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// Copyright 2017 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. #ifndef V8_WASM_WASM_ENGINE_H_ #define V8_WASM_WASM_ENGINE_H_ #include <memory> #include <unordered_set> #include "src/tasks/cancelable-task.h" #include "src/wasm/wasm-code-manager.h" #include "src/wasm/wasm-memory.h" #include "src/wasm/wasm-tier.h" #include "src/zone/accounting-allocator.h" namespace v8 { namespace internal { class AsmWasmData; class CodeTracer; class CompilationStatistics; class HeapNumber; class WasmInstanceObject; class WasmModuleObject; namespace wasm { class AsyncCompileJob; class ErrorThrower; struct ModuleWireBytes; struct WasmFeatures; class V8_EXPORT_PRIVATE CompilationResultResolver { public: virtual void OnCompilationSucceeded(Handle<WasmModuleObject> result) = 0; virtual void OnCompilationFailed(Handle<Object> error_reason) = 0; virtual ~CompilationResultResolver() = default; }; class V8_EXPORT_PRIVATE InstantiationResultResolver { public: virtual void OnInstantiationSucceeded(Handle<WasmInstanceObject> result) = 0; virtual void OnInstantiationFailed(Handle<Object> error_reason) = 0; virtual ~InstantiationResultResolver() = default; }; // The central data structure that represents an engine instance capable of // loading, instantiating, and executing WASM code. class V8_EXPORT_PRIVATE WasmEngine { public: WasmEngine(); ~WasmEngine(); // Synchronously validates the given bytes that represent an encoded WASM // module. bool SyncValidate(Isolate* isolate, const WasmFeatures& enabled, const ModuleWireBytes& bytes); // Synchronously compiles the given bytes that represent a translated // asm.js module. MaybeHandle<AsmWasmData> SyncCompileTranslatedAsmJs( Isolate* isolate, ErrorThrower* thrower, const ModuleWireBytes& bytes, Vector<const byte> asm_js_offset_table_bytes, Handle<HeapNumber> uses_bitset, LanguageMode language_mode); Handle<WasmModuleObject> FinalizeTranslatedAsmJs( Isolate* isolate, Handle<AsmWasmData> asm_wasm_data, Handle<Script> script); // Synchronously compiles the given bytes that represent an encoded WASM // module. MaybeHandle<WasmModuleObject> SyncCompile(Isolate* isolate, const WasmFeatures& enabled, ErrorThrower* thrower, const ModuleWireBytes& bytes); // Synchronously instantiate the given WASM module with the given imports. // If the module represents an asm.js module, then the supplied {memory} // should be used as the memory of the instance. MaybeHandle<WasmInstanceObject> SyncInstantiate( Isolate* isolate, ErrorThrower* thrower, Handle<WasmModuleObject> module_object, MaybeHandle<JSReceiver> imports, MaybeHandle<JSArrayBuffer> memory); // Begin an asynchronous compilation of the given bytes that represent an // encoded WASM module. // The {is_shared} flag indicates if the bytes backing the module could // be shared across threads, i.e. could be concurrently modified. void AsyncCompile(Isolate* isolate, const WasmFeatures& enabled, std::shared_ptr<CompilationResultResolver> resolver, const ModuleWireBytes& bytes, bool is_shared, const char* api_method_name_for_errors); // Begin an asynchronous instantiation of the given WASM module. void AsyncInstantiate(Isolate* isolate, std::unique_ptr<InstantiationResultResolver> resolver, Handle<WasmModuleObject> module_object, MaybeHandle<JSReceiver> imports); std::shared_ptr<StreamingDecoder> StartStreamingCompilation( Isolate* isolate, const WasmFeatures& enabled, Handle<Context> context, const char* api_method_name, std::shared_ptr<CompilationResultResolver> resolver); // Compiles the function with the given index at a specific compilation tier. // Errors are stored internally in the CompilationState. // This is mostly used for testing to force a function into a specific tier. void CompileFunction(Isolate* isolate, NativeModule* native_module, uint32_t function_index, ExecutionTier tier); // Exports the sharable parts of the given module object so that they can be // transferred to a different Context/Isolate using the same engine. std::shared_ptr<NativeModule> ExportNativeModule( Handle<WasmModuleObject> module_object); // Imports the shared part of a module from a different Context/Isolate using // the the same engine, recreating a full module object in the given Isolate. Handle<WasmModuleObject> ImportNativeModule( Isolate* isolate, std::shared_ptr<NativeModule> shared_module); WasmCodeManager* code_manager() { return &code_manager_; } WasmMemoryTracker* memory_tracker() { return &memory_tracker_; } AccountingAllocator* allocator() { return &allocator_; } // Compilation statistics for TurboFan compilations. CompilationStatistics* GetOrCreateTurboStatistics(); // Prints the gathered compilation statistics, then resets them. void DumpAndResetTurboStatistics(); // Used to redirect tracing output from {stdout} to a file. CodeTracer* GetCodeTracer(); // Remove {job} from the list of active compile jobs. std::unique_ptr<AsyncCompileJob> RemoveCompileJob(AsyncCompileJob* job); // Returns true if at least one AsyncCompileJob that belongs to the given // Isolate is currently running. bool HasRunningCompileJob(Isolate* isolate); // Deletes all AsyncCompileJobs that belong to the given context. All // compilation is aborted, no more callbacks will be triggered. This is used // when a context is disposed, e.g. because of browser navigation. void DeleteCompileJobsOnContext(Handle<Context> context); // Deletes all AsyncCompileJobs that belong to the given Isolate. All // compilation is aborted, no more callbacks will be triggered. This is used // for tearing down an isolate, or to clean it up