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Merge pull request #780 from mzgoddard/runtime-profiler

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Runtime profiler
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kchadha 2017-11-16 10:02:37 -05:00 committed by GitHub
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28
src/engine/execute.js
View file

@ -9,6 +9,18 @@ const {Map} = require('immutable');
*/
const blockUtility = new BlockUtility();
/**
* Profiler frame name for block functions.
* @const {string}
*/
const blockFunctionProfilerFrame = 'blockFunction';
/**
* Profiler frame ID for 'blockFunction'.
* @type {number}
*/
let blockFunctionProfilerId = -1;
/**
* Utility function to determine if a value is a Promise.
* @param {*} value Value to check for a Promise.
@ -207,7 +219,23 @@ const execute = function (sequencer, thread) {
let primitiveReportedValue = null;
blockUtility.sequencer = sequencer;
blockUtility.thread = thread;
if (runtime.profiler !== null) {
if (blockFunctionProfilerId === -1) {
blockFunctionProfilerId = runtime.profiler.idByName(blockFunctionProfilerFrame);
}
// The method commented below has its code inlined underneath to reduce
// the bias recorded for the profiler's calls in this time sensitive
// execute function.
//
// runtime.profiler.start(blockFunctionProfilerId, opcode);
runtime.profiler.records.push(
runtime.profiler.START, blockFunctionProfilerId, opcode, performance.now());
}
primitiveReportedValue = blockFunction(argValues, blockUtility);
if (runtime.profiler !== null) {
// runtime.profiler.stop(blockFunctionProfilerId);
runtime.profiler.records.push(runtime.profiler.STOP, performance.now());
}
if (typeof primitiveReportedValue === 'undefined') {
// No value reported - potentially a command block.

