Fix memory leak on Linux/Darwin platforms

lib/bindings/darwin.js

@@ -47,6 +47,7 @@ class DarwinBinding extends BaseBinding {
       .then(() => {
         const fd = this.fd;
         this.poller.stop();
+        this.poller.destroy();
         this.poller = null;
         this.openOptions = null;
         this.fd = null;

lib/bindings/linux.js

@@ -47,6 +47,7 @@ class LinuxBinding extends BaseBinding {
       .then(() => {
         const fd = this.fd;
         this.poller.stop();
+        this.poller.destroy();
         this.poller = null;
         this.openOptions = null;
         this.fd = null;

lib/bindings/poller.js

@@ -89,6 +89,16 @@ class Poller extends EventEmitter {
   stop() {
     logger('Stopping poller');
     this.poller.stop();
+    this.emitCanceled();
+  }
+
+  destroy() {
+    logger('Destroying poller');
+    this.poller.destroy();
+    this.emitCanceled();
+  }
+
+  emitCanceled() {
     const err = new Error('Canceled');
     err.canceled = true;
     this.emit('readable', err);

src/poller.cpp

@@ -76,6 +76,7 @@ NAN_MODULE_INIT(Poller::Init) {
 
   Nan::SetPrototypeMethod(tpl, "poll", poll);
   Nan::SetPrototypeMethod(tpl, "stop", stop);
+  Nan::SetPrototypeMethod(tpl, "destroy", destroy);
 
   constructor().Reset(Nan::GetFunction(tpl).ToLocalChecked());
   Nan::Set(target, Nan::New("Poller").ToLocalChecked(), Nan::GetFunction(tpl).ToLocalChecked());
@@ -122,6 +123,12 @@ NAN_METHOD(Poller::stop) {
   obj->stop();
 }
 
+NAN_METHOD(Poller::destroy) {
+  Poller* obj = Nan::ObjectWrap::Unwrap<Poller>(info.Holder());
+  obj->persistent().Reset();
+  delete obj;
+}
+
 inline Nan::Persistent<v8::Function> & Poller::constructor() {
   static Nan::Persistent<v8::Function> my_constructor;
   return my_constructor;

src/poller.h

@@ -26,6 +26,7 @@ class Poller : public Nan::ObjectWrap {
   static NAN_METHOD(New);
   static NAN_METHOD(poll);
   static NAN_METHOD(stop);
+  static NAN_METHOD(destroy);
   static inline Nan::Persistent<v8::Function> & constructor();
 };