Initial commit: Go 1.23 release state

test/fixedbugs/issue13160.go

@@ -0,0 +1,70 @@
+// run
+
+// Copyright 2015 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.
+
+package main
+
+import (
+	"fmt"
+	"runtime"
+)
+
+const N = 100000
+
+func main() {
+	// Allocate more Ps than processors.  This raises
+	// the chance that we get interrupted by the OS
+	// in exactly the right (wrong!) place.
+	p := runtime.NumCPU()
+	runtime.GOMAXPROCS(2 * p)
+
+	// Allocate some pointers.
+	ptrs := make([]*int, p)
+	for i := 0; i < p; i++ {
+		ptrs[i] = new(int)
+	}
+
+	// Arena where we read and write pointers like crazy.
+	collider := make([]*int, p)
+
+	done := make(chan struct{}, 2*p)
+
+	// Start writers.  They alternately write a pointer
+	// and nil to a slot in the collider.
+	for i := 0; i < p; i++ {
+		i := i
+		go func() {
+			for j := 0; j < N; j++ {
+				// Write a pointer using memmove.
+				copy(collider[i:i+1], ptrs[i:i+1])
+				// Write nil using memclr.
+				// (This is a magic loop that gets lowered to memclr.)
+				r := collider[i : i+1]
+				for k := range r {
+					r[k] = nil
+				}
+			}
+			done <- struct{}{}
+		}()
+	}
+	// Start readers.  They read pointers from slots
+	// and make sure they are valid.
+	for i := 0; i < p; i++ {
+		i := i
+		go func() {
+			for j := 0; j < N; j++ {
+				var ptr [1]*int
+				copy(ptr[:], collider[i:i+1])
+				if ptr[0] != nil && ptr[0] != ptrs[i] {
+					panic(fmt.Sprintf("bad pointer read %p!", ptr[0]))
+				}
+			}
+			done <- struct{}{}
+		}()
+	}
+	for i := 0; i < 2*p; i++ {
+		<-done
+	}
+}