chore(release): publish [skip ci]

- @ohif/viewer@3.8.4

platform/viewer/CHANGELOG.md

@@ -3,6 +3,17 @@
 All notable changes to this project will be documented in this file.
 See [Conventional Commits](https://conventionalcommits.org) for commit guidelines.
 
+## [3.8.4](https://github.com/OHIF/Viewers/compare/@ohif/viewer@3.8.3...@ohif/viewer@3.8.4) (2020-03-19)
+
+
+### Bug Fixes
+
+* Only permit web workers to be initialized once. ([#1535](https://github.com/OHIF/Viewers/issues/1535)) ([9feadd3](https://github.com/OHIF/Viewers/commit/9feadd3c6d71c1c48f7825d024ccf95d5d82606d))
+
+
+
+
+
 ## [3.8.3](https://github.com/OHIF/Viewers/compare/@ohif/viewer@3.8.2...@ohif/viewer@3.8.3) (2020-03-17)
 
 **Note:** Version bump only for package @ohif/viewer

platform/viewer/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@ohif/viewer",
-  "version": "3.8.3",
+  "version": "3.8.4",
   "description": "OHIF Viewer",
   "author": "OHIF Contributors",
   "license": "MIT",

platform/viewer/src/utils/initWebWorkers.js

@@ -1,6 +1,8 @@
 import cornerstoneWADOImageLoader from 'cornerstone-wado-image-loader';
 
-export default function initWebWorkers() {  
+let initialized = false;
+
+export default function initWebWorkers() {
   const config = {
     maxWebWorkers: Math.max(navigator.hardwareConcurrency - 1, 1),
     startWebWorkersOnDemand: true,
@@ -13,5 +15,8 @@ export default function initWebWorkers() {
     },
   };
 
-  cornerstoneWADOImageLoader.webWorkerManager.initialize(config);
+  if (!initialized) {
+    cornerstoneWADOImageLoader.webWorkerManager.initialize(config);
+    initialized = true;
+  }
 }

platform/viewer/src/utils/initWebWorkers.test.js

@@ -10,3 +10,14 @@ describe('initWebWorkers', () => {
     ).toHaveBeenCalled();
   });
 });
+
+describe('initWebWorkers', () => {
+  it("initializes cornerstoneWADOImageLoader's web workers only once", () => {
+    initWebWorkers();
+    initWebWorkers();
+
+    expect(
+      cornerstoneWADOImageLoader.webWorkerManager.initialize
+    ).toHaveBeenCalledTimes(1);
+  });
+});