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#include "env.h" #include "async_wrap.h" #include "base_object-inl.h" #include "debug_utils-inl.h" #include "diagnosticfilename-inl.h" #include "memory_tracker-inl.h" #include "node_buffer.h" #include "node_context_data.h" #include "node_errors.h" #include "node_internals.h" #include "node_options-inl.h" #include "node_process-inl.h" #include "node_v8_platform-inl.h" #include "node_worker.h" #include "req_wrap-inl.h" #include "stream_base.h" #include "tracing/agent.h" #include "tracing/traced_value.h" #include "util-inl.h" #include "v8-profiler.h" #include <algorithm> #include <atomic> #include <cinttypes> #include <cstdio> #include <iostream> #include <limits> #include <memory> namespace node { using errors::TryCatchScope; using v8::Array; using v8::Boolean; using v8::Context; using v8::EmbedderGraph; using v8::EscapableHandleScope; using v8::Function; using v8::FunctionCallbackInfo; using v8::FunctionTemplate; using v8::HandleScope; using v8::HeapSpaceStatistics; using v8::Integer; using v8::Isolate; using v8::Local; using v8::MaybeLocal; using v8::NewStringType; using v8::Number; using v8::Object; using v8::Private; using v8::Script; using v8::SnapshotCreator; using v8::StackTrace; using v8::String; using v8::Symbol; using v8::TracingController; using v8::TryCatch; using v8::Undefined; using v8::Value; using v8::WeakCallbackInfo; using v8::WeakCallbackType; using worker::Worker; int const ContextEmbedderTag::kNodeContextTag = 0x6e6f64; void* const ContextEmbedderTag::kNodeContextTagPtr = const_cast<void*>( static_cast<const void*>(&ContextEmbedderTag::kNodeContextTag)); void AsyncHooks::SetJSPromiseHooks(Local<Function> init, Local<Function> before, Local<Function> after, Local<Function> resolve) { js_promise_hooks_[0].Reset(env()->isolate(), init); js_promise_hooks_[1].Reset(env()->isolate(), before); js_promise_hooks_[2].Reset(env()->isolate(), after); js_promise_hooks_[3].Reset(env()->isolate(), resolve); for (auto it = contexts_.begin(); it != contexts_.end(); it++) { if (it->IsEmpty()) { contexts_.erase(it--); continue; } PersistentToLocal::Weak(env()->isolate(), *it) ->SetPromiseHooks(init, before, after, resolve); } } // Remember to keep this code aligned with pushAsyncContext() in JS. void AsyncHooks::push_async_context(double async_id, double trigger_async_id, Local<Object> resource) { // Since async_hooks is experimental, do only perform the check // when async_hooks is enabled. if (fields_[kCheck] > 0) { CHECK_GE(async_id, -1); CHECK_GE(trigger_async_id, -1); } uint32_t offset = fields_[kStackLength]; if (offset * 2 >= async_ids_stack_.Length()) grow_async_ids_stack(); async_ids_stack_[2 * offset] = async_id_fields_[kExecutionAsyncId]; async_ids_stack_[2 * offset + 1] = async_id_fields_[kTriggerAsyncId]; fields_[kStackLength] += 1; async_id_fields_[kExecutionAsyncId] = async_id; async_id_fields_[kTriggerAsyncId] = trigger_async_id; #ifdef DEBUG for (uint32_t i = offset; i < native_execution_async_resources_.size(); i++) CHECK(native_execution_async_resources_[i].IsEmpty()); #endif // When this call comes from JS (as a way of increasing the stack size), // `resource` will be empty, because JS caches these values anyway. if (!resource.IsEmpty()) { native_execution_async_resources_.resize(offset + 1); // Caveat: This is a v8::Local<> assignment, we do not keep a v8::Global<>! native_execution_async_resources_[offset] = resource; } } // Remember to keep this code aligned with popAsyncContext() in JS. bool AsyncHooks::pop_async_context(double async_id) { // In case of an exception then this may have already been reset, if the // stack was multiple MakeCallback()'s deep. if (UNLIKELY(fields_[kStackLength] == 0)) return false; // Ask for the async_id to be restored as a check that the stack // hasn't been corrupted. if (UNLIKELY(fields_[kCheck] > 0 && async_id_fields_[kExecutionAsyncId] != async_id)) { FailWithCorruptedAsyncStack(async_id); } uint32_t offset = fields_[kStackLength] - 1; async_id_fields_[kExecutionAsyncId] = async_ids_stack_[2 * offset]; async_id_fields_[kTriggerAsyncId] = async_ids_stack_[2 * offset + 1]; fields_[kStackLength] = offset; if (LIKELY(offset < native_execution_async_resources_.size() && !native_execution_async_resources_[offset].IsEmpty())) { #ifdef DEBUG for (uint32_t i = offset + 1; i < native_execution_async_resources_.size(); i++) { CHECK(native_execution_async_resources_[i].IsEmpty()); } #endif native_execution_async_resources_.resize(offset); if (native_execution_async_resources_.size() < native_execution_async_resources_.capacity() / 2 && native_execution_async_resources_.size() > 16) { native_execution_async_resources_.shrink_to_fit(); } } if (UNLIKELY(js_execution_async_resources()->Length() > offset)) { HandleScope handle_scope(env()->isolate()); USE(js_execution_async_resources()->Set( env()->context(), env()->length_string(), Integer::NewFromUnsigned(env()->isolate(), offset))); } return fields_[kStackLength] > 0; } void AsyncHooks::clear_async_id_stack() { if (env()->can_call_into_js()) { Isolate* isolate = env()->isolate(); HandleScope handle_scope(isolate); if (!js_execution_async_resources_.IsEmpty()) { USE(PersistentToLocal::Strong(js_execution_async_resources_) ->Set(env()->context(), env()->length_string(), Integer::NewFromUnsigned(isolate, 0))); } } native_execution_async_resources_.clear(); native_execution_async_resources_.shrink_to_fit(); async_id_fields_[kExecutionAsyncId] = 0; async_id_fields_[kTriggerAsyncId] = 0; fields_[kStackLength] = 0; } void AsyncHooks::AddContext(Local<Context> ctx) { ctx->SetPromiseHooks(js_promise_hooks_[0].IsEmpty() ? Local<Function>() : PersistentToLocal::Strong(js_promise_hooks_[0]), js_promise_hooks_[1].IsEmpty() ? Local<Function>() : PersistentToLocal::Strong(js_promise_hooks_[1]), js_promise_hooks_[2].IsEmpty() ? Local<Function>() : PersistentToLocal::Strong(js_promise_hooks_[2]), js_promise_hooks_[3].IsEmpty() ? Local<Function>() : PersistentToLocal::Strong(js_promise_hooks_[3])); size_t id = contexts_.size(); contexts_.resize(id + 1); contexts_[id].Reset(env()->isolate(), ctx); contexts_[id].SetWeak(); } void AsyncHooks::RemoveContext(Local<Context> ctx) { Isolate* isolate = env()->isolate(); HandleScope handle_scope(isolate); contexts_.erase(std::remove_if(contexts_.begin(), contexts_.end(), [&](auto&& el) { return el.IsEmpty(); }), contexts_.end()); for (auto it = contexts_.begin(); it != contexts_.end(); it++) { Local<Context> saved_context = PersistentToLocal::Weak(isolate, *it); if (saved_context == ctx) { it->Reset(); contexts_.erase(it); break; } } } AsyncHooks::DefaultTriggerAsyncIdScope::DefaultTriggerAsyncIdScope( Environment* env, double default_trigger_async_id) : async_hooks_(env->async_hooks()) { if (env->async_hooks()->fields()[AsyncHooks::kCheck] > 0) { CHECK_GE(default_trigger_async_id, 0); } old_default_trigger_async_id_ = async_hooks_->async_id_fields()[AsyncHooks::kDefaultTriggerAsyncId]; async_hooks_->async_id_fields()[AsyncHooks::kDefaultTriggerAsyncId] = default_trigger_async_id; } AsyncHooks::DefaultTriggerAsyncIdScope::~DefaultTriggerAsyncIdScope() { async_hooks_->async_id_fields()[AsyncHooks::kDefaultTriggerAsyncId] = old_default_trigger_async_id_; } AsyncHooks::DefaultTriggerAsyncIdScope::DefaultTriggerAsyncIdScope( AsyncWrap* async_wrap) : DefaultTriggerAsyncIdScope(async_wrap->env(), async_wrap->get_async_id()) {} std::vector<size_t> IsolateData::Serialize(SnapshotCreator* creator) { Isolate* isolate = creator->GetIsolate(); std::vector<size_t> indexes; HandleScope handle_scope(isolate); // XXX(joyeecheung): technically speaking, the indexes here should be // consecutive and we could just return a range instead of an array, // but that's not part of the V8 API contract so we use an array // just to be safe. #define VP(PropertyName, StringValue) V(Private, PropertyName) #define VY(PropertyName, StringValue) V(Symbol, PropertyName) #define VS(PropertyName, StringValue) V(String, PropertyName) #define V(TypeName, PropertyName) \ indexes.push_back(creator->AddData(PropertyName##_.Get(isolate))); PER_ISOLATE_PRIVATE_SYMBOL_PROPERTIES(VP) PER_ISOLATE_SYMBOL_PROPERTIES(VY) PER_ISOLATE_STRING_PROPERTIES(VS) #undef V #undef VY #undef VS #undef VP for (size_t i = 0; i < AsyncWrap::PROVIDERS_LENGTH; i++) indexes.push_back(creator->AddData(async_wrap_provider(i))); return indexes; } void IsolateData::DeserializeProperties(const std::vector<size_t>* indexes) { size_t i = 0; HandleScope handle_scope(isolate_); #define VP(PropertyName, StringValue) V(Private, PropertyName) #define VY(PropertyName, StringValue) V(Symbol, PropertyName) #define VS(PropertyName, StringValue) V(String, PropertyName) #define V(TypeName, PropertyName) \ do { \ MaybeLocal<TypeName> maybe_field = \ isolate_->GetDataFromSnapshotOnce<TypeName>((*indexes)[i++]); \ Local<TypeName> field; \ if (!maybe_field.ToLocal(&field)) { \ fprintf(stderr, "Failed to deserialize " #PropertyName "\n"); \ } \ PropertyName##_.Set(isolate_, field); \ } while (0); PER_ISOLATE_PRIVATE_SYMBOL_PROPERTIES(VP) PER_ISOLATE_SYMBOL_PROPERTIES(VY) PER_ISOLATE_STRING_PROPERTIES(VS) #undef