libgo/go/runtime/os_darwin.go - gofrontend - Git at Google

 // Copyright 2009 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 "unsafe"

 type mOS struct {
 	machport uint32 // return address for mach ipc
 	waitsema uint32 // semaphore for parking on locks
 }

 //go:noescape
 //extern mach_msg_trap
 func mach_msg_trap(h unsafe.Pointer, op int32, send_size, rcv_size, rcv_name, timeout, notify uint32) int32

 //extern mach_reply_port
 func mach_reply_port() uint32

 //extern mach_task_self
 func mach_task_self() uint32

 func unimplemented(name string) {
 	println(name, "not implemented")
 	*(*int)(unsafe.Pointer(uintptr(1231))) = 1231
 }

 //go:nosplit
 func semawakeup(mp *m) {
 	mach_semrelease(mp.mos.waitsema)
 }

 //go:nosplit
 func semacreate(mp *m) {
 	if mp.mos.waitsema != 0 {
 		return
 	}
 	systemstack(func() {
 		mp.mos.waitsema = mach_semcreate()
 	})
 }

 // Mach IPC, to get at semaphores
 // Definitions are in /usr/include/mach on a Mac.

 func macherror(r int32, fn string) {
 	print("mach error ", fn, ": ", r, "\n")
 	throw("mach error")
 }

 const _DebugMach = false

 var zerondr machndr

 func mach_msgh_bits(a, b uint32) uint32 {
 	return a | b<<8
 }

 func mach_msg(h *machheader, op int32, send_size, rcv_size, rcv_name, timeout, notify uint32) int32 {
 	// TODO: Loop on interrupt.
 	return mach_msg_trap(unsafe.Pointer(h), op, send_size, rcv_size, rcv_name, timeout, notify)
 }

 // Mach RPC (MIG)
 const (
 	_MinMachMsg = 48
 	_MachReply  = 100
 )

 type codemsg struct {
 	h    machheader
 	ndr  machndr
 	code int32
 }

 func machcall(h *machheader, maxsize int32, rxsize int32) int32 {
 	_g_ := getg()
 	port := _g_.m.mos.machport
 	if port == 0 {
 		port = mach_reply_port()
 		_g_.m.mos.machport = port
 	}

 	h.msgh_bits |= mach_msgh_bits(_MACH_MSG_TYPE_COPY_SEND, _MACH_MSG_TYPE_MAKE_SEND_ONCE)
 	h.msgh_local_port = port
 	h.msgh_reserved = 0
 	id := h.msgh_id

 	if _DebugMach {
 		p := (*[10000]unsafe.Pointer)(unsafe.Pointer(h))
 		print("send:\t")
 		var i uint32
 		for i = 0; i < h.msgh_size/uint32(unsafe.Sizeof(p[0])); i++ {
 			print(" ", p[i])
 			if i%8 == 7 {
 				print("\n\t")
 			}
 		}
 		if i%8 != 0 {
 			print("\n")
 		}
 	}
 	ret := mach_msg(h, _MACH_SEND_MSG|_MACH_RCV_MSG, h.msgh_size, uint32(maxsize), port, 0, 0)
 	if ret != 0 {
 		if _DebugMach {
 			print("mach_msg error ", ret, "\n")
 		}
 		return ret
 	}
 	if _DebugMach {
 		p := (*[10000]unsafe.Pointer)(unsafe.Pointer(h))
 		var i uint32
 		for i = 0; i < h.msgh_size/uint32(unsafe.Sizeof(p[0])); i++ {
 			print(" ", p[i])
 			if i%8 == 7 {
 				print("\n\t")
 			}
 		}
 		if i%8 != 0 {
 			print("\n")
 		}
 	}
 	if h.msgh_id != id+_MachReply {
 		if _DebugMach {
 			print("mach_msg _MachReply id mismatch ", h.msgh_id, " != ", id+_MachReply, "\n")
 		}
 		return -303 // MIG_REPLY_MISMATCH
 	}
 	// Look for a response giving the return value.
 	// Any call can send this back with an error,
 	// and some calls only have return values so they
 	// send it back on success too. I don't quite see how
 	// you know it's one of these and not the full response
 	// format, so just look if the message is right.
 	c := (*codemsg)(unsafe.Pointer(h))
 	if uintptr(h.msgh_size) == unsafe.Sizeof(*c) && h.msgh_bits&_MACH_MSGH_BITS_COMPLEX == 0 {
 		if _DebugMach {
 			print("mig result ", c.code, "\n")
 		}
 		return c.code
 	}
 	if h.msgh_size != uint32(rxsize) {
 		if _DebugMach {
 			print("mach_msg _MachReply size mismatch ", h.msgh_size, " != ", rxsize, "\n")
 		}
 		return -307 // MIG_ARRAY_TOO_LARGE
 	}
 	return 0
 }

