WIP

internal/epoll/poller.go

@@ -1,11 +1,13 @@
 package epoll
 
 import (
+	"errors"
 	"fmt"
 	"math"
 	"os"
 	"runtime"
 	"sync"
+	"time"
 
 	"github.com/cilium/ebpf/internal"
 	"github.com/cilium/ebpf/internal/unix"
@@ -119,7 +121,7 @@ func (p *Poller) Add(fd int, id int) error {
 //
 // Returns the number of pending events or an error wrapping os.ErrClosed if
 // Close is called.
-func (p *Poller) Wait(events []unix.EpollEvent, msec int) (int, error) {
+func (p *Poller) Wait(events []unix.EpollEvent, deadline time.Time) (int, error) {
 	p.epollMu.Lock()
 	defer p.epollMu.Unlock()
 
@@ -128,7 +130,15 @@ func (p *Poller) Wait(events []unix.EpollEvent, msec int) (int, error) {
 	}
 
 	for {
+		msec := int(-1)
+		if !deadline.IsZero() {
+			msec = int(time.Until(deadline).Milliseconds())
+		}
+
 		n, err := unix.EpollWait(p.epollFd, events, msec)
+		if errors.Is(err, unix.EINTR) {
+			return 0, os.ErrDeadlineExceeded
+		}
 		if temp, ok := err.(temporaryError); ok && temp.Temporary() {
 			// Retry the syscall if we were interrupted, see https://github.com/golang/go/issues/20400
 			continue

perf/reader.go

@@ -267,35 +267,26 @@ func (pr *Reader) Close() error {
 //
 // Calling Close interrupts the function.
 func (pr *Reader) Read() (Record, error) {
-	return pr.read(-1)
+	return pr.read(time.Time{})
 }
 
-// ReadTimeout is Read but will time out and return os.ErrDeadlineExceeded
+// ReadDeadline is Read but will time out and return os.ErrDeadlineExceeded
 // if the timeout expires.
-func (pr *Reader) ReadTimeout(timeout time.Duration) (Record, error) {
-	if timeout > 0 && timeout < time.Millisecond {
-		return Record{}, fmt.Errorf("non-zero timeout too small")
-	}
-
-	return pr.read(timeout)
+func (pr *Reader) ReadDeadline(deadline time.Time) (Record, error) {
+	return pr.read(deadline)
 }
 
-func (pr *Reader) read(timeout time.Duration) (Record, error) {
+func (pr *Reader) read(deadline time.Time) (Record, error) {
 	pr.mu.Lock()
 	defer pr.mu.Unlock()
 
 	if pr.rings == nil {
 		return Record{}, fmt.Errorf("perf ringbuffer: %w", ErrClosed)
 	}
 
-	msec := int(timeout.Milliseconds())
-	if timeout == -1 {
-		msec = -1
-	}
-
 	for {
 		if len(pr.epollRings) == 0 {
-			nEvents, err := pr.poller.Wait(pr.epollEvents, msec)
+			nEvents, err := pr.poller.Wait(pr.epollEvents, deadline)
 			if err != nil {
 				return Record{}, err
 			}