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// Copyright 2006-2008 the V8 project authors. All rights reserved.
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following
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// disclaimer in the documentation and/or other materials provided
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// with the distribution.
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// * Neither the name of Google Inc. nor the names of its
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// contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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// This is a JavaScript implementation of the Richards
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// benchmark from:
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//
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// http://www.cl.cam.ac.uk/~mr10/Bench.html
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//
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// The benchmark was originally implemented in BCPL by
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// Martin Richards.
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var Richards = new BenchmarkSuite('Richards', 34886, [
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new Benchmark("Richards", runRichards)
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]);
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/**
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* The Richards benchmark simulates the task dispatcher of an
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* operating system.
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**/
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function runRichards() {
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var scheduler = new Scheduler();
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scheduler.addIdleTask(ID_IDLE, 0, null, COUNT);
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var queue = new Packet(null, ID_WORKER, KIND_WORK);
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queue = new Packet(queue, ID_WORKER, KIND_WORK);
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scheduler.addWorkerTask(ID_WORKER, 1000, queue);
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queue = new Packet(null, ID_DEVICE_A, KIND_DEVICE);
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queue = new Packet(queue, ID_DEVICE_A, KIND_DEVICE);
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queue = new Packet(queue, ID_DEVICE_A, KIND_DEVICE);
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scheduler.addHandlerTask(ID_HANDLER_A, 2000, queue);
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queue = new Packet(null, ID_DEVICE_B, KIND_DEVICE);
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queue = new Packet(queue, ID_DEVICE_B, KIND_DEVICE);
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queue = new Packet(queue, ID_DEVICE_B, KIND_DEVICE);
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scheduler.addHandlerTask(ID_HANDLER_B, 3000, queue);
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scheduler.addDeviceTask(ID_DEVICE_A, 4000, null);
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scheduler.addDeviceTask(ID_DEVICE_B, 5000, null);
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scheduler.schedule();
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if (scheduler.queueCount != EXPECTED_QUEUE_COUNT ||
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scheduler.holdCount != EXPECTED_HOLD_COUNT) {
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var msg =
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"Error during execution: queueCount = " + scheduler.queueCount +
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", holdCount = " + scheduler.holdCount + ".";
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throw new Error(msg);
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}
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}
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var COUNT = 1000;
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/**
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* These two constants specify how many times a packet is queued and
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* how many times a task is put on hold in a correct run of richards.
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* They don't have any meaning a such but are characteristic of a
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* correct run so if the actual queue or hold count is different from
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* the expected there must be a bug in the implementation.
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**/
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var EXPECTED_QUEUE_COUNT = 2322;
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var EXPECTED_HOLD_COUNT = 928;
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/**
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* A scheduler can be used to schedule a set of tasks based on their relative
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* priorities. Scheduling is done by maintaining a list of task control blocks
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* which holds tasks and the data queue they are processing.
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* @constructor
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*/
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function Scheduler() {
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this.queueCount = 0;
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this.holdCount = 0;
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this.blocks = new Array(NUMBER_OF_IDS);
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this.list = null;
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this.currentTcb = null;
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this.currentId = null;
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}
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var ID_IDLE = 0;
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var ID_WORKER = 1;
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var ID_HANDLER_A = 2;
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var ID_HANDLER_B = 3;
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var ID_DEVICE_A = 4;
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var ID_DEVICE_B = 5;
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var NUMBER_OF_IDS = 6;
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var KIND_DEVICE = 0;
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var KIND_WORK = 1;
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/**
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* Add an idle task to this scheduler.
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* @param {int} id the identity of the task
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* @param {int} priority the task's priority
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* @param {Packet} queue the queue of work to be processed by the task
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* @param {int} count the number of times to schedule the task
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*/
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Scheduler.prototype.addIdleTask = function (id, priority, queue, count) {
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this.addRunningTask(id, priority, queue, new IdleTask(this, 1, count));
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};
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/**
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* Add a work task to this scheduler.
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* @param {int} id the identity of the task
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* @param {int} priority the task's priority
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* @param {Packet} queue the queue of work to be processed by the task
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*/
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Scheduler.prototype.addWorkerTask = function (id, priority, queue) {
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this.addTask(id, priority, queue, new WorkerTask(this, ID_HANDLER_A, 0));
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};
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/**
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* Add a handler task to this scheduler.
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* @param {int} id the identity of the task
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* @param {int} priority the task's priority
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* @param {Packet} queue the queue of work to be processed by the task
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*/
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Scheduler.prototype.addHandlerTask = function (id, priority, queue) {
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this.addTask(id, priority, queue, new HandlerTask(this));
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};
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/**
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* Add a handler task to this scheduler.
