runtime: break atomics out into package runtime/internal/atomic
This change breaks out most of the atomics functions in the runtime
into package runtime/internal/atomic. It adds some basic support
in the toolchain for runtime packages, and also modifies linux/arm
atomics to remove the dependency on the runtime's mutex. The mutexes
have been replaced with spinlocks.
all trybots are happy!
In addition to the trybots, I've tested on the darwin/arm64 builder,
on the darwin/arm builder, and on a ppc64le machine.
Change-Id: I6698c8e3cf3834f55ce5824059f44d00dc8e3c2f
Reviewed-on: https://go-review.googlesource.com/14204
Run-TryBot: Michael Matloob <matloob@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
diff --git a/src/runtime/stack.go b/src/runtime/stack.go
index e3087af..cce371c 100644
--- a/src/runtime/stack.go
+++ b/src/runtime/stack.go
@@ -4,7 +4,10 @@
package runtime
-import "unsafe"
+import (
+ "runtime/internal/atomic"
+ "unsafe"
+)
/*
Stack layout parameters.
@@ -806,7 +809,7 @@
// NOTE: stackguard0 may change underfoot, if another thread
// is about to try to preempt gp. Read it just once and use that same
// value now and below.
- preempt := atomicloaduintptr(&gp.stackguard0) == stackPreempt
+ preempt := atomic.Loaduintptr(&gp.stackguard0) == stackPreempt
// Be conservative about where we preempt.
// We are interested in preempting user Go code, not runtime code.
