process: remove spinner

Remove the need to call start/stop the uv_idle spinner between
MakeCallbacks. The one place where the tick processor needs to be kicked
is where a user catches uncaughtException. For that we'll now use
setImmediate, which accomplishes the same task.

src/node.cc

@@ -140,8 +140,6 @@ bool using_domains = false;
 bool no_deprecation = false;
 
 static uv_idle_t tick_spinner;
-static bool need_tick_cb;
-static Persistent<String> tick_callback_sym;
 
 static uv_check_t check_immediate_watcher;
 static uv_idle_t idle_immediate_dummy;
@@ -177,45 +175,6 @@ static uv_async_t emit_debug_enabled_async;
 Isolate* node_isolate = NULL;
 
 
-static void Spin(uv_idle_t* handle, int status) {
-  assert(handle == &tick_spinner);
-  assert(status == 0);
-
-  // Avoid entering a V8 scope.
-  if (!need_tick_cb) return;
-  need_tick_cb = false;
-
-  uv_idle_stop(&tick_spinner);
-
-  HandleScope scope(node_isolate);
-
-  if (process_tickFromSpinner.IsEmpty()) {
-    Local<Value> cb_v = process->Get(String::New("_tickFromSpinner"));
-    if (!cb_v->IsFunction()) {
-      fprintf(stderr, "process._tickFromSpinner assigned to non-function\n");
-      abort();
-    }
-    Local<Function> cb = cb_v.As<Function>();
-    process_tickFromSpinner = Persistent<Function>::New(node_isolate, cb);
-  }
-
-  TryCatch try_catch;
-
-  process_tickFromSpinner->Call(process, 0, NULL);
-
-  if (try_catch.HasCaught()) {
-    FatalException(try_catch);
-  }
-}
-
-
-static Handle<Value> NeedTickCallback(const Arguments& args) {
-  need_tick_cb = true;
-  uv_idle_start(&tick_spinner, Spin);
-  return Undefined(node_isolate);
-}
-
-
 static void CheckImmediate(uv_check_t* handle, int status) {
   assert(handle == &check_immediate_watcher);
   assert(status == 0);
@@ -2378,7 +2337,6 @@ Handle<Object> SetupProcessObject(int argc, char *argv[]) {
   // define various internal methods
   NODE_SET_METHOD(process, "_getActiveRequests", GetActiveRequests);
   NODE_SET_METHOD(process, "_getActiveHandles", GetActiveHandles);
-  NODE_SET_METHOD(process, "_needTickCallback", NeedTickCallback);
   NODE_SET_METHOD(process, "reallyExit", Exit);
   NODE_SET_METHOD(process, "abort", Abort);
   NODE_SET_METHOD(process, "chdir", Chdir);

src/node.js

@@ -285,7 +285,7 @@
       }
       // if we handled an error, then make sure any ticks get processed
       if (caught)
-        process._needTickCallback();
+        setImmediate(process._tickCallback);
       return caught;
     };
   };
@@ -316,7 +316,6 @@
   };
 
   startup.processNextTick = function() {
-    var _needTickCallback = process._needTickCallback;
     var lastThrew = false;
     var nextTickQueue = [];
     var needSpinner = true;
@@ -336,7 +335,6 @@
     process._nextDomainTick = _nextDomainTick;
     process._tickCallback = _tickCallback;
     process._tickDomainCallback = _tickDomainCallback;
-    process._tickFromSpinner = _tickFromSpinner;
 
     function tickDone() {
       if (infoBox[length] !== 0) {
@@ -348,23 +346,10 @@
           infoBox[length] = nextTickQueue.length;
         }
       }
-      if (needSpinner) {
-        _needTickCallback();
-        needSpinner = false;
-      }
       inTick = false;
       infoBox[index] = 0;
     }
 
-    function _tickFromSpinner() {
-      needSpinner = true;
-      // no callbacks to run
-      if (infoBox[length] === 0)
-        infoBox[index] = 0;
-      else
-        process._tickCallback();
-    }
-
     // run callbacks that have no domain
     // using domains will cause this to be overridden
     function _tickCallback() {
@@ -396,7 +381,7 @@
 
       if (lastThrew) {
         lastThrew = false;
-        return _needTickCallback();
+        return;
       }
 
       if (inTick) return;