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* @param {int} id the identity of the task
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* @param {int} priority the task's priority
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* @param {Packet} queue the queue of work to be processed by the task
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*/
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Scheduler.prototype.addDeviceTask = function (id, priority, queue) {
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this.addTask(id, priority, queue, new DeviceTask(this))
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};
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/**
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* Add the specified task and mark it as running.
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* @param {int} id the identity of the task
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* @param {int} priority the task's priority
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* @param {Packet} queue the queue of work to be processed by the task
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* @param {Task} task the task to add
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*/
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Scheduler.prototype.addRunningTask = function (id, priority, queue, task) {
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this.addTask(id, priority, queue, task);
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this.currentTcb.setRunning();
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};
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/**
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* Add the specified task to this scheduler.
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* @param {int} id the identity of the task
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* @param {int} priority the task's priority
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* @param {Packet} queue the queue of work to be processed by the task
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* @param {Task} task the task to add
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*/
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Scheduler.prototype.addTask = function (id, priority, queue, task) {
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this.currentTcb = new TaskControlBlock(this.list, id, priority, queue, task);
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this.list = this.currentTcb;
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this.blocks[id] = this.currentTcb;
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};
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/**
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* Execute the tasks managed by this scheduler.
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*/
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Scheduler.prototype.schedule = function () {
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this.currentTcb = this.list;
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while (this.currentTcb != null) {
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if (this.currentTcb.isHeldOrSuspended()) {
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this.currentTcb = this.currentTcb.link;
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} else {
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this.currentId = this.currentTcb.id;
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this.currentTcb = this.currentTcb.run();
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}
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}
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};
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/**
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* Release a task that is currently blocked and return the next block to run.
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* @param {int} id the id of the task to suspend
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*/
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Scheduler.prototype.release = function (id) {
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var tcb = this.blocks[id];
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if (tcb == null) return tcb;
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tcb.markAsNotHeld();
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if (tcb.priority > this.currentTcb.priority) {
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return tcb;
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} else {
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return this.currentTcb;
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}
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};
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/**
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* Block the currently executing task and return the next task control block
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* to run. The blocked task will not be made runnable until it is explicitly
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* released, even if new work is added to it.
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*/
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Scheduler.prototype.holdCurrent = function () {
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this.holdCount++;
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this.currentTcb.markAsHeld();
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return this.currentTcb.link;
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};
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/**
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* Suspend the currently executing task and return the next task control block
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* to run. If new work is added to the suspended task it will be made runnable.
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*/
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Scheduler.prototype.suspendCurrent = function () {
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this.currentTcb.markAsSuspended();
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return this.currentTcb;
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};
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/**
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* Add the specified packet to the end of the worklist used by the task
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* associated with the packet and make the task runnable if it is currently
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* suspended.
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* @param {Packet} packet the packet to add
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*/
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Scheduler.prototype.queue = function (packet) {
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var t = this.blocks[packet.id];
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if (t == null) return t;
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this.queueCount++;
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packet.link = null;
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packet.id = this.currentId;
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return t.checkPriorityAdd(this.currentTcb, packet);
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};
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/**
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* A task control block manages a task and the queue of work packages associated
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* with it.
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* @param {TaskControlBlock} link the preceding block in the linked block list
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* @param {int} id the id of this block
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* @param {int} priority the priority of this block
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* @param {Packet} queue the queue of packages to be processed by the task
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* @param {Task} task the task
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* @constructor
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*/
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function TaskControlBlock(link, id, priority, queue, task) {
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this.link = link;
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this.id = id;
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this.priority = priority;
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this.queue = queue;
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this.task = task;
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if (queue == null) {
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this.state = STATE_SUSPENDED;
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} else {
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this.state = STATE_SUSPENDED_RUNNABLE;
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}
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}
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/**
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* The task is running and is currently scheduled.
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*/
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var STATE_RUNNING = 0;
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/**
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* The task has packets left to process.
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*/
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var STATE_RUNNABLE = 1;
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/**
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* The task is not currently running. The task is not blocked as such and may
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* be started by the scheduler.
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*/
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var STATE_SUSPENDED = 2;
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/**
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* The task is blocked and cannot be run until it is explicitly released.
