--- test/org/apache/tomcat/util/bcel/TesterPerformance.java	(revision 1637495)
+++ test/org/apache/tomcat/util/bcel/TesterPerformance.java	(working copy)
@@ -17,6 +17,7 @@ 
 package org.apache.tomcat.util.bcel;
 
 import java.io.File;
+import java.io.FilterInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
@@ -34,6 +35,33 @@ 
 
     private static final String JAR_LOCATION = "/tmp/jira-libs";
 
+    /**
+     * An InputStream that returns no more than one byte on each call.
+     */
+    private static class SlowInputStream extends FilterInputStream {
+
+        public SlowInputStream(InputStream in) {
+            super(in);
+        }
+
+        @Override
+        public int read(byte[] b, int off, int len) throws IOException {
+            if (len <= 0) {
+                if (len == 0) {
+                    return 0;
+                }
+                throw new IndexOutOfBoundsException();
+            }
+            return super.read(b, off, 1);
+        }
+
+        @Override
+        public int available() throws IOException {
+            int result = super.available(); 
+            return result > 0 ? 1 : result;
+        }
+    }
+
     @Test
     public void testClassParserPerformance() throws IOException {
         File libDir = new File(JAR_LOCATION);
@@ -57,6 +85,7 @@ 
             while (jarEntryName != null) {
                 if (jarEntryName.endsWith(".class")) {
                     InputStream is = jar.getEntryInputStream();
+                    is = new SlowInputStream(is);
                     long start = System.nanoTime();
                     ClassParser cp = new ClassParser(is);
                     cp.parse();