Files
cabletest/tx.go
T

71 lines
1.5 KiB
Go

package main
import (
"sync/atomic"
"golang.org/x/sys/unix"
)
type txStats struct {
frames atomic.Uint64
bytes atomic.Uint64
errs atomic.Uint64
_ [40]byte
}
type txWorker struct {
fd int
stream uint16
spec *frameSpec
batch int
stats *txStats
startTx <-chan struct{}
}
func (w *txWorker) run(done *atomic.Bool) {
// The batch is not a multiple of the pattern count, so the pairing of pattern
// to size rotates every pass rather than settling into a fixed one.
bufs := make([][]byte, w.batch)
pats := make([]int, w.batch)
for i := range bufs {
bufs[i] = make([]byte, w.spec.maxSize)
pats[i] = i % len(patterns)
w.spec.prefill(bufs[i], pats[i])
}
hdrs, iovs := newMmsghdrs(bufs)
sizes := make([]int, w.batch)
<-w.startTx
var seq uint64
si := 0
for !done.Load() {
for i := 0; i < w.batch; i++ {
size := w.spec.sizes[si]
si++
if si == len(w.spec.sizes) {
si = 0
}
sizes[i] = size
putHeader(bufs[i], pats[i], w.stream, seq+uint64(i), size-minFrame)
iovs[i].Len = uint64(size)
}
n, err := sendmmsg(w.fd, hdrs)
if n > 0 {
var b uint64
for i := 0; i < n; i++ {
b += uint64(sizes[i])
}
w.stats.frames.Add(uint64(n))
w.stats.bytes.Add(b)
seq += uint64(n)
}
// Taking fewer of the vector than offered is the ring's room, not a frame
// lost: the rest go on the next pass.
if n < 0 && err != unix.EINTR && err != unix.EAGAIN && err != unix.ENOBUFS {
w.stats.errs.Add(1)
}
}
}