1 /* |
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2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. Oracle designates this |
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8 * particular file as subject to the "Classpath" exception as provided |
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9 * by Oracle in the LICENSE file that accompanied this code. |
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10 * |
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11 * This code is distributed in the hope that it will be useful, but WITHOUT |
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12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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14 * version 2 for more details (a copy is included in the LICENSE file that |
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15 * accompanied this code). |
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16 * |
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17 * You should have received a copy of the GNU General Public License version |
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18 * 2 along with this work; if not, write to the Free Software Foundation, |
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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20 * |
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21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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22 * or visit www.oracle.com if you need additional information or have any |
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23 * questions. |
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24 */ |
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25 |
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26 /* |
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27 * This file is available under and governed by the GNU General Public |
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28 * License version 2 only, as published by the Free Software Foundation. |
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29 * However, the following notice accompanied the original version of this |
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30 * file, and Oracle licenses the original version of this file under the BSD |
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31 * license: |
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32 */ |
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33 /* |
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34 Copyright 2009-2013 Attila Szegedi |
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35 |
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36 Licensed under both the Apache License, Version 2.0 (the "Apache License") |
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37 and the BSD License (the "BSD License"), with licensee being free to |
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38 choose either of the two at their discretion. |
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39 |
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40 You may not use this file except in compliance with either the Apache |
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41 License or the BSD License. |
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42 |
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43 If you choose to use this file in compliance with the Apache License, the |
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44 following notice applies to you: |
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45 |
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46 You may obtain a copy of the Apache License at |
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47 |
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48 http://www.apache.org/licenses/LICENSE-2.0 |
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49 |
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50 Unless required by applicable law or agreed to in writing, software |
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51 distributed under the License is distributed on an "AS IS" BASIS, |
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52 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or |
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53 implied. See the License for the specific language governing |
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54 permissions and limitations under the License. |
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55 |
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56 If you choose to use this file in compliance with the BSD License, the |
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57 following notice applies to you: |
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58 |
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59 Redistribution and use in source and binary forms, with or without |
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60 modification, are permitted provided that the following conditions are |
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61 met: |
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62 * Redistributions of source code must retain the above copyright |
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63 notice, this list of conditions and the following disclaimer. |
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64 * Redistributions in binary form must reproduce the above copyright |
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65 notice, this list of conditions and the following disclaimer in the |
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66 documentation and/or other materials provided with the distribution. |
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67 * Neither the name of the copyright holder nor the names of |
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68 contributors may be used to endorse or promote products derived from |
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69 this software without specific prior written permission. |
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70 |
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71 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS |
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72 IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
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73 TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A |
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74 PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER |
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75 BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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76 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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77 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR |
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78 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
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79 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR |
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80 OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
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81 ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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82 */ |
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83 |
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84 package jdk.internal.dynalink; |
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85 |
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86 import java.lang.invoke.CallSite; |
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87 import java.lang.invoke.MethodHandle; |
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88 import jdk.internal.dynalink.linker.GuardedInvocation; |
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89 import jdk.internal.dynalink.support.ChainedCallSite; |
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90 import jdk.internal.dynalink.support.SimpleRelinkableCallSite; |
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91 |
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92 /** |
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93 * Interface for call sites managed by a {@link DynamicLinker}. Users of |
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94 * Dynalink must use subclasses of {@link CallSite} that also implement this |
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95 * interface as their call site implementations. There is a readily usable |
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96 * {@link SimpleRelinkableCallSite} subclass that implements monomorphic inline |
