diff --git a/src/libraries/System.Private.Runtime.InteropServices.JavaScript/src/System/Runtime/InteropServices/JavaScript/SharedArrayBuffer.cs b/src/libraries/System.Private.Runtime.InteropServices.JavaScript/src/System/Runtime/InteropServices/JavaScript/SharedArrayBuffer.cs
index 256313aaf7134..463c81c714739 100644
--- a/src/libraries/System.Private.Runtime.InteropServices.JavaScript/src/System/Runtime/InteropServices/JavaScript/SharedArrayBuffer.cs
+++ b/src/libraries/System.Private.Runtime.InteropServices.JavaScript/src/System/Runtime/InteropServices/JavaScript/SharedArrayBuffer.cs
@@ -23,6 +23,21 @@ internal SharedArrayBuffer(IntPtr jsHandle, bool ownsHandle) : base(jsHandle, ow
/// The size, in bytes, of the array.
public int ByteLength => (int)GetObjectProperty("byteLength");
+ ///
+ /// Returns a new JavaScript Core SharedArrayBuffer whose contents are a copy of this SharedArrayBuffer's bytes.
+ ///
+ /// a new JavaScript Core SharedArrayBuffer
+ public SharedArrayBuffer Slice() => (SharedArrayBuffer)Invoke("slice");
+
+ ///
+ /// Returns a new JavaScript Core SharedArrayBuffer whose contents are a copy of this SharedArrayBuffer's bytes from begin,
+ /// inclusive, through to the end of the sequence, exclusive. If begin is negative, it refers to an index from the end
+ /// of the array, as opposed to from the beginning.
+ ///
+ /// a new JavaScript Core SharedArrayBuffer
+ /// Beginning index of copy zero based.
+ public SharedArrayBuffer Slice(int begin) => (SharedArrayBuffer)Invoke("slice", begin);
+
///
/// Returns a new JavaScript Core SharedArrayBuffer whose contents are a copy of this SharedArrayBuffer's bytes from begin,
/// inclusive, up to end, exclusive. If either begin or end is negative, it refers to an index from the end
diff --git a/src/libraries/System.Private.Runtime.InteropServices.JavaScript/tests/System.Private.Runtime.InteropServices.JavaScript.Tests.csproj b/src/libraries/System.Private.Runtime.InteropServices.JavaScript/tests/System.Private.Runtime.InteropServices.JavaScript.Tests.csproj
index 444b70c047928..11dec891deeeb 100644
--- a/src/libraries/System.Private.Runtime.InteropServices.JavaScript/tests/System.Private.Runtime.InteropServices.JavaScript.Tests.csproj
+++ b/src/libraries/System.Private.Runtime.InteropServices.JavaScript/tests/System.Private.Runtime.InteropServices.JavaScript.Tests.csproj
@@ -8,6 +8,7 @@
+
@@ -18,4 +19,4 @@
-
\ No newline at end of file
+
diff --git a/src/libraries/System.Private.Runtime.InteropServices.JavaScript/tests/System/Runtime/InteropServices/JavaScript/SharedArrayBufferTests.cs b/src/libraries/System.Private.Runtime.InteropServices.JavaScript/tests/System/Runtime/InteropServices/JavaScript/SharedArrayBufferTests.cs
new file mode 100644
index 0000000000000..78bd3841d4dc4
--- /dev/null
+++ b/src/libraries/System.Private.Runtime.InteropServices.JavaScript/tests/System/Runtime/InteropServices/JavaScript/SharedArrayBufferTests.cs
@@ -0,0 +1,156 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Collections.Generic;
+using Xunit;
+
+namespace System.Runtime.InteropServices.JavaScript.Tests
+{
+ public static class SharedArrayBufferTests
+ {
+ private static Function _objectPrototype;
+
+ public static IEnumerable Object_Prototype()
+ {
+ _objectPrototype ??= new Function("return Object.prototype.toString;");
+ yield return new object[] { _objectPrototype.Call() };
