RicochetTest.java revision 4183:4732a76af216
1/*
2 * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26/* @test
27 * @summary unit tests for recursive method handles
28 * @run junit/othervm -DRicochetTest.MAX_ARITY=255 test.java.lang.invoke.RicochetTest
29 */
30
31package test.java.lang.invoke;
32
33import java.lang.invoke.*;
34import java.util.*;
35import org.junit.*;
36import static java.lang.invoke.MethodType.*;
37import static java.lang.invoke.MethodHandles.*;
38import static org.junit.Assert.*;
39import static org.junit.Assume.*;
40
41
42/**
43 *
44 * @author jrose
45 */
46public class RicochetTest {
47    private static final Class CLASS = RicochetTest.class;
48    private static final int MAX_ARITY = Integer.getInteger(CLASS.getSimpleName()+".MAX_ARITY", 40);
49
50    public static void main(String... av) throws Throwable {
51        RicochetTest test = new RicochetTest();
52        if (av.length > 0)  test.testOnly = Arrays.asList(av).toString();
53        if (REPEAT == 1 || test.testOnly != null) {
54            test.testAll();
55            if (test.testOnlyTests == null)  throw new RuntimeException("no matching test: "+test.testOnly);
56        } else if (REPEAT == 0) {
57            org.junit.runner.JUnitCore.runClasses(RicochetTest.class);
58        } else {
59            verbose(1, "REPEAT="+REPEAT);
60            for (int i = 0; i < REPEAT; i++) {
61                test.testRepetition = (i+1);
62                verbose(0, "[#"+test.testRepetition+"]");
63                test.testAll();
64            }
65        }
66    }
67    int testRepetition;
68
69    public void testAll() throws Throwable {
70        testNull();
71        testBoxInteger();
72        testFilterReturnValue();
73        testFilterObject();
74        testBoxLong();
75        testFilterInteger();
76        testIntSpreads();
77        testByteSpreads();
78        testLongSpreads();
79        testIntCollects();
80        testReturns();
81    }
82
83    @Test
84    public void testNull() throws Throwable {
85        if (testRepetition > (1+REPEAT/100))  return;  // trivial test
86        if (!startTest("testNull"))  return;
87        assertEquals(opI(37), opI.invokeWithArguments(37));
88        assertEqualFunction(opI, opI);
89    }
90
91    @Test
92    public void testBoxInteger() throws Throwable {
93        if (!startTest("testBoxInteger"))  return;
94        assertEqualFunction(opI, opI.asType(opL_I.type()).asType(opI.type()));
95    }
96
97    @Test
98    public void testFilterReturnValue() throws Throwable {
99        if (!startTest("testFilterReturnValue"))  return;
100        int[] ints = { 12, 23, 34, 45, 56, 67, 78, 89 };
101        Object res = list8ints.invokeExact(ints[0], ints[1], ints[2], ints[3], ints[4], ints[5], ints[6], ints[7]);
102        assertEquals(Arrays.toString(ints), res.toString());
103        MethodHandle idreturn = filterReturnValue(list8ints, identity(Object.class));
104        res = idreturn.invokeExact(ints[0], ints[1], ints[2], ints[3], ints[4], ints[5], ints[6], ints[7]);
105        assertEquals(Arrays.toString(ints), res.toString());
106        MethodHandle add0 = addL.bindTo(0);
107        assertEqualFunction(filterReturnValue(opL2, add0), opL2);
108    }
109
110    @Test
111    public void testFilterObject() throws Throwable {
112        if (!startTest("testFilterObject"))  return;
113        MethodHandle add0 = addL.bindTo(0);
114        assertEqualFunction(sequence(opL2, add0), opL2);
115        int bump13 = -13;  // value near 20 works as long as test values are near [-80..80]
116        MethodHandle add13   = addL.bindTo(bump13);
117        MethodHandle add13_0 = addL.bindTo(opI2(bump13, 0));
118        MethodHandle add13_1 = addL.bindTo(opI2(0, bump13));
119        assertEqualFunction(sequence(opL2, add13_0),
120                            filterArguments(opL2, 0, add13));
121        assertEqualFunction(sequence(opL2, add13_1),
122                            filterArguments(opL2, 1, add13));
