121 lines
2.4 KiB
Go
121 lines
2.4 KiB
Go
// Copyright 2013 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// +build linux
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package runtime
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import "unsafe"
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//extern epoll_create
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func epollcreate(size int32) int32
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//extern epoll_create1
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func epollcreate1(flags int32) int32
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//go:noescape
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//extern epoll_ctl
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func epollctl(epfd, op, fd int32, ev *epollevent) int32
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//go:noescape
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//extern epoll_wait
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func epollwait(epfd int32, ev *epollevent, nev, timeout int32) int32
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//extern __go_fcntl_uintptr
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func fcntlUintptr(fd, cmd, arg uintptr) (uintptr, uintptr)
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func closeonexec(fd int32) {
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fcntlUintptr(uintptr(fd), _F_SETFD, _FD_CLOEXEC)
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}
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var (
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epfd int32 = -1 // epoll descriptor
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)
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func netpollinit() {
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epfd = epollcreate1(_EPOLL_CLOEXEC)
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if epfd >= 0 {
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return
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}
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epfd = epollcreate(1024)
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if epfd >= 0 {
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closeonexec(epfd)
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return
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}
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println("netpollinit: failed to create epoll descriptor", errno())
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throw("netpollinit: failed to create descriptor")
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}
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func netpolldescriptor() uintptr {
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return uintptr(epfd)
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}
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func netpollopen(fd uintptr, pd *pollDesc) int32 {
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var ev epollevent
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ev.events = _EPOLLIN | _EPOLLOUT | _EPOLLRDHUP | _EPOLLETpos
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*(**pollDesc)(unsafe.Pointer(&ev.data)) = pd
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if epollctl(epfd, _EPOLL_CTL_ADD, int32(fd), &ev) < 0 {
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return int32(errno())
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}
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return 0
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}
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func netpollclose(fd uintptr) int32 {
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var ev epollevent
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if epollctl(epfd, _EPOLL_CTL_DEL, int32(fd), &ev) < 0 {
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return int32(errno())
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}
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return 0
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}
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func netpollarm(pd *pollDesc, mode int) {
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throw("runtime: unused")
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}
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// polls for ready network connections
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// returns list of goroutines that become runnable
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func netpoll(block bool) *g {
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if epfd == -1 {
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return nil
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}
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waitms := int32(-1)
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if !block {
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waitms = 0
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}
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var events [128]epollevent
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retry:
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n := epollwait(epfd, &events[0], int32(len(events)), waitms)
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if n < 0 {
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e := errno()
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if e != _EINTR {
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println("runtime: epollwait on fd", epfd, "failed with", e)
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throw("runtime: netpoll failed")
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}
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goto retry
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}
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var gp guintptr
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for i := int32(0); i < n; i++ {
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ev := &events[i]
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if ev.events == 0 {
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continue
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}
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var mode int32
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if ev.events&(_EPOLLIN|_EPOLLRDHUP|_EPOLLHUP|_EPOLLERR) != 0 {
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mode += 'r'
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}
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if ev.events&(_EPOLLOUT|_EPOLLHUP|_EPOLLERR) != 0 {
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mode += 'w'
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}
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if mode != 0 {
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pd := *(**pollDesc)(unsafe.Pointer(&ev.data))
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netpollready(&gp, pd, mode)
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}
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}
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if block && gp == 0 {
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goto retry
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}
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return gp.ptr()
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}
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