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  1. Code Tools
  2. CODETOOLS-7900563

Incomplete coverage results for instrumented apps with custom class loaders

    Details

    • Subcomponent:
    • Resolved In Build:
      1.1
    • CPU:
      generic
    • OS:
      generic
    • Verification:
      Verified

      Description



      Name: kbR10066 Date: 12/20/2002


      Suppose we have an app which loads one of its classes via its own class loader.
      Then if we statically instrument the app and run the instrumented image, a situation
      can happen when no coverage data is generated for the class loaded via the custom
      class loader.

      To reproduce, compile the sources a.java and b.java below with -Xjcov:

      % javac -Xjcov a.java b.java

      Instrument the classes:

      % java -cp jcov.jar com.sun.tdk.jcov.InstrMain -overwrite -saveatend=a.main *class

      Run the app:

      % java -cp .:jcov.jar a
      LOADING b
      ClassLoader1@8d107f
      b@cf2c80
      LOADING b
      ClassLoader2@a8c4e7
      b@729854


      Resulting java.jcov does not contain data for class "b". JDK version used was 1.4.0.

      --- a.java ---
      import java.io.*;
      import java.security.*;

      public class a {
      public static void main(String[] args) {
      try {
      Class c1 = new ClassLoader1().loadClass("b");
      Class c2 = new ClassLoader2().loadClass("b");
      System.out.println(c1.newInstance());
      System.out.println(c2.newInstance());
      } catch (Throwable e) {
      e.printStackTrace();
      }
      }
      }

      class CL extends ClassLoader {
      final static int READ_CHUNK_SIZE = 1024;

      public static byte[] read(String name) {
      name = name.replace('.', '/') + ".class";
      byte[] arr = null;
      try {
      InputStream is = ClassLoader.getSystemResourceAsStream(name);
      int len = is.available();
      int n = 0;
      int res = 0;

      arr = new byte[len];

      do {
      res += n;
      int i = len - res;
      if (i > READ_CHUNK_SIZE) {
      i = READ_CHUNK_SIZE;
      }
      n = is.read(arr, res, i);
      } while (n > 0);

      is.close();
      } catch (Throwable e) {
      e.printStackTrace();
      return null;
      }
      return arr;
      }
      }

      class ClassLoader1 extends CL {
      protected Class loadClass(String name, boolean resolve) throws ClassNotFoundException {
      Class res = null;
      try {
      byte[] arr = read(name);
      res = defineClass(name, arr, 0, arr.length);
      } catch (Throwable e) {
      res = findSystemClass(name);
      }
      if (resolve) {
      resolveClass(res);
      }
      return res;
      }
      }

      class ClassLoader2 extends CL {
      protected Class loadClass(String name, boolean resolve) throws ClassNotFoundException {
      Class res = null;
      try {
      byte[] arr = read(name);
      res = defineClass(name, arr, 0, arr.length);
      } catch (Throwable e) {
      res = findSystemClass(name);
      }
      if (resolve) {
      resolveClass(res);
      }
      return res;
      }
      }
      --- end of a.java ---

      --- b.java ---
      public class b {
      static {
      System.out.println("LOADING b");
      }

      public b () {
      System.out.println(getClass().getClassLoader());
      }
      }
      --- end of b.java ---


      ======================================================================

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            • Assignee:
              afedorch Alexey Fedorchenko (Inactive)
              Reporter:
              klooney Kevin Looney (Inactive)
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                Updated:
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