1 files changed, 474 insertions, 0 deletions
diff --git a/src/runtime/os_darwin.go b/src/runtime/os_darwin.go
new file mode 100644
index 0000000..8562d7d
--- /dev/null
+++ b/src/runtime/os_darwin.go
@@ -0,0 +1,474 @@
+// 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 (
+	"internal/abi"
+	"unsafe"
+)
+
+type mOS struct {
+	initialized bool
+	mutex       pthreadmutex
+	cond        pthreadcond
+	count       int
+}
+
+func unimplemented(name string) {
+	println(name, "not implemented")
+	*(*int)(unsafe.Pointer(uintptr(1231))) = 1231
+}
+
+//go:nosplit
+func semacreate(mp *m) {
+	if mp.initialized {
+		return
+	}
+	mp.initialized = true
+	if err := pthread_mutex_init(&mp.mutex, nil); err != 0 {
+		throw("pthread_mutex_init")
+	}
+	if err := pthread_cond_init(&mp.cond, nil); err != 0 {
+		throw("pthread_cond_init")
+	}
+}
+
+//go:nosplit
+func semasleep(ns int64) int32 {
+	var start int64
+	if ns >= 0 {
+		start = nanotime()
+	}
+	mp := getg().m
+	pthread_mutex_lock(&mp.mutex)
+	for {
+		if mp.count > 0 {
+			mp.count--
+			pthread_mutex_unlock(&mp.mutex)
+			return 0
+		}
+		if ns >= 0 {
+			spent := nanotime() - start
+			if spent >= ns {
+				pthread_mutex_unlock(&mp.mutex)
+				return -1
+			}
+			var t timespec
+			t.setNsec(ns - spent)
+			err := pthread_cond_timedwait_relative_np(&mp.cond, &mp.mutex, &t)
+			if err == _ETIMEDOUT {
+				pthread_mutex_unlock(&mp.mutex)
+				return -1
+			}
+		} else {
+			pthread_cond_wait(&mp.cond, &mp.mutex)
+		}
+	}
+}
+
+//go:nosplit
+func semawakeup(mp *m) {
+	pthread_mutex_lock(&mp.mutex)
+	mp.count++
+	if mp.count > 0 {
+		pthread_cond_signal(&mp.cond)
+	}
+	pthread_mutex_unlock(&mp.mutex)
+}
+
+// The read and write file descriptors used by the sigNote functions.
+var sigNoteRead, sigNoteWrite int32
+
+// sigNoteSetup initializes an async-signal-safe note.
+//
+// The current implementation of notes on Darwin is not async-signal-safe,
+// because the functions pthread_mutex_lock, pthread_cond_signal, and
+// pthread_mutex_unlock, called by semawakeup, are not async-signal-safe.
+// There is only one case where we need to wake up a note from a signal
+// handler: the sigsend function. The signal handler code does not require
+// all the features of notes: it does not need to do a timed wait.
+// This is a separate implementation of notes, based on a pipe, that does
+// not support timed waits but is async-signal-safe.
+func sigNoteSetup(*note) {
+	if sigNoteRead != 0 || sigNoteWrite != 0 {
+		throw("duplicate sigNoteSetup")
+	}
+	var errno int32
+	sigNoteRead, sigNoteWrite, errno = pipe()
+	if errno != 0 {
+		throw("pipe failed")
+	}
+	closeonexec(sigNoteRead)
+	closeonexec(sigNoteWrite)
+
+	// Make the write end of the pipe non-blocking, so that if the pipe
+	// buffer is somehow full we will not block in the signal handler.
+	// Leave the read end of the pipe blocking so that we will block
+	// in sigNoteSleep.
+	setNonblock(sigNoteWrite)
+}
+
+// sigNoteWakeup wakes up a thread sleeping on a note created by sigNoteSetup.
+func sigNoteWakeup(*note) {
+	var b byte
+	write(uintptr(sigNoteWrite), unsafe.Pointer(&b), 1)
+}
+
+// sigNoteSleep waits for a note created by sigNoteSetup to be woken.
+func sigNoteSleep(*note) {
+	for {
+		var b byte
+		entersyscallblock()
+		n := read(sigNoteRead, unsafe.Pointer(&b), 1)
+		exitsyscall()
+		if n != -_EINTR {
+			return
+		}
+	}
+}
+
+// BSD interface for threading.
+func osinit() {
+	// pthread_create delayed until end of goenvs so that we
+	// can look at the environment first.
