J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 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. |
| 7 | * |
| 8 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 11 | * version 2 for more details (a copy is included in the LICENSE file that |
| 12 | * accompanied this code). |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License version |
| 15 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 17 | * |
| 18 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 19 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 20 | * have any questions. |
| 21 | */ |
| 22 | |
| 23 | /* |
| 24 | * This file is available under and governed by the GNU General Public |
| 25 | * License version 2 only, as published by the Free Software Foundation. |
| 26 | * However, the following notice accompanied the original version of this |
| 27 | * file: |
| 28 | * |
| 29 | * Written by Doug Lea with assistance from members of JCP JSR-166 |
| 30 | * Expert Group and released to the public domain, as explained at |
| 31 | * http://creativecommons.org/licenses/publicdomain |
| 32 | */ |
| 33 | |
| 34 | /* |
| 35 | * @test |
| 36 | * @bug 4486658 |
| 37 | * @compile -source 1.5 MapCheck.java |
| 38 | * @run main/timeout=240 MapCheck |
| 39 | * @summary Times and checks basic map operations |
| 40 | */ |
| 41 | |
| 42 | import java.util.*; |
| 43 | import java.io.*; |
| 44 | |
| 45 | public class MapCheck { |
| 46 | |
| 47 | static final int absentSize = 1 << 17; |
| 48 | static final int absentMask = absentSize - 1; |
| 49 | static Object[] absent = new Object[absentSize]; |
| 50 | |
| 51 | static final Object MISSING = new Object(); |
| 52 | |
| 53 | static TestTimer timer = new TestTimer(); |
| 54 | |
| 55 | static void reallyAssert(boolean b) { |
| 56 | if (!b) throw new Error("Failed Assertion"); |
| 57 | } |
| 58 | |
| 59 | public static void main(String[] args) throws Exception { |
| 60 | Class mapClass = java.util.concurrent.ConcurrentHashMap.class; |
| 61 | int numTests = 8; |
| 62 | int size = 50000; |
| 63 | |
| 64 | if (args.length > 0) { |
| 65 | try { |
| 66 | mapClass = Class.forName(args[0]); |
| 67 | } catch(ClassNotFoundException e) { |
| 68 | throw new RuntimeException("Class " + args[0] + " not found."); |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | |
| 73 | if (args.length > 1) |
| 74 | numTests = Integer.parseInt(args[1]); |
| 75 | |
| 76 | if (args.length > 2) |
| 77 | size = Integer.parseInt(args[2]); |
| 78 | |
| 79 | boolean doSerializeTest = args.length > 3; |
| 80 | |
| 81 | System.out.println("Testing " + mapClass.getName() + " trials: " + numTests + " size: " + size); |
| 82 | |
| 83 | for (int i = 0; i < absentSize; ++i) absent[i] = new Object(); |
| 84 | |
| 85 | Object[] key = new Object[size]; |
| 86 | for (int i = 0; i < size; ++i) key[i] = new Object(); |
| 87 | |
| 88 | forceMem(size * 8); |
| 89 | |
| 90 | for (int rep = 0; rep < numTests; ++rep) { |
| 91 | runTest(newMap(mapClass), key); |
| 92 | } |
| 93 | |
| 94 | TestTimer.printStats(); |
| 95 | |
| 96 | |
| 97 | if (doSerializeTest) |
| 98 | stest(newMap(mapClass), size); |
| 99 | } |
| 100 | |
| 101 | static Map newMap(Class cl) { |
| 102 | try { |
| 103 | Map m = (Map)cl.newInstance(); |
