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[wasm][cleanup] Hold wasm engine in a raw pointer

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After the --wasm-shared-engine flag was removed (in
https://crrev.com/c/1864935), there is no point any more in holding the
wasm engine in a shared_ptr. The engine is initialized once for the
whole process, and only deallocated during global tear down.

R=jkummerow@chromium.org

Bug: v8:11384
Change-Id: Id8e96eaecfcab8b44842ec323c94529e9c5a5e25
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2853589
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74253}
This commit is contained in:
Clemens Backes 2021-04-28 10:24:34 +02:00 committed by Commit Bot
parent 5a8afe011d
commit 6ad860b3ec
6 changed files with 43 additions and 97 deletions
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12
src/execution/isolate.cc
View File

@ -2692,9 +2692,10 @@ void Isolate::UnregisterManagedPtrDestructor(ManagedPtrDestructor* destructor) {
}
#if V8_ENABLE_WEBASSEMBLY
void Isolate::SetWasmEngine(std::shared_ptr<wasm::WasmEngine> engine) {
void Isolate::SetWasmEngine(wasm::WasmEngine* engine) {
DCHECK_NULL(wasm_engine_); // Only call once before {Init}.
wasm_engine_ = std::move(engine);
DCHECK_NOT_NULL(engine);
wasm_engine_ = engine;
wasm_engine_->AddIsolate(this);
}
@ -3136,10 +3137,7 @@ void Isolate::Deinit() {
if (logfile != nullptr) base::Fclose(logfile);
#if V8_ENABLE_WEBASSEMBLY
if (wasm_engine_) {
wasm_engine_->RemoveIsolate(this);
wasm_engine_.reset();
}
#endif // V8_ENABLE_WEBASSEMBLY
TearDownEmbeddedBlob();
@ -3617,11 +3615,7 @@ bool Isolate::Init(SnapshotData* startup_snapshot_data,
isolate_data_.external_reference_table()->Init(this);
#if V8_ENABLE_WEBASSEMBLY
// Setup the wasm engine.
if (wasm_engine_ == nullptr) {
SetWasmEngine(wasm::WasmEngine::GetWasmEngine());
}
DCHECK_NOT_NULL(wasm_engine_);
#endif // V8_ENABLE_WEBASSEMBLY
if (setup_delegate_ == nullptr) {

7
src/execution/isolate.h
View File

@ -1684,8 +1684,9 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
}
#if V8_ENABLE_WEBASSEMBLY
wasm::WasmEngine* wasm_engine() const { return wasm_engine_.get(); }
void SetWasmEngine(std::shared_ptr<wasm::WasmEngine> engine);
// TODO(wasm): Replace all uses by {WasmEngine::GetWasmEngine}?
wasm::WasmEngine* wasm_engine() const { return wasm_engine_; }
void SetWasmEngine(wasm::WasmEngine* engine);
void AddSharedWasmMemory(Handle<WasmMemoryObject> memory_object);
#endif // V8_ENABLE_WEBASSEMBLY
@ -2135,7 +2136,7 @@ class V8_EXPORT_PRIVATE Isolate final : private HiddenFactory {
size_t elements_deletion_counter_ = 0;
#if V8_ENABLE_WEBASSEMBLY
std::shared_ptr<wasm::WasmEngine> wasm_engine_;
wasm::WasmEngine* wasm_engine_ = nullptr;
#endif // V8_ENABLE_WEBASSEMBLY
std::unique_ptr<TracingCpuProfilerImpl> tracing_cpu_profiler_;

