github.com/varialus/godfly@v0.0.0-20130904042352-1934f9f095ab/src/pkg/runtime/netpoll_kqueue.c (about) 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 #include "runtime.h" 8 #include "defs_GOOS_GOARCH.h" 9 #include "os_GOOS.h" 10 11 // Integrated network poller (kqueue-based implementation). 12 13 int32 runtime·kqueue(void); 14 int32 runtime·kevent(int32, Kevent*, int32, Kevent*, int32, Timespec*); 15 void runtime·closeonexec(int32); 16 17 static int32 kq = -1; 18 19 void 20 runtime·netpollinit(void) 21 { 22 kq = runtime·kqueue(); 23 if(kq < 0) { 24 runtime·printf("netpollinit: kqueue failed with %d\n", -kq); 25 runtime·throw("netpollinit: kqueue failed"); 26 } 27 runtime·closeonexec(kq); 28 } 29 30 int32 31 runtime·netpollopen(uintptr fd, PollDesc *pd) 32 { 33 Kevent ev[2]; 34 int32 n; 35 36 // Arm both EVFILT_READ and EVFILT_WRITE in edge-triggered mode (EV_CLEAR) 37 // for the whole fd lifetime. The notifications are automatically unregistered 38 // when fd is closed. 39 ev[0].ident = (uint32)fd; 40 ev[0].filter = EVFILT_READ; 41 ev[0].flags = EV_ADD|EV_CLEAR; 42 ev[0].fflags = 0; 43 ev[0].data = 0; 44 ev[0].udata = (kevent_udata)pd; 45 ev[1] = ev[0]; 46 ev[1].filter = EVFILT_WRITE; 47 n = runtime·kevent(kq, ev, 2, nil, 0, nil); 48 if(n < 0) 49 return -n; 50 return 0; 51 } 52 53 int32 54 runtime·netpollclose(uintptr fd) 55 { 56 // Don't need to unregister because calling close() 57 // on fd will remove any kevents that reference the descriptor. 58 USED(fd); 59 return 0; 60 } 61 62 // Polls for ready network connections. 63 // Returns list of goroutines that become runnable. 64 G* 65 runtime·netpoll(bool block) 66 { 67 static int32 lasterr; 68 Kevent events[64], *ev; 69 Timespec ts, *tp; 70 int32 n, i, mode; 71 G *gp; 72 73 if(kq == -1) 74 return nil; 75 tp = nil; 76 if(!block) { 77 ts.tv_sec = 0; 78 ts.tv_nsec = 0; 79 tp = &ts; 80 } 81 gp = nil; 82 retry: 83 n = runtime·kevent(kq, nil, 0, events, nelem(events), tp); 84 if(n < 0) { 85 if(n != -EINTR && n != lasterr) { 86 lasterr = n; 87 runtime·printf("runtime: kevent on fd %d failed with %d\n", kq, -n); 88 } 89 goto retry; 90 } 91 for(i = 0; i < n; i++) { 92 ev = &events[i]; 93 mode = 0; 94 if(ev->filter == EVFILT_READ) 95 mode += 'r'; 96 if(ev->filter == EVFILT_WRITE) 97 mode += 'w'; 98 if(mode) 99 runtime·netpollready(&gp, (PollDesc*)ev->udata, mode); 100 } 101 if(block && gp == nil) 102 goto retry; 103 return gp; 104 }