src/runtime/os_dragonfly.go - go - Git at Google

 // Copyright 2014 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"

 const (
 	_NSIG        = 33
 	_SI_USER     = 0
 	_SS_DISABLE  = 4
 	_RLIMIT_AS   = 10
 	_SIG_BLOCK   = 1
 	_SIG_UNBLOCK = 2
 	_SIG_SETMASK = 3
 )

 type mOS struct{}

 //go:noescape
 func lwp_create(param *lwpparams) int32

 //go:noescape
 func sigaltstack(new, old *sigaltstackt)

 //go:noescape
 func sigaction(sig int32, new, old *sigactiont)

 //go:noescape
 func sigprocmask(how int32, new, old *sigset)

 //go:noescape
 func setitimer(mode int32, new, old *itimerval)

 //go:noescape
 func sysctl(mib *uint32, miblen uint32, out *byte, size *uintptr, dst *byte, ndst uintptr) int32

 //go:noescape
 func getrlimit(kind int32, limit unsafe.Pointer) int32

 func raise(sig int32)
 func raiseproc(sig int32)

 //go:noescape
 func sys_umtx_sleep(addr *uint32, val, timeout int32) int32

 //go:noescape
 func sys_umtx_wakeup(addr *uint32, val int32) int32

 func osyield()

 const stackSystem = 0

 // From DragonFly's <sys/sysctl.h>
 const (
 	_CTL_HW  = 6
 	_HW_NCPU = 3
 )

 var sigset_all = sigset{[4]uint32{^uint32(0), ^uint32(0), ^uint32(0), ^uint32(0)}}

 func getncpu() int32 {
 	mib := [2]uint32{_CTL_HW, _HW_NCPU}
 	out := uint32(0)
 	nout := unsafe.Sizeof(out)
 	ret := sysctl(&mib[0], 2, (*byte)(unsafe.Pointer(&out)), &nout, nil, 0)
 	if ret >= 0 {
 		return int32(out)
 	}
 	return 1
 }

 //go:nosplit
 func futexsleep(addr *uint32, val uint32, ns int64) {
 	systemstack(func() {
 		futexsleep1(addr, val, ns)
 	})
 }

 func futexsleep1(addr *uint32, val uint32, ns int64) {
 	var timeout int32
 	if ns >= 0 {
 		// The timeout is specified in microseconds - ensure that we
 		// do not end up dividing to zero, which would put us to sleep
 		// indefinitely...
 		timeout = timediv(ns, 1000, nil)
 		if timeout == 0 {
 			timeout = 1
 		}
 	}

 	// sys_umtx_sleep will return EWOULDBLOCK (EAGAIN) when the timeout
 	// expires or EBUSY if the mutex value does not match.
 	ret := sys_umtx_sleep(addr, int32(val), timeout)
 	if ret >= 0 || ret == -_EINTR || ret == -_EAGAIN || ret == -_EBUSY {
 		return
 	}

 	print("umtx_sleep addr=", addr, " val=", val, " ret=", ret, "\n")
 	*(*int32)(unsafe.Pointer(uintptr(0x1005))) = 0x1005
 }

 //go:nosplit
 func futexwakeup(addr *uint32, cnt uint32) {
 	ret := sys_umtx_wakeup(addr, int32(cnt))
 	if ret >= 0 {
 		return
 	}

 	systemstack(func() {
 		print("umtx_wake_addr=", addr, " ret=", ret, "\n")
 		*(*int32)(unsafe.Pointer(uintptr(0x1006))) = 0x1006
 	})
 }

 func lwp_start(uintptr)

 // May run with m.p==nil, so write barriers are not allowed.
 //go:nowritebarrier
 func newosproc(mp *m, stk unsafe.Pointer) {
 	if false {
 		print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " lwp_start=", funcPC(lwp_start), " id=", mp.id, " ostk=", &mp, "\n")
 	}

 	var oset sigset
 	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)

 	params := lwpparams{
 		start_func: funcPC(lwp_start),
 		arg:        unsafe.Pointer(mp),
 		stack:      uintptr(stk),
 		tid1:       unsafe.Pointer(&mp.procid),
 		tid2:       nil,
 	}

 	// TODO: Check for error.
 	lwp_create(&params)
 	sigprocmask(_SIG_SETMASK, &oset, nil)
 }

 func osinit() {
 	ncpu = getncpu()
 }

 var urandom_dev = []byte("/dev/urandom\x00")

 //go:nosplit
 func getRandomData(r []byte) {
 	fd := open(&urandom_dev[0], 0 /* O_RDONLY */, 0)
 	n := read(fd, unsafe.Pointer(&r[0]), int32(len(r)))
 	closefd(fd)
 	extendRandom(r, int(n))
 }

 func goenvs() {
 	goenvs_unix()
 }

 // Called to initialize a new m (including the bootstrap m).
 // Called on the parent thread (main thread in case of bootstrap), can allocate memory.
 func mpreinit(mp *m) {
 	mp.gsignal = malg(32 * 1024)
 	mp.gsignal.m = mp
 }

