github.com/vpnishe/netstack@v1.10.6/sleep/commit_arm64.s (about)

     1  // Copyright 2019 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  #include "textflag.h"
    16  
    17  #define preparingG 1
    18  
    19  // See commit_noasm.go for a description of commitSleep.
    20  //
    21  // func commitSleep(g uintptr, waitingG *uintptr) bool
    22  TEXT ·commitSleep(SB),NOSPLIT,$0-24
    23  	MOVD waitingG+8(FP), R0
    24  	MOVD $preparingG, R1
    25  	MOVD G+0(FP), R2
    26  
    27  	// Store the G in waitingG if it's still preparingG. If it's anything
    28  	// else it means a waker has aborted the sleep.
    29  again:
    30          LDAXR   (R0), R3
    31          CMP     R1, R3
    32          BNE     ok
    33          STLXR   R2, (R0), R3
    34          CBNZ    R3, again
    35  ok:
    36          CSET    EQ, R0
    37          MOVB    R0, ret+16(FP)
    38          RET