| 104 | return m; |
| 105 | } catch(Exception e) { |
| 106 | throw new RuntimeException("Can't instantiate " + cl + ": " + e); |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | |
| 111 | static void runTest(Map s, Object[] key) { |
| 112 | shuffle(key); |
| 113 | int size = key.length; |
| 114 | long startTime = System.currentTimeMillis(); |
| 115 | test(s, key); |
| 116 | long time = System.currentTimeMillis() - startTime; |
| 117 | } |
| 118 | |
| 119 | static void forceMem(int n) { |
| 120 | // force enough memory |
| 121 | Long[] junk = new Long[n]; |
| 122 | for (int i = 0; i < junk.length; ++i) junk[i] = new Long(i); |
| 123 | int sum = 0; |
| 124 | for (int i = 0; i < junk.length; ++i) |
| 125 | sum += (int)(junk[i].longValue() + i); |
| 126 | if (sum == 0) System.out.println("Useless number = " + sum); |
| 127 | junk = null; |
| 128 | // System.gc(); |
| 129 | } |
| 130 | |
| 131 | |
| 132 | static void t1(String nm, int n, Map s, Object[] key, int expect) { |
| 133 | int sum = 0; |
| 134 | int iters = 4; |
| 135 | timer.start(nm, n * iters); |
| 136 | for (int j = 0; j < iters; ++j) { |
| 137 | for (int i = 0; i < n; i++) { |
| 138 | if (s.get(key[i]) != null) ++sum; |
| 139 | } |
| 140 | } |
| 141 | timer.finish(); |
| 142 | reallyAssert (sum == expect * iters); |
| 143 | } |
| 144 | |
| 145 | static void t2(String nm, int n, Map s, Object[] key, int expect) { |
| 146 | int sum = 0; |
| 147 | timer.start(nm, n); |
| 148 | for (int i = 0; i < n; i++) { |
| 149 | if (s.remove(key[i]) != null) ++sum; |
| 150 | } |
| 151 | timer.finish(); |
| 152 | reallyAssert (sum == expect); |
| 153 | } |
| 154 | |
| 155 | static void t3(String nm, int n, Map s, Object[] key, int expect) { |
| 156 | int sum = 0; |
| 157 | timer.start(nm, n); |
| 158 | for (int i = 0; i < n; i++) { |
| 159 | if (s.put(key[i], absent[i & absentMask]) == null) ++sum; |
| 160 | } |
| 161 | timer.finish(); |
| 162 | reallyAssert (sum == expect); |
| 163 | } |
| 164 | |
| 165 | static void t4(String nm, int n, Map s, Object[] key, int expect) { |
| 166 | int sum = 0; |
| 167 | timer.start(nm, n); |
| 168 | for (int i = 0; i < n; i++) { |
| 169 | if (s.containsKey(key[i])) ++sum; |
| 170 | } |
| 171 | timer.finish(); |
| 172 | reallyAssert (sum == expect); |
| 173 | } |
| 174 | |
| 175 | static void t5(String nm, int n, Map s, Object[] key, int expect) { |
| 176 | int sum = 0; |
| 177 | timer.start(nm, n/2); |
| 178 | for (int i = n-2; i >= 0; i-=2) { |
| 179 | if (s.remove(key[i]) != null) ++sum; |
| 180 | } |
| 181 | timer.finish(); |
| 182 | reallyAssert (sum == expect); |
| 183 | } |
| 184 | |
| 185 | static void t6(String nm, int n, Map s, Object[] k1, Object[] k2) { |
| 186 | int sum = 0; |
| 187 | timer.start(nm, n * 2); |
| 188 | for (int i = 0; i < n; i++) { |
| 189 | if (s.get(k1[i]) != null) ++sum; |
| 190 | if (s.get(k2[i & absentMask]) != null) ++sum; |
| 191 | } |
| 192 | timer.finish(); |
| 193 | reallyAssert (sum == n); |
| 194 | } |
| 195 | |
| 196 | static void t7(String nm, int n, Map s, Object[] k1, Object[] k2) { |
| 197 | int sum = 0; |
| 198 | timer.start(nm, n * 2); |
| 199 | for (int i = 0; i < n; i++) { |
| 200 | if (s.containsKey(k1[i])) ++sum; |
| 201 | if (s.containsKey(k2[i & absentMask])) ++sum; |
