Steve Block | a7e24c1 | 2009-10-30 11:49:00 +0000 | [diff] [blame] | 1 | // Copyright 2006-2008 the V8 project authors. All rights reserved. |
| 2 | // Redistribution and use in source and binary forms, with or without |
| 3 | // modification, are permitted provided that the following conditions are |
| 4 | // met: |
| 5 | // |
| 6 | // * Redistributions of source code must retain the above copyright |
| 7 | // notice, this list of conditions and the following disclaimer. |
| 8 | // * Redistributions in binary form must reproduce the above |
| 9 | // copyright notice, this list of conditions and the following |
| 10 | // disclaimer in the documentation and/or other materials provided |
| 11 | // with the distribution. |
| 12 | // * Neither the name of Google Inc. nor the names of its |
| 13 | // contributors may be used to endorse or promote products derived |
| 14 | // from this software without specific prior written permission. |
| 15 | // |
| 16 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 17 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 18 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 19 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 20 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 21 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 22 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 23 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 24 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 25 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 26 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 27 | |
| 28 | |
| 29 | // This is a JavaScript implementation of the Richards |
| 30 | // benchmark from: |
| 31 | // |
| 32 | // http://www.cl.cam.ac.uk/~mr10/Bench.html |
| 33 | // |
| 34 | // The benchmark was originally implemented in BCPL by |
| 35 | // Martin Richards. |
| 36 | |
| 37 | |
| 38 | var Richards = new BenchmarkSuite('Richards', 34886, [ |
| 39 | new Benchmark("Richards", runRichards) |
| 40 | ]); |
| 41 | |
| 42 | |
| 43 | /** |
| 44 | * The Richards benchmark simulates the task dispatcher of an |
| 45 | * operating system. |
| 46 | **/ |
| 47 | function runRichards() { |
| 48 | var scheduler = new Scheduler(); |
| 49 | scheduler.addIdleTask(ID_IDLE, 0, null, COUNT); |
| 50 | |
| 51 | var queue = new Packet(null, ID_WORKER, KIND_WORK); |
| 52 | queue = new Packet(queue, ID_WORKER, KIND_WORK); |
| 53 | scheduler.addWorkerTask(ID_WORKER, 1000, queue); |
| 54 | |
| 55 | queue = new Packet(null, ID_DEVICE_A, KIND_DEVICE); |
| 56 | queue = new Packet(queue, ID_DEVICE_A, KIND_DEVICE); |
| 57 | queue = new Packet(queue, ID_DEVICE_A, KIND_DEVICE); |
| 58 | scheduler.addHandlerTask(ID_HANDLER_A, 2000, queue); |
| 59 | |
| 60 | queue = new Packet(null, ID_DEVICE_B, KIND_DEVICE); |
| 61 | queue = new Packet(queue, ID_DEVICE_B, KIND_DEVICE); |
| 62 | queue = new Packet(queue, ID_DEVICE_B, KIND_DEVICE); |
| 63 | scheduler.addHandlerTask(ID_HANDLER_B, 3000, queue); |
| 64 | |
| 65 | scheduler.addDeviceTask(ID_DEVICE_A, 4000, null); |
| 66 | |
| 67 | scheduler.addDeviceTask(ID_DEVICE_B, 5000, null); |
| 68 | |
| 69 | scheduler.schedule(); |
| 70 | |
| 71 | if (scheduler.queueCount != EXPECTED_QUEUE_COUNT || |
| 72 | scheduler.holdCount != EXPECTED_HOLD_COUNT) { |
| 73 | var msg = |