 // Semaphores!

 const (
 	tmach_semcreate = 3418
 	rmach_semcreate = tmach_semcreate + _MachReply

 	tmach_semdestroy = 3419
 	rmach_semdestroy = tmach_semdestroy + _MachReply

 	_KERN_ABORTED             = 14
 	_KERN_OPERATION_TIMED_OUT = 49
 )

 type tmach_semcreatemsg struct {
 	h      machheader
 	ndr    machndr
 	policy int32
 	value  int32
 }

 type rmach_semcreatemsg struct {
 	h         machheader
 	body      machbody
 	semaphore machport
 }

 type tmach_semdestroymsg struct {
 	h         machheader
 	body      machbody
 	semaphore machport
 }

 func mach_semcreate() uint32 {
 	var m [256]uint8
 	tx := (*tmach_semcreatemsg)(unsafe.Pointer(&m))
 	rx := (*rmach_semcreatemsg)(unsafe.Pointer(&m))

 	tx.h.msgh_bits = 0
 	tx.h.msgh_size = uint32(unsafe.Sizeof(*tx))
 	tx.h.msgh_remote_port = mach_task_self()
 	tx.h.msgh_id = tmach_semcreate
 	tx.ndr = zerondr

 	tx.policy = 0 // 0 = SYNC_POLICY_FIFO
 	tx.value = 0

 	for {
 		r := machcall(&tx.h, int32(unsafe.Sizeof(m)), int32(unsafe.Sizeof(*rx)))
 		if r == 0 {
 			break
 		}
 		if r == _KERN_ABORTED { // interrupted
 			continue
 		}
 		macherror(r, "semaphore_create")
 	}
 	if rx.body.msgh_descriptor_count != 1 {
 		unimplemented("mach_semcreate desc count")
 	}
 	return rx.semaphore.name
 }

 func mach_semdestroy(sem uint32) {
 	var m [256]uint8
 	tx := (*tmach_semdestroymsg)(unsafe.Pointer(&m))

 	tx.h.msgh_bits = _MACH_MSGH_BITS_COMPLEX
 	tx.h.msgh_size = uint32(unsafe.Sizeof(*tx))
 	tx.h.msgh_remote_port = mach_task_self()
 	tx.h.msgh_id = tmach_semdestroy
 	tx.body.msgh_descriptor_count = 1
 	tx.semaphore.name = sem
 	tx.semaphore.disposition = _MACH_MSG_TYPE_MOVE_SEND
 	tx.semaphore._type = 0

 	for {
 		r := machcall(&tx.h, int32(unsafe.Sizeof(m)), 0)
 		if r == 0 {
 			break
 		}
 		if r == _KERN_ABORTED { // interrupted
 			continue
 		}
 		macherror(r, "semaphore_destroy")
 	}
 }

 //extern semaphore_wait
 func mach_semaphore_wait(sema uint32) int32

 //extern semaphore_timedwait
 func mach_semaphore_timedwait(sema, sec, nsec uint32) int32

