src: remove custom tracking for SharedArrayBuffers

Remove custom tracking for `SharedArrayBuffer`s and their allocators
and instead let V8 do the tracking of both. This is required starting
in V8 7.9, because lifetime management for `ArrayBuffer::Allocator`s
differs from what was performed previously (i.e. it is no longer
easily possible for one Isolate to release an `ArrayBuffer` and another
to accept it into its own allocator), and the alternative would
have been adapting the `SharedArrayBuffer` tracking logic to also
apply to regular `ArrayBuffer` instances.

Refs: https://github.com/nodejs/node/pull/30044

PR-URL: https://github.com/nodejs/node/pull/30020
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

1 files changed, 0 insertions, 72 deletions

diff --git a/src/sharedarraybuffer_metadata.h b/src/sharedarraybuffer_metadata.h
deleted file mode 100644
index 4d89f08ee1..0000000000
--- a/src/sharedarraybuffer_metadata.h
+++ /dev/null
@@ -1,72 +0,0 @@
-#ifndef SRC_SHAREDARRAYBUFFER_METADATA_H_
-#define SRC_SHAREDARRAYBUFFER_METADATA_H_
-
-#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
-
-#include "node.h"
-#include <memory>
-
-namespace node {
-namespace worker {
-
-class SharedArrayBufferMetadata;
-
-// This is an object associated with a SharedArrayBuffer, which keeps track
-// of a cross-thread reference count. Once a SharedArrayBuffer is transferred
-// for the first time (or is attempted to be transferred), one of these objects
-// is created, and the SharedArrayBuffer is moved from internalized mode into
-// externalized mode (i.e. the JS engine no longer frees the memory on its own).
-//
-// This will always be referred to using a std::shared_ptr, since it keeps
-// a reference count and is guaranteed to be thread-safe.
-typedef std::shared_ptr<SharedArrayBufferMetadata>
-    SharedArrayBufferMetadataReference;
-
-class SharedArrayBufferMetadata
-    : public std::enable_shared_from_this<SharedArrayBufferMetadata> {
- public:
-  static SharedArrayBufferMetadataReference ForSharedArrayBuffer(
-      Environment* env,
-      v8::Local<v8::Context> context,
-      v8::Local<v8::SharedArrayBuffer> source);
-  ~SharedArrayBufferMetadata();
-
-  // Create a SharedArrayBuffer object for a specific Environment and Context.
-  // The created SharedArrayBuffer will be in externalized mode and has
-  // a hidden object attached to it, during whose lifetime the reference
-  // count is increased by 1.
-  v8::MaybeLocal<v8::SharedArrayBuffer> GetSharedArrayBuffer(
-      Environment* env, v8::Local<v8::Context> context);
-  std::shared_ptr<v8::ArrayBuffer::Allocator> allocator() const {
-    return allocator_;
-  }
-
-  SharedArrayBufferMetadata(SharedArrayBufferMetadata&& other) = delete;
-  SharedArrayBufferMetadata& operator=(
-      SharedArrayBufferMetadata&& other) = delete;
-  SharedArrayBufferMetadata& operator=(
-      const SharedArrayBufferMetadata&) = delete;
-  SharedArrayBufferMetadata(const SharedArrayBufferMetadata&) = delete;
-
- private:
-  SharedArrayBufferMetadata(
-      const v8::SharedArrayBuffer::Contents&,
-      std::shared_ptr<v8::ArrayBuffer::Allocator>);
-
-  // Attach a lifetime tracker object with a reference count to `target`.
-  v8::Maybe<bool> AssignToSharedArrayBuffer(
-      Environment* env,
-      v8::Local<v8::Context> context,
-      v8::Local<v8::SharedArrayBuffer> target);
-
-  v8::SharedArrayBuffer::Contents contents_;
-  std::shared_ptr<v8::ArrayBuffer::Allocator> allocator_;
-};
-
-}  // namespace worker
-}  // namespace node
-
-#endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
-
-
-#endif  // SRC_SHAREDARRAYBUFFER_METADATA_H_