V #undef VY #undef VS #undef VP for (size_t j = 0; j < AsyncWrap::PROVIDERS_LENGTH; j++) { MaybeLocal<String> maybe_field = isolate_->GetDataFromSnapshotOnce<String>((*indexes)[i++]); Local<String> field; if (!maybe_field.ToLocal(&field)) { fprintf(stderr, "Failed to deserialize AsyncWrap provider %zu\n", j); } async_wrap_providers_[j].Set(isolate_, field); } } void IsolateData::CreateProperties() { // Create string and private symbol properties as internalized one byte // strings after the platform is properly initialized. // // Internalized because it makes property lookups a little faster and // because the string is created in the old space straight away. It's going // to end up in the old space sooner or later anyway but now it doesn't go // through v8::Eternal's new space handling first. // // One byte because our strings are ASCII and we can safely skip V8's UTF-8 // decoding step. HandleScope handle_scope(isolate_); #define V(PropertyName, StringValue) \ PropertyName##_.Set( \ isolate_, \ Private::New(isolate_, \ String::NewFromOneByte( \ isolate_, \ reinterpret_cast<const uint8_t*>(StringValue), \ NewStringType::kInternalized, \ sizeof(StringValue) - 1) \ .ToLocalChecked())); PER_ISOLATE_PRIVATE_SYMBOL_PROPERTIES(V) #undef V #define V(PropertyName, StringValue) \ PropertyName##_.Set( \ isolate_, \ Symbol::New(isolate_, \ String::NewFromOneByte( \ isolate_, \ reinterpret_cast<const uint8_t*>(StringValue), \ NewStringType::kInternalized, \ sizeof(StringValue) - 1) \ .ToLocalChecked())); PER_ISOLATE_SYMBOL_PROPERTIES(V) #undef V #define V(PropertyName, StringValue) \ PropertyName##_.Set( \ isolate_, \ String::NewFromOneByte(isolate_, \ reinterpret_cast<const uint8_t*>(StringValue), \ NewStringType::kInternalized, \ sizeof(StringValue) - 1) \ .ToLocalChecked()); PER_ISOLATE_STRING_PROPERTIES(V) #undef V // Create all the provider strings that will be passed to JS. Place them in // an array so the array index matches the PROVIDER id offset. This way the // strings can be retrieved quickly. #define V(Provider) \ async_wrap_providers_[AsyncWrap::PROVIDER_ ## Provider].Set( \ isolate_, \ String::NewFromOneByte( \ isolate_, \ reinterpret_cast<const uint8_t*>(#Provider), \ NewStringType::kInternalized, \ sizeof(#Provider) - 1).ToLocalChecked()); NODE_ASYNC_PROVIDER_TYPES(V) #undef V } IsolateData::IsolateData(Isolate* isolate, uv_loop_t* event_loop, MultiIsolatePlatform* platform, ArrayBufferAllocator* node_allocator, const std::vector<size_t>* indexes) : isolate_(isolate), event_loop_(event_loop), node_allocator_(node_allocator == nullptr ? nullptr : node_allocator->GetImpl()), platform_(platform) { options_.reset( new PerIsolateOptions(*(per_process::cli_options->per_isolate))); if (indexes == nullptr) { CreateProperties(); } else { DeserializeProperties(indexes); } } void IsolateData::MemoryInfo(MemoryTracker* tracker) const { #define V(PropertyName, StringValue) \ tracker->TrackField(#PropertyName, PropertyName()); PER_ISOLATE_SYMBOL_PROPERTIES(V) PER_ISOLATE_STRING_PROPERTIES(V) #undef V tracker->TrackField("async_wrap_providers", async_wrap_providers_); if (node_allocator_ != nullptr) { tracker->TrackFieldWithSize( "node_allocator", sizeof(*node_allocator_), "NodeArrayBufferAllocator"); } tracker->TrackFieldWithSize( "platform", sizeof(*platform_), "MultiIsolatePlatform"); // TODO(joyeecheung): implement MemoryRetainer in the option classes. } void TrackingTraceStateObserver::UpdateTraceCategoryState() { if (!env_->owns_process_state() || !env_->can_call_into_js()) { // Ideally, we’d have a consistent story that treats all threads/Environment // instances equally here. However, tracing is essentially global, and this // callback is called from whichever thread calls `StartTracing()` or // `StopTracing()`. The only way to do this in a threadsafe fashion // seems to be only tracking this from the main thread, and only allowing // these state modifications from the main thread. return; } bool async_hooks_enabled = (*(TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED( TRACING_CATEGORY_NODE1(async_hooks)))) != 0; Isolate* isolate = env_->isolate(); HandleScope handle_scope(isolate); Local<Function> cb = env_->trace_category_state_function(); if (cb.IsEmpty()) return; TryCatchScope try_catch(env_); try_catch.SetVerbose(true); Local<Value> args[] = {Boolean::New(isolate, async_hooks_enabled)}; USE(cb->Call(env_->context(), Undefined(isolate), arraysize(args), args)); } void Environment::AssignToContext(Local<v8::Context> context, const ContextInfo& info) { ContextEmbedderTag::TagNodeContext(context); context->SetAlignedPointerInEmbedderData(ContextEmbedderIndex::kEnvironment, this); // Used to retrieve bindings context->SetAlignedPointerInEmbedderData( ContextEmbedderIndex::kBindingListIndex, &(this->bindings_)); #if HAVE_INSPECTOR inspector_agent()->ContextCreated(context, info); #endif // HAVE_INSPECTOR this->async_hooks()->AddContext(context); } void Environment::TryLoadAddon( const char* filename, int flags, const std::function<bool(binding::DLib*)>& was_loaded) { loaded_addons_.emplace_back(filename, flags); if (!was_loaded(&loaded_addons_.back())) { loaded_addons_.pop_back(); } } std::string Environment::GetCwd() { char cwd[PATH_MAX_BYTES]; size_t size = PATH_MAX_BYTES; const int err = uv_cwd(cwd, &size); if (err == 0) { CHECK_GT(size, 0); return cwd; } // This can fail if the cwd is deleted. In that case, fall back to // exec_path. const std::string& exec_path = exec_path_; return exec_path.substr(0, exec_path.find_last_of(kPathSeparator)); } void Environment::add_refs(int64_t diff) { task_queues_async_refs_ += diff; CHECK_GE(task_queues_async_refs_, 0); if (task_queues_async_refs_ == 0) uv_unref(reinterpret_cast<uv_handle_t*>(&task_queues_async_)); else uv_ref(reinterpret_cast<uv_handle_t*>(&task_queues_async_)); } uv_buf_t Environment::allocate_managed_buffer(const size_t suggested_size) { NoArrayBufferZeroFillScope no_zero_fill_scope(isolate_data()); std::unique_ptr<v8::BackingStore> bs = v8::ArrayBuffer::NewBackingStore(isolate(), suggested_size); uv_buf_t buf = uv_buf_init(static_cast<char*>(bs->Data()), bs->ByteLength()); released_allocated_buffers_.emplace(buf.base, std::move(bs)); return buf; } std::unique_ptr<v8::BackingStore> Environment::release_managed_buffer( const uv_buf_t& buf) { std::unique_ptr<v8::BackingStore> bs; if (buf.base != nullptr) { auto it = released_allocated_buffers_.find(buf.base); CHECK_NE(it, released_allocated_buffers_.end()); bs = std::move(it->second); released_allocated_buffers_.erase(it); } return bs; } Local<v8::FunctionTemplate> Environment::NewFunctionTemplate( v8::FunctionCallback callback, Local<v8::Signature> signature, v8::ConstructorBehavior behavior, v8::SideEffectType side_effect_type, const v8::CFunction* c_function) { return v8::FunctionTemplate::New(isolate(), callback, Local<v8::Value>(), signature, 0, behavior, side_effect_type, c_function); } void Environment::SetMethod(Local<v8::Object> that, const char* name, v8::FunctionCallback callback) { Local<v8::Context> context = isolate()->GetCurrentContext(); Local<v8::Function> function = NewFunctionTemplate(callback, Local<v8::Signature>(), v8::ConstructorBehavior::kThrow, v8::SideEffectType::kHasSideEffect) ->GetFunction(context) .ToLocalChecked(); // kInternalized strings are created in the old space. const v8::NewStringType type = v8::NewStringType::kInternalized; Local<v8::String> name_string = v8::String::NewFromUtf8(isolate(), name, type).ToLocalChecked(); that->Set(context, name_string, function).Check(); function->SetName(name_string); // NODE_SET_METHOD() compatibility. } void Environment::SetFastMethod(Local<v8::Object> that, const char* name, v8::FunctionCallback slow_callback, const v8::CFunction* c_function) { Local<v8::Context> context = isolate()->GetCurrentContext(); Local<v8::Function> function = NewFunctionTemplate(slow_callback, Local<v8::Signature>(), v8::ConstructorBehavior::kThrow, v8::SideEffectType::kHasNoSideEffect, c_function) ->GetFunction(context) .ToLocalChecked(); const v8::NewStringType type = v8::NewStringType::kInternalized; Local<v8::String> name_string = v8::String::NewFromUtf8(isolate(), name, type).ToLocalChecked(); that->Set(context, name_string, function).Check(); } void Environment::SetMethodNoSideEffect(Local<v8::Object> that, const char* name, v8::FunctionCallback callback) { Local<v8::Context> context = isolate()->GetCurrentContext(); Local<v8::Function> function = NewFunctionTemplate(callback, Local<v8::Signature>(), v8::ConstructorBehavior::kThrow, v8::SideEffectType::kHasNoSideEffect) ->GetFunction(context) .ToLocalChecked(); // kInternalized strings are created in the old space. const v8::NewStringType type = v8::NewStringType::kInternalized; Local<v8::String> name_string = v8::String::NewFromUtf8(isolate(), name, type).ToLocalChecked(); that->Set(context, name_string, function).Check(); function->SetName(name_string); // NODE_SET_METHOD() compatibility. } void Environment::SetProtoMethod(Local<v8::FunctionTemplate> that, const char* name, v8::FunctionCallback