use ErrFlushed

internal/errors.go

@@ -196,18 +196,3 @@ func (le *VerifierError) Format(f fmt.State, verb rune) {
 		fmt.Fprintf(f, "%%!%c(BADVERB)", verb)
 	}
 }
-
-type FlushCompleteError struct {
-	Err error
-}
-
-func (fe *FlushCompleteError) Error() string {
-	if fe.Err == nil {
-		return "flush complete"
-	}
-	return fmt.Sprintf("flush complete: %s", fe.Err.Error())
-}
-
-func (fe *FlushCompleteError) Unwrap() error {
-	return fe.Err
-}

perf/reader.go

@@ -18,12 +18,11 @@ import (
 )
 
 var (
-	ErrClosed = os.ErrClosed
-	errEOR    = errors.New("end of ring")
+	ErrClosed  = os.ErrClosed
+	ErrFlushed = errors.New("end of pending data")
+	errEOR     = errors.New("end of ring")
 )
 
-type FlushCompleteError = internal.FlushCompleteError
-
 var perfEventHeaderSize = binary.Size(perfEventHeader{})
 
 // perfEventHeader must match 'struct perf_event_header` in <linux/perf_event.h>.
@@ -378,7 +377,7 @@ func (pr *Reader) ReadInto(rec *Record) error {
 			if errors.Is(err, os.ErrDeadlineExceeded) {
 				// We've hit the deadline, check whether there is any data in
 				// the rings that we've not been woken up for.
-				pr.pendingErr = &FlushCompleteError{Err: os.ErrDeadlineExceeded}
+				pr.pendingErr = err
 			} else if err != nil {
 				return err
 			}
@@ -468,9 +467,9 @@ func (pr *Reader) BufferSize() int {
 }
 
 // Flush unblocks Read/ReadInto and successive Read/ReadInto calls will return pending samples at this point,
-// until you receive a FlushCompleteError error.
+// until you receive a ErrFlushed error.
 func (pr *Reader) Flush() error {
-	pr.pendingErr = &FlushCompleteError{}
+	pr.pendingErr = ErrFlushed
 	return pr.poller.Flush()
 }
 

perf/reader_test.go

@@ -92,11 +92,10 @@ func TestReaderSetDeadlinePendingEvents(t *testing.T) {
 
 	outputSamples(t, events, 5)
 
-	// another sample should not be returned before we get FlushCompleteError to indicate initial set of samples read
-	var fe *FlushCompleteError
+	// another sample should not be returned before we get ErrFlushed to indicate initial set of samples read
 	_, err = rd.Read()
-	if !errors.As(err, &fe) {
-		t.Error("Expected FlushCompleteError from second Read, got:", err)
+	if !errors.Is(err, ErrFlushed) {
+		t.Error("Expected ErrFlushed from second Read, got:", err)
 	}
 	if !errors.Is(err, os.ErrDeadlineExceeded) {
 		t.Error("Expected os.ErrDeadlineExceeded from second Read, got:", err)
@@ -135,11 +134,10 @@ func TestReaderFlushPendingEvents(t *testing.T) {
 
 	outputSamples(t, events, 5)
 
-	// another sample should not be returned before we get FlushCompleteError to indicate initial set of samples read
-	var fe *FlushCompleteError
+	// another sample should not be returned before we get ErrFlushed to indicate initial set of samples read
 	_, err = rd.Read()
-	if !errors.As(err, &fe) {
-		t.Error("Expected FlushCompleteError from second Read, got:", err)
+	if !errors.Is(err, ErrFlushed) {
+		t.Error("Expected ErrFlushed from second Read, got:", err)
 	}
 
 	// the second sample should now be read

ringbuf/reader.go

@@ -8,19 +8,17 @@ import (
 	"time"
 
 	"github.com/cilium/ebpf"
-	"github.com/cilium/ebpf/internal"
 	"github.com/cilium/ebpf/internal/epoll"
 	"github.com/cilium/ebpf/internal/unix"
 )
 
 var (
-	ErrClosed = os.ErrClosed
-	errEOR    = errors.New("end of ring")
-	errBusy   = errors.New("sample not committed yet")
+	ErrClosed  = os.ErrClosed
+	ErrFlushed = errors.New("end of pending data")
+	errEOR     = errors.New("end of ring")
+	errBusy    = errors.New("sample not committed yet")
 )
 
-type FlushCompleteError = internal.FlushCompleteError
-
 // ringbufHeader from 'struct bpf_ringbuf_hdr' in kernel/bpf/ringbuf.c
 type ringbufHeader struct {
 	Len uint32
@@ -160,7 +158,7 @@ func (r *Reader) ReadInto(rec *Record) error {
 			if errors.Is(err, os.ErrDeadlineExceeded) {
 				// Ignoring this for reading a valid entry after timeout
 				// This can occur if the producer submitted to the ring buffer with BPF_RB_NO_WAKEUP
-				r.pendingErr = &FlushCompleteError{Err: os.ErrDeadlineExceeded}
+				r.pendingErr = err
 			} else if err != nil {
 				return err
 			}
@@ -189,8 +187,8 @@ func (r *Reader) BufferSize() int {
 }
 
 // Flush unblocks Read/ReadInto and successive Read/ReadInto calls will return pending samples at this point,
-// until you receive a FlushCompleteError error.
+// until you receive a ErrFlushed error.
 func (r *Reader) Flush() error {
-	r.pendingErr = &FlushCompleteError{}
+	r.pendingErr = ErrFlushed
 	return r.poller.Flush()
 }

ringbuf/reader_test.go

@@ -298,10 +298,9 @@ func TestReaderNoWakeup(t *testing.T) {
 		t.Errorf("Expected to read 7 bytes but got %d", len(record.RawSample))
 	}
 
-	var fe *FlushCompleteError
 	_, err = rd.Read()
-	if !errors.As(err, &fe) {
-		t.Errorf("Expected FlushCompleteError from third Read but got %v", err)
+	if !errors.Is(err, ErrFlushed) {
+		t.Errorf("Expected ErrFlushed from third Read but got %v", err)
 	}
 	if !errors.Is(err, os.ErrDeadlineExceeded) {
 		t.Errorf("Expected os.ErrDeadlineExceeded from third Read but got %v", err)
@@ -362,10 +361,9 @@ func TestReaderFlushPendingEvents(t *testing.T) {
 		t.Errorf("Expected to read 7 bytes but got %d", len(record.RawSample))
 	}
 
-	var fe *FlushCompleteError
 	_, err = rd.Read()
-	if !errors.As(err, &fe) {
-		t.Errorf("Expected FlushCompleteError from third Read but got %v", err)
+	if !errors.Is(err, ErrFlushed) {
+		t.Errorf("Expected ErrFlushed from third Read but got %v", err)
 	}
 }