17
src/wasm/wasm-engine.cc
View File

@ -1561,24 +1561,29 @@ void WasmEngine::PotentiallyFinishCurrentGC() {
namespace {
DEFINE_LAZY_LEAKY_OBJECT_GETTER(std::shared_ptr<WasmEngine>,
GetSharedWasmEngine)
WasmEngine* global_wasm_engine = nullptr;
} // namespace
// static
void WasmEngine::InitializeOncePerProcess() {
*GetSharedWasmEngine() = std::make_shared<WasmEngine>();
DCHECK_NULL(global_wasm_engine);
global_wasm_engine = new WasmEngine();
}
// static
void WasmEngine::GlobalTearDown() {
GetSharedWasmEngine()->reset();
// Note: This can be called multiple times in a row (see
// test-api/InitializeAndDisposeMultiple). This is fine, as
// {global_wasm_engine} will be nullptr then.
delete global_wasm_engine;
global_wasm_engine = nullptr;
}
// static
std::shared_ptr<WasmEngine> WasmEngine::GetWasmEngine() {
return *GetSharedWasmEngine();
WasmEngine* WasmEngine::GetWasmEngine() {
DCHECK_NOT_NULL(global_wasm_engine);
return global_wasm_engine;
}
// {max_mem_pages} is declared in wasm-limits.h.

6
src/wasm/wasm-engine.h
View File

@ -357,10 +357,8 @@ class V8_EXPORT_PRIVATE WasmEngine {
static void InitializeOncePerProcess();
static void GlobalTearDown();
// Returns a reference to the WasmEngine shared by the entire process. Try to
// use {Isolate::wasm_engine} instead if it is available, which encapsulates
// engine lifetime decisions during Isolate bootstrapping.
static std::shared_ptr<WasmEngine> GetWasmEngine();
// Returns a reference to the WasmEngine shared by the entire process.
static WasmEngine* GetWasmEngine();
private:
struct CurrentGCInfo;

1
test/cctest/wasm/test-wasm-serialization.cc
View File

@ -257,7 +257,6 @@ TEST(BlockWasmCodeGenAtDeserialization) {
}
UNINITIALIZED_TEST(CompiledWasmModulesTransfer) {
i::wasm::WasmEngine::InitializeOncePerProcess();
v8::internal::AccountingAllocator allocator;
Zone zone(&allocator, ZONE_NAME);

