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

test/mjsunit/wasm/import-memory.js

Index: test/mjsunit/wasm/import-memory.js
diff --git a/test/mjsunit/wasm/import-memory.js b/test/mjsunit/wasm/import-memory.js
index 845da91d1d17bca6545d322edaeb05ef6ed9f49e..3b70332f97bc5eb95d2dbd81135df3a89204d0c2 100644
--- a/test/mjsunit/wasm/import-memory.js
+++ b/test/mjsunit/wasm/import-memory.js
@@ -40,7 +40,6 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   assertSame(memory, instance.exports.daggle);
 })();
 
-
 (function TestImportExport() {
   print("TestImportExport");
   var i1;
@@ -229,3 +228,141 @@ load("test/mjsunit/wasm/wasm-module-builder.js");
   }
   assertEquals(-1, instance.exports.grow(1));
 })();
+
+(function TestMemoryGrowWebAssemblyInstances() {
+  print("TestMemoryGrowWebAssemblyInstances");
+  let memory = new WebAssembly.Memory({initial: 1, maximum: 15});
+  var builder = new WasmModuleBuilder();
+  builder.addImportedMemory("imported_mem");
+  builder.addFunction("mem_size", kSig_i_v)
+    .addBody([kExprMemorySize, kMemoryZero])
+    .exportAs("mem_size");
+  builder.addFunction("grow", kSig_i_i)
+    .addBody([kExprGetLocal, 0, kExprGrowMemory, kMemoryZero])
+    .exportFunc();
+  var module = new WebAssembly.Module(builder.toBuffer());
+  var instances = [];
+  for (var i = 0; i < 6; i++) {
+    instances.push(new WebAssembly.Instance(module, {imported_mem: memory}));
+  }
+  function verify_mem_size(expected_pages) {
+    assertEquals(expected_pages*kPageSize,
+        memory.buffer.byteLength);
+    for (var i = 0; i < 6; i++) {
+      assertEquals(expected_pages, instances[i].exports.mem_size());
+    }
+  }
+
+  // Verify initial memory size
+  verify_mem_size(1);
+
+  // Verify memory size with interleaving calls to Memory.grow,
+  // GrowMemory opcode.
+  var current_mem_size = 1;
+  for (var i = 0; i < 5; i++) {
+    function grow(pages) { return instances[i].exports.grow(pages); }
+    assertEquals(current_mem_size, memory.grow(1));
+    verify_mem_size(++current_mem_size);
+    assertEquals(current_mem_size, instances[i].exports.grow(1));
+    verify_mem_size(++current_mem_size);
+  }
+
+  assertThrows(() => memory.grow(5));
+})();
+
+(function TestImportedMemoryGrowMultipleInstances() {
+  print("TestImportMemoryMultipleInstances");
+  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); }
+
+  function verify_mem_size(expected_pages) {
+    assertEquals(expected_pages*kPageSize, memory.buffer.byteLength);
+    for (var i = 0; i < 5; i++) {
+      assertEquals(expected_pages, instances[i].exports.mem_size());
+    }
+  }
+
+  // Verify initial memory size
+  verify_mem_size(5);
+
+  // Grow instance memory and buffer memory out of order and verify memory is
+  // updated correctly.
+  assertEquals(5, grow_instance_0(7));
+  verify_mem_size(12);
+
+  assertEquals(12, memory.grow(4));
+  verify_mem_size(16);
+
+  assertEquals(16, grow_instance_4(1));
+  verify_mem_size(17);
+
+  assertEquals(17, grow_instance_1(6));
+  verify_mem_size(23);
+
+  assertEquals(23, grow_instance_3(2));
+  verify_mem_size(25);
+
+  assertEquals(25, memory.grow(10));
+  verify_mem_size(35);
+
+  assertEquals(35, grow_instance_2(15));
+  verify_mem_size(50);
+  assertThrows(() => memory.grow(51));
+})();
+
+(function TestExportImportedMemoryGrowMultipleInstances() {
+  // TODO(gdeepti):Exported memory objects currently do not take max_size
+  // into account so this can grow past the maximum specified in the exported
+  // memory object. Assert that growing past maximum for exported objects fails.
+  print("TestExportImportedMemoryGrowMultipleInstances");
+  var instance;
+  {
+    let builder = new WasmModuleBuilder();
+    builder.addMemory(1, 11, true);
+    builder.exportMemoryAs("exported_mem");
+    builder.addFunction("mem_size", kSig_i_v)
+      .addBody([kExprMemorySize, kMemoryZero])
+      .exportFunc();
+    instance = builder.instantiate();
+  }
+  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 < 10; i++) {
+    instances.push(builder.instantiate({
+      imported_mem: instance.exports.exported_mem}));
+  }
+  function verify_mem_size(expected_pages) {
+    for (var i = 0; i < 10; i++) {
+      assertEquals(expected_pages, instances[i].exports.mem_size());
+    }
+  }
+  var current_mem_size = 1;
+  for (var i = 0; i < 10; i++) {
+    function grow(pages) { return instances[i].exports.grow(pages); }
+    assertEquals(current_mem_size, instances[i].exports.grow(1));
+    verify_mem_size(++current_mem_size);
+  }
+})();