runtime: convert openbsd/amd64 locking to libc

Switch openbsd/amd64 to locking via libc, rather than performing direct
system calls.

Update #36435

Change-Id: I5e92bd70ce557b78ff385577088a9775cc468ea9
Reviewed-on: https://go-review.googlesource.com/c/go/+/270378
Trust: Joel Sing <joel@sing.id.au>
Run-TryBot: Joel Sing <joel@sing.id.au>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/src/runtime/sys_openbsd1.go b/src/runtime/sys_openbsd1.go
new file mode 100644
index 0000000000..a201a16c53
--- /dev/null
+++ b/src/runtime/sys_openbsd1.go
@@ -0,0 +1,34 @@
+// Copyright 2020 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 openbsd,amd64
+
+package runtime
+
+import "unsafe"
+
+//go:nosplit
+//go:cgo_unsafe_args
+func thrsleep(ident uintptr, clock_id int32, tsp *timespec, lock uintptr, abort *uint32) int32 {
+	return libcCall(unsafe.Pointer(funcPC(thrsleep_trampoline)), unsafe.Pointer(&ident))
+}
+func thrsleep_trampoline()
+
+//go:nosplit
+//go:cgo_unsafe_args
+func thrwakeup(ident uintptr, n int32) int32 {
+	return libcCall(unsafe.Pointer(funcPC(thrwakeup_trampoline)), unsafe.Pointer(&ident))
+}
+func thrwakeup_trampoline()
+
+func osyield() {
+	libcCall(unsafe.Pointer(funcPC(sched_yield_trampoline)), unsafe.Pointer(nil))
+}
+func sched_yield_trampoline()
+
+//go:cgo_import_dynamic libc_thrsleep __thrsleep "libc.so"
+//go:cgo_import_dynamic libc_thrwakeup __thrwakeup "libc.so"
+//go:cgo_import_dynamic libc_sched_yield sched_yield "libc.so"
+
+//go:cgo_import_dynamic _ _ "libc.so"