From dfcfb90baa1940fb7ceb0c729d181374ed752561 Mon Sep 17 00:00:00 2001
From: Dan Caspi <danca@fb.com>
Date: Tue, 27 Sep 2016 09:33:10 -0700
Subject: [PATCH] Fix [JSValue ...] & [JSContext ...] access with custom JSC

Reviewed By: bnham

Differential Revision: D3859956

fbshipit-source-id: 966aba9a267371eb553b8be574fa247b21930d1c
---
 React/Executors/RCTJSCExecutor.h  | 17 +++++++++++++++++
 React/Executors/RCTJSCExecutor.mm |  8 ++++++++
 2 files changed, 25 insertions(+)

diff --git a/React/Executors/RCTJSCExecutor.h b/React/Executors/RCTJSCExecutor.h
index 47a259ed3..ef87c8b12 100644
--- a/React/Executors/RCTJSCExecutor.h
+++ b/React/Executors/RCTJSCExecutor.h
@@ -27,6 +27,23 @@ RCT_EXTERN NSString *const RCTJSCThreadName;
  */
 RCT_EXTERN NSString *const RCTJavaScriptContextCreatedNotification;
 
+/**
+ * A key to a reference to a JSContext class, held in the the current thread's
+ *  dictionary. The reference would point to the JSContext class in the JS VM
+ *  used in React (or ComponenetScript). It is recommended not to access it
+ *  through the thread's dictionary, but rather to use the `FBJSCurrentContext()`
+ *  accessor, which will return the current JSContext in the currently used VM.
+ */
+RCT_EXTERN NSString *const RCTFBJSContextClassKey;
+
+/**
+ * A key to a reference to a JSValue class, held in the the current thread's
+ *  dictionary. The reference would point to the JSValue class in the JS VM
+ *  used in React (or ComponenetScript). It is recommended not to access it
+ *  through the thread's dictionary, but rather to use the `FBJSValue()` accessor.
+ */
+RCT_EXTERN NSString *const RCTFBJSValueClassKey;
+
 /**
  * @experimental
  * May be used to pre-create the JSContext to make RCTJSCExecutor creation less costly.
diff --git a/React/Executors/RCTJSCExecutor.mm b/React/Executors/RCTJSCExecutor.mm
index 876527931..61fdfb495 100644
--- a/React/Executors/RCTJSCExecutor.mm
+++ b/React/Executors/RCTJSCExecutor.mm
@@ -34,6 +34,8 @@
 
 NSString *const RCTJSCThreadName = @"com.facebook.react.JavaScript";
 NSString *const RCTJavaScriptContextCreatedNotification = @"RCTJavaScriptContextCreatedNotification";
+RCT_EXTERN NSString *const RCTFBJSContextClassKey = @"_RCTFBJSContextClassKey";
+RCT_EXTERN NSString *const RCTFBJSValueClassKey = @"_RCTFBJSValueClassKey";
 
 static NSString *const RCTJSCProfilerEnabledDefaultsKey = @"RCTJSCProfilerEnabled";
 
@@ -346,6 +348,12 @@ static NSThread *newJavaScriptThread(void)
       installBasicSynchronousHooksOnContext(context);
     }
 
+    NSMutableDictionary *threadDictionary = [[NSThread currentThread] threadDictionary];
+    if (!threadDictionary[RCTFBJSContextClassKey] || !threadDictionary[RCTFBJSValueClassKey]) {
+      threadDictionary[RCTFBJSContextClassKey] = self->_jscWrapper->JSContext;
+      threadDictionary[RCTFBJSValueClassKey] = self->_jscWrapper->JSValue;
+    }
+
     __weak RCTJSCExecutor *weakSelf = self;
 
     context[@"nativeRequireModuleConfig"] = ^NSArray *(NSString *moduleName) {