1 files changed, 67 insertions, 0 deletions
diff --git a/libgo/go/runtime/internal/atomic/atomic_test.go b/libgo/go/runtime/internal/atomic/atomic_test.go
new file mode 100644
index 00000000000..d5dc552b952
--- /dev/null
+++ b/libgo/go/runtime/internal/atomic/atomic_test.go
@@ -0,0 +1,67 @@
+// 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 atomic_test
+
+import (
+	"runtime"
+	"runtime/internal/atomic"
+	"testing"
+	"unsafe"
+)
+
+func runParallel(N, iter int, f func()) {
+	defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(int(N)))
+	done := make(chan bool)
+	for i := 0; i < N; i++ {
+		go func() {
+			for j := 0; j < iter; j++ {
+				f()
+			}
+			done <- true
+		}()
+	}
+	for i := 0; i < N; i++ {
+		<-done
+	}
+}
+
+func TestXadduintptr(t *testing.T) {
+	const N = 20
+	const iter = 100000
+	inc := uintptr(100)
+	total := uintptr(0)
+	runParallel(N, iter, func() {
+		atomic.Xadduintptr(&total, inc)
+	})
+	if want := uintptr(N * iter * inc); want != total {
+		t.Fatalf("xadduintpr error, want %d, got %d", want, total)
+	}
+	total = 0
+	runParallel(N, iter, func() {
+		atomic.Xadduintptr(&total, inc)
+		atomic.Xadduintptr(&total, uintptr(-int64(inc)))
+	})
+	if total != 0 {
+		t.Fatalf("xadduintpr total error, want %d, got %d", 0, total)
+	}
+}
+
+// Tests that xadduintptr correctly updates 64-bit values. The place where
+// we actually do so is mstats.go, functions mSysStat{Inc,Dec}.
+func TestXadduintptrOnUint64(t *testing.T) {
+	/*	if runtime.BigEndian != 0 {
+		// On big endian architectures, we never use xadduintptr to update
+		// 64-bit values and hence we skip the test.  (Note that functions
+		// mSysStat{Inc,Dec} in mstats.go have explicit checks for
+		// big-endianness.)
+		return
+	}*/
+	const inc = 100
+	val := uint64(0)
+	atomic.Xadduintptr((*uintptr)(unsafe.Pointer(&val)), inc)
+	if inc != val {
+		t.Fatalf("xadduintptr should increase lower-order bits, want %d, got %d", inc, val)
+	}
+}