311
src/engine/profiler.js Normal file
View file

@ -0,0 +1,311 @@
/**
* @fileoverview
* A way to profile Scratch internal performance. Like what blocks run during a
* step? How much time do they take? How much time is spent inbetween blocks?
*
* Profiler aims for to spend as little time inside its functions while
* recording. For this it has a simple internal record structure that records a
* series of values for each START and STOP event in a single array. This lets
* all the values be pushed in one call for the array. This simplicity allows
* the contents of the start() and stop() calls to be inlined in areas that are
* called frequently enough to want even greater performance from Profiler so
* what is recorded better reflects on the profiled code and not Profiler
* itself.
*/
/**
* The next id returned for a new profile'd function.
* @type {number}
*/
let nextId = 0;
/**
* The mapping of names to ids.
* @const {Object.<string, number>}
*/
const profilerNames = {};
/**
* The START event identifier in Profiler records.
* @const {number}
*/
const START = 0;
/**
* The STOP event identifier in Profiler records.
* @const {number}
*/
const STOP = 1;
/**
* The number of cells used in the records array by a START event.
* @const {number}
*/
const START_SIZE = 4;
/**
* The number of cells used in the records array by a STOP event.
* @const {number}
*/
const STOP_SIZE = 2;
/**
* Stored reference to Performance instance provided by the Browser.
* @const {Performance}
*/
const performance = typeof window === 'object' && window.performance;
/**
* Callback handle called by Profiler for each frame it decodes from its
* records.
* @callback FrameCallback
* @param {ProfilerFrame} frame
*/
/**
* A set of information about a frame of execution that was recorded.
*/
class ProfilerFrame {
/**
* @param {number} depth Depth of the frame in the recorded stack.
*/
constructor (depth) {
/**
* The numeric id of a record symbol like Runtime._step or
* blockFunction.
* @type {number}
*/
this.id = -1;
/**
* The amount of time spent inside the recorded frame and any deeper
* frames.
* @type {number}
*/
this.totalTime = 0;
/**
* The amount of time spent only inside this record frame. Not
* including time in any deeper frames.
* @type {number}
*/
this.selfTime = 0;
/**
* An arbitrary argument for the recorded frame. For example a block
* function might record its opcode as an argument.
* @type {*}
*/
this.arg = null;
/**
* The depth of the recorded frame. This can help compare recursive
* funtions that are recorded. Each level of recursion with have a
* different depth value.
* @type {number}
*/
this.depth = depth;
}
}
class Profiler {
/**
* @param {FrameCallback} onFrame a handle called for each recorded frame.
* The passed frame value may not be stored as it'll be updated with later
* frame information. Any information that is further stored by the handler
* should make copies or reduce the information.
*/
constructor (onFrame = function () {}) {
/**
* A series of START and STOP values followed by arguments. After
* recording is complete the full set of records is reported back by
* stepping through the series to connect the relative START and STOP
* information.
* @type {Array.<*>}
*/
this.records = [];
/**
* A cache of ProfilerFrames to reuse when reporting the recorded
* frames in records.
* @type {Array.<ProfilerFrame>}
*/
this._stack = [new ProfilerFrame(0)];
/**
* A callback handle called with each decoded frame when reporting back
* all the recorded times.
* @type {FrameCallback}
*/
this.onFrame = onFrame;
/**
* A reference to the START record id constant.
* @const {number}
*/
this.START = START;
/**
* A reference to the STOP record id constant.
* @const {number}
*/
this.STOP = STOP;
}
/**
* Start recording a frame of time for an id and optional argument.
* @param {number} id The id returned by idByName for a name symbol like
* Runtime._step.
* @param {?*} arg An arbitrary argument value to store with the frame.
*/
start (id, arg) {
this.records.push(START, id, arg, performance.now());
}
/**
* Stop the current frame.
*/
stop () {
this.records.push(STOP, performance.now());
}
/**
* Decode records and report all frames to `this.onFrame`.
*/
reportFrames () {
const stack = this._stack;
let depth = 1;
// Step through the records and initialize Frame instances from the
// START and STOP events. START and STOP events are separated by events
// for deeper frames run by higher frames. Frames are stored on a stack
// and reinitialized for each START event. When a stop event is reach
// the Frame for the current depth has its final values stored and its
// passed to the current onFrame callback. This way Frames are "pushed"
// for each START event and "popped" for each STOP and handed to an
// outside handle to any desired reduction of the collected data.
for (let i = 0; i < this.records.length;) {
if (this.records[i] === START) {
if (depth >= stack.length) {
stack.push(new ProfilerFrame(depth));
}
// Store id, arg, totalTime, and initialize selfTime.
const frame = stack[depth++];
frame.id = this.records[i + 1];
frame.arg = this.records[i + 2];
// totalTime is first set as the time recorded by this START
// event. Once the STOP event is reached the stored start time
// is subtracted from the recorded stop time. The resulting
// difference is the actual totalTime, and replaces the start
// time in frame.totalTime.
//
// totalTime is used this way as a convenient member to store a
// value between the two events without needing additional
// members on the Frame or in a shadow map.
frame.totalTime = this.records[i + 3];
// selfTime is decremented until we reach the STOP event for
// this frame. totalTime will be added to it then to get the
// time difference.
frame.selfTime = 0;
i += START_SIZE;
} else if (this.records[i] === STOP) {
const now = this.records[i + 1];
const frame = stack[--depth];
// totalTime is the difference between the start event time
// stored in totalTime and the stop event time pulled from this
// record.
frame.totalTime = now - frame.totalTime;
// selfTime is the difference of this frame's totalTime and the
// sum of totalTime of deeper frames.
frame.selfTime += frame.totalTime;
// Remove this frames totalTime from the parent's selfTime.
stack[depth - 1].selfTime -= frame.totalTime;
this.onFrame(frame);
i += STOP_SIZE;
} else {
this.records.length = 0;
throw new Error('Unable to decode Profiler records.');
}
}
this.records.length = 0;
}
/**
* Lookup or create an id for a frame name.
* @param {string} name The name to return an id for.
* @return {number} The id for the passed name.
*/
idByName (name) {
return Profiler.idByName(name);
}
/**
* Reverse lookup the name from a given frame id.
* @param {number} id The id to search for.
* @return {string} The name for the given id.
*/
nameById (id) {
return Profiler.nameById(id);
}
/**
* Lookup or create an id for a frame name.
* @static
* @param {string} name The name to return an id for.
* @return {number} The id for the passed name.
*/
static idByName (name) {
if (typeof profilerNames[name] !== 'number') {
profilerNames[name] = nextId++;
}
return profilerNames[name];
}
/**
* Reverse lookup the name from a given frame id.
* @static
* @param {number} id The id to search for.
* @return {string} The name for the given id.
*/
static nameById (id) {
for (const name in profilerNames) {
if (profilerNames[name] === id) {
return name;
}
}
return null;
}
/**
* Profiler is only available on platforms with the Performance API.
* @return {boolean} Can the Profiler run in this browser?
*/
static available () {
return (
typeof window === 'object' &&
typeof window.performance !== 'undefined');
}
}
/**
* A reference to the START record id constant.
* @const {number}
*/
Profiler.START = START;
/**
* A reference to the STOP record id constant.
* @const {number}
*/
Profiler.STOP = STOP;
module.exports = Profiler;