+
+	ncpu = getncpu()
+	physPageSize = getPageSize()
+}
+
+func sysctlbynameInt32(name []byte) (int32, int32) {
+	out := int32(0)
+	nout := unsafe.Sizeof(out)
+	ret := sysctlbyname(&name[0], (*byte)(unsafe.Pointer(&out)), &nout, nil, 0)
+	return ret, out
+}
+
+//go:linkname internal_cpu_getsysctlbyname internal/cpu.getsysctlbyname
+func internal_cpu_getsysctlbyname(name []byte) (int32, int32) {
+	return sysctlbynameInt32(name)
+}
+
+const (
+	_CTL_HW      = 6
+	_HW_NCPU     = 3
+	_HW_PAGESIZE = 7
+)
+
+func getncpu() int32 {
+	// Use sysctl to fetch hw.ncpu.
+	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 && int32(out) > 0 {
+		return int32(out)
+	}
+	return 1
+}
+
+func getPageSize() uintptr {
+	// Use sysctl to fetch hw.pagesize.
+	mib := [2]uint32{_CTL_HW, _HW_PAGESIZE}
+	out := uint32(0)
+	nout := unsafe.Sizeof(out)
+	ret := sysctl(&mib[0], 2, (*byte)(unsafe.Pointer(&out)), &nout, nil, 0)
+	if ret >= 0 && int32(out) > 0 {
+		return uintptr(out)
+	}
+	return 0
+}
+
+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()
+}
+
+// May run with m.p==nil, so write barriers are not allowed.
+//
+//go:nowritebarrierrec
+func newosproc(mp *m) {
+	stk := unsafe.Pointer(mp.g0.stack.hi)
+	if false {
+		print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " id=", mp.id, " ostk=", &mp, "\n")
+	}
+
+	// Initialize an attribute object.
+	var attr pthreadattr
+	var err int32
+	err = pthread_attr_init(&attr)
+	if 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, abi.FuncPCABI0(mstart_stub), unsafe.Pointer(mp))
+	sigprocmask(_SIG_SETMASK, &oset, nil)
+	if err != 0 {
+		write(2, unsafe.Pointer(&failthreadcreate[0]), int32(len(failthreadcreate)))
+		exit(1)
+	}
+}
+
+// glue code to call mstart from pthread_create.
+func mstart_stub()
+
+// newosproc0 is a version of newosproc that can be called before the runtime
+// is initialized.
+//
+// This function is not safe to use after initialization as it does not pass an M as fnarg.
+//
+//go:nosplit
+func newosproc0(stacksize uintptr, fn uintptr) {
+	// Initialize an attribute object.
+	var attr pthreadattr
+	var err int32
+	err = pthread_attr_init(&attr)
+	if err != 0 {
+		write(2, unsafe.Pointer(&failthreadcreate[0]), int32(len(failthreadcreate)))
+		exit(1)
+	}
+
+	// The caller passes in a suggested stack size,
+	// from when we allocated the stack and thread ourselves,
+	// without libpthread. Now that we're using libpthread,
+	// we use the OS default stack size instead of the suggestion.
+	// Find out that stack size for our own stack guard.
+	if pthread_attr_getstacksize(&attr, &stacksize) != 0 {
+		write(2, unsafe.Pointer(&failthreadcreate[0]), int32(len(failthreadcreate)))
+		exit(1)
+	}
+	g0.stack.hi = stacksize // for mstart
+	memstats.stacks_sys.add(int64(stacksize))
+
+	// 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, fn, nil)
+	sigprocmask(_SIG_SETMASK, &oset, nil)
+	if err != 0 {
+		write(2, unsafe.Pointer(&failthreadcreate[0]), int32(len(failthreadcreate)))
+		exit(1)
+	}
+}
+
+var failallocatestack = []byte("runtime: failed to allocate stack for the new OS thread\n")
+var failthreadcreate = []byte("runtime: failed to create new OS thread\n")
+
+// Called to do synchronous initialization of Go code built with
+// -buildmode=c-archive or -buildmode=c-shared.
+// None of the Go runtime is initialized.
+//
+//go:nosplit
+//go:nowritebarrierrec
+func libpreinit() {
+	initsig(true)
+}
+
+// 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) // OS X wants >= 8K
+	mp.gsignal.m = mp
+	if GOOS == "darwin" && GOARCH == "arm64" {
+		// mlock the signal stack to work around a kernel bug where it may
+		// SIGILL when the signal stack is not faulted in while a signal
+		// arrives. See issue 42774.
+		mlock(unsafe.Pointer(mp.gsignal.stack.hi-physPageSize), physPageSize)
+	}
+}
+
+// Called to initialize a new m (including the bootstrap m).
+// Called on the new thread, cannot allocate memory.
+func minit() {
+	// iOS does not support alternate signal stack.
+	// The signal handler handles it directly.
+	if !(GOOS == "ios" && GOARCH == "arm64") {
+		minitSignalStack()
+	}
+	minitSignalMask()
+	getg().m.procid = uint64(pthread_self())
+}
+
+// Called from dropm to undo the effect of an minit.
