GC pauses visualization tool.

benchmarks/spinning-balls/v.js

+// Copyright 2011 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.
+
+
+/**
+ * This function provides requestAnimationFrame in a cross browser way.
+ * http://paulirish.com/2011/requestanimationframe-for-smart-animating/
+ */
+if ( !window.requestAnimationFrame ) {
+  window.requestAnimationFrame = ( function() {
+    return window.webkitRequestAnimationFrame ||
+        window.mozRequestAnimationFrame ||
+        window.oRequestAnimationFrame ||
+        window.msRequestAnimationFrame ||
+        function(callback, element) {
+          window.setTimeout( callback, 1000 / 60 );
+        };
+  } )();
+}
+
+var kNPoints = 8000;
+var kNModifications = 20;
+var kNVisiblePoints = 200;
+var kDecaySpeed = 20;
+
+var kPointRadius = 4;
+var kInitialLifeForce = 100;
+
+var livePoints = void 0;
+var dyingPoints = void 0;
+var scene = void 0;
+var renderingStartTime = void 0;
+var scene = void 0;
+var pausePlot = void 0;
+var splayTree = void 0;
+
+
+function Point(x, y, z, payload) {
+  this.x = x;
+  this.y = y;
+  this.z = z;
+
+  this.next = null;
+  this.prev = null;
+  this.payload = payload;
+  this.lifeForce = kInitialLifeForce;
+}
+
+
+Point.prototype.color = function () {
+  return "rgba(0, 0, 0, " + (this.lifeForce / kInitialLifeForce) + ")";
+};
+
+
+Point.prototype.decay = function () {
+  this.lifeForce -= kDecaySpeed;
+  return this.lifeForce <= 0;
+};
+
+
+function PointsList() {
+  this.head = null;
+  this.count = 0;
+}
+
+
+PointsList.prototype.add = function (point) {
+  if (this.head !== null) this.head.prev = point;
+  point.next = this.head;
+  this.head = point;
+  this.count++;
+}
+
+
+PointsList.prototype.remove = function (point) {
+  if (point.next !== null) {
+    point.next.prev = point.prev;
+  }
+  if (point.prev !== null) {
+    point.prev.next = point.next;
+  } else {
+    this.head = point.next;
+  }
+  this.count--;
+}
+
+
+function GeneratePayloadTree(depth, tag) {
+  if (depth == 0) {
+    return {
+      array  : [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ],
+      string : 'String for key ' + tag + ' in leaf node'
+    };
+  } else {
+    return {
+      left:  GeneratePayloadTree(depth - 1, tag),
+      right: GeneratePayloadTree(depth - 1, tag)
+    };
+  }
+}
+
+
+// To make the benchmark results predictable, we replace Math.random
+// with a 100% deterministic alternative.
+Math.random = (function() {
+  var seed = 49734321;
+  return function() {
+    // Robert Jenkins' 32 bit integer hash function.
+    seed = ((seed + 0x7ed55d16) + (seed << 12))  & 0xffffffff;
+    seed = ((seed ^ 0xc761c23c) ^ (seed >>> 19)) & 0xffffffff;
+    seed = ((seed + 0x165667b1) + (seed << 5))   & 0xffffffff;
+    seed = ((seed + 0xd3a2646c) ^ (seed << 9))   & 0xffffffff;
+    seed = ((seed + 0xfd7046c5) + (seed << 3))   & 0xffffffff;
+    seed = ((seed ^ 0xb55a4f09) ^ (seed >>> 16)) & 0xffffffff;
+    return (seed & 0xfffffff) / 0x10000000;
+  };
+})();
+
+
+function GenerateKey() {
+  // The benchmark framework guarantees that Math.random is
+  // deterministic; see base.js.
+  return Math.random();
+}
+
+function CreateNewPoint() {
+  // Insert new node with a unique key.
+  var key;
+  do { key = GenerateKey(); } while (splayTree.find(key) != null);
+
+  var point = new Point(Math.random() * 40 - 20,
+                        Math.random() * 40 - 20,
+                        Math.random() * 40 - 20,
+                        GeneratePayloadTree(5, "" + key));
+
+  livePoints.add(point);
+
+  splayTree.insert(key, point);
+  return key;
+}
+
+function ModifyPointsSet() {
+  if (livePoints.count < kNPoints) {
+    for (var i = 0; i < kNModifications; i++) {
+      CreateNewPoint();
+    }
+  } else if (kNModifications === 20) {
+    kNModifications = 80;
+    kDecay = 30;
+  }
+
+  for (var i = 0; i < kNModifications; i++) {
+    var key = CreateNewPoint();
+    var greatest = splayTree.findGreatestLessThan(key);
+    if (greatest == null) {
+      var point = splayTree.remove(key).value;
+    } else {
+      var point = splayTree.remove(greatest.key).value;
+    }
+    livePoints.remove(point);
+    point.payload = null;
+    dyingPoints.add(point);
+  }
+}
+
+
+function PausePlot(width, height, size) {
+  var canvas = document.createElement("canvas");
+  canvas.width = this.width = width;
+  canvas.height = this.height = height;
+  document.body.appendChild(canvas);
+
+  this.ctx = canvas.getContext('2d');
+
+  this.maxPause = 0;
+  this.size = size;
+
+  // Initialize cyclic buffer for pauses.
