• Ulan Degenbaev's avatar
    [runtime] Make layout descriptor helper safe for concurrent marking. · 61bf2cc6
    Ulan Degenbaev authored
    The layout descriptor helper computes the object header size using
    map->instance_size() and map->GetInObjectProperties().
    
    It races with finalization of slack tracking, which changes both
    the instance size and the in-object properties count.
    
    This patch replaces the in-object properties count byte in the map
    with the byte that stores the start offset of in-object properties.
    
    The new byte can be used in the layout descriptor to compute the
    object header size and it is immutable.
    
    This patch also renames InstanceSize to InstanceSizeInWords where
    the instance size is represented in words.
    
    Bug: chromium:786069, chromium:694255
    Change-Id: I4b48c6944d3fe8a950bd7b0ba43d75216b177a78
    Reviewed-on: https://chromium-review.googlesource.com/776720
    Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
    Reviewed-by: 's avatarIgor Sheludko <ishell@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#49461}
    61bf2cc6
layout-descriptor-inl.h 7.44 KB