v8/test/unittests/heap/local-heap-unittest.cc
Dominik Inführ 28d5f133df [heap] Fix deadlock with concurrent allocation and blocked main thread
It could happen (e.g. with --stress-background-compile) that the main
thread blocks for a background thread but the background thread requests
a GC from the main thread. This would result in a deadlock. Avoid this
by parking the main thread for potentially blocking operations and allow
allocations while the main thread is parked.

This CL introduces new states for the main thread: CollectionRequested
and ParkedCollectionRequested. These states will force Safepoint(),
Park() and Unpark() on the main thread into slow paths. The slow path
can then perform a GC on the main thread - right before parking or after
the main thread got unparked.

Bug: v8:10315
Change-Id: If7ef31622d27320613139a0b7f79086fe3200f99
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2731528
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73707}
2021-03-29 12:29:25 +00:00

193 lines
4.8 KiB
C++

// Copyright 2020 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/heap/local-heap.h"
#include "src/base/platform/condition-variable.h"
#include "src/base/platform/mutex.h"
#include "src/heap/heap.h"
#include "src/heap/parked-scope.h"
#include "src/heap/safepoint.h"
#include "test/unittests/test-utils.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace v8 {
namespace internal {
using LocalHeapTest = TestWithIsolate;
TEST_F(LocalHeapTest, Initialize) {
Heap* heap = i_isolate()->heap();
CHECK(heap->safepoint()->ContainsAnyLocalHeap());
}
TEST_F(LocalHeapTest, Current) {
Heap* heap = i_isolate()->heap();
CHECK_NULL(LocalHeap::Current());
{
LocalHeap lh(heap, ThreadKind::kMain);
CHECK_NULL(LocalHeap::Current());
}
CHECK_NULL(LocalHeap::Current());
{
LocalHeap lh(heap, ThreadKind::kMain);
CHECK_NULL(LocalHeap::Current());
}
CHECK_NULL(LocalHeap::Current());
}
namespace {
class BackgroundThread final : public v8::base::Thread {
public:
explicit BackgroundThread(Heap* heap)
: v8::base::Thread(base::Thread::Options("BackgroundThread")),
heap_(heap) {}
void Run() override {
CHECK_NULL(LocalHeap::Current());
{
LocalHeap lh(heap_, ThreadKind::kBackground);
CHECK_EQ(&lh, LocalHeap::Current());
}
CHECK_NULL(LocalHeap::Current());
}
Heap* heap_;
};
} // anonymous namespace
TEST_F(LocalHeapTest, CurrentBackground) {
Heap* heap = i_isolate()->heap();
CHECK_NULL(LocalHeap::Current());
{
LocalHeap lh(heap, ThreadKind::kMain);
auto thread = std::make_unique<BackgroundThread>(heap);
CHECK(thread->Start());
CHECK_NULL(LocalHeap::Current());
thread->Join();
CHECK_NULL(LocalHeap::Current());
}
CHECK_NULL(LocalHeap::Current());
}
namespace {
class GCEpilogue {
public:
static void Callback(void* data) {
reinterpret_cast<GCEpilogue*>(data)->was_invoked_ = true;
}
void NotifyStarted() {
base::LockGuard<base::Mutex> lock_guard(&mutex_);
started_ = true;
cv_.NotifyOne();
}
void WaitUntilStarted() {
base::LockGuard<base::Mutex> lock_guard(&mutex_);
while (!started_) {
cv_.Wait(&mutex_);
}
}
void RequestStop() {
base::LockGuard<base::Mutex> lock_guard(&mutex_);
stop_requested_ = true;
}
bool StopRequested() {
base::LockGuard<base::Mutex> lock_guard(&mutex_);
return stop_requested_;
}
bool WasInvoked() { return was_invoked_; }
private:
bool was_invoked_ = false;
bool started_ = false;
bool stop_requested_ = false;
base::Mutex mutex_;
base::ConditionVariable cv_;
};
class BackgroundThreadForGCEpilogue final : public v8::base::Thread {
public:
explicit BackgroundThreadForGCEpilogue(Heap* heap, bool parked,
GCEpilogue* epilogue)
: v8::base::Thread(base::Thread::Options("BackgroundThread")),
heap_(heap),
parked_(parked),
epilogue_(epilogue) {}
void Run() override {
LocalHeap lh(heap_, ThreadKind::kBackground);
base::Optional<UnparkedScope> unparked_scope;
if (!parked_) {
unparked_scope.emplace(&lh);
}
{
base::Optional<UnparkedScope> unparked_scope;
if (parked_) unparked_scope.emplace(&lh);
lh.AddGCEpilogueCallback(&GCEpilogue::Callback, epilogue_);
}
epilogue_->NotifyStarted();
while (!epilogue_->StopRequested()) {
lh.Safepoint();
}
{
base::Optional<UnparkedScope> unparked_scope;
if (parked_) unparked_scope.emplace(&lh);
lh.RemoveGCEpilogueCallback(&GCEpilogue::Callback, epilogue_);
}
}
Heap* heap_;
bool parked_;
GCEpilogue* epilogue_;
};
} // anonymous namespace
TEST_F(LocalHeapTest, GCEpilogue) {
Heap* heap = i_isolate()->heap();
LocalHeap lh(heap, ThreadKind::kMain);
std::array<GCEpilogue, 3> epilogue;
{
UnparkedScope unparked(&lh);
lh.AddGCEpilogueCallback(&GCEpilogue::Callback, &epilogue[0]);
}
auto thread1 =
std::make_unique<BackgroundThreadForGCEpilogue>(heap, true, &epilogue[1]);
auto thread2 = std::make_unique<BackgroundThreadForGCEpilogue>(heap, false,
&epilogue[2]);
CHECK(thread1->Start());
CHECK(thread2->Start());
epilogue[1].WaitUntilStarted();
epilogue[2].WaitUntilStarted();
{
UnparkedScope scope(&lh);
heap->PreciseCollectAllGarbage(Heap::kNoGCFlags,
GarbageCollectionReason::kTesting);
}
epilogue[1].RequestStop();
epilogue[2].RequestStop();
thread1->Join();
thread2->Join();
{
UnparkedScope unparked(&lh);
lh.RemoveGCEpilogueCallback(&GCEpilogue::Callback, &epilogue[0]);
}
for (auto& e : epilogue) {
CHECK(e.WasInvoked());
}
}
} // namespace internal
} // namespace v8