• Ulan Degenbaev's avatar
    Reland x6 [arraybuffer] Rearchitect backing store ownership · b6b7de0d
    Ulan Degenbaev authored
    This reverts commit 9da34831
    
    Original change's description:
    > "Reland x4 [arraybuffer] Rearchitect backing store ownership"
    >
    > This is a reland of bc33f5ae
    >
    > Contributed by titzer@chromium.org
    >
    > Original change's description:
    > > [arraybuffer] Rearchitect backing store ownership
    > >
    > > This CL completely rearchitects the ownership of array buffer backing stores,
    > > consolidating ownership into a {BackingStore} C++ object that is tracked
    > > throughout V8 using unique_ptr and shared_ptr where appropriate.
    > >
    > > Overall, lifetime management is simpler and more explicit. The numerous
    > > ways that array buffers were initialized have been streamlined to one
    > > Attach() method on JSArrayBuffer. The array buffer tracker in the
    > > GC implementation now manages std::shared_ptr<BackingStore> pointers,
    > > and the construction and destruction of the BackingStore object itself
    > > handles the underlying page or embedder-allocated memory.
    > >
    > > The embedder API remains unchanged for now. We use the
    > > v8::ArrayBuffer::Contents struct to hide an additional shared_ptr to
    > > keep the backing store alive properly, even in the case of aliases
    > > from live heap objects. Thus the embedder has a lower chance of making
    > > a mistake. Long-term, we should move the embedder to a model where they
    > > manage backing stores using shared_ptr to an opaque backing store object.
    >
    > TBR=yangguo@chromium.org
    >
    > BUG=v8:9380,v8:9221,chromium:986318
    >
    > Change-Id: If671a4a9ca0476e8f084efae46e0d2bf99ed99ef
    > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1731005
    > Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
    > Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
    > Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
    
    > Cr-Commit-Position: refs/heads/master@{#63041}
    
    TBR=yangguo@chromium.org
    
    Change-Id: I3cc4bb80081c662b1751234bc16a821c20e744be
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1792166
    Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
    Reviewed-by: 's avatarMichael Starzinger <mstarzinger@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#63617}
    b6b7de0d