From 71a8944b3946beff7ba7d1e65c38aa56c30227ec Mon Sep 17 00:00:00 2001
From: Kevin Gozali <fkg@fb.com>
Date: Tue, 2 Apr 2019 18:06:29 -0700
Subject: [PATCH] TM iOS: Use weak_ptr to pass around Instance to avoid
 unreleased refs

Summary:
There is a timing issue when reloading the bridge (in dev mode) and the tear down of the TurboModules. This causes `Instance` to never get freed, hence the "bridge" isn't cleaning up properly. The side effect can be bogus error saying that it's unable to find a module.

To address this, JSCallInvoker should just take in weak_ptr<Instance>.

Reviewed By: RSNara

Differential Revision: D14739181

fbshipit-source-id: f9f2a55486debaeb28d3d293df3cf1d3f6b9a031
---
 React/CxxBridge/RCTCxxBridge.mm                            | 2 +-
 ReactCommon/turbomodule/core/JSCallInvoker.cpp             | 7 ++++---
 ReactCommon/turbomodule/core/JSCallInvoker.h               | 4 ++--
 ReactCommon/turbomodule/core/platform/ios/RCTTurboModule.h | 2 +-
 4 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/React/CxxBridge/RCTCxxBridge.mm b/React/CxxBridge/RCTCxxBridge.mm
index cea1e0d840d7c6..163fe44fd1de9f 100644
--- a/React/CxxBridge/RCTCxxBridge.mm
+++ b/React/CxxBridge/RCTCxxBridge.mm
@@ -210,7 +210,7 @@ - (void) setRCTTurboModuleLookupDelegate:(id<RCTTurboModuleLookupDelegate>)turbo
   return _jsMessageThread;
 }
 
-- (std::shared_ptr<Instance>)reactInstance
+- (std::weak_ptr<Instance>)reactInstance
 {
   return _reactInstance;
 }
diff --git a/ReactCommon/turbomodule/core/JSCallInvoker.cpp b/ReactCommon/turbomodule/core/JSCallInvoker.cpp
index 848e9de9018e18..f58adb91f304f7 100644
--- a/ReactCommon/turbomodule/core/JSCallInvoker.cpp
+++ b/ReactCommon/turbomodule/core/JSCallInvoker.cpp
@@ -12,14 +12,15 @@
 namespace facebook {
 namespace react {
 
-JSCallInvoker::JSCallInvoker(std::shared_ptr<Instance> reactInstance)
+JSCallInvoker::JSCallInvoker(std::weak_ptr<Instance> reactInstance)
   : reactInstance_(reactInstance) {}
 
 void JSCallInvoker::invokeAsync(std::function<void()>&& func) {
-  if (reactInstance_ == nullptr) {
+  auto instance = reactInstance_.lock();
+  if (instance == nullptr) {
     return;
   }
-  reactInstance_->invokeAsync(std::move(func));
+  instance->invokeAsync(std::move(func));
 }
 
 } // namespace react
diff --git a/ReactCommon/turbomodule/core/JSCallInvoker.h b/ReactCommon/turbomodule/core/JSCallInvoker.h
index eff18fa878d89c..770cdf2545d39a 100644
--- a/ReactCommon/turbomodule/core/JSCallInvoker.h
+++ b/ReactCommon/turbomodule/core/JSCallInvoker.h
@@ -26,13 +26,13 @@ class Instance;
  */
 class JSCallInvoker {
 public:
-  JSCallInvoker(std::shared_ptr<Instance> reactInstance);
+  JSCallInvoker(std::weak_ptr<Instance> reactInstance);
 
   void invokeAsync(std::function<void()>&& func);
   // TODO: add sync support
 
 private:
-  std::shared_ptr<Instance> reactInstance_;
+  std::weak_ptr<Instance> reactInstance_;
 };
 
 } // namespace react
diff --git a/ReactCommon/turbomodule/core/platform/ios/RCTTurboModule.h b/ReactCommon/turbomodule/core/platform/ios/RCTTurboModule.h
index d63d6922268fa4..dbd31c8f4dfef4 100644
--- a/ReactCommon/turbomodule/core/platform/ios/RCTTurboModule.h
+++ b/ReactCommon/turbomodule/core/platform/ios/RCTTurboModule.h
@@ -91,6 +91,6 @@ class JSI_EXPORT ObjCTurboModule : public TurboModule {
 @interface RCTBridge ()
 
 - (std::shared_ptr<facebook::react::MessageQueueThread>)jsMessageThread;
-- (std::shared_ptr<facebook::react::Instance>)reactInstance;
+- (std::weak_ptr<facebook::react::Instance>)reactInstance;
 
 @end