From 9fedc481ea09a0539cd2669312429ef5416a8949 Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Mon, 17 Oct 2022 15:33:29 -0400 Subject: runtime/internal/atomic: add write barrier-enabled pointer atomics UnsafePointer.Store, UnsafePointer.CompareAndSwap were missing, although .StoreNoWB and .CompareAndSwapNoWB existed. Same for Pointer[T}. Do the linkname tricks necessary to add those methods. Change-Id: I925ee27673288accb15ebe93898f9eb01ab46a98 Reviewed-on: https://go-review.googlesource.com/c/go/+/443379 Auto-Submit: Russ Cox Reviewed-by: Austin Clements Run-TryBot: Russ Cox TryBot-Result: Gopher Robot --- src/runtime/atomic_pointer.go | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'src/runtime/atomic_pointer.go') diff --git a/src/runtime/atomic_pointer.go b/src/runtime/atomic_pointer.go index b8f0c22c63..25e0e651b4 100644 --- a/src/runtime/atomic_pointer.go +++ b/src/runtime/atomic_pointer.go @@ -35,6 +35,27 @@ func atomicstorep(ptr unsafe.Pointer, new unsafe.Pointer) { atomic.StorepNoWB(noescape(ptr), new) } +// atomic_storePointer is the implementation of runtime/internal/UnsafePointer.Store +// (like StoreNoWB but with the write barrier). +// +//go:nosplit +//go:linkname atomic_storePointer runtime/internal/atomic.storePointer +func atomic_storePointer(ptr *unsafe.Pointer, new unsafe.Pointer) { + atomicstorep(unsafe.Pointer(ptr), new) +} + +// atomic_casPointer is the implementation of runtime/internal/UnsafePointer.CompareAndSwap +// (like CompareAndSwapNoWB but with the write barrier). +// +//go:nosplit +//go:linkname atomic_casPointer runtime/internal/atomic.casPointer +func atomic_casPointer(ptr *unsafe.Pointer, old, new unsafe.Pointer) bool { + if writeBarrier.enabled { + atomicwb(ptr, new) + } + return atomic.Casp1(ptr, old, new) +} + // Like above, but implement in terms of sync/atomic's uintptr operations. // We cannot just call the runtime routines, because the race detector expects // to be able to intercept the sync/atomic forms but not the runtime forms. -- cgit v1.3