 //go:nosplit
 func msigsave(mp *m) {
 	sigprocmask(_SIG_SETMASK, nil, &mp.sigmask)
 }

 //go:nosplit
 func msigrestore(sigmask sigset) {
 	sigprocmask(_SIG_SETMASK, &sigmask, nil)
 }

 //go:nosplit
 func sigblock() {
 	sigprocmask(_SIG_SETMASK, &sigset_all, nil)
 }

 // Called to initialize a new m (including the bootstrap m).
 // Called on the new thread, cannot allocate memory.
 func minit() {
 	_g_ := getg()

 	// m.procid is a uint64, but lwp_start writes an int32. Fix it up.
 	_g_.m.procid = uint64(*(*int32)(unsafe.Pointer(&_g_.m.procid)))

 	// Initialize signal handling.

 	// On DragonFly a thread created by pthread_create inherits
 	// the signal stack of the creating thread. We always create
 	// a new signal stack here, to avoid having two Go threads
 	// using the same signal stack. This breaks the case of a
 	// thread created in C that calls sigaltstack and then calls a
 	// Go function, because we will lose track of the C code's
 	// sigaltstack, but it's the best we can do.
 	signalstack(&_g_.m.gsignal.stack)
 	_g_.m.newSigstack = true

 	// restore signal mask from m.sigmask and unblock essential signals
 	nmask := _g_.m.sigmask
 	for i := range sigtable {
 		if sigtable[i].flags&_SigUnblock != 0 {
 			nmask.__bits[(i-1)/32] &^= 1 << ((uint32(i) - 1) & 31)
 		}
 	}
 	sigprocmask(_SIG_SETMASK, &nmask, nil)
 }

 // Called from dropm to undo the effect of an minit.
 //go:nosplit
 func unminit() {
 	if getg().m.newSigstack {
 		signalstack(nil)
 	}
 }

 func memlimit() uintptr {
 	/*
 		                TODO: Convert to Go when something actually uses the result.

 				Rlimit rl;
 				extern byte runtime·text[], runtime·end[];
 				uintptr used;

 				if(runtime·getrlimit(RLIMIT_AS, &rl) != 0)
 					return 0;
 				if(rl.rlim_cur >= 0x7fffffff)
 					return 0;

 				// Estimate our VM footprint excluding the heap.
 				// Not an exact science: use size of binary plus
 				// some room for thread stacks.
 				used = runtime·end - runtime·text + (64<<20);
 				if(used >= rl.rlim_cur)
 					return 0;

 				// If there's not at least 16 MB left, we're probably
 				// not going to be able to do much. Treat as no limit.
 				rl.rlim_cur -= used;
 				if(rl.rlim_cur < (16<<20))
 					return 0;

 				return rl.rlim_cur - used;
 	*/
 	return 0
 }

 func sigtramp()

 type sigactiont struct {
 	sa_sigaction uintptr
 	sa_flags     int32
 	sa_mask      sigset
 }

 //go:nosplit
 //go:nowritebarrierrec
 func setsig(i int32, fn uintptr, restart bool) {
 	var sa sigactiont
 	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK
 	if restart {
 		sa.sa_flags |= _SA_RESTART
 	}
 	sa.sa_mask = sigset_all
 	if fn == funcPC(sighandler) {
 		fn = funcPC(sigtramp)
 	}
 	sa.sa_sigaction = fn
 	sigaction(i, &sa, nil)
 }

 //go:nosplit
 //go:nowritebarrierrec
 func setsigstack(i int32) {
 	throw("setsigstack")
 }

 //go:nosplit
 //go:nowritebarrierrec
 func getsig(i int32) uintptr {
 	var sa sigactiont
 	sigaction(i, nil, &sa)
 	if sa.sa_sigaction == funcPC(sigtramp) {
 		return funcPC(sighandler)
 	}
 	return sa.sa_sigaction
 }

 //go:nosplit
 func signalstack(s *stack) {
 	var st sigaltstackt
 	if s == nil {
 		st.ss_flags = _SS_DISABLE
 	} else {
 		st.ss_sp = s.lo
 		st.ss_size = s.hi - s.lo
 		st.ss_flags = 0
 	}
 	sigaltstack(&st, nil)
 }