+ }
+
+ [Theory]
+ [MemberData(nameof(Object_Prototype))]
+ public static void SharedArrayBuffer_NonZeroLength(Function objectPrototype)
+ {
+ SharedArrayBuffer d = new SharedArrayBuffer(50);
+ Assert.Equal("[object SharedArrayBuffer]", objectPrototype.Call(d));
+ Assert.Equal(50, d.ByteLength);
+ }
+
+ [Fact]
+ public static void SharedArrayBufferSlice()
+ {
+ SharedArrayBuffer d = new SharedArrayBuffer(50);
+ Assert.Equal(50, d.Slice().ByteLength);
+ }
+
+ [Fact]
+ public static void SharedArrayBuffer_Slice_BeginEndForFullArray()
+ {
+ SharedArrayBuffer d = new SharedArrayBuffer(50);
+ Assert.Equal(50, d.Slice(0, 50).ByteLength);
+ }
+
+ [Fact]
+ public static void SharedArrayBuffer_Slice_BeginZero()
+ {
+ SharedArrayBuffer d = new SharedArrayBuffer(50);
+ Assert.Equal(50, d.Slice(0).ByteLength);
+ }
+
+ [Fact]
+ public static void SharedArrayBuffer_Slice_BeginNegative()
+ {
+ SharedArrayBuffer d = new SharedArrayBuffer(50);
+ Assert.Equal(3, d.Slice(-3).ByteLength);
+ }
+
+ [Fact]
+ public static void SharedArrayBuffer_Slice_BeginEndSubset()
+ {
+ SharedArrayBuffer d = new SharedArrayBuffer(50);
+ Assert.Equal(3, d.Slice(1, 4).ByteLength);
+ }
+
+ [Fact]
+ public static void SharedArrayBufferSliceAndDice()
+ {
+ // create a SharedArrayBuffer with a size in bytes
+ SharedArrayBuffer buffer = new SharedArrayBuffer(16);
+ Int32Array int32View = new Int32Array(buffer); // create view
+ // produces Int32Array [0, 0, 0, 0]
+
+ int32View[1] = 42;
+
+ Assert.Equal(4, int32View.Length);
+ Assert.Equal(42, int32View[1]);
+
+ Int32Array sliced = new Int32Array(buffer.Slice(4,12));
+ // expected output: Int32Array [42, 0]
+
+ Assert.Equal(2, sliced.Length);
+ Assert.Equal(42, sliced[0]);
+ Assert.Equal(0, sliced[1]);
+ }
+
+ [Fact]
+ public static void SharedArrayBufferSliceAndDiceAndUseThroughSpan()
+ {
+ // create a SharedArrayBuffer with a size in bytes
+ SharedArrayBuffer buffer = new SharedArrayBuffer(16);
+ Int32Array int32View = new Int32Array(buffer); // create view
+ // produces Int32Array [0, 0, 0, 0]
+
+ int32View[1] = 42;
+
+ Assert.Equal(4, int32View.Length);
+ Assert.Equal(42, int32View[1]);
+
+ Int32Array sliced = new Int32Array(buffer.Slice(4,12));
+ // expected output: Int32Array [42, 0]
+
+ Span nativeArray = sliced;
+
+ int sum = 0;
+ for (int i = 0; i < nativeArray.Length; i++)
+ {
+ sum += nativeArray[i];
+ }
+
+ Assert.Equal(42, sum);
+ }
+
+ [Theory]
+ [MemberData(nameof(GetTestData), 16)]
+ public static void SharedArrayBufferSliceAndDice3_Subset(SharedArrayBuffer buffer)
+ {
+ Int32Array sliced = new Int32Array(buffer.Slice(4,12));
+
+ Assert.Equal(2, sliced.Length);
+ Assert.Equal(42, sliced[0]);
+ Assert.Equal(12, sliced[1]);
+ }
+
+ [Theory]
+ [MemberData(nameof(GetTestData), 16)]
+ public static void SharedArrayBufferSliceAndDice3_SubsetFromTheBack(SharedArrayBuffer buffer)
+ {
+ Int32Array sliced = new Int32Array(buffer.Slice(-4));
+
+ Assert.Equal(1, sliced.Length);
+ Assert.Equal(13, sliced[0]);
+ }
+
+ [Theory]
+ [MemberData(nameof(GetTestData), 16)]
+ public static void SharedArrayBufferSliceAndDice3_SubsetFromTheBackWithEnd(SharedArrayBuffer buffer)
+ {
+ Int32Array sliced = new Int32Array(buffer.Slice(-12, -4));
+
+ Assert.Equal(2, sliced.Length);
+ Assert.Equal(42, sliced[0]);
+ Assert.Equal(12, sliced[1]);
+ }
+
+ private static TheoryData GetTestData(int length)
