github.com/sagernet/gvisor@v0.0.0-20240428053021-e691de28565f/pkg/abi/linux/context.go (about)

     1  // Copyright 2021 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  package linux
    16  
    17  import (
    18  	"github.com/sagernet/gvisor/pkg/context"
    19  )
    20  
    21  // contextID is the linux package's type for context.Context.Value keys.
    22  type contextID int
    23  
    24  const (
    25  	// CtxSignalNoInfoFunc is a Context.Value key for a function to send signals.
    26  	CtxSignalNoInfoFunc contextID = iota
    27  )
    28  
    29  // SignalNoInfoFuncFromContext returns a callback function that can be used to send a
    30  // signal to the given context.
    31  func SignalNoInfoFuncFromContext(ctx context.Context) func(Signal) error {
    32  	if f := ctx.Value(CtxSignalNoInfoFunc); f != nil {
    33  		return f.(func(Signal) error)
    34  	}
    35  	return nil
    36  }