diff -r fd16c54261b3 -r 489c9b5090e2 hotspot/src/share/vm/runtime/jniPeriodicChecker.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/runtime/jniPeriodicChecker.cpp	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+# include "incls/_precompiled.incl"
+# include "incls/_jniPeriodicChecker.cpp.incl"
+
+
+// --------------------------------------------------------
+// Class to aid in periodic checking under CheckJNICalls
+class JniPeriodicCheckerTask : public PeriodicTask {
+  public:
+     JniPeriodicCheckerTask(int interval_time) : PeriodicTask(interval_time) {}
+     void task() { os::run_periodic_checks(); }
+     static void engage();
+     static void disengage();
+};
+
+
+//----------------------------------------------------------
+// Implementation of JniPeriodicChecker
+
+JniPeriodicCheckerTask*              JniPeriodicChecker::_task   = NULL;
+
+/*
+ * The engage() method is called at initialization time via
+ * Thread::create_vm() to initialize the JniPeriodicChecker and
+ * register it with the WatcherThread as a periodic task.
+ */
+void JniPeriodicChecker::engage() {
+  if (CheckJNICalls && !is_active()) {
+    // start up the periodic task
+    _task = new JniPeriodicCheckerTask(10);
+    _task->enroll();
+  }
+}
+
+
+/*
+ * the disengage() method is responsible for deactivating the periodic
+ * task. This  method is called from before_exit() in java.cpp and is only called
+ * after the WatcherThread has been stopped.
+ */
+void JniPeriodicChecker::disengage() {
+  if (CheckJNICalls && is_active()) {
+    // remove JniPeriodicChecker
+    _task->disenroll();
+    delete _task;
+    _task = NULL;
+  }
+}
+
+void jniPeriodicChecker_exit() {
+  if (!CheckJNICalls) return;
+}