| 202 | } |
| 203 | timer.finish(); |
| 204 | reallyAssert (sum == n); |
| 205 | } |
| 206 | |
| 207 | static void t8(String nm, int n, Map s, Object[] key, int expect) { |
| 208 | int sum = 0; |
| 209 | timer.start(nm, n); |
| 210 | for (int i = 0; i < n; i++) { |
| 211 | if (s.get(key[i]) != null) ++sum; |
| 212 | } |
| 213 | timer.finish(); |
| 214 | reallyAssert (sum == expect); |
| 215 | } |
| 216 | |
| 217 | |
| 218 | static void t9(Map s) { |
| 219 | int sum = 0; |
| 220 | int iters = 20; |
| 221 | timer.start("ContainsValue (/n) ", iters * s.size()); |
| 222 | int step = absentSize / iters; |
| 223 | for (int i = 0; i < absentSize; i += step) |
| 224 | if (s.containsValue(absent[i])) ++sum; |
| 225 | timer.finish(); |
| 226 | reallyAssert (sum != 0); |
| 227 | } |
| 228 | |
| 229 | |
| 230 | static void ktest(Map s, int size, Object[] key) { |
| 231 | timer.start("ContainsKey ", size); |
| 232 | Set ks = s.keySet(); |
| 233 | int sum = 0; |
| 234 | for (int i = 0; i < size; i++) { |
| 235 | if (ks.contains(key[i])) ++sum; |
| 236 | } |
| 237 | timer.finish(); |
| 238 | reallyAssert (sum == size); |
| 239 | } |
| 240 | |
| 241 | |
| 242 | static void ittest1(Map s, int size) { |
| 243 | int sum = 0; |
| 244 | timer.start("Iter Key ", size); |
| 245 | for (Iterator it = s.keySet().iterator(); it.hasNext(); ) { |
| 246 | if(it.next() != MISSING) |
| 247 | ++sum; |
| 248 | } |
| 249 | timer.finish(); |
| 250 | reallyAssert (sum == size); |
| 251 | } |
| 252 | |
| 253 | static void ittest2(Map s, int size) { |
| 254 | int sum = 0; |
| 255 | timer.start("Iter Value ", size); |
| 256 | for (Iterator it = s.values().iterator(); it.hasNext(); ) { |
| 257 | if(it.next() != MISSING) |
| 258 | ++sum; |
| 259 | } |
| 260 | timer.finish(); |
| 261 | reallyAssert (sum == size); |
| 262 | } |
| 263 | static void ittest3(Map s, int size) { |
| 264 | int sum = 0; |
| 265 | timer.start("Iter Entry ", size); |
| 266 | for (Iterator it = s.entrySet().iterator(); it.hasNext(); ) { |
| 267 | if(it.next() != MISSING) |
| 268 | ++sum; |
| 269 | } |
| 270 | timer.finish(); |
| 271 | reallyAssert (sum == size); |
| 272 | } |
| 273 | |
| 274 | static void ittest4(Map s, int size, int pos) { |
| 275 | IdentityHashMap seen = new IdentityHashMap(size); |
| 276 | reallyAssert (s.size() == size); |
| 277 | int sum = 0; |
| 278 | timer.start("Iter XEntry ", size); |
| 279 | Iterator it = s.entrySet().iterator(); |
| 280 | Object k = null; |
| 281 | Object v = null; |
| 282 | for (int i = 0; i < size-pos; ++i) { |
| 283 | Map.Entry x = (Map.Entry)(it.next()); |
| 284 | k = x.getKey(); |
| 285 | v = x.getValue(); |
| 286 | seen.put(k, k); |
| 287 | if (x != MISSING) |
| 288 | ++sum; |
| 289 | } |
| 290 | reallyAssert (s.containsKey(k)); |
| 291 | it.remove(); |
| 292 | reallyAssert (!s.containsKey(k)); |
| 293 | while (it.hasNext()) { |
| 294 | Map.Entry x = (Map.Entry)(it.next()); |
| 295 | Object k2 = x.getKey(); |
| 296 | seen.put(k2, k2); |
| 297 | if (x != MISSING) |
| 298 | ++sum; |
| 299 | } |
| 300 | |
| 301 | reallyAssert (s.size() == size-1); |
| 302 | s.put(k, v); |
| 303 | reallyAssert (seen.size() == size); |
| 304 | timer.finish(); |
| 305 | reallyAssert (sum == size); |