123        System.out.println("[testFilterObject done]");
124    }
125
126    @Test
127    public void testBoxLong() throws Throwable {
128        if (!startTest("testBoxLong"))  return;
129        assertEqualFunction(opJ, opJ.asType(opL_J.type()).asType(opJ.type()));
130    }
131
132    @Test
133    public void testFilterInteger() throws Throwable {
134        if (!startTest("testFilterInteger"))  return;
135        assertEqualFunction(opI, sequence(convI_L, opL_I));
136    }
137
138    @Test
139    public void testIntSpreads() throws Throwable {
140        if (!startTest("testIntSpreads"))  return;
141        MethodHandle id = identity(int[].class);
142        final int MAX = MAX_ARITY-2;  // 253+1 would cause parameter overflow with 'this' added
143        for (int nargs = 0; nargs <= MAX; nargs++) {
144            if (nargs > 30 && nargs < MAX-20)  nargs += 10;
145            int[] args = new int[nargs];
146            for (int j = 0; j < args.length; j++)  args[j] = (int)(j + 11);
147            //System.out.println("testIntSpreads "+Arrays.toString(args));
148            int[] args1 = (int[]) id.invokeExact(args);
149            assertArrayEquals(args, args1);
150            MethodHandle coll = id.asCollector(int[].class, nargs);
151            int[] args2 = args;
152            switch (nargs) {
153                case 0:  args2 = (int[]) coll.invokeExact(); break;
154                case 1:  args2 = (int[]) coll.invokeExact(args[0]); break;
155                case 2:  args2 = (int[]) coll.invokeExact(args[0], args[1]); break;
156                case 3:  args2 = (int[]) coll.invokeExact(args[0], args[1], args[2]); break;
157                case 4:  args2 = (int[]) coll.invokeExact(args[0], args[1], args[2], args[3]); break;
158                case 5:  args2 = (int[]) coll.invokeExact(args[0], args[1], args[2], args[3], args[4]); break;
159            }
160            assertArrayEquals(args, args2);
161            MethodHandle mh = coll.asSpreader(int[].class, nargs);
162            int[] args3 = (int[]) mh.invokeExact(args);
163            assertArrayEquals(args, args3);
164        }
165    }
166
167    @Test
168    public void testByteSpreads() throws Throwable {
169        if (!startTest("testByteSpreads"))  return;
170        MethodHandle id = identity(byte[].class);
171        final int MAX = MAX_ARITY-2;  // 253+1 would cause parameter overflow with 'this' added
172        for (int nargs = 0; nargs <= MAX; nargs++) {
173            if (nargs > 30 && nargs < MAX-20)  nargs += 10;
174            byte[] args = new byte[nargs];
175            for (int j = 0; j < args.length; j++)  args[j] = (byte)(j + 11);
176            //System.out.println("testByteSpreads "+Arrays.toString(args));
177            byte[] args1 = (byte[]) id.invokeExact(args);
178            assertArrayEquals(args, args1);
179            MethodHandle coll = id.asCollector(byte[].class, nargs);
180            byte[] args2 = args;
181            switch (nargs) {
182                case 0:  args2 = (byte[]) coll.invokeExact(); break;
183                case 1:  args2 = (byte[]) coll.invokeExact(args[0]); break;
184                case 2:  args2 = (byte[]) coll.invokeExact(args[0], args[1]); break;
185                case 3:  args2 = (byte[]) coll.invokeExact(args[0], args[1], args[2]); break;
186                case 4:  args2 = (byte[]) coll.invokeExact(args[0], args[1], args[2], args[3]); break;
187                case 5:  args2 = (byte[]) coll.invokeExact(args[0], args[1], args[2], args[3], args[4]); break;
188            }
189            assertArrayEquals(args, args2);
190            MethodHandle mh = coll.asSpreader(byte[].class, nargs);
191            byte[] args3 = (byte[]) mh.invokeExact(args);
192            assertArrayEquals(args, args3);
193        }
194    }
195
196    @Test
197    public void testLongSpreads() throws Throwable {
198        if (!startTest("testLongSpreads"))  return;
199        MethodHandle id = identity(long[].class);
