClass lock: <unowned>
    Class linking lock: <unowned>
    System class loader lock: <unowned>
    Code rewrite lock: <unowned>
    Heap lock: <unowned>
    Monitor IO lock: <unowned>
    Child death monitor: <unowned>
    Event monitor: <unowned>
    I/O monitor: <unowned>
    Alarm monitor: <unowned>
Waiting to be notified:
"Clock" (0x4d7d0)
    Sbrk lock: <unowned>
    Monitor cache expansion lock: <unowned>
    Thread queue lock: <unowned>
    Monitor registry: owner "main" (0x20a08, 1 entry)
Thread Alarm Q:
Abort

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