jsx
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a faster, safer, easier JavaScript
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JSX
// -*- mode: jsx; jsx-indent-level: 4; indent-tabs-mode: nil; -*-
// Copyright 2006-2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
import "./base.jsx";
// This is a JavaScript implementation of the Richards
// benchmark from:
//
// http://www.cl.cam.ac.uk/~mr10/Bench.html
//
// The benchmark was originally implemented in BCPL by
// Martin Richards.
class Richards {
static const COUNT = 1000;
/**
* These two constants specify how many times a packet is queued and
* how many times a task is put on hold in a correct run of richards.
* They don't have any meaning a such but are characteristic of a
* correct run so if the actual queue or hold count is different from
* the expected there must be a bug in the implementation.
**/
static const EXPECTED_QUEUE_COUNT = 2322;
static const EXPECTED_HOLD_COUNT = 928;
function constructor() {
var richards = new BenchmarkSuite('Richards', 35302, [
new Benchmark("Richards", function() { this.runRichards(); })
]);
}
/**
* The Richards benchmark simulates the task dispatcher of an
* operating system.
**/
function runRichards() : void {
var scheduler = new Scheduler();
scheduler.addIdleTask(Scheduler.ID_IDLE, 0, null, Richards.COUNT);
var queue = new Packet(null, Scheduler.ID_WORKER, Scheduler.KIND_WORK);
queue = new Packet(queue, Scheduler.ID_WORKER, Scheduler.KIND_WORK);
scheduler.addWorkerTask(Scheduler.ID_WORKER, 1000, queue);
queue = new Packet(null, Scheduler.ID_DEVICE_A, Scheduler.KIND_DEVICE);
queue = new Packet(queue, Scheduler.ID_DEVICE_A, Scheduler.KIND_DEVICE);
queue = new Packet(queue, Scheduler.ID_DEVICE_A, Scheduler.KIND_DEVICE);
scheduler.addHandlerTask(Scheduler.ID_HANDLER_A, 2000, queue);
queue = new Packet(null, Scheduler.ID_DEVICE_B, Scheduler.KIND_DEVICE);
queue = new Packet(queue, Scheduler.ID_DEVICE_B, Scheduler.KIND_DEVICE);
queue = new Packet(queue, Scheduler.ID_DEVICE_B, Scheduler.KIND_DEVICE);
scheduler.addHandlerTask(Scheduler.ID_HANDLER_B, 3000, queue);
scheduler.addDeviceTask(Scheduler.ID_DEVICE_A, 4000, null);
scheduler.addDeviceTask(Scheduler.ID_DEVICE_B, 5000, null);
scheduler.schedule();
if (scheduler.queueCount != Richards.EXPECTED_QUEUE_COUNT ||
scheduler.holdCount != Richards.EXPECTED_HOLD_COUNT) {
var msg =
"Error during execution: queueCount = " + scheduler.queueCount as string +
", holdCount = " + scheduler.holdCount as string + ".";
throw new Error(msg);
}
}
}
class Scheduler {
static const ID_IDLE = 0;
static const ID_WORKER = 1;
static const ID_HANDLER_A = 2;
static const ID_HANDLER_B = 3;
static const ID_DEVICE_A = 4;
static const ID_DEVICE_B = 5;
static const NUMBER_OF_IDS = 6;
static const KIND_DEVICE = 0;
static const KIND_WORK = 1;
var queueCount : int;
var holdCount : int;
var blocks : TaskControlBlock[];
var list : TaskControlBlock;
var currentTcb : TaskControlBlock;
var currentId : Nullable.<int>;
/**
* A scheduler can be used to schedule a set of tasks based on their relative
* priorities. Scheduling is done by maintaining a list of task control blocks
* which holds tasks and the data queue they are processing.
* @constructor
*/
function constructor() {
this.queueCount = 0;
this.holdCount = 0;
this.blocks = new Array.<TaskControlBlock>(Scheduler.NUMBER_OF_IDS);
this.list = null;
this.currentTcb = null;
this.currentId = null;
}
/**
* Add an idle task to this scheduler.
* @param id the identity of the task
* @param priority the task's priority
* @param queue the queue of work to be processed by the task
* @param count the number of times to schedule the task
*/
function addIdleTask(id : int, priority : int, queue : Packet, count : int) : void {
this.addRunningTask(id, priority, queue, new IdleTask(this, 1, count));
}
/**
* Add a work task to this scheduler.
* @param id the identity of the task
* @param priority the task's priority
* @param queue the queue of work to be processed by the task
*/
function addWorkerTask(id : int, priority : int , queue : Packet) : void {
this.addTask(id, priority, queue, new WorkerTask(this, Scheduler.ID_HANDLER_A, 0));
}
/**
* Add a handler task to this scheduler.
* @param id the identity of the task
* @param priority the task's priority
* @param queue the queue of work to be processed by the task
*/
function addHandlerTask(id : int, priority : int, queue : Packet) : void {
this.addTask(id, priority, queue, new HandlerTask(this));
}
/**
* Add a handler task to this scheduler.
