Initial commit: Go 1.23 release state

src/runtime/netpoll_kqueue_event.go

@@ -0,0 +1,80 @@
+// Copyright 2024 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.
+
+//go:build darwin || dragonfly || freebsd
+
+package runtime
+
+// Magic number of identifier used for EVFILT_USER.
+// This number had zero Google results when it's created.
+// That way, people will be directed here when this number
+// get printed somehow and they search for it.
+const kqIdent = 0xee1eb9f4
+
+func addWakeupEvent(kq int32) {
+	ev := keventt{
+		ident:  kqIdent,
+		filter: _EVFILT_USER,
+		flags:  _EV_ADD,
+	}
+	for {
+		n := kevent(kq, &ev, 1, nil, 0, nil)
+		if n == 0 {
+			break
+		}
+		if n == -_EINTR {
+			// All changes contained in the changelist should have been applied
+			// before returning EINTR. But let's be skeptical and retry it anyway,
+			// to make a 100% commitment.
+			continue
+		}
+		println("runtime: kevent for EVFILT_USER failed with", -n)
+		throw("runtime: kevent failed")
+	}
+}
+
+func wakeNetpoll(kq int32) {
+	ev := keventt{
+		ident:  kqIdent,
+		filter: _EVFILT_USER,
+		flags:  _EV_ENABLE,
+		fflags: _NOTE_TRIGGER,
+	}
+	for {
+		n := kevent(kq, &ev, 1, nil, 0, nil)
+		if n == 0 {
+			break
+		}
+		if n == -_EINTR {
+			// Check out the comment in addWakeupEvent.
+			continue
+		}
+		println("runtime: netpollBreak write failed with", -n)
+		throw("runtime: netpollBreak write failed")
+	}
+}
+
+func isWakeup(ev *keventt) bool {
+	if ev.filter == _EVFILT_USER {
+		if ev.ident == kqIdent {
+			return true
+		}
+		println("runtime: netpoll: break fd ready for", ev.ident)
+		throw("runtime: netpoll: break fd ready for something unexpected")
+	}
+	return false
+}
+
+func drainWakeupEvent(kq int32) {
+	ev := keventt{
+		ident:  kqIdent,
+		filter: _EVFILT_USER,
+		flags:  _EV_DISABLE,
+	}
+	kevent(kq, &ev, 1, nil, 0, nil)
+}
+
+func netpollIsPollDescriptor(fd uintptr) bool {
+	return fd == uintptr(kq)
+}