Refactor uv/non-uv code in Node extension

binding.gyp

@@ -859,8 +859,8 @@
         "src/node/ext/call_credentials.cc",
         "src/node/ext/channel.cc",
         "src/node/ext/channel_credentials.cc",
-        "src/node/ext/completion_queue.cc",
-        "src/node/ext/completion_queue_async_worker.cc",
+        "src/node/ext/completion_queue_threadpool.cc",
+        "src/node/ext/completion_queue_uv.cc",
         "src/node/ext/node_grpc.cc",
         "src/node/ext/server.cc",
         "src/node/ext/server_credentials.cc",

build.yaml

@@ -3710,7 +3710,6 @@ node_modules:
   - src/node/ext/channel.h
   - src/node/ext/channel_credentials.h
   - src/node/ext/completion_queue.h
-  - src/node/ext/completion_queue_async_worker.h
   - src/node/ext/server.h
   - src/node/ext/server_credentials.h
   - src/node/ext/timeval.h
@@ -3729,8 +3728,8 @@ node_modules:
   - src/node/ext/call_credentials.cc
   - src/node/ext/channel.cc
   - src/node/ext/channel_credentials.cc
-  - src/node/ext/completion_queue.cc
-  - src/node/ext/completion_queue_async_worker.cc
+  - src/node/ext/completion_queue_threadpool.cc
+  - src/node/ext/completion_queue_uv.cc
   - src/node/ext/node_grpc.cc
   - src/node/ext/server.cc
   - src/node/ext/server_credentials.cc

src/node/ext/completion_queue.h

@@ -32,6 +32,7 @@
  */
 
 #include <v8.h>
+#include <grpc/grpc.h>
 
 namespace grpc {
 namespace node {

src/node/ext/completion_queue_threadpool.cc

@@ -31,18 +31,63 @@
  *
  */
 
+/* I don't like using #ifndef, but I don't see a better way to do this */
+#ifndef GRPC_UV
+
 #include <node.h>
 #include <nan.h>
 
 #include "grpc/grpc.h"
 #include "grpc/support/log.h"
 #include "grpc/support/time.h"
-#include "completion_queue_async_worker.h"
+#include "completion_queue.h"
 #include "call.h"
 
 namespace grpc {
 namespace node {
 
+namespace {
+
+/* A worker that asynchronously calls completion_queue_next, and queues onto the
+   node event loop a call to the function stored in the event's tag. */
+class CompletionQueueAsyncWorker : public Nan::AsyncWorker {
+ public:
+  CompletionQueueAsyncWorker();
+
+  ~CompletionQueueAsyncWorker();
+  /* Calls completion_queue_next with the provided deadline, and stores the
+     event if there was one or sets an error message if there was not */
+  void Execute();
+
+  /* Returns the completion queue attached to this class */
+  static grpc_completion_queue *GetQueue();
+
+  /* Convenience function to create a worker with the given arguments and queue
+     it to run asynchronously */
+  static void Next();
+
+  /* Initialize the CompletionQueueAsyncWorker class */
+  static void Init(v8::Local<v8::Object> exports);
+
+ protected:
+  /* Called when Execute has succeeded (completed without setting an error
+     message). Calls the saved callback with the event that came from
+     completion_queue_next */
+  void HandleOKCallback();
+
+  void HandleErrorCallback();
+
+ private:
+  grpc_event result;
+
+  static grpc_completion_queue *queue;
+
+  // Number of grpc_completion_queue_next calls in the thread pool
+  static int current_threads;
+  // Number of grpc_completion_queue_next calls waiting to enter the thread pool
+  static int waiting_next_calls;
+};
+
 const int max_queue_threads = 2;
 
 using v8::Function;
@@ -137,5 +182,21 @@ void CompletionQueueAsyncWorker::HandleErrorCallback() {
   DestroyTag(result.tag);
 }
 
+}  // namespace
+
+grpc_completion_queue *GetCompletionQueue() {
+  return CompletionQueueAsyncWorker::GetQueue();
+}
+
+void CompletionQueueNext() {
+  CompletionQueueAsyncWorker::Next();
+}
+
+void CompletionQueueInit(Local<Object> exports) {
+  CompletionQueueAsyncWorker::Init(exports);
+}
+
 }  // namespace node
 }  // namespace grpc
+
+#endif  /* GRPC_UV */

src/node/ext/completion_queue_uv.cc

@@ -31,6 +31,8 @@
  *
  */
 
+#ifdef GRPC_UV
+
 #include <uv.h>
 #include <node.h>
 #include <v8.h>
@@ -38,7 +40,6 @@
 
 #include "call.h"
 #include "completion_queue.h"
-#include "completion_queue_async_worker.h"
 
 namespace grpc {
 namespace node {
@@ -81,34 +82,24 @@ void drain_completion_queue(uv_prepare_t *handle) {
 }
 
 grpc_completion_queue *GetCompletionQueue() {
-#ifdef GRPC_UV
   return queue;
-#else
-  return CompletionQueueAsyncWorker::GetQueue();
-#endif
 }
 
 void CompletionQueueNext() {
-#ifdef GRPC_UV
   if (pending_batches == 0) {
     GPR_ASSERT(!uv_is_active((uv_handle_t *)&prepare));
     uv_prepare_start(&prepare, drain_completion_queue);
   }
   pending_batches++;
-#else
-  CompletionQueueAsyncWorker::Next();
-#endif
 }
 
 void CompletionQueueInit(Local<Object> exports) {
-#ifdef GRPC_UV
   queue = grpc_completion_queue_create(NULL);
   uv_prepare_init(uv_default_loop(), &prepare);
   pending_batches = 0;
-#else
-  CompletionQueueAsyncWorker::Init(exports);
-#endif
 }
 
 }  // namespace node
 }  // namespace grpc
+
+#endif /* GRPC_UV */