nashorn/src/jdk.dynalink/share/classes/jdk/dynalink/RelinkableCallSite.java
changeset 34447 ec4c069f9436
parent 33337 af3fea63e008
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/nashorn/src/jdk.dynalink/share/classes/jdk/dynalink/RelinkableCallSite.java	Tue Nov 24 10:19:34 2015 +0100
@@ -0,0 +1,178 @@
+/*
+ * Copyright (c) 2010, 2013, 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.
+ */
+
+/*
+ * This file is available under and governed by the GNU General Public
+ * License version 2 only, as published by the Free Software Foundation.
+ * However, the following notice accompanied the original version of this
+ * file, and Oracle licenses the original version of this file under the BSD
+ * license:
+ */
+/*
+   Copyright 2009-2013 Attila Szegedi
+
+   Licensed under both the Apache License, Version 2.0 (the "Apache License")
+   and the BSD License (the "BSD License"), with licensee being free to
+   choose either of the two at their discretion.
+
+   You may not use this file except in compliance with either the Apache
+   License or the BSD License.
+
+   If you choose to use this file in compliance with the Apache License, the
+   following notice applies to you:
+
+       You may obtain a copy of the Apache License at
+
+           http://www.apache.org/licenses/LICENSE-2.0
+
+       Unless required by applicable law or agreed to in writing, software
+       distributed under the License is distributed on an "AS IS" BASIS,
+       WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+       implied. See the License for the specific language governing
+       permissions and limitations under the License.
+
+   If you choose to use this file in compliance with the BSD License, the
+   following notice applies to you:
+
+       Redistribution and use in source and binary forms, with or without
+       modification, are permitted provided that the following conditions are
+       met:
+       * Redistributions of source code must retain the above copyright
+         notice, this list of conditions and the following disclaimer.
+       * Redistributions in binary form must reproduce the above copyright
+         notice, this list of conditions and the following disclaimer in the
+         documentation and/or other materials provided with the distribution.
+       * Neither the name of the copyright holder nor the names of
+         contributors may be used to endorse or promote products derived from
+         this software without specific prior written permission.
+
+       THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+       IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+       TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+       PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER
+       BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+       CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+       SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+       BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+       WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+       OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+       ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+package jdk.dynalink;
+
+import java.lang.invoke.CallSite;
+import java.lang.invoke.MethodHandle;
+import jdk.dynalink.linker.GuardedInvocation;
+import jdk.dynalink.support.ChainedCallSite;
+import jdk.dynalink.support.SimpleRelinkableCallSite;
+
+/**
+ * Interface for call sites managed by a {@link DynamicLinker}. Users of
+ * Dynalink must use subclasses of {@link CallSite} that also implement this
+ * interface as their call site implementations. There is a readily usable
+ * {@link SimpleRelinkableCallSite} subclass that implements monomorphic inline
+ * caching strategy as well as {@link ChainedCallSite} that implements a
+ * polymorphic inline caching strategy and retains a chain of previously linked
+ * method handles. A relinkable call site will be managed by a
+ * {@link DynamicLinker} object after being associated with it using its
+ * {@link DynamicLinker#link(RelinkableCallSite)} method.
+ */
+public interface RelinkableCallSite {
+    /**
+     * Invoked by dynamic linker to initialize the relinkable call site by
+     * setting a relink-and-invoke method handle. The call site implementation
+     * is supposed to set this method handle as its target using
+     * {@link CallSite#setTarget(MethodHandle)}. Relink-and-invoke is the
+     * initial method handle set by
+     * {@link DynamicLinker#link(RelinkableCallSite)} that will cause the call
+     * site to be relinked to an appropriate target on its first invocation
+     * based on its arguments, and that linked target will then be invoked
+     * (hence the name). This linking protocol effectively delays linking until
+     * the call site is invoked with actual arguments and thus ensures that
+     * linkers can make nuanced linking decisions based on those arguments and
+     * not just on the static method type of the call site.
+     * @param relinkAndInvoke a relink-and-invoke method handle supplied by
+     * Dynalink.
+     */
+    public void initialize(MethodHandle relinkAndInvoke);
+
+    /**
+     * Returns the descriptor for this call site.
+     *
+     * @return the descriptor for this call site.
+     */
+    public CallSiteDescriptor getDescriptor();
+
+    /**
+     * This method will be called by the dynamic linker every time the call site
+     * is relinked (but see
+     * {@link #resetAndRelink(GuardedInvocation, MethodHandle)} for an
+     * exception). It will be passed a {@code GuardedInvocation} that the call
+     * site should incorporate into its target method handle. When this method
+     * is called, the call site is allowed to keep other non-invalidated
+     * invocations around for implementation of polymorphic inline caches and
+     * compose them with this invocation to form its final target.
+     *
+     * @param guardedInvocation the guarded invocation that the call site should
+     * incorporate into its target method handle.
+     * @param relinkAndInvoke a relink-and-invoke method handle. This is a
+     * method handle matching the method type of the call site that is supplied
+     * by the {@link DynamicLinker} as a callback. It should be used by this
+     * call site as the ultimate fallback when it can't invoke its target with
+     * the passed arguments. The fallback method is such that when it's invoked,
+     * it'll try to obtain an adequate target {@link GuardedInvocation} for the
+     * invocation, and subsequently invoke
+     * {@link #relink(GuardedInvocation, MethodHandle)} or
+     * {@link #resetAndRelink(GuardedInvocation, MethodHandle)}, and finally
+     * invoke the target.
+     */
+    public void relink(GuardedInvocation guardedInvocation, MethodHandle relinkAndInvoke);
+
+    /**
+     * This method will be called by the dynamic linker every time the call site
+     * is relinked <b>and</b> the linker wishes the call site to throw away any
+     * prior linkage state (that is how it differs from
+     * {@link #relink(GuardedInvocation, MethodHandle)}). It will be passed a
+     * {@code GuardedInvocation} that the call site should use to build its new
+     * target method handle. When this method is called, the call site is
+     * discouraged from keeping any previous state, and is supposed to only
+     * link the current invocation.
+     *
+     * @param guardedInvocation the guarded invocation that the call site should
+     * use to build its target method handle.
+     * @param relinkAndInvoke a relink-and-invoke method handle. This is a
+     * method handle matching the method type of the call site that is supplied
+     * by the {@link DynamicLinker} as a callback. It should be used by this
+     * call site as the ultimate fallback when it can't invoke its target with
+     * the passed arguments. The fallback method is such that when it's invoked,
+     * it'll try to obtain an adequate target {@link GuardedInvocation} for the
+     * invocation, and subsequently invoke
+     * {@link #relink(GuardedInvocation, MethodHandle)} or
+     * {@link #resetAndRelink(GuardedInvocation, MethodHandle)}, and finally
+     * invoke the target.
+     */
+    public void resetAndRelink(GuardedInvocation guardedInvocation, MethodHandle relinkAndInvoke);
+}