// Copyright 2018 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"

#define preparingG 1

// See commit_noasm.go for a description of commitSleep.
//
// func commitSleep(g uintptr, waitingG *uintptr) bool
TEXT ·commitSleep(SB),NOSPLIT,$0-24
	MOVQ waitingG+8(FP), CX
	MOVQ g+0(FP), DX

	// Store the G in waitingG if it's still preparingG. If it's anything
	// else it means a waker has aborted the sleep.
	MOVQ $preparingG, AX
	LOCK
	CMPXCHGQ DX, 0(CX)

	SETEQ AX
	MOVB AX, ret+16(FP)

	RET