| 306 | reallyAssert (s.size() == size); |
| 307 | } |
| 308 | |
| 309 | |
| 310 | static void ittest(Map s, int size) { |
| 311 | ittest1(s, size); |
| 312 | ittest2(s, size); |
| 313 | ittest3(s, size); |
| 314 | // for (int i = 0; i < size-1; ++i) |
| 315 | // ittest4(s, size, i); |
| 316 | } |
| 317 | |
| 318 | static void entest1(Hashtable ht, int size) { |
| 319 | int sum = 0; |
| 320 | |
| 321 | timer.start("Iter Enumeration Key ", size); |
| 322 | for (Enumeration en = ht.keys(); en.hasMoreElements(); ) { |
| 323 | if (en.nextElement() != MISSING) |
| 324 | ++sum; |
| 325 | } |
| 326 | timer.finish(); |
| 327 | reallyAssert (sum == size); |
| 328 | } |
| 329 | |
| 330 | static void entest2(Hashtable ht, int size) { |
| 331 | int sum = 0; |
| 332 | timer.start("Iter Enumeration Value ", size); |
| 333 | for (Enumeration en = ht.elements(); en.hasMoreElements(); ) { |
| 334 | if (en.nextElement() != MISSING) |
| 335 | ++sum; |
| 336 | } |
| 337 | timer.finish(); |
| 338 | reallyAssert (sum == size); |
| 339 | } |
| 340 | |
| 341 | |
| 342 | static void entest3(Hashtable ht, int size) { |
| 343 | int sum = 0; |
| 344 | |
| 345 | timer.start("Iterf Enumeration Key ", size); |
| 346 | Enumeration en = ht.keys(); |
| 347 | for (int i = 0; i < size; ++i) { |
| 348 | if (en.nextElement() != MISSING) |
| 349 | ++sum; |
| 350 | } |
| 351 | timer.finish(); |
| 352 | reallyAssert (sum == size); |
| 353 | } |
| 354 | |
| 355 | static void entest4(Hashtable ht, int size) { |
| 356 | int sum = 0; |
| 357 | timer.start("Iterf Enumeration Value", size); |
| 358 | Enumeration en = ht.elements(); |
| 359 | for (int i = 0; i < size; ++i) { |
| 360 | if (en.nextElement() != MISSING) |
| 361 | ++sum; |
| 362 | } |
| 363 | timer.finish(); |
| 364 | reallyAssert (sum == size); |
| 365 | } |
| 366 | |
| 367 | static void entest(Map s, int size) { |
| 368 | if (s instanceof Hashtable) { |
| 369 | Hashtable ht = (Hashtable)s; |
| 370 | // entest3(ht, size); |
| 371 | // entest4(ht, size); |
| 372 | entest1(ht, size); |
| 373 | entest2(ht, size); |
| 374 | entest1(ht, size); |
| 375 | entest2(ht, size); |
| 376 | entest1(ht, size); |
| 377 | entest2(ht, size); |
| 378 | } |
| 379 | } |
| 380 | |
| 381 | static void rtest(Map s, int size) { |
| 382 | timer.start("Remove (iterator) ", size); |
| 383 | for (Iterator it = s.keySet().iterator(); it.hasNext(); ) { |
| 384 | it.next(); |
| 385 | it.remove(); |
| 386 | } |
| 387 | timer.finish(); |
| 388 | } |
| 389 | |
| 390 | static void rvtest(Map s, int size) { |
| 391 | timer.start("Remove (iterator) ", size); |
| 392 | for (Iterator it = s.values().iterator(); it.hasNext(); ) { |
| 393 | it.next(); |
| 394 | it.remove(); |
| 395 | } |
| 396 | timer.finish(); |
| 397 | } |
| 398 | |
| 399 | |
| 400 | static void dtest(Map s, int size, Object[] key) { |
| 401 | timer.start("Put (putAll) ", size * 2); |
| 402 | Map s2 = null; |
| 403 | try { |
| 404 | s2 = (Map) (s.getClass().newInstance()); |
| 405 | s2.putAll(s); |
| 406 | } |
| 407 | catch (Exception e) { e.printStackTrace(); return; } |
| 408 | timer.finish(); |
| 409 | |
| 410 | timer.start("Iter Equals ", size * 2); |
| 411 | boolean eqt = s2.equals(s) && s.equals(s2); |
| 412 | reallyAssert (eqt); |
