[Webkit-unassigned] [Bug 182496] New: bmalloc::PerProcess<T> is not really per-process, can lead to mistakes / duplication (IsoTLSDeallocatorEntry<IsoConfig<40u>>)

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=182496

            Bug ID: 182496
           Summary: bmalloc::PerProcess<T> is not really per-process, can
                    lead to mistakes / duplication
                    (IsoTLSDeallocatorEntry<IsoConfig<40u>>)
           Product: WebKit
           Version: WebKit Nightly Build
          Hardware: Unspecified
                OS: Unspecified
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: bmalloc
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: joepeck at webkit.org
                CC: fpizlo at apple.com, ggaren at apple.com

bmalloc::PerProcess<T> is not really per-process, can lead to mistakes / duplication

The templated type doesn't export symbols, so each image (library / framework) that includes code with PerProcess<T> gets its own storage and its own instance.

The only existing duplication right now is PerProcess<IsoTLSDeallocatorEntry<IsoConfig<40u>>> gets one instance in JavaScriptCore and one in WebCore:

    JavaScriptCore`bmalloc::PerProcess<bmalloc::IsoTLSDeallocatorEntry<bmalloc::IsoConfig<40u>>>
    WebCore`bmalloc::PerProcess<bmalloc::IsoTLSDeallocatorEntry<bmalloc::IsoConfig<40u>>>

See also in bug 182474 where PerProcess<Scavenger> created multiple instances (again 1 from JSC and WebCore). This case was noticed because the constructor spawns its own thread so the duplication was causing multiple bmalloc scavenger threads.

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20180205/fd729c05/attachment-0001.html>