 //go:nosplit
 //go:nowritebarrierrec
 func updatesigmask(m sigmask) {
 	var mask sigset
 	copy(mask.__bits[:], m[:])
 	sigprocmask(_SIG_SETMASK, &mask, nil)
 }

 func unblocksig(sig int32) {
 	var mask sigset
 	mask.__bits[(sig-1)/32] |= 1 << ((uint32(sig) - 1) & 31)
 	sigprocmask(_SIG_UNBLOCK, &mask, nil)
 }
	// Copyright 2014 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"

	const (
	_NSIG = 33
	_SI_USER = 0
	_SS_DISABLE = 4
	_RLIMIT_AS = 10
	_SIG_BLOCK = 1
	_SIG_UNBLOCK = 2
	_SIG_SETMASK = 3
	)

	type mOS struct{}

	//go:noescape
	func lwp_create(param *lwpparams) int32

	//go:noescape
	func sigaltstack(new, old *sigaltstackt)

	//go:noescape
	func sigaction(sig int32, new, old *sigactiont)

	//go:noescape
	func sigprocmask(how int32, new, old *sigset)

	//go:noescape
	func setitimer(mode int32, new, old *itimerval)

	//go:noescape
	func sysctl(mib uint32, miblen uint32, out byte, size uintptr, dst byte, ndst uintptr) int32

	//go:noescape
	func getrlimit(kind int32, limit unsafe.Pointer) int32

	func raise(sig int32)
	func raiseproc(sig int32)

	//go:noescape
	func sys_umtx_sleep(addr *uint32, val, timeout int32) int32

	//go:noescape
	func sys_umtx_wakeup(addr *uint32, val int32) int32

	func osyield()

	const stackSystem = 0

	// From DragonFly's <sys/sysctl.h>
	const (
	_CTL_HW = 6
	_HW_NCPU = 3
	)

	var sigset_all = sigset{[4]uint32{^uint32(0), ^uint32(0), ^uint32(0), ^uint32(0)}}

	func getncpu() int32 {
	mib := [2]uint32{_CTL_HW, _HW_NCPU}
	out := uint32(0)
	nout := unsafe.Sizeof(out)
	ret := sysctl(&mib[0], 2, (*byte)(unsafe.Pointer(&out)), &nout, nil, 0)
	if ret >= 0 {
	return int32(out)
	}
	return 1
	}

	//go:nosplit
	func futexsleep(addr *uint32, val uint32, ns int64) {
	systemstack(func() {
	futexsleep1(addr, val, ns)
	})
	}

	func futexsleep1(addr *uint32, val uint32, ns int64) {
	var timeout int32
	if ns >= 0 {
	// The timeout is specified in microseconds - ensure that we
	// do not end up dividing to zero, which would put us to sleep
	// indefinitely...
	timeout = timediv(ns, 1000, nil)
	if timeout == 0 {
	timeout = 1
	}
	}

	// sys_umtx_sleep will return EWOULDBLOCK (EAGAIN) when the timeout
	// expires or EBUSY if the mutex value does not match.
	ret := sys_umtx_sleep(addr, int32(val), timeout)
	if ret >= 0 \|\| ret == -_EINTR \|\| ret == -_EAGAIN \|\| ret == -_EBUSY {
	return
	}

	print("umtx_sleep addr=", addr, " val=", val, " ret=", ret, "\n")
	(int32)(unsafe.Pointer(uintptr(0x1005))) = 0x1005
	}

	//go:nosplit
	func futexwakeup(addr *uint32, cnt uint32) {
	ret := sys_umtx_wakeup(addr, int32(cnt))
	if ret >= 0 {
	return
	}

	systemstack(func() {
	print("umtx_wake_addr=", addr, " ret=", ret, "\n")
	(int32)(unsafe.Pointer(uintptr(0x1006))) = 0x1006
	})
	}

	func lwp_start(uintptr)

	// May run with m.p==nil, so write barriers are not allowed.
	//go:nowritebarrier
	func newosproc(mp *m, stk unsafe.Pointer) {
	if false {
	print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " lwp_start=", funcPC(lwp_start), " id=", mp.id, " ostk=", &mp, "\n")
	}

	var oset sigset
	sigprocmask(_SIG_SETMASK, &sigset_all, &oset)

	params := lwpparams{
	start_func: funcPC(lwp_start),
	arg: unsafe.Pointer(mp),
	stack: uintptr(stk),
	tid1: unsafe.Pointer(&mp.procid),
	tid2: nil,
	}

	// TODO: Check for error.
	lwp_create(&params)
	sigprocmask(_SIG_SETMASK, &oset, nil)
	}

	func osinit() {
	ncpu = getncpu()
	}

	var urandom_dev = []byte("/dev/urandom\x00")

	//go:nosplit
	func getRandomData(r []byte) {
	fd := open(&urandom_dev[0], 0 /* O_RDONLY */, 0)
	n := read(fd, unsafe.Pointer(&r[0]), int32(len(r)))
	closefd(fd)
	extendRandom(r, int(n))
	}

	func goenvs() {
	goenvs_unix()
	}

	// Called to initialize a new m (including the bootstrap m).
	// Called on the parent thread (main thread in case of bootstrap), can allocate memory.
	func mpreinit(mp *m) {
	mp.gsignal = malg(32 * 1024)
	mp.gsignal.m = mp
	}