| 413 | timer.finish(); |
| 414 | |
| 415 | timer.start("Iter HashCode ", size * 2); |
| 416 | int shc = s.hashCode(); |
| 417 | int s2hc = s2.hashCode(); |
| 418 | reallyAssert (shc == s2hc); |
| 419 | timer.finish(); |
| 420 | |
| 421 | timer.start("Put (present) ", size); |
| 422 | s2.putAll(s); |
| 423 | timer.finish(); |
| 424 | |
| 425 | timer.start("Iter EntrySet contains ", size * 2); |
| 426 | Set es2 = s2.entrySet(); |
| 427 | int sum = 0; |
| 428 | for (Iterator i1 = s.entrySet().iterator(); i1.hasNext(); ) { |
| 429 | Object entry = i1.next(); |
| 430 | if (es2.contains(entry)) ++sum; |
| 431 | } |
| 432 | timer.finish(); |
| 433 | reallyAssert (sum == size); |
| 434 | |
| 435 | t6("Get ", size, s2, key, absent); |
| 436 | |
| 437 | Object hold = s2.get(key[size-1]); |
| 438 | s2.put(key[size-1], absent[0]); |
| 439 | timer.start("Iter Equals ", size * 2); |
| 440 | eqt = s2.equals(s) && s.equals(s2); |
| 441 | reallyAssert (!eqt); |
| 442 | timer.finish(); |
| 443 | |
| 444 | timer.start("Iter HashCode ", size * 2); |
| 445 | int s1h = s.hashCode(); |
| 446 | int s2h = s2.hashCode(); |
| 447 | reallyAssert (s1h != s2h); |
| 448 | timer.finish(); |
| 449 | |
| 450 | s2.put(key[size-1], hold); |
| 451 | timer.start("Remove (iterator) ", size * 2); |
| 452 | Iterator s2i = s2.entrySet().iterator(); |
| 453 | Set es = s.entrySet(); |
| 454 | while (s2i.hasNext()) |
| 455 | es.remove(s2i.next()); |
| 456 | timer.finish(); |
| 457 | |
| 458 | reallyAssert (s.isEmpty()); |
| 459 | |
| 460 | timer.start("Clear ", size); |
| 461 | s2.clear(); |
| 462 | timer.finish(); |
| 463 | reallyAssert (s2.isEmpty() && s.isEmpty()); |
| 464 | } |
| 465 | |
| 466 | static void stest(Map s, int size) throws Exception { |
| 467 | if (!(s instanceof Serializable)) |
| 468 | return; |
| 469 | System.out.print("Serialize : "); |
| 470 | |
| 471 | for (int i = 0; i < size; i++) { |
| 472 | s.put(new Integer(i), Boolean.TRUE); |
| 473 | } |
| 474 | |
| 475 | long startTime = System.currentTimeMillis(); |
| 476 | |
| 477 | FileOutputStream fs = new FileOutputStream("MapCheck.dat"); |
| 478 | ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(fs)); |
| 479 | out.writeObject(s); |
| 480 | out.close(); |
| 481 | |
| 482 | FileInputStream is = new FileInputStream("MapCheck.dat"); |
| 483 | ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(is)); |
| 484 | Map m = (Map)in.readObject(); |
| 485 | |
| 486 | long endTime = System.currentTimeMillis(); |
| 487 | long time = endTime - startTime; |
| 488 | |
| 489 | System.out.print(time + "ms"); |
| 490 | |
| 491 | if (s instanceof IdentityHashMap) return; |
| 492 | reallyAssert (s.equals(m)); |
| 493 | } |
| 494 | |
| 495 | |
| 496 | static void test(Map s, Object[] key) { |
| 497 | int size = key.length; |
| 498 | |
| 499 | t3("Put (absent) ", size, s, key, size); |
| 500 | t3("Put (present) ", size, s, key, 0); |
| 501 | t7("ContainsKey ", size, s, key, absent); |
| 502 | t4("ContainsKey ", size, s, key, size); |
| 503 | ktest(s, size, key); |
| 504 | t4("ContainsKey ", absentSize, s, absent, 0); |
| 505 | t6("Get ", size, s, key, absent); |
| 506 | t1("Get (present) ", size, s, key, size); |
| 507 | t1("Get (absent) ", absentSize, s, absent, 0); |