* @param id the identity of the task
* @param priority the task's priority
* @param queue the queue of work to be processed by the task
*/
function addDeviceTask(id : int, priority : int, queue : Packet) : void {
this.addTask(id, priority, queue, new DeviceTask(this));
}
/**
* Add the specified task and mark it as running.
* @param id the identity of the task
* @param priority the task's priority
* @param queue the queue of work to be processed by the task
* @param task the task to add
*/
function addRunningTask(id : int, priority : int, queue : Packet, task : Task) : void {
this.addTask(id, priority, queue, task);
this.currentTcb.setRunning();
}
/**
* Add the specified task to this scheduler.
* @param id the identity of the task
* @param priority the task's priority
* @param queue the queue of work to be processed by the task
* @param task the task to add
*/
function addTask(id : int, priority : int, queue : Packet, task : Task) : void {
this.currentTcb = new TaskControlBlock(this.list, id, priority, queue, task);
this.list = this.currentTcb;
this.blocks[id] = this.currentTcb;
}
/**
* Execute the tasks managed by this scheduler.
*/
function schedule() : void {
this.currentTcb = this.list;
while (this.currentTcb != null) {
if (this.currentTcb.isHeldOrSuspended()) {
this.currentTcb = this.currentTcb.link;
} else {
this.currentId = this.currentTcb.id;
this.currentTcb = this.currentTcb.run();
}
}
}
/**
* Release a task that is currently blocked and return the next block to run.
* @param id the id of the task to suspend
*/
function release(id : int) : TaskControlBlock {
var tcb = this.blocks[id];
if (tcb == null) return tcb;
tcb.markAsNotHeld();
if (tcb.priority > this.currentTcb.priority) {
return tcb;
} else {
return this.currentTcb;
}
}
/**
* Block the currently executing task and return the next task control block
* to run. The blocked task will not be made runnable until it is explicitly
* released, even if new work is added to it.
*/
function holdCurrent() : TaskControlBlock {
this.holdCount++;
this.currentTcb.markAsHeld();
return this.currentTcb.link;
}
/**
* Suspend the currently executing task and return the next task control block
* to run. If new work is added to the suspended task it will be made runnable.
*/
function suspendCurrent() : TaskControlBlock {
this.currentTcb.markAsSuspended();
return this.currentTcb;
}
/**
* Add the specified packet to the end of the worklist used by the task
* associated with the packet and make the task runnable if it is currently
* suspended.
* @param packet the packet to add
*/
function queue(packet : Packet) : TaskControlBlock {
var t = this.blocks[packet.id];
if (t == null) return t;
this.queueCount++;
packet.link = null;
packet.id = this.currentId;
return t.checkPriorityAdd(this.currentTcb, packet);
}
}
class TaskControlBlock {
/**
* The task is running and is currently scheduled.
*/
static const STATE_RUNNING = 0;
/**
* The task has packets left to process.
*/
static const STATE_RUNNABLE = 1;
/**
* The task is not currently running. The task is not blocked as such and may
* be started by the scheduler.
*/
static const STATE_SUSPENDED = 2;
/**
* The task is blocked and cannot be run until it is explicitly released.
*/
static const STATE_HELD = 4;
static const STATE_SUSPENDED_RUNNABLE = TaskControlBlock.STATE_SUSPENDED | TaskControlBlock.STATE_RUNNABLE;
static const STATE_NOT_HELD = ~TaskControlBlock.STATE_HELD;
var link : TaskControlBlock;
var id : int;
var priority : int;
var queue : Packet;
var task : Task;
var state : int;
/**
* A task control block manages a task and the queue of work packages associated
* with it.
* @param link the preceding block in the linked block list
* @param id the id of this block
* @param priority the priority of this block
* @param queue the queue of packages to be processed by the task
* @param task the task
* @constructor
*/
function constructor(link : TaskControlBlock, id : int, priority : int, queue : Packet, task : Task) {
this.link = link;
this.id = id;
this.priority = priority;
this.queue = queue;
this.task = task;
if (queue == null) {
this.state = TaskControlBlock.STATE_SUSPENDED;
} else {
this.state = TaskControlBlock.STATE_SUSPENDED_RUNNABLE;
}
}
function setRunning() : void {
this.state = TaskControlBlock.STATE_RUNNING;
}
function markAsNotHeld() : void {
this.state = this.state & TaskControlBlock.STATE_NOT_HELD;
}
function markAsHeld() : void {
this.state = this.state | TaskControlBlock.STATE_HELD;
}
function isHeldOrSuspended() : boolean {
return (this.state & TaskControlBlock.STATE_HELD) != 0 || (this.state == TaskControlBlock.STATE_SUSPENDED);
}
function markAsSuspended() : void {
this.state = this.state | TaskControlBlock.STATE_SUSPENDED;
}
function markAsRunnable() : void {
this.state = this.state | TaskControlBlock.STATE_RUNNABLE;
}
/**
* Runs this task, if it is ready to be run, and returns the next task to run.
