feat: drop perIsolateCaches_ in favor of v8 data slots

Author: edusperoni

NativeScript/runtime/Caches.cpp

@@ -24,7 +24,11 @@ Caches::~Caches() {
 }
 
 void Caches::Remove(v8::Isolate* isolate) {
-    Caches::perIsolateCaches_->Remove(isolate);
+    auto cache = isolate->GetData(0);
+    isolate->SetData(0, nullptr);
+    if (cache != nullptr) {
+        delete reinterpret_cast<std::shared_ptr<Caches>*>(cache);
+    }
 }
 
 void Caches::SetContext(Local<Context> context) {
@@ -35,8 +39,6 @@ Local<Context> Caches::GetContext() {
     return this->context_->Get(this->isolate_);
 }
 
-std::shared_ptr<ConcurrentMap<Isolate*, std::shared_ptr<Caches>>> Caches::perIsolateCaches_ = std::make_shared<ConcurrentMap<Isolate*, std::shared_ptr<Caches>>>();
-
 std::shared_ptr<ConcurrentMap<std::string, const Meta*>> Caches::Metadata = std::make_shared<ConcurrentMap<std::string, const Meta*>>();
 std::shared_ptr<ConcurrentMap<int, std::shared_ptr<Caches::WorkerState>>> Caches::Workers = std::make_shared<ConcurrentMap<int, std::shared_ptr<Caches::WorkerState>>>();
 

NativeScript/runtime/Caches.h

@@ -52,14 +52,20 @@ class Caches {
     static std::shared_ptr<ConcurrentMap<std::string, const Meta*>> Metadata;
     static std::shared_ptr<ConcurrentMap<int, std::shared_ptr<Caches::WorkerState>>> Workers;
 
+    inline static std::shared_ptr<Caches> Init(v8::Isolate* isolate) {
+        auto cache = std::make_shared<Caches>(isolate);
+        // create a new shared_ptr that will live until Remove is called
+        isolate->SetData(0, static_cast<void*>(new std::shared_ptr<Caches>(cache)));
+        return cache;
+    }
     inline static std::shared_ptr<Caches> Get(v8::Isolate* isolate) {
-        std::shared_ptr<Caches> cache = perIsolateCaches_->Get(isolate);
-        if (cache == nullptr) {
-            cache = std::make_shared<Caches>(isolate);
-            Caches::perIsolateCaches_->Insert(isolate, cache);
+        auto cache = isolate->GetData(0);
+        if (cache != nullptr) {
+            return *reinterpret_cast<std::shared_ptr<Caches>*>(cache);
         }
-
-        return cache;
+        // this should only happen when an isolate is accessed after disposal
+        // so we return a dummy cache
+        return std::make_shared<Caches>(isolate);
     }
     static void Remove(v8::Isolate* isolate);
 
@@ -96,7 +102,6 @@ class Caches {
     std::unique_ptr<v8::Persistent<v8::Function>> FunctionReferenceCtorFunc = std::unique_ptr<v8::Persistent<v8::Function>>(nullptr);
     std::unique_ptr<v8::Persistent<v8::Function>> UnmanagedTypeCtorFunc = std::unique_ptr<v8::Persistent<v8::Function>>(nullptr);
 private:
-    static std::shared_ptr<ConcurrentMap<v8::Isolate*, std::shared_ptr<Caches>>> perIsolateCaches_;
     v8::Isolate* isolate_;
     std::shared_ptr<v8::Persistent<v8::Context>> context_;
 };

NativeScript/runtime/Runtime.mm

@@ -79,7 +79,7 @@
 }
 
 void Runtime::Init(Isolate* isolate) {
-    std::shared_ptr<Caches> cache = Caches::Get(isolate);
+    std::shared_ptr<Caches> cache = Caches::Init(isolate);
     cache->ObjectCtorInitializer = MetadataBuilder::GetOrCreateConstructorFunctionTemplate;
     cache->StructCtorInitializer = MetadataBuilder::GetOrCreateStructCtorFunction;