1 files changed, 73 insertions, 0 deletions
diff --git a/libgo/go/runtime/os_netbsd.go b/libgo/go/runtime/os_netbsd.go
new file mode 100644
index 0000000..464ce88
--- /dev/null
+++ b/libgo/go/runtime/os_netbsd.go
@@ -0,0 +1,73 @@
+// Copyright 2014 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.
+
+package runtime
+
+import (
+	"runtime/internal/atomic"
+	"unsafe"
+)
+
+type mOS struct {
+	waitsemacount uint32
+}
+
+//go:noescape
+//extern lwp_park
+func lwp_park(abstime *timespec, unpark int32, hint, unparkhint unsafe.Pointer) int32
+
+//go:noescape
+//extern lwp_unpark
+func lwp_unpark(lwp int32, hint unsafe.Pointer) int32
+
+//go:nosplit
+func semacreate(mp *m) {
+}
+
+//go:nosplit
+func semasleep(ns int64) int32 {
+	_g_ := getg()
+
+	// Compute sleep deadline.
+	var tsp *timespec
+	if ns >= 0 {
+		var ts timespec
+		var nsec int32
+		ns += nanotime()
+		ts.set_sec(int64(timediv(ns, 1000000000, &nsec)))
+		ts.set_nsec(nsec)
+		tsp = &ts
+	}
+
+	for {
+		v := atomic.Load(&_g_.m.mos.waitsemacount)
+		if v > 0 {
+			if atomic.Cas(&_g_.m.mos.waitsemacount, v, v-1) {
+				return 0 // semaphore acquired
+			}
+			continue
+		}
+
+		// Sleep until unparked by semawakeup or timeout.
+		ret := lwp_park(tsp, 0, unsafe.Pointer(&_g_.m.mos.waitsemacount), nil)
+		if ret == _ETIMEDOUT {
+			return -1
+		}
+	}
+}
+
+//go:nosplit
+func semawakeup(mp *m) {
+	atomic.Xadd(&mp.mos.waitsemacount, 1)
+	// From NetBSD's _lwp_unpark(2) manual:
+	// "If the target LWP is not currently waiting, it will return
+	// immediately upon the next call to _lwp_park()."
+	ret := lwp_unpark(int32(mp.procid), unsafe.Pointer(&mp.mos.waitsemacount))
+	if ret != 0 && ret != _ESRCH {
+		// semawakeup can be called on signal stack.
+		systemstack(func() {
+			print("thrwakeup addr=", &mp.mos.waitsemacount, " sem=", mp.mos.waitsemacount, " ret=", ret, "\n")
+		})
+	}
+}