We constantly fight against scrambled output with --print-wasm-code and
other flags. Passing --single-threaded only partially mitigates this,
because there could still be multiple isolates (e.g. Workers), and we
sometimes failed to really execute in a single thread if that flag was
set.
Hence this CL solves the problem in a more fundamental way: Whenever a
{StdoutStream} is constructed, it implicitly takes a global recursive
mutex. The recursive mutex is needed because we still have some printing
methods that don't take a stream as parameter, and instead create their
own instance of {StdoutStream}, which should not crash of course.
The overhead of taking a mutex should be acceptable, since output to
stdout mostly happens if special tracing flags have been passed, and is
slow anyway.
This CL ensures that the {StdoutStream} is used at least for
--print-code, --print-wasm-code, and --trace-turbo-graph.
More flags can later be ported on demand.
The {JSHeapBroker} class was modified to not contain a {StdoutStream},
but instead create one on demand.
R=mlippautz@chromium.org, tebbi@chromium.orgCC=ahaas@chromium.org
Bug: v8:10506
Change-Id: Ib9cf8d76aa79553b4215bb7775e6d47a8179aafa
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2201767
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67855}
a0687c7131