gcc/libgo/runtime/netpoll_kqueue.c

119 lines
2.4 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 darwin dragonfly freebsd netbsd openbsd
#include "runtime.h"
#include "defs.h"
#include "malloc.h"
// Integrated network poller (kqueue-based implementation).
int32 runtime_kqueue(void);
int32 runtime_kevent(int32, Kevent*, int32, Kevent*, int32, Timespec*);
void runtime_closeonexec(int32);
static int32 kq = -1;
void
runtime_netpollinit(void)
{
kq = runtime_kqueue();
if(kq < 0) {
runtime_printf("netpollinit: kqueue failed with %d\n", -kq);
runtime_throw("netpollinit: kqueue failed");
}
runtime_closeonexec(kq);
}
int32
runtime_netpollopen(uintptr fd, PollDesc *pd)
{
Kevent ev[2];
int32 n;
// Arm both EVFILT_READ and EVFILT_WRITE in edge-triggered mode (EV_CLEAR)
// for the whole fd lifetime. The notifications are automatically unregistered
// when fd is closed.
ev[0].ident = (uint32)fd;
ev[0].filter = EVFILT_READ;
ev[0].flags = EV_ADD|EV_CLEAR;
ev[0].fflags = 0;
ev[0].data = 0;
ev[0].udata = (kevent_udata)pd;
ev[1] = ev[0];
ev[1].filter = EVFILT_WRITE;
n = runtime_kevent(kq, ev, 2, nil, 0, nil);
if(n < 0)
return -n;
return 0;
}
int32
runtime_netpollclose(uintptr fd)
{
// Don't need to unregister because calling close()
// on fd will remove any kevents that reference the descriptor.
USED(fd);
return 0;
}
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;
Kevent events[64], *ev;
Timespec ts, *tp;
int32 n, i, mode;
G *gp;
if(kq == -1)
return nil;
tp = nil;
if(!block) {
ts.tv_sec = 0;
ts.tv_nsec = 0;
tp = &ts;
}
gp = nil;
retry:
n = runtime_kevent(kq, nil, 0, events, nelem(events), tp);
if(n < 0) {
if(n != -EINTR && n != lasterr) {
lasterr = n;
runtime_printf("runtime: kevent on fd %d failed with %d\n", kq, -n);
}
goto retry;
}
for(i = 0; i < n; i++) {
ev = &events[i];
mode = 0;
if(ev->filter == EVFILT_READ)
mode += 'r';
if(ev->filter == EVFILT_WRITE)
mode += 'w';
if(mode)
runtime_netpollready(&gp, (PollDesc*)ev->udata, mode);
}
if(block && gp == nil)
goto retry;
return gp;
}
void
runtime_netpoll_scan(struct Workbuf** wbufp, void (*enqueue1)(struct Workbuf**, Obj))
{
USED(wbufp);
USED(enqueue1);
}