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go/src/pkg/runtime/netpoll_epoll.c
Dmitriy Vyukov 94599ea745 runtime: does not report duplicate errors in netpoll
Prevents storm of error messages if something goes wrong.
In the case of issue 5073 the epoll fd was closed by the test.
Update #5073.

R=golang-dev, r, rsc
CC=golang-dev
https://golang.org/cl/7966043
2013-03-26 20:25:43 +04:00

96 lines
2.1 KiB
C

// 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(int32 fd, PollDesc *pd)
{
EpollEvent ev;
int32 res;
ev.events = EPOLLIN|EPOLLOUT|EPOLLRDHUP|EPOLLET;
ev.data = (uint64)pd;
res = runtime·epollctl(epfd, EPOLL_CTL_ADD, fd, &ev);
return -res;
}
int32
runtime·netpollclose(int32 fd)
{
EpollEvent ev;
int32 res;
res = runtime·epollctl(epfd, EPOLL_CTL_DEL, fd, &ev);
return -res;
}
// 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;
}