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*/
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var STATE_HELD = 4;
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var STATE_SUSPENDED_RUNNABLE = STATE_SUSPENDED | STATE_RUNNABLE;
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var STATE_NOT_HELD = ~STATE_HELD;
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TaskControlBlock.prototype.setRunning = function () {
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this.state = STATE_RUNNING;
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};
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TaskControlBlock.prototype.markAsNotHeld = function () {
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this.state = this.state & STATE_NOT_HELD;
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};
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TaskControlBlock.prototype.markAsHeld = function () {
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this.state = this.state | STATE_HELD;
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};
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TaskControlBlock.prototype.isHeldOrSuspended = function () {
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return (this.state & STATE_HELD) != 0 || (this.state == STATE_SUSPENDED);
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};
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TaskControlBlock.prototype.markAsSuspended = function () {
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this.state = this.state | STATE_SUSPENDED;
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};
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TaskControlBlock.prototype.markAsRunnable = function () {
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this.state = this.state | STATE_RUNNABLE;
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};
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/**
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* Runs this task, if it is ready to be run, and returns the next task to run.
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*/
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TaskControlBlock.prototype.run = function () {
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var packet;
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if (this.state == STATE_SUSPENDED_RUNNABLE) {
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packet = this.queue;
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this.queue = packet.link;
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if (this.queue == null) {
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this.state = STATE_RUNNING;
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} else {
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this.state = STATE_RUNNABLE;
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}
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} else {
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packet = null;
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}
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return this.task.run(packet);
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};
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/**
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* Adds a packet to the worklist of this block's task, marks this as runnable if
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* necessary, and returns the next runnable object to run (the one
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* with the highest priority).
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*/
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TaskControlBlock.prototype.checkPriorityAdd = function (task, packet) {
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if (this.queue == null) {
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this.queue = packet;
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this.markAsRunnable();
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if (this.priority > task.priority) return this;
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} else {
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this.queue = packet.addTo(this.queue);
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}
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return task;
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};
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TaskControlBlock.prototype.toString = function () {
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return "tcb { " + this.task + "@" + this.state + " }";
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};
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/**
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* An idle task doesn't do any work itself but cycles control between the two
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* device tasks.
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* @param {Scheduler} scheduler the scheduler that manages this task
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* @param {int} v1 a seed value that controls how the device tasks are scheduled
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* @param {int} count the number of times this task should be scheduled
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* @constructor
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*/
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function IdleTask(scheduler, v1, count) {
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this.scheduler = scheduler;
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this.v1 = v1;
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this.count = count;
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}
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IdleTask.prototype.run = function (packet) {
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this.count--;
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|
if (this.count == 0) return this.scheduler.holdCurrent();
|
|
|
|
if ((this.v1 & 1) == 0) {
|
|
|
|
this.v1 = this.v1 >> 1;
|
|
|
|
return this.scheduler.release(ID_DEVICE_A);
|
|
|
|
} else {
|
|
|
|
this.v1 = (this.v1 >> 1) ^ 0xD008;
|
|
|
|
return this.scheduler.release(ID_DEVICE_B);
|
|
|
|
}
|
|
|
|
};
|
|
|
|
|
|
|
|
IdleTask.prototype.toString = function () {
|
|
|
|
return "IdleTask"
|
|
|
|
};
|
|
|
|
|
|
|
|
/**
|
|
|
|
* A task that suspends itself after each time it has been run to simulate
|
|
|
|
* waiting for data from an external device.
|
|
|
|
* @param {Scheduler} scheduler the scheduler that manages this task
|
|
|
|
* @constructor
|
|
|
|
*/
|
|
|
|
function DeviceTask(scheduler) {
|
|
|
|
this.scheduler = scheduler;
|
|
|
|
this.v1 = null;
|
|
|
|
}
|
|
|
|
|
|
|
|
DeviceTask.prototype.run = function (packet) {
|
|
|
|
if (packet == null) {
|
|
|
|
if (this.v1 == null) return this.scheduler.suspendCurrent();
|
|
|
|
var v = this.v1;
|
|
|
|
this.v1 = null;
|
|
|
|
return this.scheduler.queue(v);
|
|
|
|
} else {
|
|
|
|
this.v1 = packet;
|
|
|
|
return this.scheduler.holdCurrent();
|
|
|
|
}
|
|
|
|
};
|
|
|
|
|
|
|
|
DeviceTask.prototype.toString = function () {
|
|
|
|
return "DeviceTask";
|
|
|
|
};
|
|
|
|
|
|
|
|
/**
|
|
|
|
* A task that manipulates work packets.
