WorkerPool.WORKER_COUNT => mapboxgl.workerCount

js/mapbox-gl.js

@@ -1,9 +1,13 @@
 'use strict';
 
+var browser = require('./util/browser');
+
 // jshint -W079
 var mapboxgl = module.exports = {};
 
 mapboxgl.version = require('../package.json').version;
+mapboxgl.workerCount = Math.max(browser.hardwareConcurrency - 1, 1);
+
 
 mapboxgl.Map = require('./ui/map');
 mapboxgl.Control = require('./ui/control/control');

js/util/worker_pool.js

@@ -2,23 +2,28 @@
 
 var assert = require('assert');
 var WebWorker = require('./web_worker');
-var browser = require('./browser');
 
 module.exports = WorkerPool;
 
-WorkerPool.WORKER_COUNT = Math.max(browser.hardwareConcurrency - 1, 1);
-
+/**
+ * Constructs a worker pool.
+ * @private
+ */
 function WorkerPool() {
-    this.workerCount = WorkerPool.WORKER_COUNT;
     this.active = {};
 }
 
 WorkerPool.prototype = {
     acquire: function (mapId) {
         if (!this.workers) {
-            assert(typeof this.workerCount === 'number');
+            // Lazily look up the value of mapboxgl.workerCount.  This allows
+            // client code a chance to set it while circumventing cyclic
+            // dependency problems
+            var workerCount = require('../mapbox-gl').workerCount;
+            assert(typeof workerCount === 'number' && workerCount < Infinity);
+
             this.workers = [];
-            while (this.workers.length < this.workerCount) {
+            while (this.workers.length < workerCount) {
                 this.workers.push(new WebWorker());
             }
         }

test/js/mapbox-gl.js

@@ -1,12 +1,21 @@
 'use strict';
 
 var test = require('tap').test;
+var proxyquire = require('proxyquire');
 var mapboxgl = require('../../../js/mapbox-gl');
 
 test('mapboxgl', function(t) {
     t.test('version', function(t) {
         t.ok(mapboxgl.version);
         t.end();
     });
+
+    t.test('.workerCount defaults to hardwareConcurrency - 1', function (t) {
+        var mapboxgl = proxyquire('../../../js/mapbox-gl', {
+            './util/browser': { hardwareConcurrency: 15 }
+        });
+        t.equal(mapboxgl.workerCount, 14);
+        t.end();
+    });
     t.end();
 });

test/js/util/dispatcher.test.js

@@ -4,7 +4,6 @@ var test = require('tap').test;
 var proxyquire = require('proxyquire');
 var Dispatcher = require('../../../js/util/dispatcher');
 var WebWorker = require('../../../js/util/web_worker');
-var WorkerPool = require('../../../js/util/worker_pool');
 
 test('Dispatcher', function (t) {
     t.test('requests and releases workers from pool', function (t) {
@@ -31,19 +30,18 @@ test('Dispatcher', function (t) {
     });
 
     test('creates Actors with unique map id', function (t) {
-        var Dispatcher = proxyquire('../../../js/util/dispatcher', { './actor': Actor });
+        var Dispatcher = proxyquire('../../../js/util/dispatcher', {'./actor': Actor });
+        var WorkerPool = proxyquire('../../../js/util/worker_pool', {
+            '../mapbox-gl': { workerCount: 1 }
+        });
 
         var ids = [];
         function Actor (target, parent, mapId) { ids.push(mapId); }
 
-        var previousWorkerCount = WorkerPool.WORKER_COUNT;
-        WorkerPool.WORKER_COUNT = 1;
-
         var workerPool = new WorkerPool();
         var dispatchers = [new Dispatcher(workerPool, {}), new Dispatcher(workerPool, {})];
         t.same(ids, dispatchers.map(function (d) { return d.id; }));
 
-        WorkerPool.WORKER_COUNT = previousWorkerCount;
         t.end();
     });
 

test/js/util/worker_pool.test.js

@@ -2,37 +2,31 @@
 
 var test = require('tap').test;
 var proxyquire = require('proxyquire');
-var WorkerPool = require('../../../js/util/worker_pool');
 
 test('WorkerPool', function (t) {
-    t.test('.WORKER_COUNT', function (t) {
+    t.test('#acquire', function (t) {
         var WorkerPool = proxyquire('../../../js/util/worker_pool', {
-            './browser': { hardwareConcurrency: 15 }
+            '../mapbox-gl': { workerCount: 4 }
         });
-        t.equal(WorkerPool.WORKER_COUNT, 14);
-
-        WorkerPool.WORKER_COUNT = 4;
-        t.end();
-    });
-
-    t.test('#acquire', function (t) {
-        // make sure we're actually creating some workers
-        t.ok(WorkerPool.WORKER_COUNT > 0);
 
         var pool = new WorkerPool();
 
         t.notOk(pool.workers);
         var workers1 = pool.acquire('map-1');
         var workers2 = pool.acquire('map-2');
-        t.equal(workers1.length, WorkerPool.WORKER_COUNT);
-        t.equal(workers2.length, WorkerPool.WORKER_COUNT);
+        t.equal(workers1.length, 4);
+        t.equal(workers2.length, 4);
 
         // check that the two different dispatchers' workers arrays correspond
         workers1.forEach(function (w, i) { t.equal(w, workers2[i]); });
         t.end();
     });
 
     t.test('#release', function (t) {
+        var WorkerPool = proxyquire('../../../js/util/worker_pool', {
+            '../mapbox-gl': { workerCount: 4 }
+        });
+
         var pool = new WorkerPool();
         pool.acquire('map-1');
         var workers = pool.acquire('map-2');
@@ -48,7 +42,7 @@ test('WorkerPool', function (t) {
 
         t.comment('terminates workers if no dispatchers are active');
         pool.release('map-1');
-        t.equal(terminated, WorkerPool.WORKER_COUNT);
+        t.equal(terminated, 4);
         t.notOk(pool.workers);
 
         t.end();