callback) { Local<v8::Signature> signature = v8::Signature::New(isolate(), that); Local<v8::FunctionTemplate> t = NewFunctionTemplate(callback, signature, v8::ConstructorBehavior::kThrow, v8::SideEffectType::kHasSideEffect); // kInternalized strings are created in the old space. const v8::NewStringType type = v8::NewStringType::kInternalized; Local<v8::String> name_string = v8::String::NewFromUtf8(isolate(), name, type).ToLocalChecked(); that->PrototypeTemplate()->Set(name_string, t); t->SetClassName(name_string); // NODE_SET_PROTOTYPE_METHOD() compatibility. } void Environment::SetProtoMethodNoSideEffect(Local<v8::FunctionTemplate> that, const char* name, v8::FunctionCallback callback) { Local<v8::Signature> signature = v8::Signature::New(isolate(), that); Local<v8::FunctionTemplate> t = NewFunctionTemplate(callback, signature, v8::ConstructorBehavior::kThrow, v8::SideEffectType::kHasNoSideEffect); // kInternalized strings are created in the old space. const v8::NewStringType type = v8::NewStringType::kInternalized; Local<v8::String> name_string = v8::String::NewFromUtf8(isolate(), name, type).ToLocalChecked(); that->PrototypeTemplate()->Set(name_string, t); t->SetClassName(name_string); // NODE_SET_PROTOTYPE_METHOD() compatibility. } void Environment::SetInstanceMethod(Local<v8::FunctionTemplate> that, const char* name, v8::FunctionCallback callback) { Local<v8::Signature> signature = v8::Signature::New(isolate(), that); Local<v8::FunctionTemplate> t = NewFunctionTemplate(callback, signature, v8::ConstructorBehavior::kThrow, v8::SideEffectType::kHasSideEffect); // kInternalized strings are created in the old space. const v8::NewStringType type = v8::NewStringType::kInternalized; Local<v8::String> name_string = v8::String::NewFromUtf8(isolate(), name, type).ToLocalChecked(); that->InstanceTemplate()->Set(name_string, t); t->SetClassName(name_string); } void Environment::SetConstructorFunction(Local<v8::Object> that, const char* name, Local<v8::FunctionTemplate> tmpl, SetConstructorFunctionFlag flag) { SetConstructorFunction(that, OneByteString(isolate(), name), tmpl, flag); } void Environment::SetConstructorFunction(Local<v8::Object> that, Local<v8::String> name, Local<v8::FunctionTemplate> tmpl, SetConstructorFunctionFlag flag) { if (LIKELY(flag == SetConstructorFunctionFlag::SET_CLASS_NAME)) tmpl->SetClassName(name); that->Set(context(), name, tmpl->GetFunction(context()).ToLocalChecked()) .Check(); } void Environment::CreateProperties() { HandleScope handle_scope(isolate_); Local<Context> ctx = context(); { Context::Scope context_scope(ctx); Local<FunctionTemplate> templ = FunctionTemplate::New(isolate()); templ->InstanceTemplate()->SetInternalFieldCount( BaseObject::kInternalFieldCount); templ->Inherit(BaseObject::GetConstructorTemplate(this)); set_binding_data_ctor_template(templ); } // Store primordials setup by the per-context script in the environment. Local<Object> per_context_bindings = GetPerContextExports(ctx).ToLocalChecked(); Local<Value> primordials = per_context_bindings->Get(ctx, primordials_string()).ToLocalChecked(); CHECK(primordials->IsObject()); set_primordials(primordials.As<Object>()); Local<String> prototype_string = FIXED_ONE_BYTE_STRING(isolate(), "prototype"); #define V(EnvPropertyName, PrimordialsPropertyName) \ { \ Local<Value> ctor = \ primordials.As<Object>() \ ->Get(ctx, \ FIXED_ONE_BYTE_STRING(isolate(), PrimordialsPropertyName)) \ .ToLocalChecked(); \ CHECK(ctor->IsObject()); \ Local<Value> prototype = \ ctor.As<Object>()->Get(ctx, prototype_string).ToLocalChecked(); \ CHECK(prototype->IsObject()); \ set_##EnvPropertyName(prototype.As<Object>()); \ } V(primordials_safe_map_prototype_object, "SafeMap"); V(primordials_safe_set_prototype_object, "SafeSet"); V(primordials_safe_weak_map_prototype_object, "SafeWeakMap"); V(primordials_safe_weak_set_prototype_object, "SafeWeakSet"); #undef V Local<Object> process_object = node::CreateProcessObject(this).FromMaybe(Local<Object>()); set_process_object(process_object); } std::string GetExecPath(const std::vector<std::string>& argv) { char exec_path_buf[2 * PATH_MAX]; size_t exec_path_len = sizeof(exec_path_buf); std::string exec_path; if (uv_exepath(exec_path_buf, &exec_path_len) == 0) { exec_path = std::string(exec_path_buf, exec_path_len); } else { exec_path = argv[0]; } // On OpenBSD process.execPath will be relative unless we // get the full path before process.execPath is used. #if defined(__OpenBSD__) uv_fs_t req; req.ptr = nullptr; if (0 == uv_fs_realpath(nullptr, &req, exec_path.c_str(), nullptr)) { CHECK_NOT_NULL(req.ptr); exec_path = std::string(static_cast<char*>(req.ptr)); } uv_fs_req_cleanup(&req); #endif return exec_path; } Environment::Environment(IsolateData* isolate_data, Isolate* isolate, const std::vector<std::string>& args, const std::vector<std::string>& exec_args, const EnvSerializeInfo* env_info, EnvironmentFlags::Flags flags, ThreadId thread_id) : isolate_(isolate), isolate_data_(isolate_data), async_hooks_(isolate, MAYBE_FIELD_PTR(env_info, async_hooks)), immediate_info_(isolate, MAYBE_FIELD_PTR(env_info, immediate_info)), tick_info_(isolate, MAYBE_FIELD_PTR(env_info, tick_info)), timer_base_(uv_now(isolate_data->event_loop())), exec_argv_(exec_args), argv_(args), exec_path_(GetExecPath(args)), exiting_(isolate_, 1, MAYBE_FIELD_PTR(env_info, exiting)), should_abort_on_uncaught_toggle_( isolate_, 1, MAYBE_FIELD_PTR(env_info, should_abort_on_uncaught_toggle)), stream_base_state_(isolate_, StreamBase::kNumStreamBaseStateFields, MAYBE_FIELD_PTR(env_info, stream_base_state)), environment_start_time_(PERFORMANCE_NOW()), flags_(flags), thread_id_(thread_id.id == static_cast<uint64_t>(-1) ? AllocateEnvironmentThreadId().id : thread_id.id) { // We'll be creating new objects so make sure we've entered the context. HandleScope handle_scope(isolate); // Set some flags if only kDefaultFlags was passed. This can make API version // transitions easier for embedders. if (flags_ & EnvironmentFlags::kDefaultFlags) { flags_ = flags_ | EnvironmentFlags::kOwnsProcessState | EnvironmentFlags::kOwnsInspector; } set_env_vars(per_process::system_environment); enabled_debug_list_.Parse(env_vars(), isolate); // We create new copies of the per-Environment option sets, so that it is // easier to modify them after Environment creation. The defaults are // part of the per-Isolate option set, for which in turn the defaults are // part of the per-process option set. options_ = std::make_shared<EnvironmentOptions>( *isolate_data->options()->per_env); inspector_host_port_ = std::make_shared<ExclusiveAccess<HostPort>>( options_->debug_options().host_port); heap_snapshot_near_heap_limit_ = static_cast<uint32_t>(options_->heap_snapshot_near_heap_limit); if (!(flags_ & EnvironmentFlags::kOwnsProcessState)) { set_abort_on_uncaught_exception(false); } #if HAVE_INSPECTOR // We can only create the inspector agent after having cloned the options. inspector_agent_ = std::make_unique<inspector::Agent>(this); #endif if (tracing::AgentWriterHandle* writer = GetTracingAgentWriter()) { trace_state_observer_ = std::make_unique<TrackingTraceStateObserver>(this); if (TracingController* tracing_controller = writer->GetTracingController()) tracing_controller->AddTraceStateObserver(trace_state_observer_.get()); } destroy_async_id_list_.reserve(512); performance_state_ = std::make_unique<performance::PerformanceState>( isolate, MAYBE_FIELD_PTR(env_info, performance_state)); if (*TRACE_EVENT_API_GET_CATEGORY_GROUP_ENABLED( TRACING_CATEGORY_NODE1(environment)) != 0) { auto traced_value = tracing::TracedValue::Create(); traced_value->BeginArray("args"); for (const std::string& arg : args) traced_value->AppendString(arg); traced_value->EndArray(); traced_value->BeginArray("exec_args"); for (const std::string& arg : exec_args) traced_value->AppendString(arg); traced_value->EndArray(); TRACE_EVENT_NESTABLE_ASYNC_BEGIN1(TRACING_CATEGORY_NODE1(environment), "Environment", this, "args", std::move(traced_value)); } } Environment::Environment(IsolateData* isolate_data, Local<Context> context, const std::vector<std::string>& args, const std::vector<std::string>& exec_args, const EnvSerializeInfo* env_info, EnvironmentFlags::Flags flags, ThreadId thread_id) : Environment(isolate_data, context->GetIsolate(), args, exec_args, env_info, flags, thread_id) { InitializeMainContext(context, env_info); } void Environment::InitializeMainContext(Local<Context> context, const EnvSerializeInfo* env_info) { context_.Reset(context->GetIsolate(), context); AssignToContext(context, ContextInfo("")); if (env_info != nullptr) { DeserializeProperties(env_info); } else { CreateProperties(); } if (!options_->force_async_hooks_checks) { async_hooks_.no_force_checks(); } // By default, always abort when --abort-on-uncaught-exception was passed. should_abort_on_uncaught_toggle_[0] = 1; // The process is not exiting by default. set_exiting(false); performance_state_->Mark(performance::NODE_PERFORMANCE_MILESTONE_ENVIRONMENT, environment_start_time_); performance_state_->Mark(performance::NODE_PERFORMANCE_MILESTONE_NODE_START, per_process::node_start_time); if (per_process::v8_initialized) { performance_state_->Mark(performance::NODE_PERFORMANCE_MILESTONE_V8_START, performance::performance_v8_start); } } Environment::~Environment() { if (Environment** interrupt_data = interrupt_data_.load()) { // There are pending RequestInterrupt() callbacks. Tell them not to run, // then force V8 to run interrupts by compiling and running an empty script // so as not to leak memory. *interrupt_data = nullptr; Isolate::AllowJavascriptExecutionScope allow_js_here(isolate()); HandleScope handle_scope(isolate()); TryCatch try_catch(isolate()); Context::Scope context_scope(context()); #ifdef DEBUG bool consistency_check = false; isolate()->RequestInterrupt([](Isolate*, void* data) { *static_cast<bool*>(data) = true; }, &consistency_check); #endif Local<Script> script; if (Script::Compile(context(), String::Empty(isolate())).ToLocal(&script)) USE(script->Run(context())); DCHECK(consistency_check); } // FreeEnvironment() should have set this. CHECK(is_stopping()); if (heapsnapshot_near_heap_limit_callback_added_) { RemoveHeapSnapshotNearHeapLimitCallback(0); } isolate()->GetHeapProfiler()->RemoveBuildEmbedderGraphCallback( BuildEmbedderGraph, this); HandleScope handle_scope(isolate()); #if HAVE_INSPECTOR // Destroy inspector agent before erasing the context. The inspector // destructor depends on the context still being accessible. inspector_agent_.reset(); #endif context()->SetAlignedPointerInEmbedderData(ContextEmbedderIndex::kEnvironment, nullptr); if (trace_state_observer_) { tracing::AgentWriterHandle* writer = GetTracingAgentWriter(); CHECK_NOT_NULL(writer); if (TracingController* tracing_controller = writer->GetTracingController()) tracing_controller->RemoveTraceStateObserver(trace_state_observer_.get()); } TRACE_EVENT_NESTABLE_ASYNC_END0( TRACING_CATEGORY_NODE1(environment), "Environment", this); // Do not unload addons on the main thread. Some addons need to retain memory // beyond the Environment's lifetime, and unloading them early would break // them; with Worker threads, we have the opportunity to be stricter. // Also, since the main thread usually stops just before the process exits, // this is far less relevant here. if (!is_main_thread()) { // Dereference all addons that were loaded into this environment. for (binding::DLib& addon : loaded_addons_) { addon.Close(); } } CHECK_EQ(base_object_count_, 0); } void Environment::InitializeLibuv() { HandleScope handle_scope(isolate()); Context::Scope context_scope(context()); CHECK_EQ(0, uv_timer_init(event_loop(), timer_handle())); uv_unref(reinterpret_cast<uv_handle_t*>(timer_handle())); CHECK_EQ(0, uv_check_init(event_loop(), immediate_check_handle())); uv_unref(reinterpret_cast<uv_handle_t*>(immediate_check_handle())); CHECK_EQ(0, uv_idle_init(event_loop(), immediate_idle_handle())); CHECK_EQ(0, uv_check_start(immediate_check_handle(), CheckImmediate)); // Inform V8's CPU profiler when we're idle. The profiler is sampling-based // but not all samples are created equal; mark the wall clock time spent in // epoll_wait() and friends so profiling tools can filter it out. The samples // still end up in v8.log but with state=IDLE rather than state=EXTERNAL. CHECK_EQ(0, uv_prepare_init(event_loop(), &idle_prepare_handle_)); CHECK_EQ(0, uv_check_init(event_loop(), &idle_check_handle_)); CHECK_EQ(0, uv_async_init( event_loop(), &task_queues_async_, [](uv_async_t* async) { Environment* env = ContainerOf( &Environment::task_queues_async_, async); HandleScope handle_scope(env->isolate()); Context::Scope context_scope(env->context()); env->RunAndClearNativeImmediates(); })); uv_unref(reinterpret_cast<uv_handle_t*>(&idle_prepare_handle_)); uv_unref(reinterpret_cast<uv_handle_t*>(&idle_check_handle_)); uv_unref(reinterpret_cast<uv_handle_t*>(&task_queues_async_)); { Mutex::ScopedLock lock(native_immediates_threadsafe_mutex_); task_queues_async_initialized_ = true; if (native_immediates_threadsafe_.size() > 0 || native_immediates_interrupts_.size() > 0) { uv_async_send(&task_queues_async_); } } // Register clean-up cb to be called to clean up the handles // when the environment is freed, note that they are not cleaned in // the one environment per process setup, but will be called in // FreeEnvironment. RegisterHandleCleanups(); StartProfilerIdleNotifier(); } void Environment::ExitEnv() { set_can_call_into_js(false); set_stopping(true); isolate_->TerminateExecution(); SetImmediateThreadsafe([](Environment* env) { uv_stop(env->event_loop()); }); } void Environment::RegisterHandleCleanups() { HandleCleanupCb close_and_finish = [](Environment* env, uv_handle_t* handle, void* arg) { handle->data = env; env->CloseHandle(handle, [](uv_handle_t* handle) { #ifdef DEBUG memset(handle, 0xab, uv_handle_size(handle->type)); #endif }); }; auto register_handle = [&](uv_handle_t* handle) { RegisterHandleCleanup(handle, close_and_finish, nullptr); }; register_handle(reinterpret_cast<uv_handle_t*>(timer_handle())); register_handle(reinterpret_cast<uv_handle_t*>(immediate_check_handle())); register_handle(reinterpret_cast<uv_handle_t*>(immediate_idle_handle())); register_handle(reinterpret_cast<uv_handle_t*>(&idle_prepare_handle_)); register_handle(reinterpret_cast<uv_handle_t*>(&idle_check_handle_)); register_handle(reinterpret_cast<uv_handle_t*>(&task_queues_async_)); } void Environment::CleanupHandles() { { Mutex::ScopedLock lock(native_immediates_threadsafe_mutex_); task_queues_async_initialized_ = false; } Isolate::DisallowJavascriptExecutionScope disallow_js(isolate(), Isolate::DisallowJavascriptExecutionScope::THROW_ON_FAILURE); RunAndClearNativeImmediates(true /* skip unrefed SetImmediate()s */); for (ReqWrapBase* request : req_wrap_queue_) request->Cancel(); for (HandleWrap* handle : handle_wrap_queue_) handle->Close(); for (HandleCleanup& hc : handle_cleanup_queue_) hc.cb_(this, hc.handle_, hc.arg_); handle_cleanup_queue_.clear(); while (handle_cleanup_waiting_ != 0 || request_waiting_ != 0 || !handle_wrap_queue_.IsEmpty()) { uv_run(event_loop(), UV_RUN_ONCE); } } void Environment::StartProfilerIdleNotifier() { uv_prepare_start(&idle_prepare_handle_, [](uv_prepare_t* handle) { Environment* env = ContainerOf(&Environment::idle_prepare_handle_, handle); env->isolate()->SetIdle(true); }); uv_check_start(&idle_check_handle_, [](uv_check_t* handle) { Environment* env = ContainerOf(&Environment::idle_check_handle_, handle); env->isolate()->SetIdle(false); }); } void Environment::PrintSyncTrace() const { if (!trace_sync_io_) return; HandleScope handle_scope(isolate()); fprintf( stderr, "(node:%d) WARNING: Detected use of sync API\n", uv_os_getpid()); PrintStackTrace(isolate(), StackTrace::CurrentStackTrace( isolate(), stack_trace_limit(), StackTrace::kDetailed)); } MaybeLocal<Value> Environment::RunSnapshotSerializeCallback() const { EscapableHandleScope handle_scope(isolate()); if (!snapshot_serialize_callback().IsEmpty()) { Context::Scope context_scope(context()); return handle_scope.EscapeMaybe(snapshot_serialize_callback()->Call( context(), v8::Undefined(isolate()), 0, nullptr)); } return handle_scope.Escape(Undefined(isolate())); } MaybeLocal<Value> Environment::RunSnapshotDeserializeMain() const { EscapableHandleScope handle_scope(isolate()); if (!snapshot_deserialize_main().IsEmpty()) { Context::Scope context_scope(context()); return handle_scope.EscapeMaybe(snapshot_deserialize_main()->Call( context(), v8::Undefined(isolate()), 0, nullptr)); } return handle_scope.Escape(Undefined(isolate())); } void Environment::RunCleanup() { started_cleanup_ = true; TRACE_EVENT0(TRACING_CATEGORY_NODE1(environment), "RunCleanup"); bindings_.clear(); CleanupHandles(); while (!cleanup_hooks_.empty() || native_immediates_.size() > 0 || native_immediates_threadsafe_.size() > 0 || native_immediates_interrupts_.size() > 0) { // Copy into a vector, since we can't sort an unordered_set in-place. std::vector<CleanupHookCallback> callbacks( cleanup_hooks_.begin(), cleanup_hooks_.end()); // We can't erase the copied elements from `cleanup_hooks_` yet, because we // need to be able to check whether they were un-scheduled by another hook. std::sort(callbacks.begin(), callbacks.end(), [](const CleanupHookCallback& a, const CleanupHookCallback& b) { // Sort in descending order so that the most recently inserted callbacks // are run first. return a.insertion_order_counter_ > b.insertion_order_counter_; }); for (const CleanupHookCallback& cb : callbacks) { if (cleanup_hooks_.count(cb) == 0) { // This hook was removed from the `cleanup_hooks_` set during another // hook that was run earlier. Nothing to do here. continue; } cb.fn_(cb.arg_); cleanup_hooks_.erase(cb); } CleanupHandles(); } for (const int fd : unmanaged_fds_) { uv_fs_t close_req; uv_fs_close(nullptr, &close_req, fd, nullptr); uv_fs_req_cleanup(&close_req); } } void Environment::RunAtExitCallbacks() { TRACE_EVENT0(TRACING_CATEGORY_NODE1(environment), "AtExit"); for (ExitCallback at_exit : at_exit_functions_) { at_exit.cb_(at_exit.arg_); } at_exit_functions_.clear(); } void Environment::AtExit(void (*cb)(void* arg), void* arg) { at_exit_functions_.push_front(ExitCallback{cb, arg}); } void Environment::RunAndClearInterrupts() { while (native_immediates_interrupts_.size() > 0) { NativeImmediateQueue queue; { Mutex::ScopedLock lock(native_immediates_threadsafe_mutex_); queue.ConcatMove(std::move(native_immediates_interrupts_)); } DebugSealHandleScope seal_handle_scope(isolate()); while (auto head = queue.Shift()) head->Call(this); } } void Environment::RunAndClearNativeImmediates(bool only_refed) { TRACE_EVENT0(TRACING_CATEGORY_NODE1(environment), "RunAndClearNativeImmediates"); HandleScope handle_scope(isolate_); // In case the Isolate is no longer accessible just use an empty Local. This // is not an issue for InternalCallbackScope as this case is already handled // in its constructor but we avoid calls into v8 which can crash the process // in debug builds. Local<Object> obj = can_call_into_js() ? Object::New(isolate_) : Local<Object>(); InternalCallbackScope cb_scope(this, obj, {0, 0}); size_t ref_count = 0; // Handle interrupts first. These functions are not allowed to throw // exceptions, so we do not need to handle that. RunAndClearInterrupts(); auto drain_list = [&](NativeImmediateQueue* queue) { TryCatchScope try_catch(this); DebugSealHandleScope seal_handle_scope(isolate()); while (auto head = queue->Shift()) { bool is_refed = head->flags() & CallbackFlags::kRefed; if (is_refed) ref_count++; if (is_refed || !only_refed) head->Call(this); head.reset(); // Destroy now so that this is also observed by try_catch. if (UNLIKELY(try_catch.HasCaught())) { if (!try_catch.HasTerminated() && can_call_into_js()) errors::TriggerUncaughtException(isolate(), try_catch); return true; } } return false; }; while (drain_list(&native_immediates_)) {} immediate_info()->ref_count_dec(ref_count); if (immediate_info()->ref_count() == 0) ToggleImmediateRef(false); // It is safe to check .size() first, because there is a causal relationship // between pushes to the threadsafe immediate list and this function being // called. For the common case, it's worth checking the size first before // establishing a mutex lock. // This is intentionally placed after the `ref_count` handling, because when // refed threadsafe immediates are created, they are not counted towards the // count in immediate_info() either. NativeImmediateQueue threadsafe_immediates; if (native_immediates_threadsafe_.size() > 0) { Mutex::ScopedLock lock(native_immediates_threadsafe_mutex_); threadsafe_immediates.ConcatMove(std::move(native_immediates_threadsafe_)); } while (drain_list(&threadsafe_immediates)) {} } void Environment::RequestInterruptFromV8() { // The Isolate may outlive the Environment, so some logic to handle the // situation in which the Environment is destroyed before the handler runs // is required. // We allocate a new pointer to a pointer to this Environment instance, and // try to set it as interrupt_data_. If interrupt_data_ was already set, then // callbacks are already scheduled to run and we can delete our own pointer // and just return. If it was nullptr previously, the Environment** is stored; // ~Environment sets the Environment* contained in it to nullptr, so that // the callback can check whether ~Environment has already run and it is thus // not safe to access the Environment instance itself. Environment** interrupt_data = new Environment*(this); Environment** dummy = nullptr; if (!interrupt_data_.compare_exchange_strong(dummy, interrupt_data)) { delete interrupt_data; return; // Already scheduled. } isolate()->RequestInterrupt([](Isolate* isolate, void* data) { std::unique_ptr<Environment*> env_ptr { static_cast<Environment**>(data) }; Environment* env = *env_ptr; if (env == nullptr) { // The Environment has already been destroyed. That should be okay; any // callback added before the Environment shuts down would have been // handled during cleanup. return; } env->interrupt_data_.store(nullptr); env->RunAndClearInterrupts(); }, interrupt_data); } void Environment::ScheduleTimer(int64_t duration_ms) { if (started_cleanup_) return; uv_timer_start(timer_handle(), RunTimers, duration_ms, 0); } void Environment::ToggleTimerRef(bool ref) { if (started_cleanup_) return; if (ref) { uv_ref(reinterpret_cast<uv_handle_t*>(timer_handle())); } else { uv_unref(reinterpret_cast<uv_handle_t*>(timer_handle())); } } void Environment::RunTimers(uv_timer_t* handle) { Environment* env = Environment::from_timer_handle(handle); TRACE_EVENT0(TRACING_CATEGORY_NODE1(environment), "RunTimers"); if (!env->can_call_into_js()) return; HandleScope handle_scope(env->isolate()); Context::Scope context_scope(env->context()); Local<Object> process = env->process_object(); InternalCallbackScope scope(env, process, {0, 0}); Local<Function> cb = env->timers_callback_function(); MaybeLocal<Value> ret; Local<Value> arg = env->GetNow(); // This code will loop until all currently due timers will process. It is // impossible for us to end up in an infinite loop due to how the JS-side // is structured. do { TryCatchScope try_catch(env); try_catch.SetVerbose(true); ret = cb->Call(env->context(), process, 1, &arg); } while (ret.IsEmpty() && env->can_call_into_js()); // NOTE(apapirovski): If it ever becomes possible that `call_into_js` above // is reset back to `true` after being previously set to `false` then this // code becomes invalid and needs to be rewritten. Otherwise catastrophic // timers corruption will occur and all timers behaviour will become // entirely unpredictable. if (ret.IsEmpty()) return; // To allow for less JS-C++ boundary crossing, the value returned from JS // serves a few purposes: // 1. If it's 0, no more timers exist and the handle should be unrefed // 2. If it's > 0, the value represents the next timer's expiry and there // is at least one timer remaining that is refed. // 3. If it's < 0, the absolute value represents the next timer's expiry // and there are no timers that are refed. int64_t expiry_ms = ret.ToLocalChecked()->IntegerValue(env->context()).FromJust(); uv_handle_t* h = reinterpret_cast<uv_handle_t*>(handle); if (expiry_ms != 0) { int64_t duration_ms = llabs(expiry_ms) - (uv_now(env->event_loop()) - env->timer_base()); env->ScheduleTimer(duration_ms > 0 ? duration_ms : 1); if (expiry_ms > 0) uv_ref(h); else uv_unref(h); } else { uv_unref(h); } } void Environment::CheckImmediate(uv_check_t* handle) { Environment* env = Environment::from_immediate_check_handle(handle); TRACE_EVENT0(TRACING_CATEGORY_NODE1(environment), "CheckImmediate"); HandleScope scope(env->isolate()); Context::Scope context_scope(env->context()); env->RunAndClearNativeImmediates(); if (env->immediate_info()->count() == 0 || !env->can_call_into_js()) return; do { MakeCallback(env->isolate(), env->process_object(), env->immediate_callback_function(), 0, nullptr, {0, 0}).ToLocalChecked(); } while (env->immediate_info()->has_outstanding() && env->can_call_into_js()); if (env->immediate_info()->ref_count() == 0) env->ToggleImmediateRef(false); } void Environment::ToggleImmediateRef(bool ref) { if (started_cleanup_) return; if (ref) { // Idle handle is needed only to stop the event loop from blocking in poll. uv_idle_start(immediate_idle_handle(), [](uv_idle_t*){ }); } else { uv_idle_stop(immediate_idle_handle()); } } Local<Value> Environment::GetNow() { uv_update_time(event_loop()); uint64_t now = uv_now(event_loop()); CHECK_GE(now, timer_base()); now -= timer_base(); if (now <= 0xffffffff) return Integer::NewFromUnsigned(isolate(), static_cast<uint32_t>(now)); else return Number::New(isolate(), static_cast<double>(now)); } void CollectExceptionInfo(Environment* env, Local<Object> obj, int errorno, const char* err_string, const char* syscall, const char* message, const char* path, const char* dest) { obj->Set(env->context(), env->errno_string(), Integer::New(env->isolate(), errorno)).Check(); obj->Set(env->context(), env->code_string(), OneByteString(env->isolate(), err_string)).Check(); if (message != nullptr) { obj->Set(env->context(), env->message_string(), OneByteString(env->isolate(), message)).Check(); } Local<Value> path_buffer; if (path != nullptr) { path_buffer = Buffer::Copy(env->isolate(), path, strlen(path)).ToLocalChecked(); obj->Set(env->context(), env->path_string(), path_buffer).Check(); } Local<Value> dest_buffer; if (dest != nullptr) { dest_buffer = Buffer::Copy(env->isolate(), dest, strlen(dest)).ToLocalChecked(); obj->Set(env->context(), env->dest_string(), dest_buffer).Check(); } if (syscall != nullptr) { obj->Set(env->context(), env->syscall_string(), OneByteString(env->isolate(), syscall)).Check(); } } void Environment::CollectUVExceptionInfo(Local<Value> object, int errorno, const char* syscall, const char* message, const char* path, const char* dest) { if (!object->IsObject() || errorno == 0) return; Local<Object> obj = object.As<Object>(); const char* err_string = uv_err_name(errorno); if (message == nullptr || message[0] == '\0') { message = uv_strerror(errorno); } node::CollectExceptionInfo(this, obj, errorno, err_string, syscall, message, path, dest); } ImmediateInfo::ImmediateInfo(Isolate* isolate, const