73
src/engine/runtime.js
View file

@ -7,6 +7,7 @@ const Blocks = require('./blocks');
const BlockType = require('../extension-support/block-type');
const Sequencer = require('./sequencer');
const Thread = require('./thread');
const Profiler = require('./profiler');
// Virtual I/O devices.
const Clock = require('../io/clock');
@ -79,6 +80,24 @@ const ScratchBlocksConstants = {
OUTPUT_SHAPE_SQUARE: 3
};
/**
* Numeric ID for Runtime._step in Profiler instances.
* @type {number}
*/
let stepProfilerId = -1;
/**
* Numeric ID for Sequencer.stepThreads in Profiler instances.
* @type {number}
*/
let stepThreadsProfilerId = -1;
/**
* Numeric ID for RenderWebGL.draw in Profiler instances.
* @type {number}
*/
let rendererDrawProfilerId = -1;
/**
* Manages targets, scripts, and the sequencer.
* @constructor
@ -234,6 +253,13 @@ class Runtime extends EventEmitter {
keyboard: new Keyboard(this),
mouse: new Mouse(this)
};
/**
* A runtime profiler that records timed events for later playback to
* diagnose Scratch performance.
* @type {Profiler}
*/
this.profiler = null;
}
/**
@ -1055,6 +1081,12 @@ class Runtime extends EventEmitter {
* inactive threads after each iteration.
*/
_step () {
if (this.profiler !== null) {
if (stepProfilerId === -1) {
stepProfilerId = this.profiler.idByName('Runtime._step');
}
this.profiler.start(stepProfilerId);
}
// Find all edge-activated hats, and add them to threads to be evaluated.
for (const hatType in this._hats) {
if (!this._hats.hasOwnProperty(hatType)) continue;
@ -1065,7 +1097,16 @@ class Runtime extends EventEmitter {
}
this.redrawRequested = false;
this._pushMonitors();
if (this.profiler !== null) {
if (stepThreadsProfilerId === -1) {
stepThreadsProfilerId = this.profiler.idByName('Sequencer.stepThreads');
}
this.profiler.start(stepThreadsProfilerId);
}
const doneThreads = this.sequencer.stepThreads();
if (this.profiler !== null) {
this.profiler.stop();
}
this._updateGlows(doneThreads);
// Add done threads so that even if a thread finishes within 1 frame, the green
// flag will still indicate that a script ran.
@ -1074,7 +1115,16 @@ class Runtime extends EventEmitter {
this._getMonitorThreadCount([...this.threads, ...doneThreads]));
if (this.renderer) {
// @todo: Only render when this.redrawRequested or clones rendered.
if (this.profiler !== null) {
if (rendererDrawProfilerId === -1) {
rendererDrawProfilerId = this.profiler.idByName('RenderWebGL.draw');
}
this.profiler.start(rendererDrawProfilerId);
}
this.renderer.draw();
if (this.profiler !== null) {
this.profiler.stop();
}
}
if (this._refreshTargets) {
@ -1086,6 +1136,11 @@ class Runtime extends EventEmitter {
this.emit(Runtime.MONITORS_UPDATE, this._monitorState);
this._prevMonitorState = this._monitorState;
}
if (this.profiler !== null) {
this.profiler.stop();
this.profiler.reportFrames();
}
}
/**
@ -1413,6 +1468,24 @@ class Runtime extends EventEmitter {
this._step();
}, interval);
}
/**
* Turn on profiling.
* @param {Profiler/FrameCallback} onFrame A callback handle passed a
* profiling frame when the profiler reports its collected data.
*/
enableProfiling (onFrame) {
if (Profiler.available()) {
this.profiler = new Profiler(onFrame);
}
}
/**
* Turn off profiling.
*/
disableProfiling () {
this.profiler = null;
}
}
/**

