1 files changed, 32 insertions, 0 deletions
diff --git a/pkg/syncevent/waiter_amd64.s b/pkg/syncevent/waiter_amd64.s
new file mode 100644
index 000000000..5e216b045
--- /dev/null
+++ b/pkg/syncevent/waiter_amd64.s
@@ -0,0 +1,32 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "textflag.h"
+
+// See waiter_noasm_unsafe.go for a description of waiterUnlock.
+//
+// func waiterUnlock(ptr unsafe.Pointer, wg *unsafe.Pointer) bool
+TEXT ·waiterUnlock(SB),NOSPLIT,$0-24
+	MOVQ ptr+0(FP), DI
+	MOVQ wg+8(FP), SI
+
+	MOVQ $·preparingG(SB), AX
+	LOCK
+	CMPXCHGQ DI, 0(SI)
+
+	SETEQ AX
+	MOVB AX, ret+16(FP)
+
+	RET
+