| 74 | "Error during execution: queueCount = " + scheduler.queueCount + |
| 75 | ", holdCount = " + scheduler.holdCount + "."; |
| 76 | throw new Error(msg); |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | var COUNT = 1000; |
| 81 | |
| 82 | /** |
| 83 | * These two constants specify how many times a packet is queued and |
| 84 | * how many times a task is put on hold in a correct run of richards. |
| 85 | * They don't have any meaning a such but are characteristic of a |
| 86 | * correct run so if the actual queue or hold count is different from |
| 87 | * the expected there must be a bug in the implementation. |
| 88 | **/ |
| 89 | var EXPECTED_QUEUE_COUNT = 2322; |
| 90 | var EXPECTED_HOLD_COUNT = 928; |
| 91 | |
| 92 | |
| 93 | /** |
| 94 | * A scheduler can be used to schedule a set of tasks based on their relative |
| 95 | * priorities. Scheduling is done by maintaining a list of task control blocks |
| 96 | * which holds tasks and the data queue they are processing. |
| 97 | * @constructor |
| 98 | */ |
| 99 | function Scheduler() { |
| 100 | this.queueCount = 0; |
| 101 | this.holdCount = 0; |
| 102 | this.blocks = new Array(NUMBER_OF_IDS); |
| 103 | this.list = null; |
| 104 | this.currentTcb = null; |
| 105 | this.currentId = null; |
| 106 | } |
| 107 | |
| 108 | var ID_IDLE = 0; |
| 109 | var ID_WORKER = 1; |
| 110 | var ID_HANDLER_A = 2; |
| 111 | var ID_HANDLER_B = 3; |
| 112 | var ID_DEVICE_A = 4; |
| 113 | var ID_DEVICE_B = 5; |
| 114 | var NUMBER_OF_IDS = 6; |
| 115 | |
| 116 | var KIND_DEVICE = 0; |
| 117 | var KIND_WORK = 1; |
| 118 | |
| 119 | /** |
| 120 | * Add an idle task to this scheduler. |
| 121 | * @param {int} id the identity of the task |
| 122 | * @param {int} priority the task's priority |
| 123 | * @param {Packet} queue the queue of work to be processed by the task |
| 124 | * @param {int} count the number of times to schedule the task |
| 125 | */ |
| 126 | Scheduler.prototype.addIdleTask = function (id, priority, queue, count) { |
| 127 | this.addRunningTask(id, priority, queue, new IdleTask(this, 1, count)); |
| 128 | }; |
| 129 | |
| 130 | /** |
| 131 | * Add a work task to this scheduler. |
| 132 | * @param {int} id the identity of the task |
| 133 | * @param {int} priority the task's priority |
| 134 | * @param {Packet} queue the queue of work to be processed by the task |
| 135 | */ |
| 136 | Scheduler.prototype.addWorkerTask = function (id, priority, queue) { |
| 137 | this.addTask(id, priority, queue, new WorkerTask(this, ID_HANDLER_A, 0)); |
| 138 | }; |
| 139 | |
| 140 | /** |
| 141 | * Add a handler task to this scheduler. |
| 142 | * @param {int} id the identity of the task |
| 143 | * @param {int} priority the task's priority |
| 144 | * @param {Packet} queue the queue of work to be processed by the task |
| 145 | */ |
| 146 | Scheduler.prototype.addHandlerTask = function (id, priority, queue) { |
| 147 | this.addTask(id, priority, queue, new HandlerTask(this)); |
| 148 | }; |
| 149 | |
| 150 | /** |
| 151 | * Add a handler task to this scheduler. |
| 152 | * @param {int} id the identity of the task |
| 153 | * @param {int} priority the task's priority |
| 154 | * @param {Packet} queue the queue of work to be processed by the task |
| 155 | */ |
| 156 | Scheduler.prototype.addDeviceTask = function (id, priority, queue) { |
