pidfd

type Epoller ¶

type Epoller struct {
	// contains filtered or unexported fields
}

Epoller is used to monitor PID file descriptors.

When the process that PID file descriptor refers to terminates, these interfaces indicate the file descriptor as readable. Then Epoller will close the PID file descriptor and call the callback.

func NewEpoller() (*Epoller, error)

func (e *Epoller) Add(fd FD, onClose func() error) error

func (e *Epoller) Close() error

func (e *Epoller) Run() error

type FD ¶

type FD int

func Open(pid uint32, flags int) (FD, error)

func (fd FD) GetFd(targetFD int, flags int) (int, error)

func (fd FD) SendSignal(signal unix.Signal, flags int) error

func (fd FD) Waitid(info *Siginfo, options int, rusage *Rusage) error

type Rusage ¶

type Rusage = unix.Rusage

type Siginfo ¶

type Siginfo struct {
	Signo int32
	Errno int32
	Code  int32

	Pid uint32
	// contains filtered or unexported fields
}

Siginfo extends the unix.Siginfo with Pid, which used to check the process state.

From https://man7.org/linux/man-pages/man2/waitid.2.html:

If WNOHANG was specified in options and there were no children in a waitable state, then waitid() returns 0 immediately and the state of the siginfo_t structure pointed to by infop depends on the implementation. To (portably) distinguish this case from that where a child was in a waitable state, zero out the si_pid field before the call and check for a nonzero value in this field after the call returns.