+ {
+ // create a SharedArrayBuffer with a size in bytes
+ SharedArrayBuffer buffer = new SharedArrayBuffer(length);
+ Int32Array int32View = new Int32Array(buffer); // create view
+ for (int i = 0; i < int32View.Length; i ++)
+ int32View[i] = i + 10;
+
+ int32View[1] = 42;
+ return new TheoryData { buffer };
+ }
+
+ }
+}
diff --git a/src/mono/wasm/runtime/binding_support.js b/src/mono/wasm/runtime/binding_support.js
index c16b6d7727cb0..b9de49ac6e882 100644
--- a/src/mono/wasm/runtime/binding_support.js
+++ b/src/mono/wasm/runtime/binding_support.js
@@ -14,6 +14,7 @@ var BindingSupportLib = {
mono_bindings_init: function (binding_asm) {
this.BINDING_ASM = binding_asm;
},
+ mono_sab_supported: typeof SharedArrayBuffer !== "undefined",
export_functions: function (module) {
module ["mono_bindings_init"] = BINDING.mono_bindings_init.bind(BINDING);
@@ -39,7 +40,7 @@ var BindingSupportLib = {
DataView.prototype[Symbol.for("wasm type")] = 3;
Function.prototype[Symbol.for("wasm type")] = 4;
Map.prototype[Symbol.for("wasm type")] = 5;
- if (typeof SharedArrayBuffer !== "undefined")
+ if (BINDING.mono_sab_supported)
SharedArrayBuffer.prototype[Symbol.for("wasm type")] = 6;
Int8Array.prototype[Symbol.for("wasm type")] = 10;
Uint8Array.prototype[Symbol.for("wasm type")] = 11;
@@ -486,6 +487,11 @@ var BindingSupportLib = {
return this.extract_mono_obj (js_obj);
}
},
+ has_backing_array_buffer: function (js_obj) {
+ return BINDING.mono_sab_supported
+ ? js_obj.buffer instanceof ArrayBuffer || js_obj.buffer instanceof SharedArrayBuffer
+ : js_obj.buffer instanceof ArrayBuffer;
+ },
js_typed_array_to_array : function (js_obj) {
@@ -497,7 +503,7 @@ var BindingSupportLib = {
// you need to use a view. A view provides a context — that is, a data type, starting offset,
// and number of elements — that turns the data into an actual typed array.
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Typed_arrays
- if (!!(js_obj.buffer instanceof ArrayBuffer && js_obj.BYTES_PER_ELEMENT))
+ if (!!(this.has_backing_array_buffer(js_obj) && js_obj.BYTES_PER_ELEMENT))
{
var arrayType = js_obj[Symbol.for("wasm type")];
var heapBytes = this.js_typedarray_to_heap(js_obj);
@@ -523,7 +529,7 @@ var BindingSupportLib = {
// you need to use a view. A view provides a context — that is, a data type, starting offset,
// and number of elements — that turns the data into an actual typed array.
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Typed_arrays
- if (!!(typed_array.buffer instanceof ArrayBuffer && typed_array.BYTES_PER_ELEMENT))
+ if (!!(this.has_backing_array_buffer(typed_array) && typed_array.BYTES_PER_ELEMENT))
{
// Some sanity checks of what is being asked of us
// lets play it safe and throw an error here instead of assuming to much.
@@ -566,7 +572,7 @@ var BindingSupportLib = {
// you need to use a view. A view provides a context — that is, a data type, starting offset,
// and number of elements — that turns the data into an actual typed array.
// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Typed_arrays
- if (!!(typed_array.buffer instanceof ArrayBuffer && typed_array.BYTES_PER_ELEMENT))
+ if (!!(this.has_backing_array_buffer(typed_array) && typed_array.BYTES_PER_ELEMENT))
{
// Some sanity checks of what is being asked of us
// lets play it safe and throw an error here instead of assuming to much.