Revert "ConnPool check fd for bad conns (#1824)" (#1849)

This reverts commit 346bfafddd.

internal/pool/main_test.go

@@ -2,12 +2,9 @@ package pool_test
 
 import (
 	"context"
-	"fmt"
 	"net"
 	"sync"
-	"syscall"
 	"testing"
-	"time"
 
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
@@ -35,87 +32,5 @@ func perform(n int, cbs ...func(int)) {
 }
 
 func dummyDialer(context.Context) (net.Conn, error) {
-	// return &net.TCPConn{}, nil
-	return newDummyConn(), nil
-}
-
-func newDummyConn() net.Conn {
-	return &dummyConn{
-		rawConn: &dummyRawConn{},
-	}
-}
-
-var _ net.Conn = (*dummyConn)(nil)
-var _ syscall.Conn = (*dummyConn)(nil)
-
-type dummyConn struct {
-	rawConn *dummyRawConn
-}
-
-func (d *dummyConn) SyscallConn() (syscall.RawConn, error) {
-	return d.rawConn, nil
-}
-
-var errDummy = fmt.Errorf("dummyConn err")
-
-func (d *dummyConn) Read(b []byte) (n int, err error) {
-	return 0, errDummy
-}
-
-func (d *dummyConn) Write(b []byte) (n int, err error) {
-	return 0, errDummy
-}
-
-func (d *dummyConn) Close() error {
-	d.rawConn.Close()
-	return nil
-}
-
-func (d *dummyConn) LocalAddr() net.Addr {
-	return &net.TCPAddr{}
-}
-
-func (d *dummyConn) RemoteAddr() net.Addr {
-	return &net.TCPAddr{}
-}
-
-func (d *dummyConn) SetDeadline(t time.Time) error {
-	return nil
-}
-
-func (d *dummyConn) SetReadDeadline(t time.Time) error {
-	return nil
-}
-
-func (d *dummyConn) SetWriteDeadline(t time.Time) error {
-	return nil
-}
-
-var _ syscall.RawConn = (*dummyRawConn)(nil)
-
-type dummyRawConn struct {
-	closed bool
-	mux    sync.Mutex
-}
-
-func (d *dummyRawConn) Control(f func(fd uintptr)) error {
-	return nil
-}
-
-func (d *dummyRawConn) Read(f func(fd uintptr) (done bool)) error {
-	d.mux.Lock()
-	defer d.mux.Unlock()
-	if d.closed {
-		return fmt.Errorf("dummyRawConn closed")
-	}
-	return nil
-}
-
-func (d *dummyRawConn) Write(f func(fd uintptr) (done bool)) error {
-	return nil
-}
-func (d *dummyRawConn) Close() {
-	d.mux.Lock()
-	d.closed = true
-	d.mux.Unlock()
+	return &net.TCPConn{}, nil
 }