1 // Copyright 2013 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // +build darwin dragonfly freebsd netbsd openbsd 6 7 package runtime 8 9 // Integrated network poller (kqueue-based implementation). 10 11 import "unsafe" 12 13 func kqueue() int32 14 15 //go:noescape 16 func kevent(kq int32, ch *keventt, nch int32, ev *keventt, nev int32, ts *timespec) int32 17 func closeonexec(fd int32) 18 19 var ( 20 kq int32 = -1 21 netpolllasterr int32 22 ) 23 24 func netpollinit() { 25 kq = kqueue() 26 if kq < 0 { 27 println("netpollinit: kqueue failed with", -kq) 28 throw("netpollinit: kqueue failed") 29 } 30 closeonexec(kq) 31 } 32 33 func netpollopen(fd uintptr, pd *pollDesc) int32 { 34 // Arm both EVFILT_READ and EVFILT_WRITE in edge-triggered mode (EV_CLEAR) 35 // for the whole fd lifetime. The notifications are automatically unregistered 36 // when fd is closed. 37 var ev [2]keventt 38 *(*uintptr)(unsafe.Pointer(&ev[0].ident)) = fd 39 ev[0].filter = _EVFILT_READ 40 ev[0].flags = _EV_ADD | _EV_CLEAR 41 ev[0].fflags = 0 42 ev[0].data = 0 43 ev[0].udata = (*byte)(unsafe.Pointer(pd)) 44 ev[1] = ev[0] 45 ev[1].filter = _EVFILT_WRITE 46 n := kevent(kq, &ev[0], 2, nil, 0, nil) 47 if n < 0 { 48 return -n 49 } 50 return 0 51 } 52 53 func netpollclose(fd uintptr) int32 { 54 // Don't need to unregister because calling close() 55 // on fd will remove any kevents that reference the descriptor. 56 return 0 57 } 58 59 func netpollarm(pd *pollDesc, mode int) { 60 throw("unused") 61 } 62 63 // Polls for ready network connections. 64 // Returns list of goroutines that become runnable. 65 func netpoll(block bool) *g { 66 if kq == -1 { 67 return nil 68 } 69 var tp *timespec 70 var ts timespec 71 if !block { 72 tp = &ts 73 } 74 var events [64]keventt 75 retry: 76 n := kevent(kq, nil, 0, &events[0], int32(len(events)), tp) 77 if n < 0 { 78 if n != -_EINTR && n != netpolllasterr { 79 netpolllasterr = n 80 println("runtime: kevent on fd", kq, "failed with", -n) 81 } 82 goto retry 83 } 84 var gp guintptr 85 for i := 0; i < int(n); i++ { 86 ev := &events[i] 87 var mode int32 88 if ev.filter == _EVFILT_READ { 89 mode += 'r' 90 } 91 if ev.filter == _EVFILT_WRITE { 92 mode += 'w' 93 } 94 if mode != 0 { 95 netpollready(&gp, (*pollDesc)(unsafe.Pointer(ev.udata)), mode) 96 } 97 } 98 if block && gp == 0 { 99 goto retry 100 } 101 return gp.ptr() 102 } 103
