Fix call destruction bug

src/node/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));
   }

src/node/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);

src/node/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();
 }
 

src/node/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();
 }
 

src/node/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;