From 3b58459472a473da80e13182a22bd153056b3939 Mon Sep 17 00:00:00 2001
From: murgatroid99 <mlumish@google.com>
Date: Tue, 4 Apr 2017 13:43:49 -0700
Subject: [PATCH 1/2] Fix call destruction bug

---
 ext/call.cc      | 10 +++++++---
 ext/call.h       |  5 ++++-
 ext/channel.cc   |  2 +-
 ext/server.cc    |  4 ++--
 ext/server_uv.cc |  3 ++-
 5 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/ext/call.cc b/ext/call.cc
index 244546d3..62f0130d 100644
--- a/ext/call.cc
+++ b/ext/call.cc
@@ -466,8 +466,10 @@ class ServerCloseResponseOp : public Op {
   int cancelled;
 };
 
-tag::tag(Callback *callback, OpVec *ops, Call *call) :
+tag::tag(Callback *callback, OpVec *ops, Call *call, Local<Value> call_value) :
     callback(callback), ops(ops), call(call){
+  HandleScope scope;
+  call_persist.Reset(call_value);
 }
 
 tag::~tag() {
@@ -521,6 +523,7 @@ Call::Call(grpc_call *call) : wrapped_call(call),
 Call::~Call() {
   if (wrapped_call != NULL) {
     grpc_call_destroy(wrapped_call);
+    wrapped_call = NULL;
   }
 }
 
@@ -567,7 +570,8 @@ void Call::CompleteBatch(bool is_final_op) {
     this->has_final_op_completed = true;
   }
   this->pending_batches--;
-  if (this->has_final_op_completed && this->pending_batches == 0) {
+  if (this->has_final_op_completed && this->pending_batches == 0 &&
+      this->wrapped_call != NULL) {
     grpc_call_destroy(this->wrapped_call);
     this->wrapped_call = NULL;
   }
@@ -721,7 +725,7 @@ NAN_METHOD(Call::StartBatch) {
   Callback *callback = new Callback(callback_func);
   grpc_call_error error = grpc_call_start_batch(
       call->wrapped_call, &ops[0], nops, new struct tag(
-          callback, op_vector.release(), call), NULL);
+          callback, op_vector.release(), call, info.This()), NULL);
   if (error != GRPC_CALL_OK) {
     return Nan::ThrowError(nanErrorWithCode("startBatch failed", error));
   }
diff --git a/ext/call.h b/ext/call.h
index cffff00f..cceec9c4 100644
--- a/ext/call.h
+++ b/ext/call.h
@@ -109,11 +109,14 @@ class Op {
 
 typedef std::vector<unique_ptr<Op>> OpVec;
 struct tag {
-  tag(Nan::Callback *callback, OpVec *ops, Call *call);
+  tag(Nan::Callback *callback, OpVec *ops, Call *call,
+      v8::Local<v8::Value> call_value);
   ~tag();
   Nan::Callback *callback;
   OpVec *ops;
   Call *call;
+  Nan::Persistent<v8::Value, Nan::CopyablePersistentTraits<v8::Value>>
+      call_persist;
 };
 
 v8::Local<v8::Value> GetTagNodeValue(void *tag);
diff --git a/ext/channel.cc b/ext/channel.cc
index c795ff7f..1263cc0d 100644
--- a/ext/channel.cc
+++ b/ext/channel.cc
@@ -280,7 +280,7 @@ NAN_METHOD(Channel::WatchConnectivityState) {
       channel->wrapped_channel, last_state, MillisecondsToTimespec(deadline),
       GetCompletionQueue(),
       new struct tag(callback,
-                     ops.release(), NULL));
+                     ops.release(), NULL, Nan::Null()));
   CompletionQueueNext();
 }
 
diff --git a/ext/server.cc b/ext/server.cc
index ccb55aa5..f0920c84 100644
--- a/ext/server.cc
+++ b/ext/server.cc
@@ -193,7 +193,7 @@ NAN_METHOD(Server::RequestCall) {
       GetCompletionQueue(),
       GetCompletionQueue(),
       new struct tag(new Callback(info[0].As<Function>()), ops.release(),
-                     NULL));
+                     NULL, Nan::Null()));
   if (error != GRPC_CALL_OK) {
     return Nan::ThrowError(nanErrorWithCode("requestCall failed", error));
   }
@@ -246,7 +246,7 @@ NAN_METHOD(Server::TryShutdown) {
   grpc_server_shutdown_and_notify(
       server->wrapped_server, GetCompletionQueue(),
       new struct tag(new Nan::Callback(info[0].As<Function>()), ops.release(),
-                     NULL));
+                     NULL, Nan::Null()));
   CompletionQueueNext();
 }
 
diff --git a/ext/server_uv.cc b/ext/server_uv.cc
index c5e5ca9f..82e7589f 100644
--- a/ext/server_uv.cc
+++ b/ext/server_uv.cc
@@ -118,7 +118,8 @@ void Server::ShutdownServer() {
 
     grpc_server_shutdown_and_notify(
         this->wrapped_server, GetCompletionQueue(),
-        new struct tag(new Callback(**shutdown_callback), ops.release(), NULL));
+        new struct tag(new Callback(**shutdown_callback), ops.release(), NULL,
+                       Nan::Null()));
     grpc_server_cancel_all_calls(this->wrapped_server);
     CompletionQueueNext();
     this->wrapped_server = NULL;

From 60a0ed4903b2604aae01b1cb67054e798521ac48 Mon Sep 17 00:00:00 2001
From: murgatroid99 <mlumish@google.com>
Date: Thu, 6 Apr 2017 13:54:37 -0700
Subject: [PATCH 2/2] Node: consolidate call destruction logic

---
 ext/call.cc | 18 ++++++++++--------
 ext/call.h  |  2 ++
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/ext/call.cc b/ext/call.cc
index 62f0130d..769f744b 100644
--- a/ext/call.cc
+++ b/ext/call.cc
@@ -515,16 +515,20 @@ void DestroyTag(void *tag) {
   delete tag_struct;
 }
 
+void Call::DestroyCall() {
+  if (this->wrapped_call != NULL) {
+    grpc_call_destroy(this->wrapped_call);
+    this->wrapped_call = NULL;
+  }
+}
+
 Call::Call(grpc_call *call) : wrapped_call(call),
                               pending_batches(0),
                               has_final_op_completed(false) {
 }
 
 Call::~Call() {
-  if (wrapped_call != NULL) {
-    grpc_call_destroy(wrapped_call);
-    wrapped_call = NULL;
-  }
+  DestroyCall();
 }
 
 void Call::Init(Local<Object> exports) {
@@ -570,10 +574,8 @@ void Call::CompleteBatch(bool is_final_op) {
     this->has_final_op_completed = true;
   }
   this->pending_batches--;
-  if (this->has_final_op_completed && this->pending_batches == 0 &&
-      this->wrapped_call != NULL) {
-    grpc_call_destroy(this->wrapped_call);
-    this->wrapped_call = NULL;
+  if (this->has_final_op_completed && this->pending_batches == 0) {
+    this->DestroyCall();
   }
 }
 
diff --git a/ext/call.h b/ext/call.h
index cceec9c4..7fd03ca1 100644
--- a/ext/call.h
+++ b/ext/call.h
@@ -76,6 +76,8 @@ class Call : public Nan::ObjectWrap {
   Call(const Call &);
   Call &operator=(const Call &);
 
+  void DestroyCall();
+
   static NAN_METHOD(New);
   static NAN_METHOD(StartBatch);
   static NAN_METHOD(Cancel);