*/
function run() : TaskControlBlock {
var packet;
if (this.state == TaskControlBlock.STATE_SUSPENDED_RUNNABLE) {
packet = this.queue;
this.queue = packet.link;
if (this.queue == null) {
this.state = TaskControlBlock.STATE_RUNNING;
} else {
this.state = TaskControlBlock.STATE_RUNNABLE;
}
} else {
packet = null;
}
return this.task.run(packet);
}
/**
* Adds a packet to the worklist of this block's task, marks this as runnable if
* necessary, and returns the next runnable object to run (the one
* with the highest priority).
*/
function checkPriorityAdd(task : TaskControlBlock, packet : Packet) : TaskControlBlock {
if (this.queue == null) {
this.queue = packet;
this.markAsRunnable();
if (this.priority > task.priority) return this;
} else {
this.queue = packet.addTo(this.queue);
}
return task;
}
override function toString() : string {
return "tcb { " + this.task.toString() + "@" + this.state.toString() + " }";
}
}
abstract class Task {
var scheduler : Scheduler;
function constructor(scheduler : Scheduler) {
this.scheduler = scheduler;
}
abstract function run(packet : Packet) : TaskControlBlock;
}
class IdleTask extends Task {
var v1 : int;
var count : int;
/**
* An idle task doesn't do any work itself but cycles control between the two
* device tasks.
* @param scheduler the scheduler that manages this task
* @param v1 a seed value that controls how the device tasks are scheduled
* @param count the number of times this task should be scheduled
* @constructor
*/
function constructor(scheduler : Scheduler, v1 : int, count : int) {
super(scheduler);
this.v1 = v1;
this.count = count;
}
override function run(packet : Packet) : TaskControlBlock {
this.count--;
if (this.count == 0) return this.scheduler.holdCurrent();
if ((this.v1 & 1) == 0) {
this.v1 = this.v1 >> 1;
return this.scheduler.release(Scheduler.ID_DEVICE_A);
} else {
this.v1 = (this.v1 >> 1) ^ 0xD008;
return this.scheduler.release(Scheduler.ID_DEVICE_B);
}
}
override function toString() : string {
return "IdleTask";
}
}
class DeviceTask extends Task {
var v1 : Packet;
/**
* A task that suspends itself after each time it has been run to simulate
* waiting for data from an external device.
* @param scheduler the scheduler that manages this task
* @constructor
*/
function constructor(scheduler : Scheduler) {
super(scheduler);
this.v1 = null;
}
override function run(packet : Packet) : TaskControlBlock {
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();
}
}
override function toString() : string {
return "DeviceTask";
}
}
class WorkerTask extends Task {
var v1 : int;
var v2 : int;
/**
* A task that manipulates work packets.
* @param scheduler the scheduler that manages this task
* @param v1 a seed used to specify how work packets are manipulated
* @param v2 another seed used to specify how work packets are manipulated
* @constructor
*/
function constructor(scheduler : Scheduler, v1 : int, v2 : int) {
super(scheduler);
this.v1 = v1;
this.v2 = v2;
}
override function run(packet : Packet) : TaskControlBlock {
if (packet == null) {
return this.scheduler.suspendCurrent();
} else {
if (this.v1 == Scheduler.ID_HANDLER_A) {
this.v1 = Scheduler.ID_HANDLER_B;
} else {
this.v1 = Scheduler.ID_HANDLER_A;
}
packet.id = this.v1;
packet.a1 = 0;
for (var i = 0; i < Packet.DATA_SIZE; i++) {
this.v2++;
if (this.v2 > 26) this.v2 = 1;
packet.a2[i] = this.v2;
}
return this.scheduler.queue(packet);
}
}
override function toString() : string {
return "WorkerTask";
}
}
class HandlerTask extends Task {
var v1 : Packet;
var v2 : Packet;
/**
* A task that manipulates work packets and then suspends itself.
* @param scheduler the scheduler that manages this task
* @constructor
*/
function constructor(scheduler : Scheduler) {
super(scheduler);
this.v1 = null;
this.v2 = null;
}
override function run(packet : Packet) : TaskControlBlock {
if (packet != null) {
if (packet.kind == Scheduler.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 < Packet.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();
}
override function toString() : string {
return "HandlerTask";
}
}
/* --- *
* P a c k e t
* --- */
class Packet {
static const DATA_SIZE = 4;
var link : Packet;
var id : int;
var kind : int;
var a1 : int;
var a2 : int[];
/**
* 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 link the tail of the linked list of packets
* @param id an ID for this packet
* @param kind the type of this packet
* @constructor
*/
function constructor(link : Packet, id : int, kind : int) {
this.link = link;
this.id = id;
this.kind = kind;
this.a1 = 0;
this.a2 = new Array.<int>(Packet.DATA_SIZE);
}
/**
* Add this packet to the end of a worklist, and return the worklist.
* @param queue the worklist to add this packet to
*/
function addTo(queue : Packet) : Packet {
this.link = null;
if (queue == null) return this;
var peek, next = queue;
while ((peek = next.link) != null)
next = peek;
next.link = this;
return queue;
}
override function toString() : string {
return "Packet";
}
}
// vim: set expandtab: