unix: add SysctlClockinfo on darwin

Add type Clockinfo and the SysctlClockinfo function to query clock rate
information from the kernel.

Change-Id: Ic29edcacee3b3f6125bb218b82c2a2496c39213a
Reviewed-on: https://go-review.googlesource.com/c/sys/+/170297
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

unix/syscall_darwin.go

@@ -144,6 +144,23 @@ func getAttrList(path string, attrList attrList, attrBuf []byte, options uint) (
 
 //sys getattrlist(path *byte, list unsafe.Pointer, buf unsafe.Pointer, size uintptr, options int) (err error)
 
+func SysctlClockinfo(name string) (*Clockinfo, error) {
+	mib, err := sysctlmib(name)
+	if err != nil {
+		return nil, err
+	}
+
+	n := uintptr(SizeofClockinfo)
+	var ci Clockinfo
+	if err := sysctl(mib, (*byte)(unsafe.Pointer(&ci)), &n, nil, 0); err != nil {
+		return nil, err
+	}
+	if n != SizeofClockinfo {
+		return nil, EIO
+	}
+	return &ci, nil
+}
+
 //sysnb pipe() (r int, w int, err error)
 
 func Pipe(p []int) (err error) {

unix/syscall_darwin_test.go

@@ -61,3 +61,12 @@ func TestUtimesNanoAt(t *testing.T) {
 		t.Errorf("UtimesNanoAt: wrong mtime: got %v, expected %v", st.Mtimespec, expected)
 	}
 }
+
+func TestSysctlClockinfo(t *testing.T) {
+	ci, err := unix.SysctlClockinfo("kern.clockrate")
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("tick = %v, tickadj = %v, hz = %v, profhz = %v, stathz = %v",
+		ci.Tick, ci.Tickadj, ci.Hz, ci.Profhz, ci.Stathz)
+}

unix/types_darwin.go

@@ -275,3 +275,9 @@ const (
 // uname
 
 type Utsname C.struct_utsname
+
+// Clockinfo
+
+const SizeofClockinfo = C.sizeof_struct_clockinfo
+
+type Clockinfo C.struct_clockinfo

unix/zsyscall_darwin_amd64.1_11.go

@@ -683,6 +683,16 @@ func Chroot(path string) (err error) {
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
+func ClockGettime(clockid int32, time *Timespec) (err error) {
+	_, _, e1 := Syscall(SYS_CLOCK_GETTIME, uintptr(clockid), uintptr(unsafe.Pointer(time)), 0)
+	if e1 != 0 {
+		err = errnoErr(e1)
+	}
+	return
+}
+
+// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
+
 func Close(fd int) (err error) {
 	_, _, e1 := Syscall(SYS_CLOSE, uintptr(fd), 0, 0)
 	if e1 != 0 {

unix/ztypes_darwin_386.go

@@ -487,3 +487,13 @@ type Utsname struct {
 	Version  [256]byte
 	Machine  [256]byte
 }
+
+const SizeofClockinfo = 0x14
+
+type Clockinfo struct {
+	Hz      int32
+	Tick    int32
+	Tickadj int32
+	Stathz  int32
+	Profhz  int32
+}

unix/ztypes_darwin_amd64.go

@@ -497,3 +497,13 @@ type Utsname struct {
 	Version  [256]byte
 	Machine  [256]byte
 }
+
+const SizeofClockinfo = 0x14
+
+type Clockinfo struct {
+	Hz      int32
+	Tick    int32
+	Tickadj int32
+	Stathz  int32
+	Profhz  int32
+}

unix/ztypes_darwin_arm.go

@@ -488,3 +488,13 @@ type Utsname struct {
 	Version  [256]byte
 	Machine  [256]byte
 }
+
+const SizeofClockinfo = 0x14
+
+type Clockinfo struct {
+	Hz      int32
+	Tick    int32
+	Tickadj int32
+	Stathz  int32
+	Profhz  int32
+}

unix/ztypes_darwin_arm64.go

@@ -497,3 +497,13 @@ type Utsname struct {
 	Version  [256]byte
 	Machine  [256]byte
 }
+
+const SizeofClockinfo = 0x14
+
+type Clockinfo struct {
+	Hz      int32
+	Tick    int32
+	Tickadj int32
+	Stathz  int32
+	Profhz  int32
+}