+//
+//go:nosplit
+func unminit() {
+	// iOS does not support alternate signal stack.
+	// See minit.
+	if !(GOOS == "ios" && GOARCH == "arm64") {
+		unminitSignals()
+	}
+}
+
+// Called from exitm, but not from drop, to undo the effect of thread-owned
+// resources in minit, semacreate, or elsewhere. Do not take locks after calling this.
+func mdestroy(mp *m) {
+}
+
+//go:nosplit
+func osyield_no_g() {
+	usleep_no_g(1)
+}
+
+//go:nosplit
+func osyield() {
+	usleep(1)
+}
+
+const (
+	_NSIG        = 32
+	_SI_USER     = 0 /* empirically true, but not what headers say */
+	_SIG_BLOCK   = 1
+	_SIG_UNBLOCK = 2
+	_SIG_SETMASK = 3
+	_SS_DISABLE  = 4
+)
+
+//extern SigTabTT runtime·sigtab[];
+
+type sigset uint32
+
+var sigset_all = ^sigset(0)
+
+//go:nosplit
+//go:nowritebarrierrec
+func setsig(i uint32, fn uintptr) {
+	var sa usigactiont
+	sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
+	sa.sa_mask = ^uint32(0)
+	if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
+		if iscgo {
+			fn = abi.FuncPCABI0(cgoSigtramp)
+		} else {
+			fn = abi.FuncPCABI0(sigtramp)
+		}
+	}
+	*(*uintptr)(unsafe.Pointer(&sa.__sigaction_u)) = fn
+	sigaction(i, &sa, nil)
+}
+
+// sigtramp is the callback from libc when a signal is received.
+// It is called with the C calling convention.
+func sigtramp()
+func cgoSigtramp()
+
+//go:nosplit
+//go:nowritebarrierrec
+func setsigstack(i uint32) {
+	var osa usigactiont
+	sigaction(i, nil, &osa)
+	handler := *(*uintptr)(unsafe.Pointer(&osa.__sigaction_u))
+	if osa.sa_flags&_SA_ONSTACK != 0 {
+		return
+	}
+	var sa usigactiont
+	*(*uintptr)(unsafe.Pointer(&sa.__sigaction_u)) = handler
+	sa.sa_mask = osa.sa_mask
+	sa.sa_flags = osa.sa_flags | _SA_ONSTACK
+	sigaction(i, &sa, nil)
+}
+
+//go:nosplit
+//go:nowritebarrierrec
+func getsig(i uint32) uintptr {
+	var sa usigactiont
+	sigaction(i, nil, &sa)
+	return *(*uintptr)(unsafe.Pointer(&sa.__sigaction_u))
+}
+
+// setSignaltstackSP sets the ss_sp field of a stackt.
+//
+//go:nosplit
+func setSignalstackSP(s *stackt, sp uintptr) {
+	*(*uintptr)(unsafe.Pointer(&s.ss_sp)) = sp
+}
+
+//go:nosplit
+//go:nowritebarrierrec
+func sigaddset(mask *sigset, i int) {
+	*mask |= 1 << (uint32(i) - 1)
+}
+
+func sigdelset(mask *sigset, i int) {
+	*mask &^= 1 << (uint32(i) - 1)
+}
+
+func setProcessCPUProfiler(hz int32) {
+	setProcessCPUProfilerTimer(hz)
+}
+
+func setThreadCPUProfiler(hz int32) {
+	setThreadCPUProfilerHz(hz)
+}
+
+//go:nosplit
+func validSIGPROF(mp *m, c *sigctxt) bool {
+	return true
+}
+
+//go:linkname executablePath os.executablePath
+var executablePath string
+
+func sysargs(argc int32, argv **byte) {
+	// skip over argv, envv and the first string will be the path
+	n := argc + 1
+	for argv_index(argv, n) != nil {
+		n++
+	}
+	executablePath = gostringnocopy(argv_index(argv, n+1))
+
+	// strip "executable_path=" prefix if available, it's added after OS X 10.11.
+	const prefix = "executable_path="
+	if len(executablePath) > len(prefix) && executablePath[:len(prefix)] == prefix {
+		executablePath = executablePath[len(prefix):]
+	}
+}
+
+func signalM(mp *m, sig int) {
+	pthread_kill(pthread(mp.procid), uint32(sig))
+}
+
+// sigPerThreadSyscall is only used on linux, so we assign a bogus signal
+// number.
+const sigPerThreadSyscall = 1 << 31
+
+//go:nosplit
+func runPerThreadSyscall() {
+	throw("runPerThreadSyscall only valid on linux")
+}