SerializeInfo* info) : fields_(isolate, kFieldsCount, MAYBE_FIELD_PTR(info, fields)) {} ImmediateInfo::SerializeInfo ImmediateInfo::Serialize( Local<Context> context, SnapshotCreator* creator) { return {fields_.Serialize(context, creator)}; } void ImmediateInfo::Deserialize(Local<Context> context) { fields_.Deserialize(context); } std::ostream& operator<<(std::ostream& output, const ImmediateInfo::SerializeInfo& i) { output << "{ " << i.fields << " }"; return output; } void ImmediateInfo::MemoryInfo(MemoryTracker* tracker) const { tracker->TrackField("fields", fields_); } TickInfo::SerializeInfo TickInfo::Serialize(Local<Context> context, SnapshotCreator* creator) { return {fields_.Serialize(context, creator)}; } void TickInfo::Deserialize(Local<Context> context) { fields_.Deserialize(context); } std::ostream& operator<<(std::ostream& output, const TickInfo::SerializeInfo& i) { output << "{ " << i.fields << " }"; return output; } void TickInfo::MemoryInfo(MemoryTracker* tracker) const { tracker->TrackField("fields", fields_); } TickInfo::TickInfo(Isolate* isolate, const SerializeInfo* info) : fields_( isolate, kFieldsCount, info == nullptr ? nullptr : &(info->fields)) {} AsyncHooks::AsyncHooks(Isolate* isolate, const SerializeInfo* info) : async_ids_stack_(isolate, 16 * 2, MAYBE_FIELD_PTR(info, async_ids_stack)), fields_(isolate, kFieldsCount, MAYBE_FIELD_PTR(info, fields)), async_id_fields_( isolate, kUidFieldsCount, MAYBE_FIELD_PTR(info, async_id_fields)), info_(info) { HandleScope handle_scope(isolate); if (info == nullptr) { clear_async_id_stack(); // Always perform async_hooks checks, not just when async_hooks is enabled. // TODO(AndreasMadsen): Consider removing this for LTS releases. // See discussion in https://github.com/nodejs/node/pull/15454 // When removing this, do it by reverting the commit. Otherwise the test // and flag changes won't be included. fields_[kCheck] = 1; // kDefaultTriggerAsyncId should be -1, this indicates that there is no // specified default value and it should fallback to the executionAsyncId. // 0 is not used as the magic value, because that indicates a missing // context which is different from a default context. async_id_fields_[AsyncHooks::kDefaultTriggerAsyncId] = -1; // kAsyncIdCounter should start at 1 because that'll be the id the execution // context during bootstrap (code that runs before entering uv_run()). async_id_fields_[AsyncHooks::kAsyncIdCounter] = 1; } } void AsyncHooks::Deserialize(Local<Context> context) { async_ids_stack_.Deserialize(context); fields_.Deserialize(context); async_id_fields_.Deserialize(context); Local<Array> js_execution_async_resources; if (info_->js_execution_async_resources != 0) { js_execution_async_resources = context->GetDataFromSnapshotOnce<Array>( info_->js_execution_async_resources).ToLocalChecked(); } else { js_execution_async_resources = Array::New(context->GetIsolate()); } js_execution_async_resources_.Reset( context->GetIsolate(), js_execution_async_resources); // The native_execution_async_resources_ field requires v8::Local<> instances // for async calls whose resources were on the stack as JS objects when they // were entered. We cannot recreate this here; however, storing these values // on the JS equivalent gives the same result, so we do that instead. for (size_t i = 0; i < info_->native_execution_async_resources.size(); ++i) { if (info_->native_execution_async_resources[i] == SIZE_MAX) continue; Local<Object> obj = context->GetDataFromSnapshotOnce<Object>( info_->native_execution_async_resources[i]) .ToLocalChecked(); js_execution_async_resources->Set(context, i, obj).Check(); } info_ = nullptr; } std::ostream& operator<<(std::ostream& output, const std::vector<SnapshotIndex>& v) { output << "{ "; for (const SnapshotIndex i : v) { output << i << ", "; } output << " }"; return output; } std::ostream& operator<<(std::ostream& output, const AsyncHooks::SerializeInfo& i) { output << "{\n" << " " << i.async_ids_stack << ", // async_ids_stack\n" << " " << i.fields << ", // fields\n" << " " << i.async_id_fields << ", // async_id_fields\n" << " " << i.js_execution_async_resources << ", // js_execution_async_resources\n" << " " << i.native_execution_async_resources << ", // native_execution_async_resources\n" << "}"; return output; } AsyncHooks::SerializeInfo AsyncHooks::Serialize(Local<Context> context, SnapshotCreator* creator) { SerializeInfo info; info.async_ids_stack = async_ids_stack_.Serialize(context, creator); info.fields = fields_.Serialize(context, creator); info.async_id_fields = async_id_fields_.Serialize(context, creator); if (!js_execution_async_resources_.IsEmpty()) { info.js_execution_async_resources = creator->AddData( context, js_execution_async_resources_.Get(context->GetIsolate())); CHECK_NE(info.js_execution_async_resources, 0); } else { info.js_execution_async_resources = 0; } info.native_execution_async_resources.resize( native_execution_async_resources_.size()); for (size_t i = 0; i < native_execution_async_resources_.size(); i++) { info.native_execution_async_resources[i] = native_execution_async_resources_[i].IsEmpty() ? SIZE_MAX : creator->AddData( context, native_execution_async_resources_[i]); } CHECK_EQ(contexts_.size(), 1); CHECK_EQ(contexts_[0], env()->context()); CHECK(js_promise_hooks_[0].IsEmpty()); CHECK(js_promise_hooks_[1].IsEmpty()); CHECK(js_promise_hooks_[2].IsEmpty()); CHECK(js_promise_hooks_[3].IsEmpty()); return info; } void AsyncHooks::MemoryInfo(MemoryTracker* tracker) const { tracker->TrackField("async_ids_stack", async_ids_stack_); tracker->TrackField("fields", fields_); tracker->TrackField("async_id_fields", async_id_fields_); tracker->TrackField("js_promise_hooks", js_promise_hooks_); } void AsyncHooks::grow_async_ids_stack() { async_ids_stack_.reserve(async_ids_stack_.Length() * 3); env()->async_hooks_binding()->Set( env()->context(), env()->async_ids_stack_string(), async_ids_stack_.GetJSArray()).Check(); } void AsyncHooks::FailWithCorruptedAsyncStack(double expected_async_id) { fprintf(stderr, "Error: async hook stack has become corrupted (" "actual: %.f, expected: %.f)\n", async_id_fields_.GetValue(kExecutionAsyncId), expected_async_id); DumpBacktrace(stderr); fflush(stderr); if (!env()->abort_on_uncaught_exception()) exit(1); fprintf(stderr, "\n"); fflush(stderr); ABORT_NO_BACKTRACE(); } void Environment::Exit(int exit_code) { if (options()->trace_exit) { HandleScope handle_scope(isolate()); Isolate::DisallowJavascriptExecutionScope disallow_js( isolate(), Isolate::DisallowJavascriptExecutionScope::CRASH_ON_FAILURE); if (is_main_thread()) { fprintf(stderr, "(node:%d) ", uv_os_getpid()); } else { fprintf(stderr, "(node:%d, thread:%" PRIu64 ") ", uv_os_getpid(), thread_id()); } fprintf( stderr, "WARNING: Exited the environment with code %d\n", exit_code); PrintStackTrace(isolate(), StackTrace::CurrentStackTrace( isolate(), stack_trace_limit(), StackTrace::kDetailed)); } process_exit_handler_(this, exit_code); } void Environment::stop_sub_worker_contexts() { DCHECK_EQ(Isolate::GetCurrent(), isolate()); while (!sub_worker_contexts_.empty()) { Worker* w = *sub_worker_contexts_.begin(); remove_sub_worker_context(w); w->Exit(1); w->JoinThread(); } } Environment* Environment::worker_parent_env() const { if (worker_context() == nullptr) return nullptr; return worker_context()->env(); } void Environment::AddUnmanagedFd(int fd) { if (!tracks_unmanaged_fds()) return; auto result = unmanaged_fds_.insert(fd); if (!result.second) { ProcessEmitWarning( this, "File descriptor %d opened in unmanaged mode twice", fd); } } void Environment::RemoveUnmanagedFd(int fd) { if (!tracks_unmanaged_fds()) return; size_t removed_count = unmanaged_fds_.erase(fd); if (removed_count == 0) { ProcessEmitWarning( this, "File descriptor %d closed but not opened in unmanaged mode", fd); } } void Environment::PrintInfoForSnapshotIfDebug() { if (enabled_debug_list()->enabled(DebugCategory::MKSNAPSHOT)) { fprintf(stderr, "BaseObjects at the exit of the Environment:\n"); PrintAllBaseObjects(); fprintf(stderr, "\nNative modules without cache:\n"); for (const auto& s : native_modules_without_cache) { fprintf(stderr, "%s\n", s.c_str()); } fprintf(stderr, "\nNative modules with cache:\n"); for (const auto& s : native_modules_with_cache) { fprintf(stderr, "%s\n", s.c_str()); } fprintf(stderr, "\nStatic bindings (need to be registered):\n"); for (const auto mod : internal_bindings) { fprintf(stderr, "%s:%s\n", mod->nm_filename, mod->nm_modname); } } } void Environment::PrintAllBaseObjects() { size_t i = 0; std::cout << "BaseObjects\n"; ForEachBaseObject([&](BaseObject* obj) { std::cout << "#" << i++ << " " << obj << ": " << obj->MemoryInfoName() << "\n"; }); } void Environment::VerifyNoStrongBaseObjects() { // When a process exits cleanly, i.e. because the event loop ends up without // things to wait for, the Node.js objects that are left on the heap should // be: // // 1. weak, i.e. ready for garbage collection once no longer referenced, or // 2. detached, i.e. scheduled for destruction once no longer referenced, or // 3. an unrefed libuv handle, i.e. does not keep the event loop