Fix transaction memory leak issue

lib/dialects/connector-manager.js

@@ -24,5 +24,11 @@ module.exports = (function(){
     this.connect()
   }
 
+  ConnectorManager.prototype.cleanup = function() {
+    if (this.onProcessExit) {
+      process.removeListener('exit', this.onProcessExit)
+    }
+  }
+
   return ConnectorManager
 })()

lib/dialects/mariadb/connector-manager.js

@@ -142,7 +142,7 @@ module.exports = (function() {
       })
     }
 
-    process.on('exit', function () {
+    this.onProcessExit = function () {
       //be nice & close our connections on exit
       if (self.pool) {
         self.pool.drain()
@@ -151,7 +151,9 @@ module.exports = (function() {
       }
 
       return
-    })
+    }.bind(this);
+    
+    process.on('exit', this.onProcessExit)
   }
 
   Utils._.extend(ConnectorManager.prototype, require("../connector-manager").prototype)

lib/dialects/mysql/connector-manager.js

@@ -143,7 +143,7 @@ module.exports = (function() {
       })
     }
 
-    process.on('exit', function () {
+    this.onProcessExit = function () {
       //be nice & close our connections on exit
       if (self.pool) {
         self.pool.drain()
@@ -152,7 +152,9 @@ module.exports = (function() {
       }
 
       return
-    })
+    }.bind(this);
+    
+    process.on('exit', this.onProcessExit)
   }
 
   Utils._.extend(ConnectorManager.prototype, require("../connector-manager").prototype);

lib/dialects/postgres/connector-manager.js

@@ -30,9 +30,11 @@ module.exports = (function() {
     this.clientDrained = true
     this.maxConcurrentQueries = (this.config.maxConcurrentQueries || 50)
 
-    process.on('exit', function() {
+    this.onProcessExit = function () {
       this.disconnect()
-    }.bind(this))
+    }.bind(this);
+    
+    process.on('exit', this.onProcessExit)
   }
   Utils._.extend(ConnectorManager.prototype, require("../connector-manager").prototype)
 

lib/transaction-manager.js

@@ -35,6 +35,11 @@ TransactionManager.prototype.getConnectorManager = function(uuid) {
   return this.connectorManagers[uuid]
 }
 
+TransactionManager.prototype.releaseConnectionManager = function(uuid) {
+  this.connectorManagers[uuid].cleanup();
+  delete this.connectorManagers[uuid]
+}
+
 TransactionManager.prototype.query = function(sql, callee, options) {
   options      = options || {}
   options.uuid = 'default'

lib/transaction.js

@@ -25,6 +25,7 @@ Transaction.prototype.commit = function() {
     .getQueryInterface()
     .commitTransaction(this, {})
     .proxy(this)
+    .done(this.cleanup.bind(this))
 }
 
 
@@ -34,6 +35,7 @@ Transaction.prototype.rollback = function() {
     .getQueryInterface()
     .rollbackTransaction(this, {})
     .proxy(this)
+    .done(this.cleanup.bind(this))
 }
 
 Transaction.prototype.prepareEnvironment = function(callback) {
@@ -76,6 +78,10 @@ Transaction.prototype.setIsolationLevel = function(callback) {
     .error(onError.bind(this))
 }
 
+Transaction.prototype.cleanup = function() {
+  this.sequelize.transactionManager.releaseConnectionManager(this.id)
+}
+
 // private
 
 var onError = function(err) {