gvisor.dev/gvisor@v0.0.0-20240520182842-f9d4d51c7e0f/pkg/atomicbitops/atomicbitops_arm64.go (about)

     1  // Copyright 2022 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  //go:build arm64
    16  // +build arm64
    17  
    18  package atomicbitops
    19  
    20  import (
    21  	"runtime"
    22  
    23  	"golang.org/x/sys/cpu"
    24  	"gvisor.dev/gvisor/pkg/cpuid"
    25  )
    26  
    27  var arm64HasATOMICS bool
    28  
    29  func init() {
    30  	// The gvisor cpuid package only works on Linux.
    31  	// For all other operating systems, use Go's x/sys/cpu package
    32  	// to get the one bit we care about here.
    33  	//
    34  	// See https://github.com/google/gvisor/issues/7849.
    35  	if runtime.GOOS == "linux" {
    36  		arm64HasATOMICS = cpuid.HostFeatureSet().HasFeature(cpuid.ARM64FeatureATOMICS)
    37  	} else {
    38  		arm64HasATOMICS = cpu.ARM64.HasATOMICS
    39  	}
    40  }