• Clemens Hammacher's avatar
    Revert "[arraybuffer] Rearchitect backing store ownership" · bf92fbf4
    Clemens Hammacher authored
    This reverts commit 31cd5d83.
    
    Reason for revert: It breaks my heart to revert this, but it fails differently on several bots, e.g. https://ci.chromium.org/p/v8/builders/ci/V8%20Linux%20-%20debug/26671.
    
    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.
    > 
    > R=​mlippautz@chromium.org
    > BUG=v8:9380,v8:9221
    > 
    > Change-Id: I48fae5ac85dcf6172a83f252439e77e7c1a16ccd
    > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1584323
    > Commit-Queue: Ben Titzer <titzer@chromium.org>
    > Reviewed-by: Ben Titzer <titzer@chromium.org>
    > Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
    > Reviewed-by: Yang Guo <yangguo@chromium.org>
    > Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
    > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
    > Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
    > Cr-Commit-Position: refs/heads/master@{#62572}
    
    TBR=ulan@chromium.org,yangguo@chromium.org,mstarzinger@chromium.org,titzer@chromium.org,gdeepti@chromium.org,mlippautz@chromium.org
    
    Change-Id: Ib35788ba8c31192d90cbc72df3dbc41030f109de
    No-Presubmit: true
    No-Tree-Checks: true
    No-Try: true
    Bug: v8:9380, v8:9221
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1691034Reviewed-by: 's avatarClemens Hammacher <clemensh@chromium.org>
    Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#62578}
    bf92fbf4
d8.h 19.7 KB