72
src/engine/sequencer.js
View file

@ -2,6 +2,42 @@ const Timer = require('../util/timer');
const Thread = require('./thread');
const execute = require('./execute.js');
/**
* Profiler frame name for stepping a single thread.
* @const {string}
*/
const stepThreadProfilerFrame = 'Sequencer.stepThread';
/**
* Profiler frame name for the inner loop of stepThreads.
* @const {string}
*/
const stepThreadsInnerProfilerFrame = 'Sequencer.stepThreads#inner';
/**
* Profiler frame name for execute.
* @const {string}
*/
const executeProfilerFrame = 'execute';
/**
* Profiler frame ID for stepThreadProfilerFrame.
* @type {number}
*/
let stepThreadProfilerId = -1;
/**
* Profiler frame ID for stepThreadsInnerProfilerFrame.
* @type {number}
*/
let stepThreadsInnerProfilerId = -1;
/**
* Profiler frame ID for executeProfilerFrame.
* @type {number}
*/
let executeProfilerId = -1;
class Sequencer {
constructor (runtime) {
/**
@ -47,6 +83,13 @@ class Sequencer {
numActiveThreads > 0 &&
this.timer.timeElapsed() < WORK_TIME &&
(this.runtime.turboMode || !this.runtime.redrawRequested)) {
if (this.runtime.profiler !== null) {
if (stepThreadsInnerProfilerId === -1) {
stepThreadsInnerProfilerId = this.runtime.profiler.idByName(stepThreadsInnerProfilerFrame);
}
this.runtime.profiler.start(stepThreadsInnerProfilerId);
}
numActiveThreads = 0;
// Attempt to run each thread one time.
for (let i = 0; i < this.runtime.threads.length; i++) {
@ -69,7 +112,16 @@ class Sequencer {
if (activeThread.status === Thread.STATUS_RUNNING ||
activeThread.status === Thread.STATUS_YIELD) {
// Normal-mode thread: step.
if (this.runtime.profiler !== null) {
if (stepThreadProfilerId === -1) {
stepThreadProfilerId = this.runtime.profiler.idByName(stepThreadProfilerFrame);
}
this.runtime.profiler.start(stepThreadProfilerId);
}
this.stepThread(activeThread);
if (this.runtime.profiler !== null) {
this.runtime.profiler.stop();
}
activeThread.warpTimer = null;
if (activeThread.isKilled) {
i--; // if the thread is removed from the list (killed), do not increase index
@ -82,6 +134,10 @@ class Sequencer {
// We successfully ticked once. Prevents running STATUS_YIELD_TICK
// threads on the next tick.
ranFirstTick = true;
if (this.runtime.profiler !== null) {
this.runtime.profiler.stop();
}
}
// Filter inactive threads from `this.runtime.threads`.
numActiveThreads = 0;
@ -129,7 +185,23 @@ class Sequencer {
// Execute the current block.
// Save the current block ID to notice if we did control flow.
currentBlockId = thread.peekStack();
if (this.runtime.profiler !== null) {
if (executeProfilerId === -1) {
executeProfilerId = this.runtime.profiler.idByName(executeProfilerFrame);
}
// The method commented below has its code inlined underneath to
// reduce the bias recorded for the profiler's calls in this
// time sensitive stepThread method.
//
// this.runtime.profiler.start(executeProfilerId, null);
this.runtime.profiler.records.push(
this.runtime.profiler.START, executeProfilerId, null, performance.now());
}
execute(this, thread);
if (this.runtime.profiler !== null) {
// this.runtime.profiler.stop();
this.runtime.profiler.records.push(this.runtime.profiler.STOP, performance.now());
}
thread.blockGlowInFrame = currentBlockId;
// If the thread has yielded or is waiting, yield to other threads.
if (thread.status === Thread.STATUS_YIELD) {

