I'm not 100% sure what you mean by "copy made atomically" means in this context. But if you mean is calling a value receiver method safe for concurrently, then the answer is no.
In fact it can be the source of subtle races. Take for example this simple program (https://play.golang.org/p/Wk5LHxEJ8dQ): package main import "fmt" type Split struct { MutValue uint64 CostValue uint64 } func (s Split) GetConstValue() uint64 { return s.CostValue } var Sum uint64 func main() { theOne := Split{7, 3} fmt.Print("Start ") go func() { for { theOne.MutValue += 1 } }() for { Sum += theOne.GetConstValue() } } If you run this with the race detector on, you will see that there is a race between " theOne.MutValue += 1" and "Sum += theOne.GetConstValue()". At first glance it might seem like this should be ok, since the body of GetConstValue() only reads a non-changing variable, and does not touch MutValue . But in fact calling the function does a copy, and so also reads "MutValue", which is being concurrently modified, hence the race. If GetConstValue() is changed to take a pointer receiver, then the race goes away. On Tuesday, June 8, 2021 at 6:08:56 AM UTC-4 Ian Davis wrote: > This question came to me while reading the recent thread titled "Knowing > from documentation whether an interface is holding a pointer or a struct?" > > When a method with a non-pointer receiver is called, is the copy made > atomically? My intuition says it must be but perhaps someone else can > confirm it? > > If so, how does it work? > > Ian > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/a2ebc1d7-0a3e-4a70-a4a0-ab88fd675d34n%40googlegroups.com.