200        final int MAX = (MAX_ARITY - 2) / 2;  // 253/2+1 would cause parameter overflow with 'this' added
201        for (int nargs = 0; nargs <= MAX; nargs++) {
202            if (nargs > 30 && nargs < MAX-20)  nargs += 10;
203            long[] args = new long[nargs];
204            for (int j = 0; j < args.length; j++)  args[j] = (long)(j + 11);
205            //System.out.println("testLongSpreads "+Arrays.toString(args));
206            long[] args1 = (long[]) id.invokeExact(args);
207            assertArrayEquals(args, args1);
208            MethodHandle coll = id.asCollector(long[].class, nargs);
209            long[] args2 = args;
210            switch (nargs) {
211                case 0:  args2 = (long[]) coll.invokeExact(); break;
212                case 1:  args2 = (long[]) coll.invokeExact(args[0]); break;
213                case 2:  args2 = (long[]) coll.invokeExact(args[0], args[1]); break;
214                case 3:  args2 = (long[]) coll.invokeExact(args[0], args[1], args[2]); break;
215                case 4:  args2 = (long[]) coll.invokeExact(args[0], args[1], args[2], args[3]); break;
216                case 5:  args2 = (long[]) coll.invokeExact(args[0], args[1], args[2], args[3], args[4]); break;
217            }
218            assertArrayEquals(args, args2);
219            MethodHandle mh = coll.asSpreader(long[].class, nargs);
220            long[] args3 = (long[]) mh.invokeExact(args);
221            assertArrayEquals(args, args3);
222        }
223    }
224
225    @Test
226    public void testIntCollects() throws Throwable {
227        if (!startTest("testIntCollects"))  return;
228        for (MethodHandle lister : INT_LISTERS) {
229            int outputs = lister.type().parameterCount();
230            for (int collects = 0; collects <= Math.min(outputs, INT_COLLECTORS.length-1); collects++) {
231                int inputs = outputs - 1 + collects;
232                if (inputs < 0)  continue;
233                for (int pos = 0; pos + collects <= inputs; pos++) {
234                    MethodHandle collector = INT_COLLECTORS[collects];
235                    int[] args = new int[inputs];
236                    int ap = 0, arg = 31;
237                    for (int i = 0; i < pos; i++)
238                        args[ap++] = arg++ + 0;
239                    for (int i = 0; i < collects; i++)
240                        args[ap++] = arg++ + 10;
241                    while (ap < args.length)
242                        args[ap++] = arg++ + 20;
243                    // calculate piecemeal:
244                    //System.out.println("testIntCollects "+Arrays.asList(lister, pos, collector)+" on "+Arrays.toString(args));
245                    int[] collargs = Arrays.copyOfRange(args, pos, pos+collects);
246                    int coll = (int) collector.asSpreader(int[].class, collargs.length).invokeExact(collargs);
247                    int[] listargs = Arrays.copyOfRange(args, 0, outputs);
248                    System.arraycopy(args, pos+collects, listargs, pos+1, outputs - (pos+1));
249                    listargs[pos] = coll;
250                    //System.out.println("  coll="+coll+" listargs="+Arrays.toString(listargs));
251                    Object expect = lister.asSpreader(int[].class, listargs.length).invokeExact(listargs);
252                    //System.out.println("  expect="+expect);
253
254                    // now use the combined MH, and test the output:
255                    MethodHandle mh = collectArguments(lister, pos, INT_COLLECTORS[collects]);
256                    if (mh == null)  continue;  // no infix collection, yet
257                    assert(mh.type().parameterCount() == inputs);
258                    Object observe = mh.asSpreader(int[].class, args.length).invokeExact(args);
259                    assertEquals(expect, observe);
260                }
261            }
262        }
263    }
264
265    private static MethodHandle collectArguments(MethodHandle lister, int pos, MethodHandle collector) {