67
src/playground/playground.js
View file

@ -40,6 +40,72 @@ const getAssetUrl = function (asset) {
return assetUrlParts.join('');
};
const addProfilerPanels = function (
stats, vm, panelName = 'BLK%', panelFg = '#fff', panelBg = '#111') {
vm.runtime.enableProfiling();
if (vm.runtime.profiler === null) {
// Profiler isn't available on the local system.
return;
}
const blockPercentPanel = stats.addPanel(new window.Stats.Panel(panelName, panelFg, panelBg));
// Store the profiler reference for later.
const profiler = vm.runtime.profiler;
// Set profiler to null to disable profiling until later.
vm.runtime.profiler = null;
const stepThreadsProfilerId = profiler.idByName('Sequencer.stepThreads');
const blockFunctionProfilerId = profiler.idByName('blockFunction');
let blockFunctionTime = 0;
const stepValues = [];
let lastUpdate = Date.now();
// Collect time used by `blockFunction` calls in `execute` and add a column
// to the stats graph of the average for the last second of recordings.
profiler.onFrame = function ({id, totalTime}) {
if (id === stepThreadsProfilerId && totalTime > 0) {
// This frame wraps Sequencer.stepThreads.
// Push the most recently summed blockFunctionTime.
stepValues.push(blockFunctionTime / totalTime * 100);
// Every second, average the pushed values and render that as a new
// column in the stats graph.
if (Date.now() - lastUpdate > 1000) {
lastUpdate = Date.now();
const average = stepValues.reduce(
(a, b) => a + b,
0) / stepValues.length;
blockPercentPanel.update(average, 100);
stepValues.length = 0;
}
blockFunctionTime = 0;
} else if (id === blockFunctionProfilerId) {
// This frame wraps around each blockFunction call.
blockFunctionTime += totalTime;
}
};
// Set the stats panel to not display by default.
blockPercentPanel.dom.style.display = 'none';
// When the parent of the stats graphs is clicked, check if the
// blockPercentPanel is visible. If it is visible, enable profiling by
// setting the runtime's profiler to the stored Profiler instance. If it is
// not visible, disable profiling by setting the profiler to null.
stats.dom.addEventListener('click', () => {
if (blockPercentPanel.dom.style.display === 'block') {
vm.runtime.profiler = profiler;
} else {
vm.runtime.profiler = null;
}
});
return blockPercentPanel;
};
window.onload = function () {
// Lots of global variables to make debugging easier
// Instantiate the VM.
@ -99,6 +165,7 @@ window.onload = function () {
const stats = new window.Stats();
document.getElementById('tab-renderexplorer').appendChild(stats.dom);
stats.dom.style.position = 'relative';
addProfilerPanels(stats, vm, 'BLK%', '#fff', '#111');
stats.begin();
// Playground data tabs.