|
|
|
|
* @param {Scheduler} scheduler the scheduler that manages this task
|
|
|
|
* @param {int} v1 a seed used to specify how work packets are manipulated
|
|
|
|
* @param {int} v2 another seed used to specify how work packets are manipulated
|
|
|
|
* @constructor
|
|
|
|
*/
|
|
|
|
function WorkerTask(scheduler, v1, v2) {
|
|
|
|
this.scheduler = scheduler;
|
|
|
|
this.v1 = v1;
|
|
|
|
this.v2 = v2;
|
|
|
|
}
|
|
|
|
|
|
|
|
WorkerTask.prototype.run = function (packet) {
|
|
|
|
if (packet == null) {
|
|
|
|
return this.scheduler.suspendCurrent();
|
|
|
|
} else {
|
|
|
|
if (this.v1 == ID_HANDLER_A) {
|
|
|
|
this.v1 = ID_HANDLER_B;
|
|
|
|
} else {
|
|
|
|
this.v1 = ID_HANDLER_A;
|
|
|
|
}
|
|
|
|
packet.id = this.v1;
|
|
|
|
packet.a1 = 0;
|
|
|
|
for (var i = 0; i < DATA_SIZE; i++) {
|
|
|
|
this.v2++;
|
|
|
|
if (this.v2 > 26) this.v2 = 1;
|
|
|
|
packet.a2[i] = this.v2;
|
|
|
|
}
|
|
|
|
return this.scheduler.queue(packet);
|
|
|
|
}
|
|
|
|
};
|
|
|
|
|
|
|
|
WorkerTask.prototype.toString = function () {
|
|
|
|
return "WorkerTask";
|
|
|
|
};
|
|
|
|
|
|
|
|
/**
|
|
|
|
* A task that manipulates work packets and then suspends itself.
|
|
|
|
* @param {Scheduler} scheduler the scheduler that manages this task
|
|
|
|
* @constructor
|
|
|
|
*/
|
|
|
|
function HandlerTask(scheduler) {
|
|
|
|
this.scheduler = scheduler;
|
|
|
|
this.v1 = null;
|
|
|
|
this.v2 = null;
|
|
|
|
}
|
|
|
|
|
|
|
|
HandlerTask.prototype.run = function (packet) {
|
|
|
|
if (packet != null) {
|
|
|
|
if (packet.kind == KIND_WORK) {
|
|
|
|
this.v1 = packet.addTo(this.v1);
|
|
|
|
} else {
|
|
|
|
this.v2 = packet.addTo(this.v2);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
if (this.v1 != null) {
|
|
|
|
var count = this.v1.a1;
|
|
|
|
var v;
|
|
|
|
if (count < DATA_SIZE) {
|
|
|
|
if (this.v2 != null) {
|
|
|
|
v = this.v2;
|
|
|
|
this.v2 = this.v2.link;
|
|
|
|
v.a1 = this.v1.a2[count];
|
|
|
|
this.v1.a1 = count + 1;
|
|
|
|
return this.scheduler.queue(v);
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
v = this.v1;
|
|
|
|
this.v1 = this.v1.link;
|
|
|
|
return this.scheduler.queue(v);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return this.scheduler.suspendCurrent();
|
|
|
|
};
|
|
|
|
|
|
|
|
HandlerTask.prototype.toString = function () {
|
|
|
|
return "HandlerTask";
|
|
|
|
};
|
|
|
|
|
|
|
|
/* --- *
|
|
|
|
* P a c k e t
|
|
|
|
* --- */
|
|
|
|
|
|
|
|
var DATA_SIZE = 4;
|
|
|
|
|
|
|
|
/**
|
|
|
|
* A simple package of data that is manipulated by the tasks. The exact layout
|
|
|
|
* of the payload data carried by a packet is not importaint, and neither is the
|
|
|
|
* nature of the work performed on packets by the tasks.
|
|
|
|
*
|
|
|
|
* Besides carrying data, packets form linked lists and are hence used both as
|
|
|
|
* data and worklists.
|
|
|
|
* @param {Packet} link the tail of the linked list of packets
|
|
|
|
* @param {int} id an ID for this packet
|
|
|
|
* @param {int} kind the type of this packet
|
|
|
|
* @constructor
|
|
|
|
*/
|
|
|
|
function Packet(link, id, kind) {
|
|
|
|
this.link = link;
|
|
|
|
this.id = id;
|
|
|
|
this.kind = kind;
|
|
|
|
this.a1 = 0;
|
|
|
|
this.a2 = new Array(DATA_SIZE);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* Add this packet to the end of a worklist, and return the worklist.
|
|
|
|
* @param {Packet} queue the worklist to add this packet to
|
|
|
|
*/
|
|
|
|
Packet.prototype.addTo = function (queue) {
|
|
|
|
this.link = null;
|
|
|
|
if (queue == null) return this;
|
|
|
|
var peek, next = queue;
|
|
|
|
while ((peek = next.link) != null)
|
|
|
|
next = peek;
|
|
|
|
next.link = this;
|
|
|
|
return queue;
|
|
|
|
};
|
|
|
|
|
|
|
|
Packet.prototype.toString = function () {
|
|
|
|
return "Packet";
|
|
|
|
};
|