| 157 | this.addTask(id, priority, queue, new DeviceTask(this)) |
| 158 | }; |
| 159 | |
| 160 | /** |
| 161 | * Add the specified task and mark it as running. |
| 162 | * @param {int} id the identity of the task |
| 163 | * @param {int} priority the task's priority |
| 164 | * @param {Packet} queue the queue of work to be processed by the task |
| 165 | * @param {Task} task the task to add |
| 166 | */ |
| 167 | Scheduler.prototype.addRunningTask = function (id, priority, queue, task) { |
| 168 | this.addTask(id, priority, queue, task); |
| 169 | this.currentTcb.setRunning(); |
| 170 | }; |
| 171 | |
| 172 | /** |
| 173 | * Add the specified task to this scheduler. |
| 174 | * @param {int} id the identity of the task |
| 175 | * @param {int} priority the task's priority |
| 176 | * @param {Packet} queue the queue of work to be processed by the task |
| 177 | * @param {Task} task the task to add |
| 178 | */ |
| 179 | Scheduler.prototype.addTask = function (id, priority, queue, task) { |
| 180 | this.currentTcb = new TaskControlBlock(this.list, id, priority, queue, task); |
| 181 | this.list = this.currentTcb; |
| 182 | this.blocks[id] = this.currentTcb; |
| 183 | }; |
| 184 | |
| 185 | /** |
| 186 | * Execute the tasks managed by this scheduler. |
| 187 | */ |
| 188 | Scheduler.prototype.schedule = function () { |
| 189 | this.currentTcb = this.list; |
| 190 | while (this.currentTcb != null) { |
| 191 | if (this.currentTcb.isHeldOrSuspended()) { |
| 192 | this.currentTcb = this.currentTcb.link; |
| 193 | } else { |
| 194 | this.currentId = this.currentTcb.id; |
| 195 | this.currentTcb = this.currentTcb.run(); |
| 196 | } |
| 197 | } |
| 198 | }; |
| 199 | |
| 200 | /** |
| 201 | * Release a task that is currently blocked and return the next block to run. |
| 202 | * @param {int} id the id of the task to suspend |
| 203 | */ |
| 204 | Scheduler.prototype.release = function (id) { |
| 205 | var tcb = this.blocks[id]; |
| 206 | if (tcb == null) return tcb; |
| 207 | tcb.markAsNotHeld(); |
| 208 | if (tcb.priority > this.currentTcb.priority) { |
| 209 | return tcb; |
| 210 | } else { |
| 211 | return this.currentTcb; |
| 212 | } |
| 213 | }; |
| 214 | |
| 215 | /** |
| 216 | * Block the currently executing task and return the next task control block |
| 217 | * to run. The blocked task will not be made runnable until it is explicitly |
| 218 | * released, even if new work is added to it. |
| 219 | */ |
| 220 | Scheduler.prototype.holdCurrent = function () { |
| 221 | this.holdCount++; |
| 222 | this.currentTcb.markAsHeld(); |
| 223 | return this.currentTcb.link; |
| 224 | }; |
| 225 | |
| 226 | /** |
| 227 | * Suspend the currently executing task and return the next task control block |
| 228 | * to run. If new work is added to the suspended task it will be made runnable. |
| 229 | */ |
| 230 | Scheduler.prototype.suspendCurrent = function () { |
| 231 | this.currentTcb.markAsSuspended(); |
| 232 | return this.currentTcb; |
| 233 | }; |
| 234 | |
| 235 | /** |
| 236 | * Add the specified packet to the end of the worklist used by the task |
| 237 | * associated with the packet and make the task runnable if it is currently |
| 238 | * suspended. |
| 239 | * @param {Packet} packet the packet to add |
| 240 | */ |
| 241 | Scheduler.prototype.queue = function (packet) { |
| 242 | var t = this.blocks[packet.id]; |
