Revert of [wasm] WebAssembly.Memory object can be referenced by multiple Instance objects.

test/mjsunit/wasm/memory-instance-validation.js

-// Copyright 2016 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Flags: --expose-wasm --expose-gc
-
-load("test/mjsunit/wasm/wasm-constants.js");
-load("test/mjsunit/wasm/wasm-module-builder.js");
-
-// This test verifies that when instances are exported, Gc'ed, the other
-// instances in the chain still maintain a consistent view of the memory.
-(function ValidateSharedInstanceMemory() {
-  print("ValidateSharedInstanceMemory");
-  let memory = new WebAssembly.Memory({initial: 5, maximum: 100});
-  var builder = new WasmModuleBuilder();
-  builder.addImportedMemory("imported_mem");
-  builder.addFunction("mem_size", kSig_i_v)
-    .addBody([kExprMemorySize, kMemoryZero])
-    .exportFunc();
-  builder.addFunction("grow", kSig_i_i)
-    .addBody([kExprGetLocal, 0, kExprGrowMemory, kMemoryZero])
-    .exportFunc();
-  var instances = [];
-  for (var i = 0; i < 5; i++) {
-    instances.push(builder.instantiate({imported_mem: memory}));
-  }
-  function grow_instance_0(pages) { return instances[0].exports.grow(pages); }
-  function grow_instance_1(pages) { return instances[1].exports.grow(pages); }
-  function grow_instance_2(pages) { return instances[2].exports.grow(pages); }
-  function grow_instance_3(pages) { return instances[3].exports.grow(pages); }
-  function grow_instance_4(pages) { return instances[4].exports.grow(pages); }
-
-  var start_index = 0;
-  var end_index = 5;
-  function verify_mem_size(expected_pages) {
-    assertEquals(expected_pages*kPageSize, memory.buffer.byteLength);
-    for (var i = start_index; i < end_index; i++) {
-      assertEquals(expected_pages, instances[i].exports.mem_size());
-    }
-  }
-
-  // Verify initial memory size of all instances, grow and verify that all
-  // instances are updated correctly.
-  verify_mem_size(5);
-  assertEquals(5, memory.grow(6));
-  verify_mem_size(11);
-
-  instances[1] = null;
-  gc();
-
-  // i[0] - i[2] - i[3] - i[4]
-  start_index = 2;
-  verify_mem_size(11);
-  assertEquals(11, instances[0].exports.mem_size());
-  assertEquals(11, grow_instance_2(10));
-  assertEquals(21*kPageSize, memory.buffer.byteLength);
-  verify_mem_size(21);
-  assertEquals(21, instances[0].exports.mem_size());
-
-  instances[4] = null;
-  gc();
-
-  // i[0] - i[2] - i[3]
-  assertEquals(21, instances[0].exports.mem_size());
-  assertEquals(21, instances[2].exports.mem_size());
-  assertEquals(21, instances[3].exports.mem_size());
-  assertEquals(21, memory.grow(2));
-  assertEquals(23*kPageSize, memory.buffer.byteLength);
-  assertEquals(23, instances[0].exports.mem_size());
-  assertEquals(23, instances[2].exports.mem_size());
-  assertEquals(23, instances[3].exports.mem_size());
-
-  instances[0] = null;
-  gc();
-
-  // i[2] - i[3]
-  assertEquals(23, instances[2].exports.mem_size());
-  assertEquals(23, instances[3].exports.mem_size());
-  assertEquals(23, grow_instance_3(5));
-  assertEquals(28*kPageSize, memory.buffer.byteLength);
-  assertEquals(28, instances[2].exports.mem_size());
-  assertEquals(28, instances[3].exports.mem_size());
-
-  // Instantiate a new instance and verify that it can be grown correctly.
-  instances.push(builder.instantiate({imported_mem: memory}));
-  function grow_instance_5(pages) { return instances[5].exports.grow(pages); }
-
-  // i[2] - i[3] - i[5]
-  assertEquals(28, instances[2].exports.mem_size());
-  assertEquals(28, instances[3].exports.mem_size());
-  assertEquals(28, instances[5].exports.mem_size());
-  assertEquals(28, grow_instance_5(2));
-  assertEquals(30*kPageSize, memory.buffer.byteLength);
-  assertEquals(30, instances[2].exports.mem_size());
-  assertEquals(30, instances[3].exports.mem_size());
-  assertEquals(30, instances[5].exports.mem_size());
-  assertEquals(30, memory.grow(5));
-  assertEquals(35*kPageSize, memory.buffer.byteLength);
-  assertEquals(35, instances[2].exports.mem_size());
-  assertEquals(35, instances[3].exports.mem_size());
-  assertEquals(35, instances[5].exports.mem_size());
-
-})();