| // 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 |
| |
| #include "runtime.h" |
| #include "defs_GOOS_GOARCH.h" |
| |
| int32 runtime·epollcreate(int32 size); |
| int32 runtime·epollcreate1(int32 flags); |
| int32 runtime·epollctl(int32 epfd, int32 op, int32 fd, EpollEvent *ev); |
| int32 runtime·epollwait(int32 epfd, EpollEvent *ev, int32 nev, int32 timeout); |
| void runtime·closeonexec(int32 fd); |
| |
| static int32 epfd = -1; // epoll descriptor |
| |
| void |
| runtime·netpollinit(void) |
| { |
| epfd = runtime·epollcreate1(EPOLL_CLOEXEC); |
| if(epfd >= 0) |
| return; |
| epfd = runtime·epollcreate(1024); |
| if(epfd >= 0) { |
| runtime·closeonexec(epfd); |
| return; |
| } |
| runtime·printf("netpollinit: failed to create descriptor (%d)\n", -epfd); |
| runtime·throw("netpollinit: failed to create descriptor"); |
| } |
| |
| int32 |
| runtime·netpollopen(uintptr fd, PollDesc *pd) |
| { |
| EpollEvent ev; |
| int32 res; |
| |
| ev.events = EPOLLIN|EPOLLOUT|EPOLLRDHUP|EPOLLET; |
| ev.data = (uint64)pd; |
| res = runtime·epollctl(epfd, EPOLL_CTL_ADD, (int32)fd, &ev); |
| return -res; |
| } |
| |
| int32 |
| runtime·netpollclose(uintptr fd) |
| { |
| EpollEvent ev; |
| int32 res; |
| |
| res = runtime·epollctl(epfd, EPOLL_CTL_DEL, (int32)fd, &ev); |
| return -res; |
| } |
| |
| void |
| runtime·netpollarm(PollDesc* pd, int32 mode) |
| { |
| USED(pd, mode); |
| runtime·throw("unused"); |
| } |
| |
| // polls for ready network connections |
| // returns list of goroutines that become runnable |
| G* |
| runtime·netpoll(bool block) |
| { |
| static int32 lasterr; |
| EpollEvent events[128], *ev; |
| int32 n, i, waitms, mode; |
| G *gp; |
| |
| if(epfd == -1) |
| return nil; |
| waitms = -1; |
| if(!block) |
| waitms = 0; |
| retry: |
| n = runtime·epollwait(epfd, events, nelem(events), waitms); |
| if(n < 0) { |
| if(n != -EINTR && n != lasterr) { |
| lasterr = n; |
| runtime·printf("runtime: epollwait on fd %d failed with %d\n", epfd, -n); |
| } |
| goto retry; |
| } |
| gp = nil; |
| for(i = 0; i < n; i++) { |
| ev = &events[i]; |
| if(ev->events == 0) |
| continue; |
| mode = 0; |
| if(ev->events & (EPOLLIN|EPOLLRDHUP|EPOLLHUP|EPOLLERR)) |
| mode += 'r'; |
| if(ev->events & (EPOLLOUT|EPOLLHUP|EPOLLERR)) |
| mode += 'w'; |
| if(mode) |
| runtime·netpollready(&gp, (void*)ev->data, mode); |
| } |
| if(block && gp == nil) |
| goto retry; |
| return gp; |
| } |