| 243 | if (t == null) return t; |
| 244 | this.queueCount++; |
| 245 | packet.link = null; |
| 246 | packet.id = this.currentId; |
| 247 | return t.checkPriorityAdd(this.currentTcb, packet); |
| 248 | }; |
| 249 | |
| 250 | /** |
| 251 | * A task control block manages a task and the queue of work packages associated |
| 252 | * with it. |
| 253 | * @param {TaskControlBlock} link the preceding block in the linked block list |
| 254 | * @param {int} id the id of this block |
| 255 | * @param {int} priority the priority of this block |
| 256 | * @param {Packet} queue the queue of packages to be processed by the task |
| 257 | * @param {Task} task the task |
| 258 | * @constructor |
| 259 | */ |
| 260 | function TaskControlBlock(link, id, priority, queue, task) { |
| 261 | this.link = link; |
| 262 | this.id = id; |
| 263 | this.priority = priority; |
| 264 | this.queue = queue; |
| 265 | this.task = task; |
| 266 | if (queue == null) { |
| 267 | this.state = STATE_SUSPENDED; |
| 268 | } else { |
| 269 | this.state = STATE_SUSPENDED_RUNNABLE; |
| 270 | } |
| 271 | } |
| 272 | |
| 273 | /** |
| 274 | * The task is running and is currently scheduled. |
| 275 | */ |
| 276 | var STATE_RUNNING = 0; |
| 277 | |
| 278 | /** |
| 279 | * The task has packets left to process. |
| 280 | */ |
| 281 | var STATE_RUNNABLE = 1; |
| 282 | |
| 283 | /** |
| 284 | * The task is not currently running. The task is not blocked as such and may |
| 285 | * be started by the scheduler. |
| 286 | */ |
| 287 | var STATE_SUSPENDED = 2; |
| 288 | |
| 289 | /** |
| 290 | * The task is blocked and cannot be run until it is explicitly released. |
| 291 | */ |
| 292 | var STATE_HELD = 4; |
| 293 | |
| 294 | var STATE_SUSPENDED_RUNNABLE = STATE_SUSPENDED | STATE_RUNNABLE; |
| 295 | var STATE_NOT_HELD = ~STATE_HELD; |
| 296 | |
| 297 | TaskControlBlock.prototype.setRunning = function () { |
| 298 | this.state = STATE_RUNNING; |
| 299 | }; |
| 300 | |
| 301 | TaskControlBlock.prototype.markAsNotHeld = function () { |
| 302 | this.state = this.state & STATE_NOT_HELD; |
| 303 | }; |
| 304 | |
| 305 | TaskControlBlock.prototype.markAsHeld = function () { |
| 306 | this.state = this.state | STATE_HELD; |
| 307 | }; |
| 308 | |
| 309 | TaskControlBlock.prototype.isHeldOrSuspended = function () { |
| 310 | return (this.state & STATE_HELD) != 0 || (this.state == STATE_SUSPENDED); |
| 311 | }; |
| 312 | |
| 313 | TaskControlBlock.prototype.markAsSuspended = function () { |
| 314 | this.state = this.state | STATE_SUSPENDED; |
| 315 | }; |
| 316 | |
| 317 | TaskControlBlock.prototype.markAsRunnable = function () { |
| 318 | this.state = this.state | STATE_RUNNABLE; |
| 319 | }; |
| 320 | |
| 321 | /** |
| 322 | * Runs this task, if it is ready to be run, and returns the next task to run. |
| 323 | */ |
| 324 | TaskControlBlock.prototype.run = function () { |
| 325 | var packet; |
| 326 | if (this.state == STATE_SUSPENDED_RUNNABLE) { |
| 327 | packet = this.queue; |
| 328 | this.queue = packet.link; |
| 329 | if (this.queue == null) { |
| 330 | this.state = STATE_RUNNING; |
| 331 | } else { |
| 332 | this.state = STATE_RUNNABLE; |
| 333 | } |
| 334 | } else { |
| 335 | packet = null; |
| 336 | } |
| 337 | return this.task.run(packet); |
| 338 | }; |
| 339 | |
| 340 | /** |
| 341 | * Adds a packet to the worklist of this block's task, marks this as runnable if |
