// Copyright 2018 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. #if !V8_ENABLE_WEBASSEMBLY #error This header should only be included if WebAssembly is enabled. #endif // !V8_ENABLE_WEBASSEMBLY #ifndef V8_WASM_WASM_IMPORT_WRAPPER_CACHE_H_ #define V8_WASM_WASM_IMPORT_WRAPPER_CACHE_H_ #include "src/base/platform/mutex.h" #include "src/compiler/wasm-compiler.h" namespace v8 { namespace internal { class Counters; namespace wasm { class WasmCode; class WasmEngine; using FunctionSig = Signature<ValueType>; // Implements a cache for import wrappers. class WasmImportWrapperCache { public: struct CacheKey { CacheKey(const compiler::WasmImportCallKind& _kind, const FunctionSig* _sig, int _expected_arity, Suspend _suspend) : kind(_kind), signature(_sig), expected_arity(_expected_arity == kDontAdaptArgumentsSentinel ? 0 : _expected_arity), suspend(_suspend) {} bool operator==(const CacheKey& rhs) const { return kind == rhs.kind && signature == rhs.signature && expected_arity == rhs.expected_arity && suspend == rhs.suspend; } compiler::WasmImportCallKind kind; const FunctionSig* signature; int expected_arity; Suspend suspend; }; class CacheKeyHash { public: size_t operator()(const CacheKey& key) const { return base::hash_combine(static_cast<uint8_t>(key.kind), key.signature, key.expected_arity); } }; // Helper class to modify the cache under a lock. class V8_NODISCARD ModificationScope { public: explicit ModificationScope(WasmImportWrapperCache* cache) : cache_(cache), guard_(&cache->mutex_) {} V8_EXPORT_PRIVATE WasmCode*& operator[](const CacheKey& key); private: WasmImportWrapperCache* const cache_; base::MutexGuard guard_; }; // Not thread-safe, use ModificationScope to get exclusive write access to the // cache. V8_EXPORT_PRIVATE WasmCode*& operator[](const CacheKey& key); // Thread-safe. Assumes the key exists in the map. V8_EXPORT_PRIVATE WasmCode* Get(compiler::WasmImportCallKind kind, const FunctionSig* sig, int expected_arity, Suspend suspend) const; // Thread-safe. Returns nullptr if the key doesn't exist in the map. WasmCode* MaybeGet(compiler::WasmImportCallKind kind, const FunctionSig* sig, int expected_arity, Suspend suspend) const; ~WasmImportWrapperCache(); private: mutable base::Mutex mutex_; std::unordered_map<CacheKey, WasmCode*, CacheKeyHash> entry_map_; }; } // namespace wasm } // namespace internal } // namespace v8 #endif // V8_WASM_WASM_IMPORT_WRAPPER_CACHE_H_