1 files changed, 58 insertions, 0 deletions
diff --git a/src/runtime/os_openbsd_libc.go b/src/runtime/os_openbsd_libc.go
new file mode 100644
index 0000000..2edb035
--- /dev/null
+++ b/src/runtime/os_openbsd_libc.go
@@ -0,0 +1,58 @@
+// 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 openbsd,arm64
+
+package runtime
+
+import (
+	"unsafe"
+)
+
+var failThreadCreate = []byte("runtime: failed to create new OS thread\n")
+
+// mstart_stub provides glue code to call mstart from pthread_create.
+func mstart_stub()
+
+// May run with m.p==nil, so write barriers are not allowed.
+//go:nowritebarrierrec
+func newosproc(mp *m) {
+	if false {
+		print("newosproc m=", mp, " g=", mp.g0, " id=", mp.id, " ostk=", &mp, "\n")
+	}
+
+	// Initialize an attribute object.
+	var attr pthreadattr
+	if err := pthread_attr_init(&attr); err != 0 {
+		write(2, unsafe.Pointer(&failThreadCreate[0]), int32(len(failThreadCreate)))
+		exit(1)
+	}
+
+	// Find out OS stack size for our own stack guard.
+	var stacksize uintptr
+	if pthread_attr_getstacksize(&attr, &stacksize) != 0 {
+		write(2, unsafe.Pointer(&failThreadCreate[0]), int32(len(failThreadCreate)))
+		exit(1)
+	}
+	mp.g0.stack.hi = stacksize // for mstart
+
+	// Tell the pthread library we won't join with this thread.
+	if pthread_attr_setdetachstate(&attr, _PTHREAD_CREATE_DETACHED) != 0 {
+		write(2, unsafe.Pointer(&failThreadCreate[0]), int32(len(failThreadCreate)))
+		exit(1)
+	}
+
+	// Finally, create the thread. It starts at mstart_stub, which does some low-level
+	// setup and then calls mstart.
+	var oset sigset
+	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
+	err := pthread_create(&attr, funcPC(mstart_stub), unsafe.Pointer(mp))
+	sigprocmask(_SIG_SETMASK, &oset, nil)
+	if err != 0 {
+		write(2, unsafe.Pointer(&failThreadCreate[0]), int32(len(failThreadCreate)))
+		exit(1)
+	}
+
+	pthread_attr_destroy(&attr)
+}