/
epoll.go
98 lines (90 loc) · 1.92 KB
/
epoll.go
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// +build linux
package aio
// #include <errno.h>
// #include <fcntl.h>
// #include <sys/epoll.h>
import "C"
import (
"syscall"
"time"
"unsafe"
)
type poller int
func newPoller() (poller, error) {
fd, err := C.epoll_create1(C.O_CLOEXEC)
if err != nil {
return 0, err
}
return poller(fd), nil
}
func (p poller) Add(fd int, flags Flags) error {
var ev C.struct_epoll_event
if flags&In != 0 {
ev.events |= C.EPOLLIN
}
if flags&Out != 0 {
ev.events |= C.EPOLLOUT
}
if flags&OneShot != 0 {
ev.events |= C.EPOLLONESHOT
}
var dataFd = (*C.int)(unsafe.Pointer(&ev.data))
*dataFd = C.int(fd)
ok, err := C.epoll_ctl(C.int(p), C.EPOLL_CTL_ADD, C.int(fd), &ev)
if ok < 0 && err != nil {
if err == syscall.EEXIST {
// Try MOD
ok, err = C.epoll_ctl(C.int(p), C.EPOLL_CTL_MOD, C.int(fd), &ev)
}
}
if ok >= 0 {
err = nil
}
return err
}
func (p poller) Delete(fd int) error {
var ev C.struct_epoll_event
// event must be non-NULL in kernels < 2.6.9
ok, err := C.epoll_ctl(C.int(p), C.EPOLL_CTL_DEL, C.int(fd), &ev)
if ok < 0 {
return err
}
return nil
}
func (p poller) Wait(duration time.Duration) ([]event, error) {
const maxEvents = 64
inEvents := make([]C.struct_epoll_event, maxEvents)
var timeout C.int
if duration < 0 {
timeout = -1
} else {
timeout = C.int(duration / time.Millisecond)
}
n, err := C.epoll_wait(C.int(p), (*C.struct_epoll_event)(unsafe.Pointer(&inEvents[0])), maxEvents, timeout)
if err != nil {
if err == syscall.EINTR {
err = nil
}
return nil, err
}
events := make([]event, int(n))
for ii := 0; ii < int(n); ii++ {
inEvent := inEvents[ii]
var flags Flags
if inEvent.events&C.EPOLLIN != 0 {
flags |= In
}
if inEvent.events&C.EPOLLOUT != 0 {
flags |= Out
}
if inEvent.events&C.EPOLLONESHOT != 0 {
flags |= OneShot
}
fd := (*C.int)(unsafe.Pointer(&inEvent.data))
events[ii] = event{
fd: int(*fd),
flags: flags,
}
}
return events, nil
}