alive, or // 4. an inactive libuv handle (essentially the same here) // // There are a few exceptions to this rule, but generally, if there are // C++-backed Node.js objects on the heap that do not fall into the above // categories, we may be looking at a potential memory leak. Most likely, // the cause is a missing MakeWeak() call on the corresponding object. // // In order to avoid this kind of problem, we check the list of BaseObjects // for these criteria. Currently, we only do so when explicitly instructed to // or when in debug mode (where --verify-base-objects is always-on). if (!options()->verify_base_objects) return; ForEachBaseObject([](BaseObject* obj) { if (obj->IsNotIndicativeOfMemoryLeakAtExit()) return; fprintf(stderr, "Found bad BaseObject during clean exit: %s\n", obj->MemoryInfoName().c_str()); fflush(stderr); ABORT(); }); } EnvSerializeInfo Environment::Serialize(SnapshotCreator* creator) { EnvSerializeInfo info; Local<Context> ctx = context(); SerializeBindingData(this, creator, &info); // Currently all modules are compiled without cache in builtin snapshot // builder. info.native_modules = std::vector<std::string>( native_modules_without_cache.begin(), native_modules_without_cache.end()); info.async_hooks = async_hooks_.Serialize(ctx, creator); info.immediate_info = immediate_info_.Serialize(ctx, creator); info.tick_info = tick_info_.Serialize(ctx, creator); info.performance_state = performance_state_->Serialize(ctx, creator); info.exiting = exiting_.Serialize(ctx, creator); info.stream_base_state = stream_base_state_.Serialize(ctx, creator); info.should_abort_on_uncaught_toggle = should_abort_on_uncaught_toggle_.Serialize(ctx, creator); size_t id = 0; #define V(PropertyName, TypeName) \ do { \ Local<TypeName> field = PropertyName(); \ if (!field.IsEmpty()) { \ size_t index = creator->AddData(field); \ info.persistent_templates.push_back({#PropertyName, id, index}); \ } \ id++; \ } while (0); ENVIRONMENT_STRONG_PERSISTENT_TEMPLATES(V) #undef V id = 0; #define V(PropertyName, TypeName) \ do { \ Local<TypeName> field = PropertyName(); \ if (!field.IsEmpty()) { \ size_t index = creator->AddData(ctx, field); \ info.persistent_values.push_back({#PropertyName, id, index}); \ } \ id++; \ } while (0); ENVIRONMENT_STRONG_PERSISTENT_VALUES(V) #undef V info.context = creator->AddData(ctx, context()); return info; } std::ostream& operator<<(std::ostream& output, const std::vector<PropInfo>& vec) { output << "{\n"; for (const auto& info : vec) { output << " { \"" << info.name << "\", " << std::to_string(info.id) << ", " << std::to_string(info.index) << " },\n"; } output << "}"; return output; } std::ostream& operator<<(std::ostream& output, const std::vector<std::string>& vec) { output << "{\n"; for (const auto& info : vec) { output << " \"" << info << "\",\n"; } output << "}"; return output; } std::ostream& operator<<(std::ostream& output, const EnvSerializeInfo& i) { output << "{\n" << "// -- bindings begins --\n" << i.bindings << ",\n" << "// -- bindings ends --\n" << "// -- native_modules begins --\n" << i.native_modules << ",\n" << "// -- native_modules ends --\n" << "// -- async_hooks begins --\n" << i.async_hooks << ",\n" << "// -- async_hooks ends --\n" << i.tick_info << ", // tick_info\n" << i.immediate_info << ", // immediate_info\n" << "// -- performance_state begins --\n" << i.performance_state << ",\n" << "// -- performance_state ends --\n" << i.exiting << ", // exiting\n" << i.stream_base_state << ", // stream_base_state\n" << i.should_abort_on_uncaught_toggle << ", // should_abort_on_uncaught_toggle\n" << "// -- persistent_templates begins --\n" << i.persistent_templates << ",\n" << "// persistent_templates ends --\n" << "// -- persistent_values begins --\n" << i.persistent_values << ",\n" << "// -- persistent_values ends --\n" << i.context << ", // context\n" << "}"; return output; } void Environment::EnqueueDeserializeRequest(DeserializeRequestCallback cb, Local<Object> holder, int index, InternalFieldInfo* info) { DCHECK_EQ(index, BaseObject::kEmbedderType); DeserializeRequest request{cb, {isolate(), holder}, index, info}; deserialize_requests_.push_back(std::move(request)); } void Environment::RunDeserializeRequests() { HandleScope scope(isolate()); Local<Context> ctx = context(); Isolate* is = isolate(); while (!deserialize_requests_.empty()) { DeserializeRequest request(std::move(deserialize_requests_.front())); deserialize_requests_.pop_front(); Local<Object> holder = request.holder.Get(is); request.cb(ctx, holder, request.index, request.info); request.holder.Reset(); request.info->Delete(); } } void Environment::DeserializeProperties(const EnvSerializeInfo* info) { Local<Context> ctx = context(); RunDeserializeRequests(); native_modules_in_snapshot = info->native_modules; async_hooks_.Deserialize(ctx); immediate_info_.Deserialize(ctx); tick_info_.Deserialize(ctx); performance_state_->Deserialize(ctx); exiting_.Deserialize(ctx); stream_base_state_.Deserialize(ctx); should_abort_on_uncaught_toggle_.Deserialize(ctx); if (enabled_debug_list_.enabled(DebugCategory::MKSNAPSHOT)) { fprintf(stderr, "deserializing...\n"); std::cerr << *info << "\n"; } const std::vector<PropInfo>& templates = info->persistent_templates; size_t i = 0; // index to the array size_t id = 0; #define SetProperty(PropertyName, TypeName, vector, type, from) \ do { \ if (vector.size() > i && id == vector[i].id) { \ const PropInfo& d = vector[i]; \ DCHECK_EQ(d.name, #PropertyName); \ MaybeLocal<TypeName> maybe_field = \ from->GetDataFromSnapshotOnce<TypeName>(d.index); \ Local<TypeName> field; \ if (!maybe_field.ToLocal(&field)) { \ fprintf(stderr, \ "Failed to deserialize environment " #type " " #PropertyName \ "\n"); \ } \ set_##PropertyName(field); \ i++; \ } \ } while (0); \ id++; #define V(PropertyName, TypeName) SetProperty(PropertyName, TypeName, \ templates, template, isolate_) ENVIRONMENT_STRONG_PERSISTENT_TEMPLATES(V); #undef V i = 0; // index to the array id = 0; const std::vector<PropInfo>& values = info->persistent_values; #define V(PropertyName, TypeName) SetProperty(PropertyName, TypeName, \ values, value, ctx) ENVIRONMENT_STRONG_PERSISTENT_VALUES(V); #undef V #undef SetProperty MaybeLocal<Context> maybe_ctx_from_snapshot = ctx->GetDataFromSnapshotOnce<Context>(info->context); Local<Context> ctx_from_snapshot; if (!maybe_ctx_from_snapshot.ToLocal(&ctx_from_snapshot)) { fprintf(stderr, "Failed to deserialize context back reference from the snapshot\n"); } CHECK_EQ(ctx_from_snapshot, ctx); } uint64_t GuessMemoryAvailableToTheProcess() { uint64_t free_in_system = uv_get_free_memory(); size_t allowed = uv_get_constrained_memory(); if (allowed == 0) { return free_in_system; } size_t rss; int err = uv_resident_set_memory(&rss); if (err) { return free_in_system; } if (allowed < rss) { // Something is probably wrong. Fallback to the free memory. return free_in_system; } // There may still be room for swap, but we will just leave it here. return allowed - rss; } void Environment::BuildEmbedderGraph(Isolate* isolate, EmbedderGraph* graph, void* data) { MemoryTracker tracker(isolate, graph); Environment* env = static_cast<Environment*>(data); tracker.Track(env); env->ForEachBaseObject([&](BaseObject* obj) { if (obj->IsDoneInitializing()) tracker.Track(obj); }); } size_t Environment::NearHeapLimitCallback(void* data, size_t current_heap_limit, size_t initial_heap_limit) { Environment* env = static_cast<Environment*>(data); Debug(env, DebugCategory::DIAGNOSTICS, "Invoked NearHeapLimitCallback, processing=%d, " "current_limit=%" PRIu64 ", " "initial_limit=%" PRIu64 "\n", env->is_in_heapsnapshot_heap_limit_callback_, static_cast<uint64_t>(current_heap_limit), static_cast<uint64_t>(initial_heap_limit)); size_t max_young_gen_size = env->isolate_data()->max_young_gen_size; size_t young_gen_size = 0; size_t old_gen_size = 0; HeapSpaceStatistics stats; size_t num_heap_spaces = env->isolate()->NumberOfHeapSpaces(); for (size_t i = 0; i < num_heap_spaces; ++i) { env->isolate()->GetHeapSpaceStatistics(&stats, i); if (strcmp(stats.space_name(), "new_space") == 0 || strcmp(stats.space_name(), "new_large_object_space") == 0) { young_gen_size += stats.space_used_size(); } else { old_gen_size += stats.space_used_size(); } } Debug(env, DebugCategory::DIAGNOSTICS, "max_young_gen_size=%" PRIu64 ", " "young_gen_size=%" PRIu64 ", " "old_gen_size=%" PRIu64 ", " "total_size=%" PRIu64 "\n", static_cast<uint64_t>(max_young_gen_size), static_cast<uint64_t>(young_gen_size), static_cast<uint64_t>(old_gen_size), static_cast<uint64_t>(young_gen_size + old_gen_size)); uint64_t available = GuessMemoryAvailableToTheProcess(); // TODO(joyeecheung): get a better estimate about the native memory // usage into the overhead, e.g. based on the count of objects. uint64_t estimated_overhead = max_young_gen_size; Debug(env, DebugCategory::DIAGNOSTICS, "Estimated available memory=%" PRIu64 ", " "estimated overhead=%" PRIu64 "\n", static_cast<uint64_t>(available), static_cast<uint64_t>(estimated_overhead)); // This might be hit when the snapshot is being taken in another // NearHeapLimitCallback invocation. // When taking the snapshot, objects in the young generation may be // promoted to the old generation, result in increased heap usage, // but it should be no more than the young generation size. // Ideally, this should be as small as possible - the heap limit // can only be restored when the heap usage falls down below the // new limit, so in a heap with unbounded growth the isolate // may eventually crash with this new limit - effectively raising // the heap limit to the new one. size_t new_limit = current_heap_limit + max_young_gen_size; if (env->is_in_heapsnapshot_heap_limit_callback_) { Debug(env, DebugCategory::DIAGNOSTICS, "Not generating snapshots in nested callback. " "new_limit=%" PRIu64 "\n", static_cast<uint64_t>(new_limit)); return new_limit; } // Estimate whether the snapshot is going to use up all the memory // available to the process. If so, just give up to prevent the system // from killing the process for a system OOM. if (estimated_overhead > available) { Debug(env, DebugCategory::DIAGNOSTICS, "Not generating snapshots because it's too risky.