to be reused. void DeleteCompileJobsOnIsolate(Isolate* isolate); // Manage the set of Isolates that use this WasmEngine. void AddIsolate(Isolate* isolate); void RemoveIsolate(Isolate* isolate); template <typename T, typename... Args> std::unique_ptr<T> NewBackgroundCompileTask(Args&&... args) { return base::make_unique<T>(&background_compile_task_manager_, std::forward<Args>(args)...); } // Trigger code logging for this WasmCode in all Isolates which have access to // the NativeModule containing this code. This method can be called from // background threads. void LogCode(WasmCode*); // Enable code logging for the given Isolate. Initially, code logging is // enabled if {WasmCode::ShouldBeLogged(Isolate*)} returns true during // {AddIsolate}. void EnableCodeLogging(Isolate*); // This is called from the foreground thread of the Isolate to log all // outstanding code objects (added via {LogCode}). void LogOutstandingCodesForIsolate(Isolate*); // Create a new NativeModule. The caller is responsible for its // lifetime. The native module will be given some memory for code, // which will be page size aligned. The size of the initial memory // is determined with a heuristic based on the total size of wasm // code. The native module may later request more memory. // TODO(titzer): isolate is only required here for CompilationState. std::shared_ptr<NativeModule> NewNativeModule( Isolate* isolate, const WasmFeatures& enabled_features, std::shared_ptr<const WasmModule> module); std::shared_ptr<NativeModule> NewNativeModule( Isolate* isolate, const WasmFeatures& enabled_features, size_t code_size_estimate, bool can_request_more, std::shared_ptr<const WasmModule> module); void FreeNativeModule(NativeModule*); // Sample the code size of the given {NativeModule} in all isolates that have // access to it. Call this after top-tier compilation finished. // This will spawn foreground tasks that do *not* keep the NativeModule alive. void SampleTopTierCodeSizeInAllIsolates(const std::shared_ptr<NativeModule>&); // Called by each Isolate to report its live code for a GC cycle. First // version reports an externally determined set of live code (might be empty), // second version gets live code from the execution stack of that isolate. void ReportLiveCodeForGC(Isolate*, Vector<WasmCode*>); void ReportLiveCodeFromStackForGC(Isolate*); // Add potentially dead code. The occurrence in the set of potentially dead // code counts as a reference, and is decremented on the next GC. // Returns {true} if the code was added to the set of potentially dead code, // {false} if an entry already exists. The ref count is *unchanged* in any // case. V8_WARN_UNUSED_RESULT bool AddPotentiallyDeadCode(WasmCode*); // Free dead code. using DeadCodeMap = std::unordered_map<NativeModule*, std::vector<WasmCode*>>; void FreeDeadCode(const DeadCodeMap&); void FreeDeadCodeLocked(const DeadCodeMap&); // Call on process start and exit. static void InitializeOncePerProcess(); static void GlobalTearDown(); // Constructs a WasmEngine instance. Depending on whether we are sharing // engines this might be a pointer to a new instance or to a shared one. static std::shared_ptr<WasmEngine> GetWasmEngine(); private: struct CurrentGCInfo; struct IsolateInfo; struct NativeModuleInfo; AsyncCompileJob* CreateAsyncCompileJob( Isolate* isolate, const WasmFeatures& enabled, std::unique_ptr<byte[]> bytes_copy, size_t length, Handle<Context> context, const char* api_method_name, std::shared_ptr<CompilationResultResolver> resolver); void TriggerGC(int8_t gc_sequence_index); // Remove an isolate from the outstanding isolates of the current GC. Returns // true if the isolate was still outstanding, false otherwise. Hold {mutex_} // when calling this method. bool RemoveIsolateFromCurrentGC(Isolate*); // Finish a GC if there are no more outstanding isolates. Hold {mutex_} when // calling this method. void PotentiallyFinishCurrentGC(); WasmMemoryTracker memory_tracker_; WasmCodeManager code_manager_; AccountingAllocator allocator_; // Task manager managing all background compile jobs. Before shut down of the // engine, they must all be finished because they access the allocator. CancelableTaskManager background_compile_task_manager_; // This mutex protects all information which is mutated concurrently or // fields that are initialized lazily on the first access. base::Mutex mutex_; ////////////////////////////////////////////////////////////////////////////// // Protected by {mutex_}: // We use an AsyncCompileJob as the key for itself so that we can delete the // job from the map when it is finished. std::unordered_map<AsyncCompileJob*, std::unique_ptr<AsyncCompileJob>> async_compile_jobs_; std::unique_ptr<CompilationStatistics> compilation_stats_; std::unique_ptr<CodeTracer> code_tracer_; // Set of isolates which use this WasmEngine. std::unordered_map<Isolate*, std::unique_ptr<IsolateInfo>> isolates_; // Set of native modules managed by this engine. std::unordered_map<NativeModule*, std::unique_ptr<NativeModuleInfo>> native_modules_; // Size of code that became dead since the last GC. If this exceeds a certain // threshold, a new GC is triggered. size_t new_potentially_dead_code_size_ = 0; // If an engine-wide GC is currently running, this pointer stores information // about that. std::unique_ptr<CurrentGCInfo> current_gc_info_; // End of fields protected by {mutex_}. ////////////////////////////////////////////////////////////////////////////// DISALLOW_COPY_AND_ASSIGN(WasmEngine); }; } // namespace wasm } // namespace internal } // namespace v8 #endif // V8_WASM_WASM_ENGINE_H_