 //extern semaphore_signal
 func mach_semaphore_signal(sema uint32) int32

 //extern semaphore_signal_all
 func mach_semaphore_signal_all(sema uint32) int32

 func semasleep1(ns int64) int32 {
 	_g_ := getg()

 	if ns >= 0 {
 		var nsecs int32
 		secs := timediv(ns, 1000000000, &nsecs)
 		r := mach_semaphore_timedwait(_g_.m.mos.waitsema, uint32(secs), uint32(nsecs))
 		if r == _KERN_ABORTED || r == _KERN_OPERATION_TIMED_OUT {
 			return -1
 		}
 		if r != 0 {
 			macherror(r, "semaphore_wait")
 		}
 		return 0
 	}

 	for {
 		r := mach_semaphore_wait(_g_.m.mos.waitsema)
 		if r == 0 {
 			break
 		}
 		// Note: We don't know how this call (with no timeout) can get _KERN_OPERATION_TIMED_OUT,
 		// but it does reliably, though at a very low rate, on OS X 10.8, 10.9, 10.10, and 10.11.
 		// See golang.org/issue/17161.
 		if r == _KERN_ABORTED || r == _KERN_OPERATION_TIMED_OUT { // interrupted
 			continue
 		}
 		macherror(r, "semaphore_wait")
 	}
 	return 0
 }

 //go:nosplit
 func semasleep(ns int64) int32 {
 	var r int32
 	systemstack(func() {
 		r = semasleep1(ns)
 	})
 	return r
 }

 //go:nosplit
 func mach_semrelease(sem uint32) {
 	for {
 		r := mach_semaphore_signal(sem)
 		if r == 0 {
 			break
 		}
 		if r == _KERN_ABORTED { // interrupted
 			continue
 		}

 		// mach_semrelease must be completely nosplit,
 		// because it is called from Go code.
 		// If we're going to die, start that process on the system stack
 		// to avoid a Go stack split.
 		systemstack(func() { macherror(r, "semaphore_signal") })
 	}
 }

 type machheader struct {
 	msgh_bits        uint32
 	msgh_size        uint32
 	msgh_remote_port uint32
 	msgh_local_port  uint32
 	msgh_reserved    uint32
 	msgh_id          int32
 }

 type machndr struct {
 	mig_vers     uint8
 	if_vers      uint8
 	reserved1    uint8
 	mig_encoding uint8
 	int_rep      uint8
 	char_rep     uint8
 	float_rep    uint8
 	reserved2    uint8
 }
	// Copyright 2009 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 "unsafe"

	type mOS struct {
	machport uint32 // return address for mach ipc
	waitsema uint32 // semaphore for parking on locks
	}

	//go:noescape
	//extern mach_msg_trap
	func mach_msg_trap(h unsafe.Pointer, op int32, send_size, rcv_size, rcv_name, timeout, notify uint32) int32

	//extern mach_reply_port
	func mach_reply_port() uint32

	//extern mach_task_self
	func mach_task_self() uint32

	func unimplemented(name string) {
	println(name, "not implemented")
	(int)(unsafe.Pointer(uintptr(1231))) = 1231
	}

	//go:nosplit
	func semawakeup(mp *m) {
	mach_semrelease(mp.mos.waitsema)
	}

	//go:nosplit
	func semacreate(mp *m) {
	if mp.mos.waitsema != 0 {
	return
	}
	systemstack(func() {
	mp.mos.waitsema = mach_semcreate()
	})
	}

	// Mach IPC, to get at semaphores
	// Definitions are in /usr/include/mach on a Mac.

	func macherror(r int32, fn string) {
	print("mach error ", fn, ": ", r, "\n")
	throw("mach error")
	}

	const _DebugMach = false

	var zerondr machndr

	func mach_msgh_bits(a, b uint32) uint32 {
	return a \| b<<8
	}

	func mach_msg(h *machheader, op int32, send_size, rcv_size, rcv_name, timeout, notify uint32) int32 {
	// TODO: Loop on interrupt.
	return mach_msg_trap(unsafe.Pointer(h), op, send_size, rcv_size, rcv_name, timeout, notify)
	}

