Copy BSD implementation to v3

v3/load/load_bsd.go

@@ -1,3 +1,4 @@
+//go:build freebsd || openbsd
 // +build freebsd openbsd
 
 package load
@@ -37,6 +38,12 @@ func AvgWithContext(ctx context.Context) (*AvgStat, error) {
 	return ret, nil
 }
 
+type forkstat struct {
+	forks    int
+	vforks   int
+	__tforks int
+}
+
 // Misc returns miscellaneous host-wide statistics.
 // darwin use ps command to get process running/blocked count.
 // Almost same as Darwin implementation, but state is different.
@@ -64,5 +71,11 @@ func MiscWithContext(ctx context.Context) (*MiscStat, error) {
 		}
 	}
 
+	f, err := getForkStat()
+	if err != nil {
+		return nil, err
+	}
+	ret.ProcsCreated = f.forks
+
 	return &ret, nil
 }

v3/load/load_freebsd.go

@@ -0,0 +1,7 @@
+// +build freebsd
+
+package load
+
+func getForkStat() (forkstat, error) {
+	return forkstat{}, nil
+}

v3/load/load_openbsd.go

@@ -0,0 +1,17 @@
+// +build openbsd
+
+package load
+
+import (
+	"unsafe"
+
+	"golang.org/x/sys/unix"
+)
+
+func getForkStat() (forkstat, error) {
+	b, err := unix.SysctlRaw("kern.forkstat")
+	if err != nil {
+		return forkstat{}, err
+	}
+	return *(*forkstat)(unsafe.Pointer((&b[0]))), nil
+}