1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation. Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 */
24
25 package jdk.nashorn.internal.runtime.arrays;
26
27 import static jdk.nashorn.internal.codegen.CompilerConstants.staticCall;
28 import static jdk.nashorn.internal.lookup.Lookup.MH;
29 import static jdk.nashorn.internal.runtime.JSType.getAccessorTypeIndex;
30 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.INVALID_PROGRAM_POINT;
31 import static jdk.nashorn.internal.runtime.UnwarrantedOptimismException.isValid;
32 import java.lang.invoke.MethodHandle;
33 import java.lang.invoke.MethodHandles;
34 import java.lang.invoke.MethodType;
35 import java.lang.invoke.SwitchPoint;
36 import jdk.dynalink.CallSiteDescriptor;
37 import jdk.dynalink.linker.GuardedInvocation;
38 import jdk.dynalink.linker.LinkRequest;
39 import jdk.nashorn.internal.codegen.types.Type;
40 import jdk.nashorn.internal.lookup.Lookup;
41 import jdk.nashorn.internal.runtime.ScriptObject;
42 import jdk.nashorn.internal.runtime.linker.NashornCallSiteDescriptor;
43 import jdk.nashorn.internal.runtime.logging.Logger;
44
45 /**
46 * Interface implemented by all arrays that are directly accessible as underlying
47 * native arrays
48 */
49 @Logger(name="arrays")
50 public abstract class ContinuousArrayData extends ArrayData {
51 /**
52 * Constructor
53 * @param length length (elementLength)
54 */
55 protected ContinuousArrayData(final long length) {
56 super(length);
57 }
58
59 /**
60 * Check if we can put one more element at the end of this continuous
61 * array without reallocating, or if we are overwriting an already
62 * allocated element
63 *
64 * @param index index to check
65 * @return true if we don't need to do any array reallocation to fit an element at index
66 */
67 public final boolean hasRoomFor(final int index) {
68 return has(index) || (index == length() && ensure(index) == this);
69 }
70
71 /**
72 * Check if an arraydata is empty
73 * @return true if empty
74 */
75 public boolean isEmpty() {
76 return length() == 0L;
77 }
78
79 /**
80 * Return element getter for a certain type at a certain program point
81 * @param returnType return type
82 * @param programPoint program point
83 * @return element getter or null if not supported (used to implement slow linkage instead
84 * as fast isn't possible)
85 */
86 public abstract MethodHandle getElementGetter(final Class<?> returnType, final int programPoint);
87
88 /**
89 * Return element getter for a certain type at a certain program point
90 * @param elementType element type
91 * @return element setter or null if not supported (used to implement slow linkage instead
92 * as fast isn't possible)
93 */
94 public abstract MethodHandle getElementSetter(final Class<?> elementType);
95
96 /**
97 * Version of has that throws a class cast exception if element does not exist
98 * used for relinking
99 *
100 * @param index index to check - currently only int indexes
101 * @return index
102 */
103 protected final int throwHas(final int index) {
104 if (!has(index)) {
105 throw new ClassCastException();
106 }
107 return index;
108 }
109
110 @Override
111 public abstract ContinuousArrayData copy();
112
113 /**
114 * Returns the type used to store an element in this array
115 * @return element type
116 */
117 public abstract Class<?> getElementType();
118
119 @Override
120 public Type getOptimisticType() {
121 return Type.typeFor(getElementType());
122 }
123
124 /**
125 * Returns the boxed type of the type used to store an element in this array
126 * @return element type
127 */
128 public abstract Class<?> getBoxedElementType();
129
130 /**
131 * Get the widest element type of two arrays. This can be done faster in subclasses, but
132 * this works for all ContinuousArrayDatas and for where more optimal checks haven't been
133 * implemented.
