containerd/linux/shim/service_linux.go
Stephen J Day cd72819b53
archive, cio, cmd, linux: use buffer pools
To avoid buffer bloat in long running processes, we try to use buffer
pools where possible. This is meant to address shim memory usage issues,
but may not be the root cause.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2018-01-22 13:52:06 -08:00

96 lines
2.0 KiB
Go

package shim
import (
"context"
"io"
"sync"
"syscall"
"github.com/containerd/console"
"github.com/containerd/fifo"
"github.com/pkg/errors"
)
type linuxPlatform struct {
epoller *console.Epoller
}
func (p *linuxPlatform) CopyConsole(ctx context.Context, console console.Console, stdin, stdout, stderr string, wg, cwg *sync.WaitGroup) (console.Console, error) {
if p.epoller == nil {
return nil, errors.New("uninitialized epoller")
}
epollConsole, err := p.epoller.Add(console)
if err != nil {
return nil, err
}
if stdin != "" {
in, err := fifo.OpenFifo(ctx, stdin, syscall.O_RDONLY, 0)
if err != nil {
return nil, err
}
cwg.Add(1)
go func() {
cwg.Done()
p := bufPool.Get().(*[]byte)
defer bufPool.Put(p)
io.CopyBuffer(epollConsole, in, *p)
}()
}
outw, err := fifo.OpenFifo(ctx, stdout, syscall.O_WRONLY, 0)
if err != nil {
return nil, err
}
outr, err := fifo.OpenFifo(ctx, stdout, syscall.O_RDONLY, 0)
if err != nil {
return nil, err
}
wg.Add(1)
cwg.Add(1)
go func() {
cwg.Done()
p := bufPool.Get().(*[]byte)
defer bufPool.Put(p)
io.CopyBuffer(outw, epollConsole, *p)
epollConsole.Close()
outr.Close()
outw.Close()
wg.Done()
}()
return epollConsole, nil
}
func (p *linuxPlatform) ShutdownConsole(ctx context.Context, cons console.Console) error {
if p.epoller == nil {
return errors.New("uninitialized epoller")
}
epollConsole, ok := cons.(*console.EpollConsole)
if !ok {
return errors.Errorf("expected EpollConsole, got %#v", cons)
}
return epollConsole.Shutdown(p.epoller.CloseConsole)
}
func (p *linuxPlatform) Close() error {
return p.epoller.Close()
}
// initialize a single epoll fd to manage our consoles. `initPlatform` should
// only be called once.
func (s *Service) initPlatform() error {
if s.platform != nil {
return nil
}
epoller, err := console.NewEpoller()
if err != nil {
return errors.Wrap(err, "failed to initialize epoller")
}
s.platform = &linuxPlatform{
epoller: epoller,
}
go epoller.Wait()
return nil
}