Shared buffer fixes (denoland#1644)

* makes `libdeno.shared` a `SharedArrayBuffer` instead of a regular `ArrayBuffer`. * fixes `libdeno.shared` becoming undefined after accessing it once.
motammi · Feb 9, 2019 · bbe2004 · bbe2004
1 parent 7380b19
commit bbe2004
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Showing 4 changed files with 22 additions and 6 deletions.
diff --git a/libdeno/binding.cc b/libdeno/binding.cc
@@ -316,14 +316,15 @@ void Shared(v8::Local<v8::Name> property,
  if (d->shared_.data_ptr == nullptr) {
  return;
  }
- v8::Local<v8::ArrayBuffer> ab;
+ v8::Local<v8::SharedArrayBuffer> ab;
  if (d->shared_ab_.IsEmpty()) {
  // Lazily initialize the persistent external ArrayBuffer.
- ab = v8::ArrayBuffer::New(isolate, d->shared_.data_ptr, d->shared_.data_len,
- v8::ArrayBufferCreationMode::kExternalized);
+ ab = v8::SharedArrayBuffer::New(isolate, d->shared_.data_ptr,
+ d->shared_.data_len,
+ v8::ArrayBufferCreationMode::kExternalized);
  d->shared_ab_.Reset(isolate, ab);
  }
- info.GetReturnValue().Set(ab);
+ info.GetReturnValue().Set(d->shared_ab_);
 }
 
 void DenoIsolate::ClearModules() {

diff --git a/libdeno/internal.h b/libdeno/internal.h
@@ -46,6 +46,7 @@ class DenoIsolate {
  }
 
  ~DenoIsolate() {
+ shared_ab_.Reset();
  if (snapshot_creator_) {
  delete snapshot_creator_;
  } else {
@@ -98,7 +99,7 @@ class DenoIsolate {
  v8::Persistent<v8::Function> recv_;
  v8::StartupData snapshot_;
  v8::Persistent<v8::ArrayBuffer> global_import_buf_;
- v8::Persistent<v8::ArrayBuffer> shared_ab_;
+ v8::Persistent<v8::SharedArrayBuffer> shared_ab_;
 };
 
 class UserDataScope {

diff --git a/libdeno/libdeno_test.cc b/libdeno/libdeno_test.cc
@@ -289,3 +289,16 @@ TEST(LibDenoTest, Utf8Bug) {
  EXPECT_EQ(nullptr, deno_last_exception(d));
  deno_delete(d);
 }
+
+TEST(LibDenoTest, SharedAtomics) {
+ int32_t s[] = {0, 1, 2};
+ deno_buf shared = {nullptr, 0, reinterpret_cast<uint8_t*>(s), sizeof s};
+ Deno* d = deno_new(deno_config{0, empty, shared, nullptr});
+ deno_execute(d, nullptr, "a.js",
+ "Atomics.add(new Int32Array(libdeno.shared), 0, 1)");
+ EXPECT_EQ(nullptr, deno_last_exception(d));
+ EXPECT_EQ(s[0], 1);
+ EXPECT_EQ(s[1], 1);
+ EXPECT_EQ(s[2], 2);
+ deno_delete(d);
+}
diff --git a/libdeno/libdeno_test.js b/libdeno/libdeno_test.js
@@ -136,7 +136,8 @@ global.CheckPromiseErrors = () => {
 
 global.Shared = () => {
  const ab = libdeno.shared;
- assert(ab instanceof ArrayBuffer);
+ assert(ab instanceof SharedArrayBuffer);
+ assert(libdeno.shared != undefined);
  assert(ab.byteLength === 3);
  const ui8 = new Uint8Array(ab);
  assert(ui8[0] === 0);