| 342 | * necessary, and returns the next runnable object to run (the one |
| 343 | * with the highest priority). |
| 344 | */ |
| 345 | TaskControlBlock.prototype.checkPriorityAdd = function (task, packet) { |
| 346 | if (this.queue == null) { |
| 347 | this.queue = packet; |
| 348 | this.markAsRunnable(); |
| 349 | if (this.priority > task.priority) return this; |
| 350 | } else { |
| 351 | this.queue = packet.addTo(this.queue); |
| 352 | } |
| 353 | return task; |
| 354 | }; |
| 355 | |
| 356 | TaskControlBlock.prototype.toString = function () { |
| 357 | return "tcb { " + this.task + "@" + this.state + " }"; |
| 358 | }; |
| 359 | |
| 360 | /** |
| 361 | * An idle task doesn't do any work itself but cycles control between the two |
| 362 | * device tasks. |
| 363 | * @param {Scheduler} scheduler the scheduler that manages this task |
| 364 | * @param {int} v1 a seed value that controls how the device tasks are scheduled |
| 365 | * @param {int} count the number of times this task should be scheduled |
| 366 | * @constructor |
| 367 | */ |
| 368 | function IdleTask(scheduler, v1, count) { |
| 369 | this.scheduler = scheduler; |
| 370 | this.v1 = v1; |
| 371 | this.count = count; |
| 372 | } |
| 373 | |
| 374 | IdleTask.prototype.run = function (packet) { |
| 375 | this.count--; |
| 376 | if (this.count == 0) return this.scheduler.holdCurrent(); |
| 377 | if ((this.v1 & 1) == 0) { |
| 378 | this.v1 = this.v1 >> 1; |
| 379 | return this.scheduler.release(ID_DEVICE_A); |
| 380 | } else { |
| 381 | this.v1 = (this.v1 >> 1) ^ 0xD008; |
| 382 | return this.scheduler.release(ID_DEVICE_B); |
| 383 | } |
| 384 | }; |
| 385 | |
| 386 | IdleTask.prototype.toString = function () { |
| 387 | return "IdleTask" |
| 388 | }; |
| 389 | |
| 390 | /** |
| 391 | * A task that suspends itself after each time it has been run to simulate |
| 392 | * waiting for data from an external device. |
| 393 | * @param {Scheduler} scheduler the scheduler that manages this task |
| 394 | * @constructor |
| 395 | */ |
| 396 | function DeviceTask(scheduler) { |
| 397 | this.scheduler = scheduler; |
| 398 | this.v1 = null; |
| 399 | } |
| 400 | |
| 401 | DeviceTask.prototype.run = function (packet) { |
| 402 | if (packet == null) { |
| 403 | if (this.v1 == null) return this.scheduler.suspendCurrent(); |
| 404 | var v = this.v1; |
| 405 | this.v1 = null; |
| 406 | return this.scheduler.queue(v); |
| 407 | } else { |
| 408 | this.v1 = packet; |
| 409 | return this.scheduler.holdCurrent(); |
| 410 | } |
| 411 | }; |
| 412 | |
| 413 | DeviceTask.prototype.toString = function () { |
| 414 | return "DeviceTask"; |
| 415 | }; |
| 416 | |
| 417 | /** |
| 418 | * A task that manipulates work packets. |
| 419 | * @param {Scheduler} scheduler the scheduler that manages this task |
| 420 | * @param {int} v1 a seed used to specify how work packets are manipulated |
| 421 | * @param {int} v2 another seed used to specify how work packets are manipulated |
| 422 | * @constructor |
| 423 | */ |
| 424 | function WorkerTask(scheduler, v1, v2) { |
| 425 | this.scheduler = scheduler; |
| 426 | this.v1 = v1; |
| 427 | this.v2 = v2; |
| 428 | } |
| 429 | |
| 430 | WorkerTask.prototype.run = function (packet) { |
| 431 | if (packet == null) { |
| 432 | return this.scheduler.suspendCurrent(); |
