mirror of
https://github.com/golang/go
synced 2024-11-18 07:44:51 -07:00
a9e6cebde2
This pragma cancels the effect of go:nowritebarrierrec. This is useful in the scheduler because there are places where we enter a function without a valid P (and hence cannot have write barriers), but then obtain a P. This allows us to annotate the function with go:nowritebarrierrec and split out the part after we've obtained a P into a go:yeswritebarrierrec function. Change-Id: Ic8ce4b6d3c074a1ecd8280ad90eaf39f0ffbcc2a Reviewed-on: https://go-review.googlesource.com/30938 Reviewed-by: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Keith Randall <khr@golang.org>
79 lines
974 B
Go
79 lines
974 B
Go
// errorcheck -+
|
|
|
|
// Copyright 2016 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
// Test go:nowritebarrier and related directives.
|
|
|
|
package p
|
|
|
|
type t struct {
|
|
f *t
|
|
}
|
|
|
|
var x t
|
|
var y *t
|
|
|
|
//go:nowritebarrier
|
|
func a1() {
|
|
x.f = y // ERROR "write barrier prohibited"
|
|
a2() // no error
|
|
}
|
|
|
|
//go:noinline
|
|
func a2() {
|
|
x.f = y
|
|
}
|
|
|
|
//go:nowritebarrierrec
|
|
func b1() {
|
|
b2()
|
|
}
|
|
|
|
//go:noinline
|
|
func b2() {
|
|
x.f = y // ERROR "write barrier prohibited by caller"
|
|
}
|
|
|
|
// Test recursive cycles through nowritebarrierrec and yeswritebarrierrec.
|
|
|
|
//go:nowritebarrierrec
|
|
func c1() {
|
|
c2()
|
|
}
|
|
|
|
//go:yeswritebarrierrec
|
|
func c2() {
|
|
c3()
|
|
}
|
|
|
|
func c3() {
|
|
x.f = y
|
|
c4()
|
|
}
|
|
|
|
//go:nowritebarrierrec
|
|
func c4() {
|
|
c2()
|
|
}
|
|
|
|
//go:nowritebarrierrec
|
|
func d1() {
|
|
d2()
|
|
}
|
|
|
|
func d2() {
|
|
d3()
|
|
}
|
|
|
|
func d3() {
|
|
x.f = y // ERROR "write barrier prohibited by caller"
|
|
d4()
|
|
}
|
|
|
|
//go:yeswritebarrierrec
|
|
func d4() {
|
|
d2()
|
|
}
|