• Andreas Haas's avatar
    [wasm] Fix return value of concurrent memory.grow · 401190ba
    Andreas Haas authored
    When memory.grow was executed concurrently on multiple threads a data
    race could happen such that two memory.grow operations result in the
    same return value. With this CL the return value of memory.grow is
    unique, given that memory.grow actually grows the memory.
    
    As a concrete example, assume a shared WebAssembly memory initially has
    a size of 100. Assume two threads call memory.grow concurrently with a
    parameter `10`. Then with the existing code, memory would grow correctly
    to a size of 120, but the data race may cause both memory.grow
    operations to return 100. With the change in this CL one memory.grow
    operation would return 100, the other would return 110.
    
    R=gdeepti@chromium.org
    CC=rreverser@google.com
    
    Bug: chromium:1067621
    Change-Id: Ib22b5135714a56799e0818ccb39e5dce327e5f8e
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2144113Reviewed-by: 's avatarBen Smith <binji@chromium.org>
    Reviewed-by: 's avatarDeepti Gandluri <gdeepti@chromium.org>
    Commit-Queue: Andreas Haas <ahaas@chromium.org>
    Cr-Commit-Position: refs/heads/master@{#67135}
    401190ba
backing-store-unittest.cc 4.45 KB