github.com/jlmucb/cloudproxy@v0.0.0-20170830161738-b5aa0b619bc4/go/apps/roughtime/agl_roughtime/monotime/monotime.go (about)

     1  // Copyright 2016 The Roughtime 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 monotime provides access to the system's monotonic clock.
    16  package monotime
    17  
    18  import (
    19  	"unsafe"
    20  	"time"
    21  )
    22  
    23  var _ = unsafe.Sizeof(0)
    24  
    25  //go:noescape
    26  //go:linkname nanotime runtime.nanotime
    27  func nanotime() int64
    28  
    29  // Now returns the monotonic duration since an unspecified epoch.
    30  func Now() time.Duration {
    31  	return time.Duration(nanotime()) * time.Nanosecond
    32  }