2019-04-29 21:25:05 +00:00
|
|
|
// Copyright 2018 The gVisor Authors.
|
2018-04-27 17:37:02 +00:00
|
|
|
//
|
|
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
|
|
// you may not use this file except in compliance with the License.
|
|
|
|
// You may obtain a copy of the License at
|
|
|
|
//
|
|
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
//
|
|
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
|
|
// See the License for the specific language governing permissions and
|
|
|
|
// limitations under the License.
|
|
|
|
|
|
|
|
package time
|
|
|
|
|
|
|
|
import (
|
|
|
|
"syscall"
|
|
|
|
"unsafe"
|
|
|
|
)
|
|
|
|
|
|
|
|
// syscallTSCReferenceClocks is the standard referenceClocks, collecting
|
|
|
|
// samples using CLOCK_GETTIME and RDTSC.
|
|
|
|
type syscallTSCReferenceClocks struct {
|
|
|
|
tscCycleClock
|
|
|
|
}
|
|
|
|
|
|
|
|
// Sample implements sampler.Sample.
|
|
|
|
func (syscallTSCReferenceClocks) Sample(c ClockID) (sample, error) {
|
|
|
|
var s sample
|
|
|
|
|
|
|
|
s.before = Rdtsc()
|
|
|
|
|
|
|
|
// Don't call clockGettime to avoid a call which may call morestack.
|
|
|
|
var ts syscall.Timespec
|
|
|
|
_, _, e := syscall.RawSyscall(syscall.SYS_CLOCK_GETTIME, uintptr(c), uintptr(unsafe.Pointer(&ts)), 0)
|
|
|
|
if e != 0 {
|
|
|
|
return sample{}, e
|
|
|
|
}
|
|
|
|
|
|
|
|
s.after = Rdtsc()
|
|
|
|
s.ref = ReferenceNS(ts.Nano())
|
|
|
|
|
|
|
|
return s, nil
|
|
|
|
}
|
|
|
|
|
|
|
|
// clockGettime calls SYS_CLOCK_GETTIME, returning time in nanoseconds.
|
|
|
|
func clockGettime(c ClockID) (ReferenceNS, error) {
|
|
|
|
var ts syscall.Timespec
|
|
|
|
_, _, e := syscall.RawSyscall(syscall.SYS_CLOCK_GETTIME, uintptr(c), uintptr(unsafe.Pointer(&ts)), 0)
|
|
|
|
if e != 0 {
|
|
|
|
return 0, e
|
|
|
|
}
|
|
|
|
|
|
|
|
return ReferenceNS(ts.Nano()), nil
|
|
|
|
}
|