runtime: add a note on SetFinalizer doc about method receiver

A method receiver can be collected during the execution of that method.
This does make sense when thinking about how the GC would work, but
also seems not very obvious, so a point in the docs can increase the
chance of avoiding issues caused by missing KeepAlive of method
receivers.

Change-Id: I6817237dd022b5729dbdcda1b9f70c7059605575
GitHub-Last-Rev: 878bf3fde7
GitHub-Pull-Request: golang/go#67777
Reviewed-on: https://go-review.googlesource.com/c/go/+/589735
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
This commit is contained in:
Anuraag Agrawal 2024-06-06 04:24:26 +00:00 committed by Gopher Robot
parent cf501e05e1
commit f7c330eac7

View file

@ -377,9 +377,11 @@ func blockUntilEmptyFinalizerQueue(timeout int64) bool {
// In order to use finalizers correctly, the program must ensure that
// the object is reachable until it is no longer required.
// Objects stored in global variables, or that can be found by tracing
// pointers from a global variable, are reachable. For other objects,
// pass the object to a call of the [KeepAlive] function to mark the
// last point in the function where the object must be reachable.
// pointers from a global variable, are reachable. A function argument or
// receiver may become unreachable at the last point where the function
// mentions it. To make an unreachable object reachable, pass the object
// to a call of the [KeepAlive] function to mark the last point in the
// function where the object must be reachable.
//
// For example, if p points to a struct, such as os.File, that contains
// a file descriptor d, and p has a finalizer that closes that file