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97 * caching strategy as well as {@link ChainedCallSite} that implements a |
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98 * polymorphic inline caching strategy and retains a chain of previously linked |
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99 * method handles. A relinkable call site will be managed by a |
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100 * {@link DynamicLinker} object after being associated with it using its |
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101 * {@link DynamicLinker#link(RelinkableCallSite)} method. |
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102 */ |
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103 public interface RelinkableCallSite { |
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104 /** |
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105 * Invoked by dynamic linker to initialize the relinkable call site by |
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106 * setting a relink-and-invoke method handle. The call site implementation |
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107 * is supposed to set this method handle as its target using |
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108 * {@link CallSite#setTarget(MethodHandle)}. Relink-and-invoke is the |
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109 * initial method handle set by |
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110 * {@link DynamicLinker#link(RelinkableCallSite)} that will cause the call |
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111 * site to be relinked to an appropriate target on its first invocation |
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112 * based on its arguments, and that linked target will then be invoked |
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113 * (hence the name). This linking protocol effectively delays linking until |
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114 * the call site is invoked with actual arguments and thus ensures that |
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115 * linkers can make nuanced linking decisions based on those arguments and |
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116 * not just on the static method type of the call site. |
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117 * @param relinkAndInvoke a relink-and-invoke method handle supplied by |
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118 * Dynalink. |
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119 */ |
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120 public void initialize(MethodHandle relinkAndInvoke); |
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121 |
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122 /** |
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123 * Returns the descriptor for this call site. |
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124 * |
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125 * @return the descriptor for this call site. |
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126 */ |
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127 public CallSiteDescriptor getDescriptor(); |
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128 |
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129 /** |
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130 * This method will be called by the dynamic linker every time the call site |
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131 * is relinked (but see |
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132 * {@link #resetAndRelink(GuardedInvocation, MethodHandle)} for an |
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133 * exception). It will be passed a {@code GuardedInvocation} that the call |
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134 * site should incorporate into its target method handle. When this method |
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135 * is called, the call site is allowed to keep other non-invalidated |
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136 * invocations around for implementation of polymorphic inline caches and |
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137 * compose them with this invocation to form its final target. |
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138 * |
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139 * @param guardedInvocation the guarded invocation that the call site should |
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140 * incorporate into its target method handle. |
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141 * @param relinkAndInvoke a relink-and-invoke method handle. This is a |
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142 * method handle matching the method type of the call site that is supplied |
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143 * by the {@link DynamicLinker} as a callback. It should be used by this |
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144 * call site as the ultimate fallback when it can't invoke its target with |
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145 * the passed arguments. The fallback method is such that when it's invoked, |
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146 * it'll try to obtain an adequate target {@link GuardedInvocation} for the |
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147 * invocation, and subsequently invoke |
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148 * {@link #relink(GuardedInvocation, MethodHandle)} or |
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149 * {@link #resetAndRelink(GuardedInvocation, MethodHandle)}, and finally |
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150 * invoke the target. |
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151 */ |
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152 public void relink(GuardedInvocation guardedInvocation, MethodHandle relinkAndInvoke); |
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153 |
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154 /** |
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155 * This method will be called by the dynamic linker every time the call site |
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156 * is relinked <b>and</b> the linker wishes the call site to throw away any |
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157 * prior linkage state (that is how it differs from |
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158 * {@link #relink(GuardedInvocation, MethodHandle)}). It will be passed a |
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159 * {@code GuardedInvocation} that the call site should use to build its new |
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160 * target method handle. When this method is called, the call site is |
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161 * discouraged from keeping any previous state, and is supposed to only |
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162 * link the current invocation. |
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163 * |
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164 * @param guardedInvocation the guarded invocation that the call site should |
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165 * use to build its target method handle. |
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166 * @param relinkAndInvoke a relink-and-invoke method handle. This is a |
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167 * method handle matching the method type of the call site that is supplied |
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168 * by the {@link DynamicLinker} as a callback. It should be used by this |
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169 * call site as the ultimate fallback when it can't invoke its target with |
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170 * the passed arguments. The fallback method is such that when it's invoked, |
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171 * it'll try to obtain an adequate target {@link GuardedInvocation} for the |
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172 * invocation, and subsequently invoke |
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173 * {@link #relink(GuardedInvocation, MethodHandle)} or |
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174 * {@link #resetAndRelink(GuardedInvocation, MethodHandle)}, and finally |
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175 * invoke the target. |
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176 */ |
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177 public void resetAndRelink(GuardedInvocation guardedInvocation, MethodHandle relinkAndInvoke); |
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178 } |
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