266        int collects = collector.type().parameterCount();
267        int outputs = lister.type().parameterCount();
268        if (pos == outputs - 1)
269            return MethodHandles.filterArguments(lister, pos,
270                        collector.asSpreader(int[].class, collects))
271                            .asCollector(int[].class, collects);
272        //return MethodHandles.collectArguments(lister, pos, collector); //no such animal
273        return null;
274    }
275
276    private static final Class<?>[] RETURN_TYPES = {
277        Object.class, String.class, Integer.class,
278        int.class, long.class,
279        boolean.class, byte.class, char.class, short.class,
280        float.class, double.class,
281        void.class,
282    };
283
284    @Test
285    public void testReturns() throws Throwable {
286        if (!startTest("testReturns"))  return;
287        // fault injection:
288        int faultCount = 0;  // total of 1296 tests
289        faultCount = Integer.getInteger("testReturns.faultCount", 0);
290        for (Class<?> ret : RETURN_TYPES) {
291            // make a complicated identity function and pass something through it
292            System.out.println(ret.getSimpleName());
293            Class<?> vret = (ret == void.class) ? Void.class : ret;
294            MethodHandle id = // (vret)->ret
295                identity(vret).asType(methodType(ret, vret));
296            final int LENGTH = 4;
297            int[] index = {0};
298            Object vals = java.lang.reflect.Array.newInstance(vret, LENGTH);
299            MethodHandle indexGetter =  //()->int
300                insertArguments(arrayElementGetter(index.getClass()), 0, index, 0);
301            MethodHandle valSelector =  // (int)->vret
302                arrayElementGetter(vals.getClass()).bindTo(vals);
303            MethodHandle valGetter =  // ()->vret
304                foldArguments(valSelector, indexGetter);
305            if (ret != void.class) {
306                for (int i = 0; i < LENGTH; i++) {
307                    Object val = (i + 50);
308                    if (ret == boolean.class)  val = (i % 3 == 0);
309                    if (ret == String.class)   val = "#"+i;
310                    if (ret == char.class)     val = (char)('a'+i);
311                    if (ret == byte.class)     val = (byte)~i;
312                    if (ret == short.class)    val = (short)(1<<i);
313                    java.lang.reflect.Array.set(vals, i, val);
314                }
315            }
316            for (int i = 0; i < LENGTH; i++) {
317                Object val = java.lang.reflect.Array.get(vals, i);
318                System.out.println(i+" => "+val);
319                index[0] = i;
320                if (--faultCount == 0)  index[0] ^= 1;
321                Object x = valGetter.invokeWithArguments();
322                assertEquals(val, x);
323                // make a return-filter call:  x = id(valGetter())
324                if (--faultCount == 0)  index[0] ^= 1;
325                x = filterReturnValue(valGetter, id).invokeWithArguments();
326                assertEquals(val, x);
327                // make a filter call:  x = id(*,valGetter(),*)
328                for (int len = 1; len <= 4; len++) {
329                    for (int pos = 0; pos < len; pos++) {
330                        MethodHandle proj = id;  // lambda(..., vret x,...){x}
331                        for (int j = 0; j < len; j++) {
332                            if (j == pos)  continue;
333                            proj = dropArguments(proj, j, Object.class);
334                        }
335                        assert(proj.type().parameterCount() == len);
336                        // proj: (Object*, pos: vret, Object*)->ret
337                        assertEquals(vret, proj.type().parameterType(pos));
338                        MethodHandle vgFilter = dropArguments(valGetter, 0, Object.class);
339                        if (--faultCount == 0)  index[0] ^= 1;
