arraybuffer-transfer.js

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load(libdir + "asm.js");

function module(stdlib, foreign, buffer) {

  "use asm";

  var i32 = new stdlib.Int32Array(buffer);

  function zero() {

    return i32[0] | 0;

  return zero;

const byteLength = BUF_MIN;

let buffer = new ArrayBuffer(byteLength);

let i32 = new Int32Array(buffer);

let zero = module(globalThis, null, buffer);

const magic = 0xbadf00d;

assertEq(zero(), 0);

assertEq(i32[0], 0);

i32[0] = magic;

assertEq(zero(), magic);

assertEq(i32[0], magic);

assertEq(buffer.detached, false);

assertEq(buffer.byteLength, byteLength);

if (isAsmJSCompilationAvailable()) {

  // asm.js compilation is enabled.

  assertEq(isAsmJSModule(module), true);

  assertEq(isAsmJSFunction(zero), true);

  // Can't transfer asm.js prepared array buffers.

  assertThrowsInstanceOf(() => buffer.transfer(), TypeError);

  // |buffer| is still attached.

  assertEq(buffer.detached, false);

  assertEq(buffer.byteLength, byteLength);

  // Access still returns the original value.

  assertEq(zero(), magic);

  assertEq(i32[0], magic);

} else {

  // asm.js compilation is disabled.

  assertEq(isAsmJSModule(module), false);

  assertEq(isAsmJSFunction(zero), false);

  let copy = buffer.transfer();

  assertEq(buffer.detached, true);

  assertEq(buffer.byteLength, 0);

  assertEq(copy.detached, false);

  assertEq(copy.byteLength, byteLength);

  // Access returns undefined when detached.

  assertEq(zero(), 0);

  assertEq(i32[0], undefined);