provide option (not exposed currently) to turn off mysql query queuing

lib/dialects/mysql/connector-manager.js

@@ -14,6 +14,8 @@ module.exports = (function() {
     this.activeQueue = []
     this.maxConcurrentQueries = (this.config.maxConcurrentQueries || 50)
     this.poolCfg = this.config.pool
+    this.pendingQueries = 0;
+    this.useQueue = false;
 
     var self = this
 
@@ -47,41 +49,69 @@ module.exports = (function() {
     })
   }
 
-  Utils._.extend(ConnectorManager.prototype, require("../connector-manager").prototype)
+  Utils._.extend(ConnectorManager.prototype, require("../connector-manager").prototype);
 
-  var isConnecting = false
+  var isConnecting = false;
 
   ConnectorManager.prototype.query = function(sql, callee, options) {
-    if(!this.isConnected && !this.pool) this.connect()
+    if (!this.isConnected && !this.pool) this.connect();
 
+    if (this.useQueue) {
       var queueItem = {
         query: new Query(this.client, this.sequelize, callee, options || {}),
         sql: sql
+      };
+
+      enqueue.call(this, queueItem);
+      return queueItem.query;
     }
 
-    enqueue.call(this, queueItem)
+    var self = this, query = new Query(this.client, this.sequelize, callee, options || {});
+    this.pendingQueries++;
+
+    query.done(function() {
+      self.pendingQueries--;
+      if (self.pool) self.pool.release(query.client);
+      else {
+        if (self.pendingQueries === 0) {
+          setTimeout(function() {
+            self.pendingQueries === 0 && self.disconnect.call(self);
+          }, 1);
+        }
+      }
+    });
+
+    if (!this.pool) query.run(sql);
+    else {
+      this.pool.acquire(function(err, client) {
+        if (err) return query.emit('error', err);
 
-    return queueItem.query
+        query.client = client;
+        query.run(sql);
+        return;
+      });
     }
 
+    return query;
+  };
+
   ConnectorManager.prototype.connect = function() {
-    var self = this
+    var self = this;
     // in case database is slow to connect, prevent orphaning the client
     if (this.isConnecting || this.pool) {
-      return
+      return;
     }
     connect.call(self, function(err, client) {
-      self.client = client
-      return
-    })
-    return
-  }
+      self.client = client;
+      return;
+    });
+    return;
+  };
 
   ConnectorManager.prototype.disconnect = function() {
-    if (this.client)
-      disconnect.call(this, this.client)
-    return
-  }
+    if (this.client) disconnect.call(this, this.client);
+    return;
+  };
 
 
   // private