134 *
135 * @param otherData another ContinuousArrayData
136 * @return the widest boxed element type
137 */
138 public ContinuousArrayData widest(final ContinuousArrayData otherData) {
139 final Class<?> elementType = getElementType();
140 return Type.widest(elementType, otherData.getElementType()) == elementType ? this : otherData;
141 }
142
143 /**
144 * Look up a continuous array element getter
145 * @param get getter, sometimes combined with a has check that throws CCE on failure for relink
146 * @param returnType return type
147 * @param programPoint program point
148 * @return array getter
149 */
150 protected final MethodHandle getContinuousElementGetter(final MethodHandle get, final Class<?> returnType, final int programPoint) {
151 return getContinuousElementGetter(getClass(), get, returnType, programPoint);
152 }
153
154 /**
155 * Look up a continuous array element setter
156 * @param set setter, sometimes combined with a has check that throws CCE on failure for relink
157 * @param returnType return type
158 * @return array setter
159 */
160 protected final MethodHandle getContinuousElementSetter(final MethodHandle set, final Class<?> returnType) {
161 return getContinuousElementSetter(getClass(), set, returnType);
162 }
163
164 /**
165 * Return element getter for a {@link ContinuousArrayData}
166 * @param clazz clazz for exact type guard
167 * @param getHas has getter
168 * @param returnType return type
169 * @param programPoint program point
170 * @return method handle for element setter
171 */
172 protected MethodHandle getContinuousElementGetter(final Class<? extends ContinuousArrayData> clazz, final MethodHandle getHas, final Class<?> returnType, final int programPoint) {
173 final boolean isOptimistic = isValid(programPoint);
174 final int fti = getAccessorTypeIndex(getHas.type().returnType());
175 final int ti = getAccessorTypeIndex(returnType);
176 MethodHandle mh = getHas;
177
178 if (isOptimistic) {
179 if (ti < fti) {
180 mh = MH.insertArguments(ArrayData.THROW_UNWARRANTED.methodHandle(), 1, programPoint);
181 }
182 }
183 mh = MH.asType(mh, mh.type().changeReturnType(returnType).changeParameterType(0, clazz));
184
185 if (!isOptimistic) {
186 //for example a & array[17];
187 return Lookup.filterReturnType(mh, returnType);
188 }
189 return mh;
190 }
191
192 /**
193 * Return element setter for a {@link ContinuousArrayData}
194 * @param clazz class for exact type guard
195 * @param setHas set has guard
196 * @param elementType element type
197 * @return method handle for element setter
198 */
199 protected MethodHandle getContinuousElementSetter(final Class<? extends ContinuousArrayData> clazz, final MethodHandle setHas, final Class<?> elementType) {
200 return MH.asType(setHas, setHas.type().changeParameterType(2, elementType).changeParameterType(0, clazz));
201 }
202
203 /** Fast access guard - it is impractical for JIT performance reasons to use only CCE asType as guard :-(, also we need
204 the null case explicitly, which is the one that CCE doesn't handle */
205 protected static final MethodHandle FAST_ACCESS_GUARD =
206 MH.dropArguments(
207 staticCall(
208 MethodHandles.lookup(),
209 ContinuousArrayData.class,
210 "guard",
211 boolean.class,
212 Class.class,
213 ScriptObject.class).methodHandle(),
214 2,
215 int.class);
216
217 @SuppressWarnings("unused")
218 private static boolean guard(final Class<? extends ContinuousArrayData> clazz, final ScriptObject sobj) {
219 return sobj != null && sobj.getArray().getClass() == clazz;
220 }
221
222 /**
223 * Return a fast linked array getter, or null if we have to dispatch to super class
224 * @param desc descriptor
225 * @param request link request
226 * @return invocation or null if needs to be sent to slow relink
227 */
228 @Override
229 public GuardedInvocation findFastGetIndexMethod(final Class<? extends ArrayData> clazz, final CallSiteDescriptor desc, final LinkRequest request) {
230 final MethodType callType = desc.getMethodType();
231 final Class<?> indexType = callType.parameterType(1);
232 final Class<?> returnType = callType.returnType();
233
234 if (ContinuousArrayData.class.isAssignableFrom(clazz) && indexType == int.class) {
235 final Object[] args = request.getArguments();
236 final int index = (int)args[args.length - 1];
