doc: add SharedArrayBuffer to Buffer documentation

PR-URL: #15489
Reviewed-By: Joyee Cheung <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Ruben Bridgewater <[email protected]>
Reviewed-By: Michaël Zasso <[email protected]>

Author: ThomasdenH

doc/api/buffer.md

@@ -63,8 +63,8 @@ differently based on what arguments are provided:
   a fast-but-uninitialized `Buffer` versus creating a slower-but-safer `Buffer`.
 * Passing a string, array, or `Buffer` as the first argument copies the
   passed object's data into the `Buffer`.
-* Passing an [`ArrayBuffer`] returns a `Buffer` that shares allocated memory with
-  the given [`ArrayBuffer`].
+* Passing an [`ArrayBuffer`] or a [`SharedArrayBuffer`] returns a `Buffer` that
+  shares allocated memory with the given array buffer.
 
 Because the behavior of `new Buffer()` changes significantly based on the type
 of value passed as the first argument, applications that do not properly
@@ -350,16 +350,16 @@ deprecated: v6.0.0
 > [`Buffer.from(arrayBuffer[, byteOffset [, length]])`][`Buffer.from(arrayBuffer)`]
 > instead.
 
-* `arrayBuffer` {ArrayBuffer} An [`ArrayBuffer`] or the `.buffer` property of a
-  [`TypedArray`].
+* `arrayBuffer` {ArrayBuffer|SharedArrayBuffer} An [`ArrayBuffer`],
+  [`SharedArrayBuffer`] or the `.buffer` property of a [`TypedArray`].
 * `byteOffset` {integer} Index of first byte to expose. **Default:** `0`
 * `length` {integer} Number of bytes to expose.
   **Default:** `arrayBuffer.length - byteOffset`
 
-This creates a view of the [`ArrayBuffer`] without copying the underlying
-memory. For example, when passed a reference to the `.buffer` property of a
-[`TypedArray`] instance, the newly created `Buffer` will share the same
-allocated memory as the [`TypedArray`].
+This creates a view of the [`ArrayBuffer`] or [`SharedArrayBuffer`] without
+copying the underlying memory. For example, when passed a reference to the
+`.buffer` property of a [`TypedArray`] instance, the newly created `Buffer` will
+share the same allocated memory as the [`TypedArray`].
 
 The optional `byteOffset` and `length` arguments specify a memory range within
 the `arrayBuffer` that will be shared by the `Buffer`.
@@ -611,8 +611,8 @@ A `TypeError` will be thrown if `size` is not a number.
 added: v0.1.90
 -->
 
-* `string` {string|Buffer|TypedArray|DataView|ArrayBuffer} A value to
-  calculate the length of.
+* `string` {string|Buffer|TypedArray|DataView|ArrayBuffer|SharedArrayBuffer} A
+  value to calculate the length of.
 * `encoding` {string} If `string` is a string, this is its encoding.
   **Default:** `'utf8'`
 * Returns: {integer} The number of bytes contained within `string`.
@@ -635,8 +635,8 @@ console.log(`${str}: ${str.length} characters, ` +
             `${Buffer.byteLength(str, 'utf8')} bytes`);
 ```
 
-When `string` is a `Buffer`/[`DataView`]/[`TypedArray`]/[`ArrayBuffer`], the
-actual byte length is returned.
+When `string` is a `Buffer`/[`DataView`]/[`TypedArray`]/[`ArrayBuffer`]/
+[`SharedArrayBuffer`], the actual byte length is returned.
 
 Otherwise, converts to `String` and returns the byte length of string.
 
@@ -733,8 +733,8 @@ A `TypeError` will be thrown if `array` is not an `Array`.
 added: v5.10.0
 -->
 
-* `arrayBuffer` {ArrayBuffer} An [`ArrayBuffer`] or the `.buffer` property of a
-  [`TypedArray`].
+* `arrayBuffer` {ArrayBuffer|SharedArrayBuffer} An [`ArrayBuffer`],
+  [`SharedArrayBuffer`], or the `.buffer` property of a [`TypedArray`].
 * `byteOffset` {integer} Index of first byte to expose. **Default:** `0`
 * `length` {integer} Number of bytes to expose.
   **Default:** `arrayBuffer.length - byteOffset`
@@ -778,7 +778,8 @@ const buf = Buffer.from(ab, 0, 2);
 console.log(buf.length);
 ```
 
-A `TypeError` will be thrown if `arrayBuffer` is not an [`ArrayBuffer`].
+A `TypeError` will be thrown if `arrayBuffer` is not an [`ArrayBuffer`] or a
+[`SharedArrayBuffer`].
 
 ### Class Method: Buffer.from(buffer)
 <!-- YAML
@@ -2544,6 +2545,7 @@ console.log(buf);
 [RFC1345]: https://tools.ietf.org/html/rfc1345
 [RFC4648, Section 5]: https://tools.ietf.org/html/rfc4648#section-5
 [`String.prototype.length`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/length
+[`SharedArrayBuffer`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/SharedArrayBuffer
 [`String#indexOf()`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/indexOf
 [`String#lastIndexOf()`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/lastIndexOf
 [`TypedArray`]: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray