Fabric: New UIManager registration process (beginning)

Summary:
This diff introduces a new integration concept (called RuntimeExecutor) which consolidates `Runtime` and the dispatching mechanism.
As simple as that:
`using RuntimeExecutor = std::function<void(std::function<void(facebook::jsi::Runtime &runtime)> &&callback)>;`

Reviewed By: fkgozali

Differential Revision: D12816746

fbshipit-source-id: 9e27ef16b98af861d494fe50c7e50bd0536e6aaf

React/Base/RCTBridge+Private.h

@@ -144,6 +144,8 @@ RCT_EXTERN void RCTRegisterModule(Class);
 
 @interface RCTCxxBridge : RCTBridge
 
+@property (nonatomic) void *runtime;
+
 - (instancetype)initWithParentBridge:(RCTBridge *)bridge NS_DESIGNATED_INITIALIZER;
 
 @end

React/CxxBridge/RCTCxxBridge.mm

@@ -57,6 +57,7 @@ static NSString *const RCTJSThreadName = @"com.facebook.react.JavaScript";
 typedef void (^RCTPendingCall)();
 
 using namespace facebook::jsc;
+using namespace facebook::jsi;
 using namespace facebook::react;
 
 /**
@@ -1229,4 +1230,13 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithBundleURL:(__unused NSURL *)bundleUR
   return _wasBatchActive;
 }
 
+- (void *)runtime
+{
+  if (!_reactInstance) {
+    return nullptr;
+  }
+
+  return _reactInstance->getJavaScriptContext();
+}
+
 @end

React/Fabric/RCTSurfacePresenter.h

@@ -79,9 +79,9 @@ NS_ASSUME_NONNULL_BEGIN
 
 @end
 
-@interface RCTBridge (RCTSurfacePresenter)
+@interface RCTBridge (Deprecated)
 
-- (RCTSurfacePresenter *)surfacePresenter;
+@property (nonatomic) RCTSurfacePresenter *surfacePresenter;
 
 @end
 

React/Fabric/RCTSurfacePresenter.mm

@@ -7,7 +7,10 @@
 
 #import "RCTSurfacePresenter.h"
 
+#import <objc/runtime.h>
 #import <mutex>
+#import <jsi/jsi.h>
+#import <cxxreact/MessageQueueThread.h>
 
 #import <React/RCTAssert.h>
 #import <React/RCTBridge+Private.h>
@@ -153,6 +156,14 @@ using namespace facebook::react;
   auto contextContainer = std::make_shared<ContextContainer>();
 
   auto messageQueueThread = _batchedBridge.jsMessageThread;
+  auto runtime = (facebook::jsi::Runtime *)((RCTCxxBridge *)_batchedBridge).runtime;
+
+  RuntimeExecutor runtimeExecutor =
+    [runtime, messageQueueThread](std::function<void(facebook::jsi::Runtime &runtime)> &&callback) {
+      messageQueueThread->runOnQueue([runtime, callback = std::move(callback)]() {
+        callback(*runtime);
+      });
+    };
 
   EventBeatFactory synchronousBeatFactory = [messageQueueThread]() {
     return std::make_unique<MainRunLoopEventBeat>(messageQueueThread);
@@ -165,8 +176,7 @@ using namespace facebook::react;
   contextContainer->registerInstance<EventBeatFactory>(synchronousBeatFactory, "synchronous");
   contextContainer->registerInstance<EventBeatFactory>(asynchronousBeatFactory, "asynchronous");
 
-  contextContainer->registerInstance(_uiManagerInstaller, "uimanager-installer");
-  contextContainer->registerInstance(_uiManagerUninstaller, "uimanager-uninstaller");
+  contextContainer->registerInstance(runtimeExecutor, "runtime-executor");
 
   contextContainer->registerInstance(std::make_shared<ImageManager>((__bridge void *)[_bridge imageLoader]));
 
@@ -307,3 +317,17 @@ using namespace facebook::react;
 }
 
 @end
+
+@implementation RCTBridge (Deprecated)
+
+- (void)setSurfacePresenter:(RCTSurfacePresenter *)surfacePresenter
+{
+  objc_setAssociatedObject(self, @selector(surfacePresenter), surfacePresenter, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
+}
+
+- (RCTSurfacePresenter *)surfacePresenter
+{
+  return objc_getAssociatedObject(self, @selector(surfacePresenter));
+}
+
+@end