tree 9c4d342a3aa847830c9b676307602ac3e2c49338
parent 2bbb2f3c1fddded8092c1c8c049c472737faf12a
author Martin Kustermann <kustermann@google.com> 1558488226 +0000
committer commit-bot@chromium.org <commit-bot@chromium.org> 1558488226 +0000

[vm/kernel] Use GC-tracked ExternalTypedData/TypedDataView for kernel buffers

Until now we often leaked kernel buffers (e.g. hot reload buffers) because various
objects were referencing ExternalTypedData objects pointing into the middle of
c-allocated memory. This made it impossible for the GC to determine when the last
reference is gone.

This CL ensures that the actual buffers are *always* made available via
ExternalTypedData and any inner pointers into it are created via TypedDataViews.

The embedder guarantees to the free kernel buffers it has provided to:
    - Dart_CreateIsolateFromKernel
    - Dart_LoadScriptFromKernel
    - Dart_LoadLibraryFromKernel
    - Dart_SetDartLibrarySourcesKernel
on isolate shutdown.

All other kernel buffers will get a finalizer attached, which ensures the
kernel buffers get freed by the GC once they are no longer referenced:
    - Kernel blobs for expression evaluation
    - Kernel blobs for Hot-Reload
    - Kernel blobs for cc tests

Fixes https://github.com/dart-lang/sdk/issues/33973
Fixes https://github.com/dart-lang/sdk/issues/36857
Issue https://github.com/dart-lang/sdk/issues/37030

Change-Id: I1cc410c94c0f4b229413e793728a261afcb10aaf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/103130
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>