diff -r 836adbf7a2cd -r 3317bb8137f4 jdk/src/java.instrument/share/native/libinstrument/Reentrancy.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/java.instrument/share/native/libinstrument/Reentrancy.c	Sun Aug 17 15:54:13 2014 +0100
@@ -0,0 +1,165 @@
+/*
+ * Copyright (c) 2003, 2008, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+
+/*
+ * Copyright 2003 Wily Technology, Inc.
+ */
+
+#include    <jni.h>
+#include    <jvmti.h>
+
+#include    "JPLISAssert.h"
+#include    "Reentrancy.h"
+#include    "JPLISAgent.h"
+
+/*
+ *  This module provides some utility functions to support the "same thread" re-entrancy management.
+ *  Uses JVMTI TLS to store a single bit per thread.
+ *  Non-zero means the thread is already inside; zero means the thread is not inside.
+ */
+
+/*
+ *  Local prototypes
+ */
+
+/* Wrapper around set that does the set then re-fetches to make sure it worked.
+ * Degenerates to a simple set when assertions are disabled.
+ * This routine is only here because of a bug in the JVMTI where set to 0 fails.
+ */
+jvmtiError
+confirmingTLSSet(   jvmtiEnv *      jvmtienv,
+                    jthread         thread,
+                    const void *    newValue);
+
+/* Confirmation routine only; used to assure that the TLS slot holds the value we expect it to. */
+void
+assertTLSValue( jvmtiEnv *      jvmtienv,
+                jthread         thread,
+                const void *    expected);
+
+
+#define JPLIS_CURRENTLY_INSIDE_TOKEN                ((void *) 0x7EFFC0BB)
+#define JPLIS_CURRENTLY_OUTSIDE_TOKEN               ((void *) 0)
+
+
+jvmtiError
+confirmingTLSSet(   jvmtiEnv *      jvmtienv,
+                    jthread         thread,
+                    const void *    newValue) {
+    jvmtiError  error;
+
+    error = (*jvmtienv)->SetThreadLocalStorage(
+                                    jvmtienv,
+                                    thread,
+                                    newValue);
+    check_phase_ret_blob(error, error);
+
+#if JPLISASSERT_ENABLEASSERTIONS
+    assertTLSValue( jvmtienv,
+                    thread,
+                    newValue);
+#endif
+
+    return error;
+}
+
+void
+assertTLSValue( jvmtiEnv *      jvmtienv,
+                jthread         thread,
+                const void *    expected) {
+    jvmtiError  error;
+    void *      test = (void *) 0x99999999;
+
+    /* now check if we do a fetch we get what we wrote */
+    error = (*jvmtienv)->GetThreadLocalStorage(
+                                jvmtienv,
+                                thread,
+                                &test);
+    check_phase_ret(error);
+    jplis_assert(error == JVMTI_ERROR_NONE);
+    jplis_assert(test == expected);
+}
+
+jboolean
+tryToAcquireReentrancyToken(    jvmtiEnv *  jvmtienv,
+                                jthread     thread) {
+    jboolean    result      = JNI_FALSE;
+    jvmtiError  error       = JVMTI_ERROR_NONE;
+    void *      storedValue = NULL;
+
+    error = (*jvmtienv)->GetThreadLocalStorage(
+                                jvmtienv,
+                                thread,
+                                &storedValue);
+    check_phase_ret_false(error);
+    jplis_assert(error == JVMTI_ERROR_NONE);
+    if ( error == JVMTI_ERROR_NONE ) {
+        /* if this thread is already inside, just return false and short-circuit */
+        if ( storedValue == JPLIS_CURRENTLY_INSIDE_TOKEN ) {
+            result = JNI_FALSE;
+        }
+        else {
+            /* stuff in the sentinel and return true */
+#if JPLISASSERT_ENABLEASSERTIONS
+            assertTLSValue( jvmtienv,
+                            thread,
+                            JPLIS_CURRENTLY_OUTSIDE_TOKEN);
+#endif
+            error = confirmingTLSSet (  jvmtienv,
+                                        thread,
+                                        JPLIS_CURRENTLY_INSIDE_TOKEN);
+            check_phase_ret_false(error);
+            jplis_assert(error == JVMTI_ERROR_NONE);
+            if ( error != JVMTI_ERROR_NONE ) {
+                result = JNI_FALSE;
+            }
+            else {
+                result = JNI_TRUE;
+            }
+        }
+    }
+    return result;
+}
+
+
+void
+releaseReentrancyToken(         jvmtiEnv *  jvmtienv,
+                                jthread     thread)  {
+    jvmtiError  error       = JVMTI_ERROR_NONE;
+
+/* assert we hold the token */
+#if JPLISASSERT_ENABLEASSERTIONS
+    assertTLSValue( jvmtienv,
+                    thread,
+                    JPLIS_CURRENTLY_INSIDE_TOKEN);
+#endif
+
+    error = confirmingTLSSet(   jvmtienv,
+                                thread,
+                                JPLIS_CURRENTLY_OUTSIDE_TOKEN);
+    check_phase_ret(error);
+    jplis_assert(error == JVMTI_ERROR_NONE);
+
+}