Files
cabletest/ts_test.go
T

100 lines
2.7 KiB
Go

package main
import (
"testing"
"unsafe"
"golang.org/x/sys/unix"
)
func putCmsg(buf []byte, off int, level, typ int32, dataLen int) int {
h := (*unix.Cmsghdr)(unsafe.Pointer(&buf[off]))
h.SetLen(unix.CmsgLen(dataLen))
h.Level = level
h.Type = typ
return off + unix.CmsgSpace(dataLen)
}
func putStamp(buf []byte, off int, raw unix.Timespec) int {
next := putCmsg(buf, off, unix.SOL_SOCKET, unix.SCM_TIMESTAMPING, scmTimestampingLen)
ts := (*[3]unix.Timespec)(unsafe.Pointer(&buf[off+cmsgDataOff]))
ts[2] = raw
return next
}
func TestHwTimestampReadsRawHardwareClock(t *testing.T) {
buf := make([]byte, cmsgLen)
n := putStamp(buf, 0, unix.Timespec{Sec: 5, Nsec: 7})
got, ok := hwTimestamp(buf[:n])
if !ok || got != 5e9+7 {
t.Errorf("hwTimestamp = %d, %v; want 5000000007, true", got, ok)
}
}
func TestHwTimestampSkipsOtherMessages(t *testing.T) {
buf := make([]byte, cmsgLen)
off := putCmsg(buf, 0, unix.SOL_SOCKET, unix.SCM_RIGHTS, 4)
n := putStamp(buf, off, unix.Timespec{Sec: 1, Nsec: 2})
got, ok := hwTimestamp(buf[:n])
if !ok || got != 1e9+2 {
t.Errorf("hwTimestamp = %d, %v; want 1000000002, true", got, ok)
}
}
func TestHwTimestampRejectsZeroStamp(t *testing.T) {
buf := make([]byte, cmsgLen)
n := putStamp(buf, 0, unix.Timespec{})
if got, ok := hwTimestamp(buf[:n]); ok {
t.Errorf("hwTimestamp = %d, %v; want a zero stamp refused", got, ok)
}
}
func TestHwTimestampWithoutAStamp(t *testing.T) {
buf := make([]byte, cmsgLen)
n := putCmsg(buf, 0, unix.SOL_SOCKET, unix.SCM_RIGHTS, 4)
if _, ok := hwTimestamp(buf[:n]); ok {
t.Error("a buffer carrying no timestamp yielded one")
}
if _, ok := hwTimestamp(nil); ok {
t.Error("an empty buffer yielded a timestamp")
}
}
func TestHwTimestampRefusesBadLengths(t *testing.T) {
buf := make([]byte, cmsgLen)
n := putStamp(buf, 0, unix.Timespec{Sec: 1})
if _, ok := hwTimestamp(buf[:n-1]); ok {
t.Error("a message running past the buffer yielded a timestamp")
}
short := make([]byte, cmsgLen)
putCmsg(short, 0, unix.SOL_SOCKET, unix.SCM_TIMESTAMPING, scmTimestampingLen)
(*unix.Cmsghdr)(unsafe.Pointer(&short[0])).SetLen(unix.SizeofCmsghdr - 1)
if _, ok := hwTimestamp(short); ok {
t.Error("a message shorter than its own header yielded a timestamp")
}
trunc := make([]byte, cmsgLen)
tn := putCmsg(trunc, 0, unix.SOL_SOCKET, unix.SCM_TIMESTAMPING, scmTimestampingLen/3)
if _, ok := hwTimestamp(trunc[:tn]); ok {
t.Error("a truncated stamp yielded a timestamp")
}
}
func BenchmarkHwTimestamp(b *testing.B) {
buf := make([]byte, cmsgLen)
n := putStamp(buf, 0, unix.Timespec{Sec: 5, Nsec: 7})
oob := buf[:n]
b.ReportAllocs()
for b.Loop() {
if _, ok := hwTimestamp(oob); !ok {
b.Fatal("no timestamp")
}
}
}