How to initializes the components in source code

[shenjing023]

I want to study the source code of Weaver. When using weaver multi deploy, it calls the function startMain to initialize the components.

func (d *deployer) startMain() error {
	return d.activateComponent(&protos.ActivateComponentRequest{
		Component: runtime.Main,
	})
}

However, I couldn't find the code that actually initializes the components, something like this:

for _,v:=range d.groups{
   d.ActivateComponent()
}

I would like to know where the code that initializes the components is called.

[rgrandl]

The main component is usually started by the deployer. However,the activations of all the other components are done by the weavelets.

E.g.,

// Implementation of the main component. Has references to `Component1` and `Component2`.
type main struct {
  weaver.Implements[weaver.Main]
  c1 weaver.Ref[Component1]
  c2 weaver.Ref[Component2]

...

// Implementation of the `Component1`. Has references to `Component1` and `Component2`.
type component1Impl struct {
  weaver.Implements[Component1]
  c3 weaver.Ref[Component3]
}

The callgraph is as follows:

main ---> Component 1 ---> Component 3
        |
        ---> Component2

The multi deployer will start component main which under the hood will run 2 weavelets that will run main. When a main weavelet starts, it will activate components that he has references to; in this case main will activate component Component1 and Component2.

Once weavelets for Component1 are started, the weavelets for Component1 will activate Component3.

Other deployers work in a similar way.

[rgrandl]

Feel free to reopen if you have more questions.