--- /dev/null	2013-11-25 16:34:39.360817680 +0100
+++ new/test/compiler/uncommontrap/TestSpecTrapClassUnloading.java	2014-02-21 09:27:53.192413040 +0100
@@ -0,0 +1,97 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 8031752
+ * @summary speculative traps need to be cleaned up at GC
+ * @run main/othervm -XX:-TieredCompilation -XX:-UseOnStackReplacement -XX:-BackgroundCompilation -XX:+UnlockExperimentalVMOptions -XX:+UseTypeSpeculation -XX:TypeProfileLevel=222 -XX:CompileCommand=exclude,java.lang.reflect.Method::invoke -XX:CompileCommand=exclude,sun.reflect.DelegatingMethodAccessorImpl::invoke -Xmx1M TestSpecTrapClassUnloading
+ *
+ */
+
+import java.lang.reflect.Method;
+
+public class TestSpecTrapClassUnloading {
+    static class B {
+        final public boolean m(Object o) {
+            if (o.getClass() == B.class) {
+                return true;
+            }
+            return false;
+        }
+    }
+
+    static class MemoryChunk {
+        MemoryChunk other;
+        long[] array;
+        MemoryChunk(MemoryChunk other) {
+            other = other;
+            array = new long[1024 * 1024 * 1024];
+        }
+    }
+
+    static void m1(B b, Object o) {
+        b.m(o);
+    }
+    
+    static void m2(B b, Object o) {
+        b.m(o);
+    }
+
+    public static void main(String[] args) throws Exception {
+        Method m = B.class.getMethod("m", Object.class);
+        Object o = new Object();
+        B b = new B();
+
+        // add speculative trap in B.m() for m1
+        for (int i = 0; i < 20000; i++) {
+            m1(b, b);
+        }
+        m1(b, o);
+
+        // add speculative trap in B.m() for code generated by reflection
+        for (int i = 0; i < 20000; i++) {
+            m.invoke(b, b);
+        }
+        m.invoke(b, o);
+        
+        m = null;
+
+        // add speculative trap in B.m() for m2
+        for (int i = 0; i < 20000; i++) {
+            m2(b, b);
+        }
+        m2(b, o);
+
+        // Exhaust memory which causes the code generated by
+        // reflection to be unloaded but B.m() is not.
+        MemoryChunk root = null;
+        try {
+            while (true) {
+                root = new MemoryChunk(root);
+            }
+        } catch(OutOfMemoryError e) {
+            root = null;
+        }
+    }
+}
--- old/src/share/vm/oops/methodData.cpp	2014-02-21 09:27:53.373279220 +0100
+++ new/src/share/vm/oops/methodData.cpp	2014-02-21 09:27:53.213273599 +0100
@@ -1517,17 +1517,74 @@
   return m->is_compiled_lambda_form();
 }
 
-void MethodData::clean_method_data(BoolObjectClosure* is_alive) {
-  for (ProfileData* data = first_data();
-       is_valid(data);
-       data = next_data(data)) {
-    data->clean_weak_klass_links(is_alive);
+void MethodData::clean_extra_data_helper(DataLayout* dp, int shift, bool reset) {
+  if (shift == 0) {
+    return;
   }
-  ParametersTypeData* parameters = parameters_type_data();
-  if (parameters != NULL) {
-    parameters->clean_weak_klass_links(is_alive);
+  if (!reset) {
+    // Move all cells of trap entry at dp left by "shift" cells
+    intptr_t* start = (intptr_t*)dp;
+    intptr_t* end = (intptr_t*)next_extra(dp);
+    for (intptr_t* ptr = start; ptr < end; ptr++) {
+      *(ptr-shift) = *ptr;
+    }
+  } else {
+    // Reset "shift" cells stopping at dp
+    intptr_t* start = ((intptr_t*)dp) - shift;
+    intptr_t* end = (intptr_t*)dp;
+    for (intptr_t* ptr = start; ptr < end; ptr++) {
+      *ptr = 0;
+    }
   }
+}
 
+// Remove SpeculativeTrapData entries that reference an unloaded
+// method
+void MethodData::clean_extra_data(BoolObjectClosure* is_alive) {
+  DataLayout* dp  = extra_data_base();
+  DataLayout* end = extra_data_limit();
+
+  int shift = 0;
+  for (; dp < end; dp = next_extra(dp)) {
+    switch(dp->tag()) {
+    case DataLayout::speculative_trap_data_tag: {
+      SpeculativeTrapData* data = new SpeculativeTrapData(dp);
+      Method* m = data->method();
+      assert(m != NULL, "should have a method");
+      if (!m->method_holder()->is_loader_alive(is_alive)) {
+        // "shift" accumulates the number of cells for dead
+        // SpeculativeTrapData entries that have been seen so
+        // far. Following entries must be shifted left by that many
+        // cells to remove the dead SpeculativeTrapData entries.
+        shift += (int)((intptr_t*)next_extra(dp) - (intptr_t*)dp); 
+      } else {
+        // Shift this entry left if it follows dead
+        // SpeculativeTrapData entries
+        clean_extra_data_helper(dp, shift);
+      }
+      break;
+    }
+    case dp->DataLayout::bit_data_tag:
+      // Shift this entry left if it follows dead SpeculativeTrapData
+      // entries
+      clean_extra_data_helper(dp, shift);
+      continue;
+    case DataLayout::no_tag:
+    case DataLayout::arg_info_data_tag:
+      // We are at end of the live trap entries. The previous "shift"
+      // cells contain entries that are either dead or were shifted
+      // left. They need to be reset to no_tag
+      clean_extra_data_helper(dp, shift, true);
+      return;
+    default:
+      fatal(err_msg("unexpected tag %d", dp->tag()));
+    }
+  }
+}
+
+// Verify there's no unloaded method referenced by a
+// SpeculativeTrapData entry
+void MethodData::verify_extra_data_clean(BoolObjectClosure* is_alive) {
 #ifdef ASSERT
   DataLayout* dp  = extra_data_base();
   DataLayout* end = extra_data_limit();
@@ -1551,3 +1608,18 @@
   }
 #endif
 }
+
+void MethodData::clean_method_data(BoolObjectClosure* is_alive) {
+  for (ProfileData* data = first_data();
+       is_valid(data);
+       data = next_data(data)) {
+    data->clean_weak_klass_links(is_alive);
+  }
+  ParametersTypeData* parameters = parameters_type_data();
+  if (parameters != NULL) {
+    parameters->clean_weak_klass_links(is_alive);
+  }
+
+  clean_extra_data(is_alive);
+  verify_extra_data_clean(is_alive);
+}
--- old/src/share/vm/oops/methodData.hpp	2014-02-21 09:27:53.375005774 +0100
+++ new/src/share/vm/oops/methodData.hpp	2014-02-21 09:27:53.235110900 +0100
@@ -2180,6 +2180,10 @@
   static bool profile_parameters_jsr292_only();
   static bool profile_all_parameters();
 
+  void clean_extra_data(BoolObjectClosure* is_alive);
+  void clean_extra_data_helper(DataLayout* dp, int shift, bool reset = false);
+  void verify_extra_data_clean(BoolObjectClosure* is_alive);
+
 public:
   static int header_size() {
     return sizeof(MethodData)/wordSize;