1 files changed, 101 insertions, 0 deletions
diff --git a/src/runtime/netpoll_kqueue.go b/src/runtime/netpoll_kqueue.go
new file mode 100644
index 000000000..d6d55b97b
--- /dev/null
+++ b/src/runtime/netpoll_kqueue.go
@@ -0,0 +1,101 @@
+// 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
+
+package runtime
+
+// Integrated network poller (kqueue-based implementation).
+
+import "unsafe"
+
+func kqueue() int32
+
+//go:noescape
+func kevent(kq int32, ch *keventt, nch int32, ev *keventt, nev int32, ts *timespec) int32
+func closeonexec(fd int32)
+
+var (
+	kq             int32 = -1
+	netpolllasterr int32
+)
+
+func netpollinit() {
+	kq = kqueue()
+	if kq < 0 {
+		println("netpollinit: kqueue failed with", -kq)
+		gothrow("netpollinit: kqueue failed")
+	}
+	closeonexec(kq)
+}
+
+func netpollopen(fd uintptr, pd *pollDesc) int32 {
+	// 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.
+	var ev [2]keventt
+	*(*uintptr)(unsafe.Pointer(&ev[0].ident)) = fd
+	ev[0].filter = _EVFILT_READ
+	ev[0].flags = _EV_ADD | _EV_CLEAR
+	ev[0].fflags = 0
+	ev[0].data = 0
+	ev[0].udata = (*byte)(unsafe.Pointer(pd))
+	ev[1] = ev[0]
+	ev[1].filter = _EVFILT_WRITE
+	n := kevent(kq, &ev[0], 2, nil, 0, nil)
+	if n < 0 {
+		return -n
+	}
+	return 0
+}
+
+func netpollclose(fd uintptr) int32 {
+	// Don't need to unregister because calling close()
+	// on fd will remove any kevents that reference the descriptor.
+	return 0
+}
+
+func netpollarm(pd *pollDesc, mode int) {
+	gothrow("unused")
+}
+
+// Polls for ready network connections.
+// Returns list of goroutines that become runnable.
+func netpoll(block bool) (gp *g) {
+	if kq == -1 {
+		return
+	}
+	var tp *timespec
+	var ts timespec
+	if !block {
+		tp = &ts
+	}
+	var events [64]keventt
+retry:
+	n := kevent(kq, nil, 0, &events[0], int32(len(events)), tp)
+	if n < 0 {
+		if n != -_EINTR && n != netpolllasterr {
+			netpolllasterr = n
+			println("runtime: kevent on fd", kq, "failed with", -n)
+		}
+		goto retry
+	}
+	for i := 0; i < int(n); i++ {
+		ev := &events[i]
+		var mode int32
+		if ev.filter == _EVFILT_READ {
+			mode += 'r'
+		}
+		if ev.filter == _EVFILT_WRITE {
+			mode += 'w'
+		}
+		if mode != 0 {
+			netpollready((**g)(noescape(unsafe.Pointer(&gp))), (*pollDesc)(unsafe.Pointer(ev.udata)), mode)
+		}
+	}
+	if block && gp == nil {
+		goto retry
+	}
+	return gp
+}