91
test/cctest/wasm/test-wasm-shared-engine.cc
View File

@ -22,40 +22,15 @@ namespace internal {
namespace wasm {
namespace test_wasm_shared_engine {
// Helper class representing a WebAssembly engine that is capable of being
// shared between multiple Isolates, sharing the underlying generated code.
class SharedEngine {
public:
~SharedEngine() {
// Ensure no remaining uses exist.
CHECK(wasm_engine_.unique());
}
WasmEngine* engine() const { return wasm_engine_.get(); }
WasmCodeManager* code_manager() const { return engine()->code_manager(); }
int NumberOfExportedEngineUses() const {
// This class holds one implicit use itself, which we discount.
return static_cast<int>(wasm_engine_.use_count()) - 1;
}
std::shared_ptr<WasmEngine> ExportEngineForSharing() { return wasm_engine_; }
private:
std::shared_ptr<WasmEngine> wasm_engine_ = std::make_unique<WasmEngine>();
};
// Helper type definition representing a WebAssembly module shared between
// multiple Isolates with implicit reference counting.
using SharedModule = std::shared_ptr<NativeModule>;
// Helper class representing an Isolate based on a given shared WebAssembly
// engine available at construction time.
// Helper class representing an Isolate that uses the process-wide (shared) wasm
// engine.
class SharedEngineIsolate {
public:
explicit SharedEngineIsolate(SharedEngine* engine)
: isolate_(v8::Isolate::Allocate()) {
isolate()->SetWasmEngine(engine->ExportEngineForSharing());
SharedEngineIsolate() : isolate_(v8::Isolate::Allocate()) {
v8::Isolate::CreateParams create_params;
create_params.array_buffer_allocator = CcTest::array_buffer_allocator();
v8::Isolate::Initialize(isolate_, create_params);
@ -111,19 +86,16 @@ class SharedEngineIsolate {
// with a shared WebAssembly engine available at construction time.
class SharedEngineThread : public v8::base::Thread {
public:
SharedEngineThread(SharedEngine* engine,
explicit SharedEngineThread(
std::function<void(SharedEngineIsolate*)> callback)
: Thread(Options("SharedEngineThread")),
engine_(engine),
callback_(callback) {}
: Thread(Options("SharedEngineThread")), callback_(callback) {}
void Run() override {
SharedEngineIsolate isolate(engine_);
SharedEngineIsolate isolate;
callback_(&isolate);
}
private:
SharedEngine* engine_;
std::function<void(SharedEngineIsolate*)> callback_;
};
@ -201,34 +173,16 @@ Handle<WasmInstanceObject> CompileAndInstantiateAsync(
} // namespace
TEST(SharedEngineUseCount) {
SharedEngine engine;
CHECK_EQ(0, engine.NumberOfExportedEngineUses());
{
SharedEngineIsolate isolate(&engine);
CHECK_EQ(1, engine.NumberOfExportedEngineUses());
}
CHECK_EQ(0, engine.NumberOfExportedEngineUses());
{
SharedEngineIsolate isolate1(&engine);
CHECK_EQ(1, engine.NumberOfExportedEngineUses());
SharedEngineIsolate isolate2(&engine);
CHECK_EQ(2, engine.NumberOfExportedEngineUses());
}
CHECK_EQ(0, engine.NumberOfExportedEngineUses());
}
TEST(SharedEngineRunSeparated) {
SharedEngine engine;
{
SharedEngineIsolate isolate(&engine);
SharedEngineIsolate isolate;
HandleScope scope(isolate.isolate());
ZoneBuffer* buffer = BuildReturnConstantModule(isolate.zone(), 23);
Handle<WasmInstanceObject> instance = isolate.CompileAndInstantiate(buffer);
CHECK_EQ(23, isolate.Run(instance));
}
{
SharedEngineIsolate isolate(&engine);
SharedEngineIsolate isolate;
HandleScope scope(isolate.isolate());
ZoneBuffer* buffer = BuildReturnConstantModule(isolate.zone(), 42);
Handle<WasmInstanceObject> instance = isolate.CompileAndInstantiate(buffer);
@ -237,10 +191,9 @@ TEST(SharedEngineRunSeparated) {
}
TEST(SharedEngineRunImported) {
SharedEngine engine;
SharedModule module;
{
SharedEngineIsolate isolate(&engine);
SharedEngineIsolate isolate;
HandleScope scope(isolate.isolate());
ZoneBuffer* buffer = BuildReturnConstantModule(isolate.zone(), 23);
Handle<WasmInstanceObject> instance = isolate.CompileAndInstantiate(buffer);
@ -248,7 +201,7 @@ TEST(SharedEngineRunImported) {
CHECK_EQ(23, isolate.Run(instance));
}
{
SharedEngineIsolate isolate(&engine);
