blob: 1614b66c8a76d36222dd2189084258aa0474f051 [file] [log] [blame]
// 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 {
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) {
entersyscallblock()
var b byte
read(sigNoteRead, unsafe.Pointer(&b), 1)
exitsyscall()
}
// 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()
}
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
//mSysStatInc(&memstats.stacks_sys, stacksize) //TODO: do this?
// 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, funcPC(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
mSysStatInc(&memstats.stacks_sys, 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
}
// Called to initialize a new m (including the bootstrap m).
// Called on the new thread, cannot allocate memory.
func minit() {
// The alternate signal stack is buggy on arm and arm64.
// The signal handler handles it directly.
if GOARCH != "arm" && GOARCH != "arm64" {
minitSignalStack()
}
minitSignalMask()
}
// Called from dropm to undo the effect of an minit.
//go:nosplit
func unminit() {
// The alternate signal stack is buggy on arm and arm64.
// See minit.
if GOARCH != "arm" && GOARCH != "arm64" {
unminitSignals()
}
}
//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 runtimeĀ·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 == funcPC(sighandler) {
if iscgo {
fn = funcPC(cgoSigtramp)
} else {
fn = funcPC(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)
}
//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):]
}
}