// Copyright 2013 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. // +build linux package runtime import "unsafe" func epollcreate(size int32) int32 func epollcreate1(flags int32) int32 //go:noescape func epollctl(epfd, op, fd int32, ev *epollevent) int32 //go:noescape func epollwait(epfd int32, ev *epollevent, nev, timeout int32) int32 func closeonexec(fd int32) var ( epfd int32 = -1 // epoll descriptor netpolllasterr int32 ) func netpollinit() { epfd = epollcreate1(_EPOLL_CLOEXEC) if epfd >= 0 { return } epfd = epollcreate(1024) if epfd >= 0 { closeonexec(epfd) return } println("netpollinit: failed to create epoll descriptor", -epfd) throw("netpollinit: failed to create descriptor") } func netpollopen(fd uintptr, pd *pollDesc) int32 { var ev epollevent ev.events = _EPOLLIN | _EPOLLOUT | _EPOLLRDHUP | _EPOLLET *(**pollDesc)(unsafe.Pointer(&ev.data)) = pd return -epollctl(epfd, _EPOLL_CTL_ADD, int32(fd), &ev) } func netpollclose(fd uintptr) int32 { var ev epollevent return -epollctl(epfd, _EPOLL_CTL_DEL, int32(fd), &ev) } func netpollarm(pd *pollDesc, mode int) { throw("unused") } // polls for ready network connections // returns list of goroutines that become runnable func netpoll(block bool) *g { if epfd == -1 { return nil } waitms := int32(-1) if !block { waitms = 0 } var events [128]epollevent retry: n := epollwait(epfd, &events[0], int32(len(events)), waitms) if n < 0 { if n != -_EINTR && n != netpolllasterr { netpolllasterr = n println("runtime: epollwait on fd", epfd, "failed with", -n) } goto retry } var gp guintptr for i := int32(0); i < n; i++ { ev := &events[i] if ev.events == 0 { continue } var mode int32 if ev.events&(_EPOLLIN|_EPOLLRDHUP|_EPOLLHUP|_EPOLLERR) != 0 { mode += 'r' } if ev.events&(_EPOLLOUT|_EPOLLHUP|_EPOLLERR) != 0 { mode += 'w' } if mode != 0 { pd := *(**pollDesc)(unsafe.Pointer(&ev.data)) netpollready(&gp, pd, mode) } } if block && gp == 0 { goto retry } return gp.ptr() }