\n"); env->RemoveHeapSnapshotNearHeapLimitCallback(0); // The new limit must be higher than current_heap_limit or V8 might // crash. return new_limit; } // Take the snapshot synchronously. env->is_in_heapsnapshot_heap_limit_callback_ = true; std::string dir = env->options()->diagnostic_dir; if (dir.empty()) { dir = env->GetCwd(); } DiagnosticFilename name(env, "Heap", "heapsnapshot"); std::string filename = dir + kPathSeparator + (*name); Debug(env, DebugCategory::DIAGNOSTICS, "Start generating %s...\n", *name); heap::WriteSnapshot(env->isolate(), filename.c_str()); env->heap_limit_snapshot_taken_ += 1; Debug(env, DebugCategory::DIAGNOSTICS, "%" PRIu32 "/%" PRIu32 " snapshots taken.\n", env->heap_limit_snapshot_taken_, env->heap_snapshot_near_heap_limit_); // Don't take more snapshots than the limit specified. if (env->heap_limit_snapshot_taken_ == env->heap_snapshot_near_heap_limit_) { Debug(env, DebugCategory::DIAGNOSTICS, "Removing the near heap limit callback"); env->RemoveHeapSnapshotNearHeapLimitCallback(0); } FPrintF(stderr, "Wrote snapshot to %s\n", filename.c_str()); // Tell V8 to reset the heap limit once the heap usage falls down to // 95% of the initial limit. env->isolate()->AutomaticallyRestoreInitialHeapLimit(0.95); env->is_in_heapsnapshot_heap_limit_callback_ = false; // The new limit must be higher than current_heap_limit or V8 might // crash. return new_limit; } inline size_t Environment::SelfSize() const { size_t size = sizeof(*this); // Remove non pointer fields that will be tracked in MemoryInfo() // TODO(joyeecheung): refactor the MemoryTracker interface so // this can be done for common types within the Track* calls automatically // if a certain scope is entered. size -= sizeof(async_hooks_); size -= sizeof(tick_info_); size -= sizeof(immediate_info_); return size; } void Environment::MemoryInfo(MemoryTracker* tracker) const { // Iteratable STLs have their own sizes subtracted from the parent // by default. tracker->TrackField("isolate_data", isolate_data_); tracker->TrackField("native_modules_with_cache", native_modules_with_cache); tracker->TrackField("native_modules_without_cache", native_modules_without_cache); tracker->TrackField("destroy_async_id_list", destroy_async_id_list_); tracker->TrackField("exec_argv", exec_argv_); tracker->TrackField("exiting", exiting_); tracker->TrackField("should_abort_on_uncaught_toggle", should_abort_on_uncaught_toggle_); tracker->TrackField("stream_base_state", stream_base_state_); tracker->TrackFieldWithSize( "cleanup_hooks", cleanup_hooks_.size() * sizeof(CleanupHookCallback)); tracker->TrackField("async_hooks", async_hooks_); tracker->TrackField("immediate_info", immediate_info_); tracker->TrackField("tick_info", tick_info_); #define V(PropertyName, TypeName) \ tracker->TrackField(#PropertyName, PropertyName()); ENVIRONMENT_STRONG_PERSISTENT_VALUES(V) #undef V // FIXME(joyeecheung): track other fields in Environment. // Currently MemoryTracker is unable to track these // correctly: // - Internal types that do not implement MemoryRetainer yet // - STL containers with MemoryRetainer* inside // - STL containers with numeric types inside that should not have their // nodes elided e.g. numeric keys in maps. // We also need to make sure that when we add a non-pointer field as its own // node, we shift its sizeof() size out of the Environment node. } void Environment::RunWeakRefCleanup() { isolate()->ClearKeptObjects(); } // Not really any better place than env.cc at this moment. BaseObject::BaseObject(Environment* env, Local<Object> object) : persistent_handle_(env->isolate(), object), env_(env) { CHECK_EQ(false, object.IsEmpty()); CHECK_GE(object->InternalFieldCount(), BaseObject::kInternalFieldCount); object->SetAlignedPointerInInternalField(BaseObject::kEmbedderType, &kNodeEmbedderId); object->SetAlignedPointerInInternalField(BaseObject::kSlot, static_cast<void*>(this)); env->AddCleanupHook(DeleteMe, static_cast<void*>(this)); env->modify_base_object_count(1); } BaseObject::~BaseObject() { env()->modify_base_object_count(-1); env()->RemoveCleanupHook(DeleteMe, static_cast<void*>(this)); if (UNLIKELY(has_pointer_data())) { PointerData* metadata = pointer_data(); CHECK_EQ(metadata->strong_ptr_count, 0); metadata->self = nullptr; if (metadata->weak_ptr_count == 0) delete metadata; } if (persistent_handle_.IsEmpty()) { // This most likely happened because the weak callback below cleared it. return; } { HandleScope handle_scope(env()->isolate()); object()->SetAlignedPointerInInternalField(BaseObject::kSlot, nullptr); } } void BaseObject::MakeWeak() { if (has_pointer_data()) { pointer_data()->wants_weak_jsobj = true; if (pointer_data()->strong_ptr_count > 0) return; } persistent_handle_.SetWeak( this, [](const WeakCallbackInfo<BaseObject>& data) { BaseObject* obj = data.GetParameter(); // Clear the persistent handle so that ~BaseObject() doesn't attempt // to mess with internal fields, since the JS object may have // transitioned into an invalid state. // Refs: https://github.com/nodejs/node/issues/18897 obj->persistent_handle_.Reset(); CHECK_IMPLIES(obj->has_pointer_data(), obj->pointer_data()->strong_ptr_count == 0); obj->OnGCCollect(); }, WeakCallbackType::kParameter); } // This just has to be different from the Chromium ones: // https://source.chromium.org/chromium/chromium/src/+/main:gin/public/gin_embedders.h;l=18-23;drc=5a758a97032f0b656c3c36a3497560762495501a // Otherwise, when Node is loaded in an isolate which uses cppgc, cppgc will // misinterpret the data stored in the embedder fields and try to garbage // collect them. uint16_t kNodeEmbedderId = 0x90de; void BaseObject::LazilyInitializedJSTemplateConstructor( const FunctionCallbackInfo<Value>& args) { DCHECK(args.IsConstructCall()); CHECK_GE(args.This()->InternalFieldCount(), BaseObject::kInternalFieldCount); args.This()->SetAlignedPointerInInternalField(BaseObject::kEmbedderType, &kNodeEmbedderId); args.This()->SetAlignedPointerInInternalField(BaseObject::kSlot, nullptr); } Local<FunctionTemplate> BaseObject::MakeLazilyInitializedJSTemplate( Environment* env) { Local<FunctionTemplate> t = env->NewFunctionTemplate(LazilyInitializedJSTemplateConstructor); t->Inherit(BaseObject::GetConstructorTemplate(env)); t->InstanceTemplate()->SetInternalFieldCount(BaseObject::kInternalFieldCount); return t; } BaseObject::PointerData* BaseObject::pointer_data() { if (!has_pointer_data()) { PointerData* metadata = new PointerData(); metadata->wants_weak_jsobj = persistent_handle_.IsWeak(); metadata->self = this; pointer_data_ = metadata; } CHECK(has_pointer_data()); return pointer_data_; } void BaseObject::decrease_refcount() { CHECK(has_pointer_data()); PointerData* metadata = pointer_data(); CHECK_GT(metadata->strong_ptr_count, 0); unsigned int new_refcount = --metadata->strong_ptr_count; if (new_refcount == 0) { if (metadata->is_detached) { OnGCCollect(); } else if (metadata->wants_weak_jsobj && !persistent_handle_.IsEmpty()) { MakeWeak(); } } } void BaseObject::increase_refcount() { unsigned int prev_refcount = pointer_data()->strong_ptr_count++; if (prev_refcount == 0 && !persistent_handle_.IsEmpty()) persistent_handle_.ClearWeak(); } void BaseObject::DeleteMe(void* data) { BaseObject* self = static_cast<BaseObject*>(data); if (self->has_pointer_data() && self->pointer_data()->strong_ptr_count > 0) { return self->Detach(); } delete self; } bool BaseObject::IsDoneInitializing() const { return true; } Local<Object> BaseObject::WrappedObject() const { return object(); } bool BaseObject::IsRootNode() const { return !persistent_handle_.IsWeak(); } Local<FunctionTemplate> BaseObject::GetConstructorTemplate(Environment* env) { Local<FunctionTemplate> tmpl = env->base_object_ctor_template(); if (tmpl.IsEmpty()) { tmpl = env->NewFunctionTemplate(nullptr); tmpl->SetClassName(FIXED_ONE_BYTE_STRING(env->isolate(), "BaseObject")); env->set_base_object_ctor_template(tmpl); } return tmpl; } bool BaseObject::IsNotIndicativeOfMemoryLeakAtExit() const { return IsWeakOrDetached(); } } // namespace node