| 508 | t2("Remove (absent) ", absentSize, s, absent, 0); |
| 509 | t5("Remove (present) ", size, s, key, size / 2); |
| 510 | t3("Put (half present) ", size, s, key, size / 2); |
| 511 | |
| 512 | ittest(s, size); |
| 513 | entest(s, size); |
| 514 | t9(s); |
| 515 | rtest(s, size); |
| 516 | |
| 517 | t4("ContainsKey ", size, s, key, 0); |
| 518 | t2("Remove (absent) ", size, s, key, 0); |
| 519 | t3("Put (presized) ", size, s, key, size); |
| 520 | dtest(s, size, key); |
| 521 | } |
| 522 | |
| 523 | static class TestTimer { |
| 524 | private String name; |
| 525 | private long numOps; |
| 526 | private long startTime; |
| 527 | private String cname; |
| 528 | |
| 529 | static final java.util.TreeMap accum = new java.util.TreeMap(); |
| 530 | |
| 531 | static void printStats() { |
| 532 | for (Iterator it = accum.entrySet().iterator(); it.hasNext(); ) { |
| 533 | Map.Entry e = (Map.Entry)(it.next()); |
| 534 | Stats stats = ((Stats)(e.getValue())); |
| 535 | int n = stats.number; |
| 536 | double t; |
| 537 | if (n > 0) |
| 538 | t = stats.sum / n; |
| 539 | else |
| 540 | t = stats.least; |
| 541 | long nano = Math.round(1000000.0 * t); |
| 542 | System.out.println(e.getKey() + ": " + nano); |
| 543 | } |
| 544 | } |
| 545 | |
| 546 | void start(String name, long numOps) { |
| 547 | this.name = name; |
| 548 | this.cname = classify(); |
| 549 | this.numOps = numOps; |
| 550 | startTime = System.currentTimeMillis(); |
| 551 | } |
| 552 | |
| 553 | |
| 554 | String classify() { |
| 555 | if (name.startsWith("Get")) |
| 556 | return "Get "; |
| 557 | else if (name.startsWith("Put")) |
| 558 | return "Put "; |
| 559 | else if (name.startsWith("Remove")) |
| 560 | return "Remove "; |
| 561 | else if (name.startsWith("Iter")) |
| 562 | return "Iter "; |
| 563 | else |
| 564 | return null; |
| 565 | } |
| 566 | |
| 567 | void finish() { |
| 568 | long endTime = System.currentTimeMillis(); |
| 569 | long time = endTime - startTime; |
| 570 | double timePerOp = ((double)time)/numOps; |
| 571 | |
| 572 | Object st = accum.get(name); |
| 573 | if (st == null) |
| 574 | accum.put(name, new Stats(timePerOp)); |
| 575 | else { |
| 576 | Stats stats = (Stats) st; |
| 577 | stats.sum += timePerOp; |
| 578 | stats.number++; |
| 579 | if (timePerOp < stats.least) stats.least = timePerOp; |
| 580 | } |
| 581 | |
| 582 | if (cname != null) { |
| 583 | st = accum.get(cname); |
| 584 | if (st == null) |
| 585 | accum.put(cname, new Stats(timePerOp)); |
| 586 | else { |
| 587 | Stats stats = (Stats) st; |
| 588 | stats.sum += timePerOp; |
| 589 | stats.number++; |
| 590 | if (timePerOp < stats.least) stats.least = timePerOp; |
| 591 | } |
| 592 | } |
| 593 | |
| 594 | } |
| 595 | |
| 596 | } |
| 597 | |
| 598 | static class Stats { |
| 599 | double sum = 0; |
| 600 | double least; |
| 601 | int number = 0; |
| 602 | Stats(double t) { least = t; } |
| 603 | } |
| 604 | |
| 605 | static Random rng = new Random(); |
| 606 | |
| 607 | static void shuffle(Object[] keys) { |
| 608 | int size = keys.length; |
| 609 | for (int i=size; i>1; i--) { |
| 610 | int r = rng.nextInt(i); |
| 611 | Object t = keys[i-1]; |
| 612 | keys[i-1] = keys[r]; |
| 613 | keys[r] = t; |
| 614 | } |
| 615 | } |
| 616 | |
| 617 | } |