Remove init path dependency on ArrayBuffer

facebook · Aug 21, 2019 · ee548c3 · ee548c3
1 parent 935526e
commit ee548c3
Showing 1 changed file with 11 additions and 7 deletions.
diff --git a/packages/scheduler/src/SchedulerProfiling.js b/packages/scheduler/src/SchedulerProfiling.js
@@ -16,17 +16,21 @@ let runIdCounter: number = 0;
 let mainThreadIdCounter: number = 0;
 
 const profilingStateSize = 4;
-export const sharedProfilingBuffer =
-  // $FlowFixMe Flow doesn't know about SharedArrayBuffer
-  typeof SharedArrayBuffer === 'function'
+export const sharedProfilingBuffer = enableProfiling
+  ? // $FlowFixMe Flow doesn't know about SharedArrayBuffer
+    typeof SharedArrayBuffer === 'function'
     ? new SharedArrayBuffer(profilingStateSize * Int32Array.BYTES_PER_ELEMENT)
     : // $FlowFixMe Flow doesn't know about ArrayBuffer
-      new ArrayBuffer(profilingStateSize * Int32Array.BYTES_PER_ELEMENT);
-
-const profilingState = enableProfiling
-  ? new Int32Array(sharedProfilingBuffer)
+      typeof ArrayBuffer === 'function'
+      ? new ArrayBuffer(profilingStateSize * Int32Array.BYTES_PER_ELEMENT)
+      : null // Don't crash the init path on IE9
   : null;
 
+const profilingState =
+  enableProfiling && sharedProfilingBuffer !== null
+    ? new Int32Array(sharedProfilingBuffer)
+    : null;
+
 const PRIORITY = 0;
 const CURRENT_TASK_ID = 1;
 const CURRENT_RUN_ID = 2;