237
238 if (has(index)) {
239 final MethodHandle getArray = ScriptObject.GET_ARRAY.methodHandle();
240 final int programPoint = NashornCallSiteDescriptor.isOptimistic(desc) ? NashornCallSiteDescriptor.getProgramPoint(desc) : INVALID_PROGRAM_POINT;
241 MethodHandle getElement = getElementGetter(returnType, programPoint);
242 if (getElement != null) {
243 getElement = MH.filterArguments(getElement, 0, MH.asType(getArray, getArray.type().changeReturnType(clazz)));
244 final MethodHandle guard = MH.insertArguments(FAST_ACCESS_GUARD, 0, clazz);
245 return new GuardedInvocation(getElement, guard, (SwitchPoint)null, ClassCastException.class);
246 }
247 }
248 }
249
250 return null;
251 }
252
253 /**
254 * Return a fast linked array setter, or null if we have to dispatch to super class
255 * @param desc descriptor
256 * @param request link request
257 * @return invocation or null if needs to be sent to slow relink
258 */
259 @Override
260 public GuardedInvocation findFastSetIndexMethod(final Class<? extends ArrayData> clazz, final CallSiteDescriptor desc, final LinkRequest request) { // array, index, value
261 final MethodType callType = desc.getMethodType();
262 final Class<?> indexType = callType.parameterType(1);
263 final Class<?> elementType = callType.parameterType(2);
264
265 if (ContinuousArrayData.class.isAssignableFrom(clazz) && indexType == int.class) {
266 final Object[] args = request.getArguments();
267 final int index = (int)args[args.length - 2];
268
269 if (hasRoomFor(index)) {
270 MethodHandle setElement = getElementSetter(elementType); //Z(continuousarraydata, int, int), return true if successful
271 if (setElement != null) {
272 //else we are dealing with a wider type than supported by this callsite
273 MethodHandle getArray = ScriptObject.GET_ARRAY.methodHandle();
274 getArray = MH.asType(getArray, getArray.type().changeReturnType(getClass()));
275 setElement = MH.filterArguments(setElement, 0, getArray);
276 final MethodHandle guard = MH.insertArguments(FAST_ACCESS_GUARD, 0, clazz);
277 return new GuardedInvocation(setElement, guard, (SwitchPoint)null, ClassCastException.class); //CCE if not a scriptObject anymore
278 }
279 }
280 }
281
282 return null;
283 }
284
285 /**
286 * Specialization - fast push implementation
287 * @param arg argument
288 * @return new array length
289 */
290 public double fastPush(final int arg) {
291 throw new ClassCastException(String.valueOf(getClass())); //type is wrong, relink
292 }
293
294 /**
295 * Specialization - fast push implementation
296 * @param arg argument
297 * @return new array length
298 */
299 public double fastPush(final long arg) {
300 throw new ClassCastException(String.valueOf(getClass())); //type is wrong, relink
301 }
302
303 /**
304 * Specialization - fast push implementation
305 * @param arg argument
306 * @return new array length
307 */
308 public double fastPush(final double arg) {
309 throw new ClassCastException(String.valueOf(getClass())); //type is wrong, relink
310 }
311
312 /**
313 * Specialization - fast push implementation
314 * @param arg argument
315 * @return new array length
316 */
317 public double fastPush(final Object arg) {
318 throw new ClassCastException(String.valueOf(getClass())); //type is wrong, relink
319 }
320
321 /**
322 * Specialization - fast pop implementation
323 * @return element value
324 */
325 public int fastPopInt() {
326 throw new ClassCastException(String.valueOf(getClass())); //type is wrong, relink
327 }
328
329 /**
330 * Specialization - fast pop implementation
331 * @return element value
332 */
333 public double fastPopDouble() {
334 throw new ClassCastException(String.valueOf(getClass())); //type is wrong, relink
335 }
336
337 /**
338 * Specialization - fast pop implementation
339 * @return element value
340 */
341 public Object fastPopObject() {
342 throw new ClassCastException(String.valueOf(getClass())); //type is wrong, relink
343 }
344
345 /**
346 * Specialization - fast concat implementation
347 * @param otherData data to concat
348 * @return new arraydata
349 */
350 public ContinuousArrayData fastConcat(final ContinuousArrayData otherData) {
351 throw new ClassCastException(String.valueOf(getClass()) + " != " + String.valueOf(otherData.getClass()));
352 }
353 }