src: make CleanupHandles() tear down handles/reqs

Previously, handles would not be closed when the current `Environment`
stopped, which is acceptable in a single-`Environment`-per-process
situation, but would otherwise create memory and file descriptor
leaks.

Also, introduce a generic way to close handles via the
`Environment::CloseHandle()` function, which automatically keeps
track of whether a close callback has been called yet or not.

Many thanks for Stephen Belanger for reviewing the original version of
this commit in the Ayo.js project.

Refs: https://github.com/ayojs/ayo/pull/85
PR-URL: https://github.com/nodejs/node/pull/19377
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/handle_wrap.h b/src/handle_wrap.h
index e7a335f514..fd2d002dce 100644
--- a/src/handle_wrap.h
+++ b/src/handle_wrap.h
@@ -70,11 +70,17 @@ class HandleWrap : public AsyncWrap {
 
   inline uv_handle_t* GetHandle() const { return handle_; }
 
+  void Close(v8::Local<v8::Value> close_callback = v8::Local<v8::Value>());
+
  protected:
   HandleWrap(Environment* env,
              v8::Local<v8::Object> object,
              uv_handle_t* handle,
              AsyncWrap::ProviderType provider);
+  virtual void OnClose() {}
+
+  void MarkAsInitialized();
+  void MarkAsUninitialized();
 
  private:
   friend class Environment;