src: Node implementation of v8::Platform

Node.js currently uses the V8 implementation of the DefaultPlatform
which schedules VM tasks on a V8 managed thread pool. Since the Node.js
event loop is not aware of these tasks, the Node.js process may exit
while there are outstanding VM tasks. This will become problematic once
asynchronous wasm compilation lands in V8.

This PR introduces a Node.js specific implementation of the v8::Platform
on top of libuv so that the event loop is aware of outstanding VM tasks.

PR-URL: https://github.com/nodejs/node/pull/14001
Fixes: https://github.com/nodejs/node/issues/3665
Fixes: https://github.com/nodejs/node/issues/8496
Fixes: https://github.com/nodejs/node/issues/12980
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>

1 files changed, 13 insertions, 2 deletions

diff --git a/test/cctest/node_test_fixture.h b/test/cctest/node_test_fixture.h
index e52b1b5dfd..f30823a8fd 100644
--- a/test/cctest/node_test_fixture.h
+++ b/test/cctest/node_test_fixture.h
@@ -66,7 +66,12 @@ struct Argv {
   int nr_args_;
 };
 
+uv_loop_t current_loop;
+
 class NodeTestFixture : public ::testing::Test {
+ public:
+  static uv_loop_t* CurrentLoop() { return &current_loop; }
+
  protected:
   v8::Isolate::CreateParams params_;
   ArrayBufferAllocator allocator_;
@@ -77,7 +82,8 @@ class NodeTestFixture : public ::testing::Test {
   }
 
   virtual void SetUp() {
-    platform_ = v8::platform::CreateDefaultPlatform();
+    CHECK_EQ(0, uv_loop_init(&current_loop));
+    platform_ = new node::NodePlatform(8, &current_loop, nullptr);
     v8::V8::InitializePlatform(platform_);
     v8::V8::Initialize();
     params_.array_buffer_allocator = &allocator_;
@@ -86,13 +92,18 @@ class NodeTestFixture : public ::testing::Test {
 
   virtual void TearDown() {
     if (platform_ == nullptr) return;
+    platform_->Shutdown();
+    while (uv_loop_alive(&current_loop)) {
+      uv_run(&current_loop, UV_RUN_ONCE);
+    }
     v8::V8::ShutdownPlatform();
     delete platform_;
     platform_ = nullptr;
+    CHECK_EQ(0, uv_loop_close(&current_loop));
   }
 
  private:
-  v8::Platform* platform_ = nullptr;
+  node::NodePlatform* platform_ = nullptr;
 };
 
 #endif  // TEST_CCTEST_NODE_TEST_FIXTURE_H_