340                        x = filterArguments(proj, pos, vgFilter).invokeWithArguments(new Object[len]);
341                        assertEquals(val, x);
342                    }
343                }
344                // make a fold call:
345                for (int len = 0; len <= 4; len++) {
346                    for (int fold = 0; fold <= len; fold++) {
347                        MethodHandle proj = id;  // lambda(ret x, ...){x}
348                        if (ret == void.class)  proj = constant(Object.class, null);
349                        int arg0 = (ret == void.class ? 0 : 1);
350                        for (int j = 0; j < len; j++) {
351                            proj = dropArguments(proj, arg0, Object.class);
352                        }
353                        assert(proj.type().parameterCount() == arg0 + len);
354                        // proj: (Object*, pos: vret, Object*)->ret
355                        if (arg0 != 0)  assertEquals(vret, proj.type().parameterType(0));
356                        MethodHandle vgFilter = valGetter.asType(methodType(ret));
357                        for (int j = 0; j < fold; j++) {
358                            vgFilter = dropArguments(vgFilter, j, Object.class);
359                        }
360                        x = foldArguments(proj, vgFilter).invokeWithArguments(new Object[len]);
361                        if (--faultCount == 0)  index[0] ^= 1;
362                        assertEquals(val, x);
363                    }
364                }
365            }
366        }
367        //System.out.println("faultCount="+faultCount);
368    }
369
370    private static MethodHandle sequence(MethodHandle mh1, MethodHandle... mhs) {
371        MethodHandle res = mh1;
372        for (MethodHandle mh2 : mhs)
373            res = filterReturnValue(res, mh2);
374        return res;
375    }
376    private static void assertEqualFunction(MethodHandle x, MethodHandle y) throws Throwable {
377        assertEquals(x.type(), y.type()); //??
378        MethodType t = x.type();
379        if (t.parameterCount() == 0) {
380            assertEqualFunctionAt(null, x, y);
381            return;
382        }
383        Class<?> ptype = t.parameterType(0);
384        if (ptype == long.class || ptype == Long.class) {
385            for (long i = -10; i <= 10; i++) {
386                assertEqualFunctionAt(i, x, y);
387            }
388        } else {
389            for (int i = -10; i <= 10; i++) {
390                assertEqualFunctionAt(i, x, y);
391            }
392        }
393    }
394    private static void assertEqualFunctionAt(Object v, MethodHandle x, MethodHandle y) throws Throwable {
395        Object[] args = new Object[x.type().parameterCount()];
396        Arrays.fill(args, v);
397        Object xval = invokeWithCatch(x, args);
398        Object yval = invokeWithCatch(y, args);
399        String msg = "ok";
400        if (!Objects.equals(xval, yval)) {
401            msg = ("applying "+x+" & "+y+" to "+v);
402        }
403        assertEquals(msg, xval, yval);
404    }
405    private static Object invokeWithCatch(MethodHandle mh, Object... args) throws Throwable {
406        try {
407            return mh.invokeWithArguments(args);
408        } catch (Throwable ex) {
409            System.out.println("threw: "+mh+Arrays.asList(args));
410            ex.printStackTrace();
411            return ex;
412        }
413    }
414
415    private static final Lookup LOOKUP = lookup();
416    private static MethodHandle findStatic(String name,
417                                           Class<?> rtype,
418                                           Class<?>... ptypes) {
419        try {
420            return LOOKUP.findStatic(LOOKUP.lookupClass(), name, methodType(rtype, ptypes));
421        } catch (ReflectiveOperationException ex) {
422            throw new RuntimeException(ex);
423        }
424    }
425    private static MethodHandle findStatic(String name,
426                                           Class<?> rtype,
