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Fix data race on CompilationState callbacks

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The vector of callbacks can only be accessed from main threads.
Otherwise we get flaky data races. Those showed up after removing the
finisher task (https://crrev.com/c/1335553/2).

R=mstarzinger@chromium.org

Bug: v8:7921
Change-Id: I0429ae87427601952723f6e3ad1e02eb0e59a6e1
Reviewed-on: https://chromium-review.googlesource.com/c/1378174
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58244}
This commit is contained in:
Clemens Hammacher 2018-12-14 15:18:27 +01:00 committed by Commit Bot
parent 2a7a827f68
commit 21440dd3d4
1 changed files with 17 additions and 9 deletions
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26
src/wasm/module-compiler.cc
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@ -205,16 +205,16 @@ class CompilationStateImpl {
std::vector<WasmCode*> code_to_log_;
};
class FreeCallbacksTask : public Task {
class FreeCallbacksTask : public CancelableTask {
public:
explicit FreeCallbacksTask(
std::vector<CompilationState::callback_t> callbacks)
: callbacks_(std::move(callbacks)) {}
explicit FreeCallbacksTask(CompilationStateImpl* comp_state)
: CancelableTask(&comp_state->foreground_task_manager_),
compilation_state_(comp_state) {}
void Run() override { callbacks_.clear(); }
void RunInternal() override { compilation_state_->callbacks_.clear(); }
private:
std::vector<CompilationState::callback_t> callbacks_;
CompilationStateImpl* const compilation_state_;
};
void NotifyOnEvent(CompilationEvent event, const VoidResult* error_result);
@ -272,9 +272,16 @@ class CompilationStateImpl {
// End of fields protected by {mutex_}.
//////////////////////////////////////////////////////////////////////////////
// Callback functions to be called on compilation events.
// Callback functions to be called on compilation events. Only accessible from
// the foreground thread.
std::vector<CompilationState::callback_t> callbacks_;
// Remember whether {Abort()} was called. When set from the foreground this
// ensures no more callbacks will be called afterwards. No guarantees when set
// from the background. Only needs to be atomic so that it can be set from
// foreground and background.
std::atomic<bool> aborted_{false};
CancelableTaskManager background_task_manager_;
CancelableTaskManager foreground_task_manager_;
std::shared_ptr<v8::TaskRunner> foreground_task_runner_;
@ -3220,11 +3227,11 @@ void CompilationStateImpl::Abort() {
// No more callbacks after abort. Don't free the std::function objects here,
// since this might clear references in the embedder, which is only allowed on
// the main thread.
aborted_.store(true);
if (!callbacks_.empty()) {
foreground_task_runner_->PostTask(
base::make_unique<FreeCallbacksTask>(std::move(callbacks_)));
base::make_unique<FreeCallbacksTask>(this));
}
DCHECK(callbacks_.empty());
}
void CompilationStateImpl::SetError(uint32_t func_index,
@ -3251,6 +3258,7 @@ void CompilationStateImpl::SetError(uint32_t func_index,
void CompilationStateImpl::NotifyOnEvent(CompilationEvent event,
const VoidResult* error_result) {
if (aborted_.load()) return;
HandleScope scope(isolate_);
for (auto& callback : callbacks_) callback(event, error_result);
// If no more events are expected after this one, clear the callbacks to free