application

Documentation

Overview

An application is a sort of root for a supervision tree. It's primary function is to call a context.CancelFunc when the children crashes exceed the restart intensity.

While it does wrap a [supervisor], it is intentially not configurable. The idea is that that's a domain specific problem that should be handled in your app.

For most apps, something like this should be in your [main]:

package main

import (
	"context"

	"github.com/uberbrodt/erl-go/erl"
	"github.com/uberbrodt/erl-go/erl/application"
	"github.com/uberbrodt/erl-go/erl/supervisor"

)

var App *application.App

func init() {
	// set to true to get a lot of logs
	erl.SetDebugLog(false)
}

type MyApp struct{}

 // Pass in config via the args parameter
func (ba *MyApp) Start(self erl.PID, args any) (erl.PID, error) {

 // start children based on config
	children := []supervisor.ChildSpec{ }
	return supervisor.StartDefaultLink(self, children, supervisor.NewSupFlags())
}

// do any cleanup here. should run unless there's a fatal error in the runtime.
func (ba *MyApp) Stop() error {
	return nil
}

func main() {
	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGINT, syscall.SIGTERM)
	defer cancel()

	 // parse flags, load a real config here.
	 conf := make(map[string]any)
	 App := application.Start(&MyApp{}, conf, cancel)

	<-ctx.Done()
	if !app.App.Stopped() {
		app.App.Stop()
	}

}

Index

• type App
  • func Start(app Application, args any, cancel context.CancelFunc) *App
  • func (ap *App) Receive(self erl.PID, inbox <-chan any) error
  • func (ap *App) Stop() error
  • func (ap *App) Stopped() bool
• type Application

Types

type App

type App struct {
	// contains filtered or unexported fields
}

func Start

func Start(app Application, args any, cancel context.CancelFunc) *App

Starts a process with the Application callback. This is the root of an app, and can be used to start supervisors of worker processes.

func (*App) Receive

func (ap *App) Receive(self erl.PID, inbox <-chan any) error

func (*App) Stop

func (ap *App) Stop() error

stops the app, sending exitreason.SupervisorShutdown to itself to all its children, calls the Application.Stop() method on the app.

func (*App) Stopped

func (ap *App) Stopped() bool

type Application

type Application interface {
	Start(self erl.PID, args any) (erl.PID, error)
	Stop() error
}