	//go:nosplit
	func msigsave(mp *m) {
	sigprocmask(_SIG_SETMASK, nil, &mp.sigmask)
	}

	//go:nosplit
	func msigrestore(sigmask sigset) {
	sigprocmask(_SIG_SETMASK, &sigmask, nil)
	}

	//go:nosplit
	func sigblock() {
	sigprocmask(_SIG_SETMASK, &sigset_all, nil)
	}

	// Called to initialize a new m (including the bootstrap m).
	// Called on the new thread, cannot allocate memory.
	func minit() {
	_g_ := getg()

	// m.procid is a uint64, but lwp_start writes an int32. Fix it up.
	_g_.m.procid = uint64((int32)(unsafe.Pointer(&_g_.m.procid)))

	// Initialize signal handling.

	// On DragonFly a thread created by pthread_create inherits
	// the signal stack of the creating thread. We always create
	// a new signal stack here, to avoid having two Go threads
	// using the same signal stack. This breaks the case of a
	// thread created in C that calls sigaltstack and then calls a
	// Go function, because we will lose track of the C code's
	// sigaltstack, but it's the best we can do.
	signalstack(&_g_.m.gsignal.stack)
	_g_.m.newSigstack = true

	// restore signal mask from m.sigmask and unblock essential signals
	nmask := _g_.m.sigmask
	for i := range sigtable {
	if sigtable[i].flags&_SigUnblock != 0 {
	nmask.__bits[(i-1)/32] &^= 1 << ((uint32(i) - 1) & 31)
	}
	}
	sigprocmask(_SIG_SETMASK, &nmask, nil)
	}

	// Called from dropm to undo the effect of an minit.
	//go:nosplit
	func unminit() {
	if getg().m.newSigstack {
	signalstack(nil)
	}
	}

	func memlimit() uintptr {
	/*
	TODO: Convert to Go when something actually uses the result.

	Rlimit rl;
	extern byte runtime·text[], runtime·end[];
	uintptr used;

	if(runtime·getrlimit(RLIMIT_AS, &rl) != 0)
	return 0;
	if(rl.rlim_cur >= 0x7fffffff)
	return 0;

	// Estimate our VM footprint excluding the heap.
	// Not an exact science: use size of binary plus
	// some room for thread stacks.
	used = runtime·end - runtime·text + (64<<20);
	if(used >= rl.rlim_cur)
	return 0;

	// If there's not at least 16 MB left, we're probably
	// not going to be able to do much. Treat as no limit.
	rl.rlim_cur -= used;
	if(rl.rlim_cur < (16<<20))
	return 0;

	return rl.rlim_cur - used;
	*/
	return 0
	}

	func sigtramp()

	type sigactiont struct {
	sa_sigaction uintptr
	sa_flags int32
	sa_mask sigset
	}

	//go:nosplit
	//go:nowritebarrierrec
	func setsig(i int32, fn uintptr, restart bool) {
	var sa sigactiont
	sa.sa_flags = _SA_SIGINFO \| _SA_ONSTACK
	if restart {
	sa.sa_flags \|= _SA_RESTART
	}
	sa.sa_mask = sigset_all
	if fn == funcPC(sighandler) {
	fn = funcPC(sigtramp)
	}
	sa.sa_sigaction = fn
	sigaction(i, &sa, nil)
	}

	//go:nosplit
	//go:nowritebarrierrec
	func setsigstack(i int32) {
	throw("setsigstack")
	}

	//go:nosplit
	//go:nowritebarrierrec
	func getsig(i int32) uintptr {
	var sa sigactiont
	sigaction(i, nil, &sa)
	if sa.sa_sigaction == funcPC(sigtramp) {
	return funcPC(sighandler)
	}
	return sa.sa_sigaction
	}

	//go:nosplit
	func signalstack(s *stack) {
	var st sigaltstackt
	if s == nil {
	st.ss_flags = _SS_DISABLE
	} else {
	st.ss_sp = s.lo
	st.ss_size = s.hi - s.lo
	st.ss_flags = 0
	}
	sigaltstack(&st, nil)
	}

	//go:nosplit
	//go:nowritebarrierrec
	func updatesigmask(m sigmask) {
	var mask sigset
	copy(mask.__bits[:], m[:])
	sigprocmask(_SIG_SETMASK, &mask, nil)
	}

	func unblocksig(sig int32) {
	var mask sigset
	mask.__bits[(sig-1)/32] \|= 1 << ((uint32(sig) - 1) & 31)
	sigprocmask(_SIG_UNBLOCK, &mask, nil)
	}