	// Mach RPC (MIG)
	const (
	_MinMachMsg = 48
	_MachReply = 100
	)

	type codemsg struct {
	h machheader
	ndr machndr
	code int32
	}

	func machcall(h *machheader, maxsize int32, rxsize int32) int32 {
	_g_ := getg()
	port := _g_.m.mos.machport
	if port == 0 {
	port = mach_reply_port()
	_g_.m.mos.machport = port
	}

	h.msgh_bits \|= mach_msgh_bits(_MACH_MSG_TYPE_COPY_SEND, _MACH_MSG_TYPE_MAKE_SEND_ONCE)
	h.msgh_local_port = port
	h.msgh_reserved = 0
	id := h.msgh_id

	if _DebugMach {
	p := (*[10000]unsafe.Pointer)(unsafe.Pointer(h))
	print("send:\t")
	var i uint32
	for i = 0; i < h.msgh_size/uint32(unsafe.Sizeof(p[0])); i++ {
	print(" ", p[i])
	if i%8 == 7 {
	print("\n\t")
	}
	}
	if i%8 != 0 {
	print("\n")
	}
	}
	ret := mach_msg(h, _MACH_SEND_MSG\|_MACH_RCV_MSG, h.msgh_size, uint32(maxsize), port, 0, 0)
	if ret != 0 {
	if _DebugMach {
	print("mach_msg error ", ret, "\n")
	}
	return ret
	}
	if _DebugMach {
	p := (*[10000]unsafe.Pointer)(unsafe.Pointer(h))
	var i uint32
	for i = 0; i < h.msgh_size/uint32(unsafe.Sizeof(p[0])); i++ {
	print(" ", p[i])
	if i%8 == 7 {
	print("\n\t")
	}
	}
	if i%8 != 0 {
	print("\n")
	}
	}
	if h.msgh_id != id+_MachReply {
	if _DebugMach {
	print("mach_msg _MachReply id mismatch ", h.msgh_id, " != ", id+_MachReply, "\n")
	}
	return -303 // MIG_REPLY_MISMATCH
	}
	// Look for a response giving the return value.
	// Any call can send this back with an error,
	// and some calls only have return values so they
	// send it back on success too. I don't quite see how
	// you know it's one of these and not the full response
	// format, so just look if the message is right.
	c := (*codemsg)(unsafe.Pointer(h))
	if uintptr(h.msgh_size) == unsafe.Sizeof(*c) && h.msgh_bits&_MACH_MSGH_BITS_COMPLEX == 0 {
	if _DebugMach {
	print("mig result ", c.code, "\n")
	}
	return c.code
	}
	if h.msgh_size != uint32(rxsize) {
	if _DebugMach {
	print("mach_msg _MachReply size mismatch ", h.msgh_size, " != ", rxsize, "\n")
	}
	return -307 // MIG_ARRAY_TOO_LARGE
	}
	return 0
	}

	// Semaphores!

	const (
	tmach_semcreate = 3418
	rmach_semcreate = tmach_semcreate + _MachReply

	tmach_semdestroy = 3419
	rmach_semdestroy = tmach_semdestroy + _MachReply

	_KERN_ABORTED = 14
	_KERN_OPERATION_TIMED_OUT = 49
	)

	type tmach_semcreatemsg struct {
	h machheader
	ndr machndr
	policy int32
	value int32
	}

	type rmach_semcreatemsg struct {
	h machheader
	body machbody
	semaphore machport
	}

	type tmach_semdestroymsg struct {
	h machheader
	body machbody
	semaphore machport
	}

	func mach_semcreate() uint32 {
	var m [256]uint8
	tx := (*tmach_semcreatemsg)(unsafe.Pointer(&m))
	rx := (*rmach_semcreatemsg)(unsafe.Pointer(&m))

	tx.h.msgh_bits = 0
	tx.h.msgh_size = uint32(unsafe.Sizeof(*tx))
	tx.h.msgh_remote_port = mach_task_self()
	tx.h.msgh_id = tmach_semcreate
	tx.ndr = zerondr