427                                           List<?> ptypes) {
428        return findStatic(name, rtype, ptypes.toArray(new Class<?>[ptypes.size()]));
429    }
430    static int getProperty(String name, int dflt) {
431        String qual = LOOKUP.lookupClass().getName();
432        String prop = System.getProperty(qual+"."+name);
433        if (prop == null)  prop = System.getProperty(name);
434        if (prop == null)  return dflt;
435        return Integer.parseInt(prop);
436    }
437
438    private static int opI(int... xs) {
439        stress();
440        int base = 100;
441        int z = 0;
442        for (int x : xs) {
443            z = (z * base) + (x % base);
444        }
445        verbose("opI", xs.length, xs, z);
446        return z;
447    }
448    private static int opI2(int x, int y) { return opI(x, y); }  // x*100 + y%100
449    private static int opI3(int x, int y, int z) { return opI(x, y, z); }
450    private static int opI4(int w, int x, int y, int z) { return opI(w, x, y, z); }
451    private static int opI(int x) { return opI2(x, 37); }
452    private static Object opI_L(int x) { return (Object) opI(x); }
453    private static long opJ3(long x, long y, long z) { return (long) opI3((int)x, (int)y, (int)z); }
454    private static long opJ2(long x, long y) { return (long) opI2((int)x, (int)y); }
455    private static long opJ(long x) { return (long) opI((int)x); }
456    private static Object opL2(Object x, Object y) { return (Object) opI2((int)x, (int)y); }
457    private static Object opL(Object x) { return (Object) opI((int)x); }
458    private static int opL2_I(Object x, Object y) { return (int) opI2((int)x, (int)y); }
459    private static int opL_I(Object x) { return (int) opI((int)x); }
460    private static long opL_J(Object x) { return (long) opI((int)x); }
461    private static final MethodHandle opI, opI2, opI3, opI4, opI_L, opJ, opJ2, opJ3, opL2, opL, opL2_I, opL_I, opL_J;
462    static {
463        opI4 = findStatic("opI4", int.class, int.class, int.class, int.class, int.class);
464        opI3 = findStatic("opI3", int.class, int.class, int.class, int.class);
465        opI2 = findStatic("opI2", int.class, int.class, int.class);
466        opI = findStatic("opI", int.class, int.class);
467        opI_L = findStatic("opI_L", Object.class, int.class);
468        opJ = findStatic("opJ", long.class, long.class);
469        opJ2 = findStatic("opJ2", long.class, long.class, long.class);
470        opJ3 = findStatic("opJ3", long.class, long.class, long.class, long.class);
471        opL2 = findStatic("opL2", Object.class, Object.class, Object.class);
472        opL = findStatic("opL", Object.class, Object.class);
473        opL2_I = findStatic("opL2_I", int.class, Object.class, Object.class);
474        opL_I = findStatic("opL_I", int.class, Object.class);
475        opL_J = findStatic("opL_J", long.class, Object.class);
476    }
477    private static final MethodHandle[] INT_COLLECTORS = {
478        constant(int.class, 42), opI, opI2, opI3, opI4
479    };
480    private static final MethodHandle[] LONG_COLLECTORS = {
481        constant(long.class, 42), opJ, opJ2, opJ3
482    };
483
484    private static int addI(int x, int y) { stress(); return x+y; }
485    private static Object addL(Object x, Object y) { return addI((int)x, (int)y); }
486    private static final MethodHandle addI, addL;
487    static {
488        addI = findStatic("addI", int.class, int.class, int.class);
489        addL = findStatic("addL", Object.class, Object.class, Object.class);
490    }
491
492    private static Object list8ints(int a, int b, int c, int d, int e, int f, int g, int h) {
493        return Arrays.asList(a, b, c, d, e, f, g, h);
494    }
495    private static Object list8longs(long a, long b, long c, long d, long e, long f, long g, long h) {
496        return Arrays.asList(a, b, c, d, e, f, g, h);
497    }
498    private static final MethodHandle list8ints = findStatic("list8ints", Object.class,
