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// 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
#include "runtime.h"
#include "defs_GOOS_GOARCH.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(int32 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 = fd;
ev[0].filter = EVFILT_READ;
ev[0].flags = EV_ADD|EV_RECEIPT|EV_CLEAR;
ev[0].fflags = 0;
ev[0].data = 0;
ev[0].udata = (byte*)pd;
ev[1] = ev[0];
ev[1].filter = EVFILT_WRITE;
n = runtime_kevent(kq, ev, 2, ev, 2, nil);
if(n < 0)
return -n;
if(n != 2 ||
(ev[0].flags&EV_ERROR) == 0 || ev[0].ident != fd || ev[0].filter != EVFILT_READ ||
(ev[1].flags&EV_ERROR) == 0 || ev[1].ident != fd || ev[1].filter != EVFILT_WRITE)
return EFAULT; // just to mark out from other errors
if(ev[0].data != 0)
return ev[0].data;
if(ev[1].data != 0)
return ev[1].data;
return 0;
}
int32
runtime_netpollclose(int32 fd)
{
// Don't need to unregister because calling close()
// on fd will remove any kevents that reference the descriptor.
USED(fd);
return 0;
}
// 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;
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];
if(ev->filter == EVFILT_READ)
runtime_netpollready(&gp, (PollDesc*)ev->udata, 'r');
if(ev->filter == EVFILT_WRITE)
runtime_netpollready(&gp, (PollDesc*)ev->udata, 'w');
}
if(block && gp == nil)
goto retry;
return gp;
}
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