SharedEngineIsolate isolate;
HandleScope scope(isolate.isolate());
Handle<WasmInstanceObject> instance = isolate.ImportInstance(module);
CHECK_EQ(23, isolate.Run(instance));
@ -256,15 +209,14 @@ TEST(SharedEngineRunImported) {
}
TEST(SharedEngineRunThreadedBuildingSync) {
SharedEngine engine;
SharedEngineThread thread1(&engine, [](SharedEngineIsolate* isolate) {
SharedEngineThread thread1([](SharedEngineIsolate* isolate) {
HandleScope scope(isolate->isolate());
ZoneBuffer* buffer = BuildReturnConstantModule(isolate->zone(), 23);
Handle<WasmInstanceObject> instance =
isolate->CompileAndInstantiate(buffer);
CHECK_EQ(23, isolate->Run(instance));
});
SharedEngineThread thread2(&engine, [](SharedEngineIsolate* isolate) {
SharedEngineThread thread2([](SharedEngineIsolate* isolate) {
HandleScope scope(isolate->isolate());
ZoneBuffer* buffer = BuildReturnConstantModule(isolate->zone(), 42);
Handle<WasmInstanceObject> instance =
@ -278,15 +230,14 @@ TEST(SharedEngineRunThreadedBuildingSync) {
}
TEST(SharedEngineRunThreadedBuildingAsync) {
SharedEngine engine;
SharedEngineThread thread1(&engine, [](SharedEngineIsolate* isolate) {
SharedEngineThread thread1([](SharedEngineIsolate* isolate) {
HandleScope scope(isolate->isolate());
ZoneBuffer* buffer = BuildReturnConstantModule(isolate->zone(), 23);
Handle<WasmInstanceObject> instance =
CompileAndInstantiateAsync(isolate, buffer);
CHECK_EQ(23, isolate->Run(instance));
});
SharedEngineThread thread2(&engine, [](SharedEngineIsolate* isolate) {
SharedEngineThread thread2([](SharedEngineIsolate* isolate) {
HandleScope scope(isolate->isolate());
ZoneBuffer* buffer = BuildReturnConstantModule(isolate->zone(), 42);
Handle<WasmInstanceObject> instance =
@ -300,21 +251,20 @@ TEST(SharedEngineRunThreadedBuildingAsync) {
}
TEST(SharedEngineRunThreadedExecution) {
SharedEngine engine;
SharedModule module;
{
SharedEngineIsolate isolate(&engine);
SharedEngineIsolate isolate;
HandleScope scope(isolate.isolate());
ZoneBuffer* buffer = BuildReturnConstantModule(isolate.zone(), 23);
Handle<WasmInstanceObject> instance = isolate.CompileAndInstantiate(buffer);
module = isolate.ExportInstance(instance);
}
SharedEngineThread thread1(&engine, [module](SharedEngineIsolate* isolate) {
SharedEngineThread thread1([module](SharedEngineIsolate* isolate) {
HandleScope scope(isolate->isolate());
Handle<WasmInstanceObject> instance = isolate->ImportInstance(module);
CHECK_EQ(23, isolate->Run(instance));
});
SharedEngineThread thread2(&engine, [module](SharedEngineIsolate* isolate) {
SharedEngineThread thread2([module](SharedEngineIsolate* isolate) {
HandleScope scope(isolate->isolate());
Handle<WasmInstanceObject> instance = isolate->ImportInstance(module);
CHECK_EQ(23, isolate->Run(instance));
@ -326,10 +276,9 @@ TEST(SharedEngineRunThreadedExecution) {
}
TEST(SharedEngineRunThreadedTierUp) {
SharedEngine engine;
SharedModule module;
{
SharedEngineIsolate isolate(&engine);
SharedEngineIsolate isolate;
HandleScope scope(isolate.isolate());
ZoneBuffer* buffer = BuildReturnConstantModule(isolate.zone(), 23);
Handle<WasmInstanceObject> instance = isolate.CompileAndInstantiate(buffer);
@ -338,7 +287,7 @@ TEST(SharedEngineRunThreadedTierUp) {
constexpr int kNumberOfThreads = 5;
std::list<SharedEngineThread> threads;
for (int i = 0; i < kNumberOfThreads; ++i) {
threads.emplace_back(&engine, [module](SharedEngineIsolate* isolate) {
threads.emplace_back([module](SharedEngineIsolate* isolate) {
constexpr int kNumberOfIterations = 100;
HandleScope scope(isolate->isolate());
Handle<WasmInstanceObject> instance = isolate->ImportInstance(module);
@ -347,7 +296,7 @@ TEST(SharedEngineRunThreadedTierUp) {
}
});
}
threads.emplace_back(&engine, [module](SharedEngineIsolate* isolate) {
threads.emplace_back([module](SharedEngineIsolate* isolate) {
HandleScope scope(isolate->isolate());
Handle<WasmInstanceObject> instance = isolate->ImportInstance(module);
WasmFeatures detected = WasmFeatures::None();