499                                                             Collections.nCopies(8, int.class));
500    private static final MethodHandle list8longs = findStatic("list8longs", Object.class,
501                                                              Collections.nCopies(8, long.class));
502    private static final MethodHandle[] INT_LISTERS, LONG_LISTERS;
503    static {
504        int listerCount = list8ints.type().parameterCount() + 1;
505        INT_LISTERS  = new MethodHandle[listerCount];
506        LONG_LISTERS = new MethodHandle[listerCount];
507        MethodHandle lister = list8ints;
508        MethodHandle llister = list8longs;
509        for (int i = listerCount - 1; ; i--) {
510            INT_LISTERS[i] = lister;
511            LONG_LISTERS[i] = llister;
512            if (i == 0)  break;
513            lister  = insertArguments(lister,  i-1, (int)0);
514            llister = insertArguments(llister, i-1, (long)0);
515        }
516    }
517
518    private static Object  convI_L(int     x) { stress(); return (Object)  x; }
519    private static int     convL_I(Object  x) { stress(); return (int)     x; }
520    private static Object  convJ_L(long    x) { stress(); return (Object)  x; }
521    private static long    convL_J(Object  x) { stress(); return (long)    x; }
522    private static int     convJ_I(long    x) { stress(); return (int)     x; }
523    private static long    convI_J(int     x) { stress(); return (long)    x; }
524    private static final MethodHandle convI_L, convL_I, convJ_L, convL_J, convJ_I, convI_J;
525    static {
526        convI_L = findStatic("convI_L", Object.class, int.class);
527        convL_I = findStatic("convL_I", int.class, Object.class);
528        convJ_L = findStatic("convJ_L", Object.class, long.class);
529        convL_J = findStatic("convL_J", long.class, Object.class);
530        convJ_I = findStatic("convJ_I", int.class, long.class);
531        convI_J = findStatic("convI_J", long.class, int.class);
532    }
533
534    // stress modes:
535    private static final int REPEAT = getProperty("REPEAT", 0);
536    private static final int STRESS = getProperty("STRESS", 0);
537    private static /*v*/ int STRESS_COUNT;
538    private static final Object[] SINK = new Object[4];
539    private static void stress() {
540        if (STRESS <= 0) return;
541        int count = STRESS + (STRESS_COUNT++ & 0x1);  // non-constant value
542        for (int i = 0; i < count; i++) {
543            SINK[i % SINK.length] = new Object[STRESS + i % (SINK.length + 1)];
544        }
545    }
546
547    // verbosity:
548    private static final int VERBOSITY = getProperty("VERBOSITY", 0) + (REPEAT == 0 ? 0 : -1);
549    private static void verbose(Object a, Object b, Object c, Object d) {
550        if (VERBOSITY <= 0)  return;
551        verbose(1, a, b, c, d);
552    }
553    private static void verbose(Object a, Object b, Object c) {
554        if (VERBOSITY <= 0)  return;
555        verbose(1, a, b, c);
556    }
557    private static void verbose(int level, Object a, Object... bcd) {
558        if (level > VERBOSITY)  return;
559        String m = a.toString();
560        if (bcd != null && bcd.length > 0) {
561            List<Object> l = new ArrayList<>(bcd.length);
562            for (Object x : bcd) {
563                if (x instanceof Object[])  x = Arrays.asList((Object[])x);
564                if (x instanceof int[])     x = Arrays.toString((int[])x);
565                if (x instanceof long[])    x = Arrays.toString((long[])x);
566                l.add(x);
567            }
568            m = m+Arrays.asList(bcd);
569        }
570        System.out.println(m);
571    }
572    String testOnly;
573    String testOnlyTests;
574    private boolean startTest(String name) {
575        if (testOnly != null && !testOnly.contains(name))
576            return false;
577        verbose(0, "["+name+"]");
578        testOnlyTests = (testOnlyTests == null) ? name : testOnlyTests+" "+name;
579        return true;
580    }
581
582}
583