github.com/ttpreport/gvisor-ligolo@v0.0.0-20240123134145-a858404967ba/pkg/sentry/kernel/time/context.go (about)

     1  // Copyright 2018 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 time
    16  
    17  import (
    18  	"github.com/ttpreport/gvisor-ligolo/pkg/context"
    19  )
    20  
    21  // contextID is the time package's type for context.Context.Value keys.
    22  type contextID int
    23  
    24  const (
    25  	// CtxRealtimeClock is a Context.Value key for the current real time.
    26  	CtxRealtimeClock contextID = iota
    27  )
    28  
    29  // RealtimeClockFromContext returns the real time clock associated with context
    30  // ctx.
    31  func RealtimeClockFromContext(ctx context.Context) Clock {
    32  	if v := ctx.Value(CtxRealtimeClock); v != nil {
    33  		return v.(Clock)
    34  	}
    35  	return nil
    36  }
    37  
    38  // NowFromContext returns the current real time associated with context ctx.
    39  func NowFromContext(ctx context.Context) Time {
    40  	if clk := RealtimeClockFromContext(ctx); clk != nil {
    41  		return clk.Now()
    42  	}
    43  	panic("encountered context without RealtimeClock")
    44  }