	tx.policy = 0 // 0 = SYNC_POLICY_FIFO
	tx.value = 0

	for {
	r := machcall(&tx.h, int32(unsafe.Sizeof(m)), int32(unsafe.Sizeof(*rx)))
	if r == 0 {
	break
	}
	if r == _KERN_ABORTED { // interrupted
	continue
	}
	macherror(r, "semaphore_create")
	}
	if rx.body.msgh_descriptor_count != 1 {
	unimplemented("mach_semcreate desc count")
	}
	return rx.semaphore.name
	}

	func mach_semdestroy(sem uint32) {
	var m [256]uint8
	tx := (*tmach_semdestroymsg)(unsafe.Pointer(&m))

	tx.h.msgh_bits = _MACH_MSGH_BITS_COMPLEX
	tx.h.msgh_size = uint32(unsafe.Sizeof(*tx))
	tx.h.msgh_remote_port = mach_task_self()
	tx.h.msgh_id = tmach_semdestroy
	tx.body.msgh_descriptor_count = 1
	tx.semaphore.name = sem
	tx.semaphore.disposition = _MACH_MSG_TYPE_MOVE_SEND
	tx.semaphore._type = 0

	for {
	r := machcall(&tx.h, int32(unsafe.Sizeof(m)), 0)
	if r == 0 {
	break
	}
	if r == _KERN_ABORTED { // interrupted
	continue
	}
	macherror(r, "semaphore_destroy")
	}
	}

	//extern semaphore_wait
	func mach_semaphore_wait(sema uint32) int32

	//extern semaphore_timedwait
	func mach_semaphore_timedwait(sema, sec, nsec uint32) int32

	//extern semaphore_signal
	func mach_semaphore_signal(sema uint32) int32

	//extern semaphore_signal_all
	func mach_semaphore_signal_all(sema uint32) int32

	func semasleep1(ns int64) int32 {
	_g_ := getg()

	if ns >= 0 {
	var nsecs int32
	secs := timediv(ns, 1000000000, &nsecs)
	r := mach_semaphore_timedwait(_g_.m.mos.waitsema, uint32(secs), uint32(nsecs))
	if r == _KERN_ABORTED \|\| r == _KERN_OPERATION_TIMED_OUT {
	return -1
	}
	if r != 0 {
	macherror(r, "semaphore_wait")
	}
	return 0
	}

	for {
	r := mach_semaphore_wait(_g_.m.mos.waitsema)
	if r == 0 {
	break
	}
	// Note: We don't know how this call (with no timeout) can get _KERN_OPERATION_TIMED_OUT,
	// but it does reliably, though at a very low rate, on OS X 10.8, 10.9, 10.10, and 10.11.
	// See golang.org/issue/17161.
	if r == _KERN_ABORTED \|\| r == _KERN_OPERATION_TIMED_OUT { // interrupted
	continue
	}
	macherror(r, "semaphore_wait")
	}
	return 0
	}

	//go:nosplit
	func semasleep(ns int64) int32 {
	var r int32
	systemstack(func() {
	r = semasleep1(ns)
	})
	return r
	}

	//go:nosplit
	func mach_semrelease(sem uint32) {
	for {
	r := mach_semaphore_signal(sem)
	if r == 0 {
	break
	}
	if r == _KERN_ABORTED { // interrupted
	continue
	}

	// mach_semrelease must be completely nosplit,
	// because it is called from Go code.
	// If we're going to die, start that process on the system stack
	// to avoid a Go stack split.
	systemstack(func() { macherror(r, "semaphore_signal") })
	}
	}

	type machheader struct {
	msgh_bits uint32
	msgh_size uint32
	msgh_remote_port uint32
	msgh_local_port uint32
	msgh_reserved uint32
	msgh_id int32
	}

	type machndr struct {
	mig_vers uint8
	if_vers uint8
	reserved1 uint8
	mig_encoding uint8
	int_rep uint8
	char_rep uint8
	float_rep uint8
	reserved2 uint8
	}