+  this.pauses = new Array(this.size);
+  this.start = this.size;
+  this.idx = 0;
+}
+
+
+PausePlot.prototype.addPause = function (p) {
+  if (this.idx === this.size) {
+    this.idx = 0;
+  }
+
+  if (this.idx === this.start) {
+    this.start++;
+  }
+
+  if (this.start === this.size) {
+    this.start = 0;
+  }
+
+  this.pauses[this.idx++] = p;
+};
+
+
+PausePlot.prototype.iteratePauses = function (f) {
+  if (this.start < this.idx) {
+    for (var i = this.start; i < this.idx; i++) {
+      f.call(this, i - this.start, this.pauses[i]);
+    }
+  } else {
+    for (var i = this.start; i < this.size; i++) {
+      f.call(this, i - this.start, this.pauses[i]);
+    }
+
+    var offs = this.size - this.start;
+    for (var i = 0; i < this.idx; i++) {
+      f.call(this, i + offs, this.pauses[i]);
+    }
+  }
+};
+
+
+PausePlot.prototype.draw = function () {
+  var first = null;
+  this.iteratePauses(function (i, v) {
+    if (first === null) {
+      first = v;
+    }
+    this.maxPause = Math.max(v, this.maxPause);
+  });
+
+  var dx = this.width / this.size;
+  var dy = this.height / this.maxPause;
+
+  this.ctx.save();
+  this.ctx.clearRect(0, 0, 480, 240);
+  this.ctx.beginPath();
+  this.ctx.moveTo(1, dy * this.pauses[this.start]);
+  var p = first;
+  this.iteratePauses(function (i, v) {
+    var delta = v - p;
+    var x = 1 + dx * i;
+    var y = dy * v;
+    this.ctx.lineTo(x, y);
+    if (delta > 2 * (p / 3)) {
+      this.ctx.font = "bold 12px sans-serif";
+      this.ctx.textBaseline = "bottom";
+      this.ctx.fillText(v + "ms", x + 2, y);
+    }
+    p = v;
+  });
+  this.ctx.strokeStyle = "black";
+  this.ctx.stroke();
+  this.ctx.restore();
+}
+
+
+function Scene(width, height) {
+  var canvas = document.createElement("canvas");
+  canvas.width = width;
+  canvas.height = height;
+  document.body.appendChild(canvas);
+
+  this.ctx = canvas.getContext('2d');
+  this.width = canvas.width;
+  this.height = canvas.height;
+
+  // Projection configuration.
+  this.x0 = canvas.width / 2;
+  this.y0 = canvas.height / 2;
+  this.z0 = 100;
+  this.f  = 1000;  // Focal length.
+
+  // Camera is rotating around y-axis.
+  this.angle = 0;
+}
+
+
+Scene.prototype.drawPoint = function (x, y, z, color) {
+  // Rotate the camera around y-axis.
+  var rx = x * Math.cos(this.angle) - z * Math.sin(this.angle);
+  var ry = y;
+  var rz = x * Math.sin(this.angle) + z * Math.cos(this.angle);
+
+  // Perform perspective projection.
+  var px = (this.f * rx) / (rz - this.z0) + this.x0;
+  var py = (this.f * ry) / (rz - this.z0) + this.y0;
+
+  this.ctx.save();
+  this.ctx.fillStyle = color
+  this.ctx.beginPath();
+  this.ctx.arc(px, py, kPointRadius, 0, 2 * Math.PI, true);
+  this.ctx.fill();
+  this.ctx.restore();
+};
+
+
+Scene.prototype.drawDyingPoints = function () {
+  var point_next = null;
+  for (var point = dyingPoints.head; point !== null; point = point_next) {
+    // Rotate the scene around y-axis.
+    scene.drawPoint(point.x, point.y, point.z, point.color());
+
+    point_next = point.next;
+
+    // Decay the current point and remove it from the list
+    // if it's life-force ran out.
+    if (point.decay()) {
+      dyingPoints.remove(point);
+    }
+  }
+};
+
+
+Scene.prototype.draw = function () {
+  this.ctx.save();
+  this.ctx.clearRect(0, 0, this.width, this.height);
+  this.drawDyingPoints();
+  this.ctx.restore();
+
+  this.angle += Math.PI / 90.0;
+};
+
+
+function render() {
+  if (typeof renderingStartTime === 'undefined') {
+    renderingStartTime = Date.now();
+  }
+
+  ModifyPointsSet();
+
+  scene.draw();
+
+  var renderingEndTime = Date.now();
+  var pause = renderingEndTime - renderingStartTime;
+  pausePlot.addPause(pause);
+  renderingStartTime = renderingEndTime;
+
+  pausePlot.draw();
+
+  div.innerHTML =
+      livePoints.count + "/" + dyingPoints.count + " " +
+      pause + "(max = " + pausePlot.maxPause + ") ms" ;
+
+  // Schedule next frame.
+  requestAnimationFrame(render);
+}
+
+
+function init() {
+  livePoints = new PointsList;
+  dyingPoints = new PointsList;
+
+  splayTree = new SplayTree();
+
+  scene = new Scene(640, 480);
+
+  div = document.createElement("div");
+  document.body.appendChild(div);
+
+  pausePlot = new PausePlot(480, 240, 160);
+}
+
+
+init();
+render();