| 433 | } else { |
| 434 | if (this.v1 == ID_HANDLER_A) { |
| 435 | this.v1 = ID_HANDLER_B; |
| 436 | } else { |
| 437 | this.v1 = ID_HANDLER_A; |
| 438 | } |
| 439 | packet.id = this.v1; |
| 440 | packet.a1 = 0; |
| 441 | for (var i = 0; i < DATA_SIZE; i++) { |
| 442 | this.v2++; |
| 443 | if (this.v2 > 26) this.v2 = 1; |
| 444 | packet.a2[i] = this.v2; |
| 445 | } |
| 446 | return this.scheduler.queue(packet); |
| 447 | } |
| 448 | }; |
| 449 | |
| 450 | WorkerTask.prototype.toString = function () { |
| 451 | return "WorkerTask"; |
| 452 | }; |
| 453 | |
| 454 | /** |
| 455 | * A task that manipulates work packets and then suspends itself. |
| 456 | * @param {Scheduler} scheduler the scheduler that manages this task |
| 457 | * @constructor |
| 458 | */ |
| 459 | function HandlerTask(scheduler) { |
| 460 | this.scheduler = scheduler; |
| 461 | this.v1 = null; |
| 462 | this.v2 = null; |
| 463 | } |
| 464 | |
| 465 | HandlerTask.prototype.run = function (packet) { |
| 466 | if (packet != null) { |
| 467 | if (packet.kind == KIND_WORK) { |
| 468 | this.v1 = packet.addTo(this.v1); |
| 469 | } else { |
| 470 | this.v2 = packet.addTo(this.v2); |
| 471 | } |
| 472 | } |
| 473 | if (this.v1 != null) { |
| 474 | var count = this.v1.a1; |
| 475 | var v; |
| 476 | if (count < DATA_SIZE) { |
| 477 | if (this.v2 != null) { |
| 478 | v = this.v2; |
| 479 | this.v2 = this.v2.link; |
| 480 | v.a1 = this.v1.a2[count]; |
| 481 | this.v1.a1 = count + 1; |
| 482 | return this.scheduler.queue(v); |
| 483 | } |
| 484 | } else { |
| 485 | v = this.v1; |
| 486 | this.v1 = this.v1.link; |
| 487 | return this.scheduler.queue(v); |
| 488 | } |
| 489 | } |
| 490 | return this.scheduler.suspendCurrent(); |
| 491 | }; |
| 492 | |
| 493 | HandlerTask.prototype.toString = function () { |
| 494 | return "HandlerTask"; |
| 495 | }; |
| 496 | |
| 497 | /* --- * |
| 498 | * P a c k e t |
| 499 | * --- */ |
| 500 | |
| 501 | var DATA_SIZE = 4; |
| 502 | |
| 503 | /** |
| 504 | * A simple package of data that is manipulated by the tasks. The exact layout |
| 505 | * of the payload data carried by a packet is not importaint, and neither is the |
| 506 | * nature of the work performed on packets by the tasks. |
| 507 | * |
| 508 | * Besides carrying data, packets form linked lists and are hence used both as |
| 509 | * data and worklists. |
| 510 | * @param {Packet} link the tail of the linked list of packets |
| 511 | * @param {int} id an ID for this packet |
| 512 | * @param {int} kind the type of this packet |
| 513 | * @constructor |
| 514 | */ |
| 515 | function Packet(link, id, kind) { |
| 516 | this.link = link; |
| 517 | this.id = id; |
| 518 | this.kind = kind; |
| 519 | this.a1 = 0; |
| 520 | this.a2 = new Array(DATA_SIZE); |
| 521 | } |
| 522 | |
| 523 | /** |
| 524 | * Add this packet to the end of a worklist, and return the worklist. |
| 525 | * @param {Packet} queue the worklist to add this packet to |
| 526 | */ |
| 527 | Packet.prototype.addTo = function (queue) { |
| 528 | this.link = null; |
| 529 | if (queue == null) return this; |
| 530 | var peek, next = queue; |
| 531 | while ((peek = next.link) != null) |
| 532 | next = peek; |
| 533 | next.link = this; |
| 534 | return queue; |
| 535 | }; |
| 536 | |
| 537 | Packet.prototype.toString = function () { |
| 538 | return "Packet"; |
| 539 | }; |