github.com/google/netstack@v0.0.0-20191123085552-55fcc16cd0eb/tcpip/time_unsafe.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  // +build go1.9
    16  // +build !go1.15
    17  
    18  // Check go:linkname function signatures when updating Go version.
    19  
    20  package tcpip
    21  
    22  import (
    23  	_ "time"   // Used with go:linkname.
    24  	_ "unsafe" // Required for go:linkname.
    25  )
    26  
    27  // StdClock implements Clock with the time package.
    28  type StdClock struct{}
    29  
    30  var _ Clock = (*StdClock)(nil)
    31  
    32  //go:linkname now time.now
    33  func now() (sec int64, nsec int32, mono int64)
    34  
    35  // NowNanoseconds implements Clock.NowNanoseconds.
    36  func (*StdClock) NowNanoseconds() int64 {
    37  	sec, nsec, _ := now()
    38  	return sec*1e9 + int64(nsec)
    39  }
    40  
    41  // NowMonotonic implements Clock.NowMonotonic.
    42  func (*StdClock) NowMonotonic() int64 {
    43  	_, _, mono := now()
    44  	return mono
    45  }