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// Copyright 2011 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 (
"runtime/internal/atomic"
"runtime/internal/sys"
"unsafe"
)
type mOS struct {
waitsemacount uint32
}
//go:noescape
func setitimer(mode int32, new, old *itimerval)
//go:noescape
func sigaction(sig uint32, new, old *sigactiont)
//go:noescape
func sigaltstack(new, old *stackt)
//go:noescape
func obsdsigprocmask(how int32, new sigset) sigset
//go:nosplit
//go:nowritebarrierrec
func sigprocmask(how int32, new, old *sigset) {
n := sigset(0)
if new != nil {
n = *new
}
r := obsdsigprocmask(how, n)
if old != nil {
*old = r
}
}
//go:noescape
func sysctl(mib *uint32, miblen uint32, out *byte, size *uintptr, dst *byte, ndst uintptr) int32
func raiseproc(sig uint32)
func getthrid() int32
func thrkill(tid int32, sig int)
//go:noescape
func tfork(param *tforkt, psize uintptr, mm *m, gg *g, fn uintptr) int32
//go:noescape
func thrsleep(ident uintptr, clock_id int32, tsp *timespec, lock uintptr, abort *uint32) int32
//go:noescape
func thrwakeup(ident uintptr, n int32) int32
func osyield()
func kqueue() int32
//go:noescape
func kevent(kq int32, ch *keventt, nch int32, ev *keventt, nev int32, ts *timespec) int32
func pipe() (r, w int32, errno int32)
func pipe2(flags int32) (r, w int32, errno int32)
func closeonexec(fd int32)
func setNonblock(fd int32)
const (
_ESRCH = 3
_EWOULDBLOCK = _EAGAIN
_ENOTSUP = 91
// From OpenBSD's sys/time.h
_CLOCK_REALTIME = 0
_CLOCK_VIRTUAL = 1
_CLOCK_PROF = 2
_CLOCK_MONOTONIC = 3
)
type sigset uint32
var sigset_all = ^sigset(0)
// From OpenBSD's <sys/sysctl.h>
const (
_CTL_KERN = 1
_KERN_OSREV = 3
_CTL_HW = 6
_HW_NCPU = 3
_HW_PAGESIZE = 7
_HW_NCPUONLINE = 25
)
func sysctlInt(mib []uint32) (int32, bool) {
var out int32
nout := unsafe.Sizeof(out)
ret := sysctl(&mib[0], uint32(len(mib)), (*byte)(unsafe.Pointer(&out)), &nout, nil, 0)
if ret < 0 {
return 0, false
}
return out, true
}
func getncpu() int32 {
// Try hw.ncpuonline first because hw.ncpu would report a number twice as
// high as the actual CPUs running on OpenBSD 6.4 with hyperthreading
// disabled (hw.smt=0). See https://golang.org/issue/30127
if n, ok := sysctlInt([]uint32{_CTL_HW, _HW_NCPUONLINE}); ok {
return int32(n)
}
if n, ok := sysctlInt([]uint32{_CTL_HW, _HW_NCPU}); ok {
return int32(n)
}
return 1
}
func getPageSize() uintptr {
if ps, ok := sysctlInt([]uint32{_CTL_HW, _HW_PAGESIZE}); ok {
return uintptr(ps)
}
return 0
}
func getOSRev() int {
if osrev, ok := sysctlInt([]uint32{_CTL_KERN, _KERN_OSREV}); ok {
return int(osrev)
}
return 0
}
//go:nosplit
func semacreate(mp *m) {
}
//go:nosplit
func semasleep(ns int64) int32 {
_g_ := getg()
// Compute sleep deadline.
var tsp *timespec
if ns >= 0 {
var ts timespec
ts.setNsec(ns + nanotime())
tsp = &ts
}
for {
v := atomic.Load(&_g_.m.waitsemacount)
if v > 0 {
if atomic.Cas(&_g_.m.waitsemacount, v, v-1) {
return 0 // semaphore acquired
}
continue
}
// Sleep until woken by semawakeup or timeout; or abort if waitsemacount != 0.
//
// From OpenBSD's __thrsleep(2) manual:
// "The abort argument, if not NULL, points to an int that will
// be examined [...] immediately before blocking. If that int
// is non-zero then __thrsleep() will immediately return EINTR
// without blocking."
ret := thrsleep(uintptr(unsafe.Pointer(&_g_.m.waitsemacount)), _CLOCK_MONOTONIC, tsp, 0, &_g_.m.waitsemacount)
if ret == _EWOULDBLOCK {
return -1
}
}
}
//go:nosplit
func semawakeup(mp *m) {
atomic.Xadd(&mp.waitsemacount, 1)
ret := thrwakeup(uintptr(unsafe.Pointer(&mp.waitsemacount)), 1)
if ret != 0 && ret != _ESRCH {
// semawakeup can be called on signal stack.
systemstack(func() {
print("thrwakeup addr=", &mp.waitsemacount, " sem=", mp.waitsemacount, " ret=", ret, "\n")
})
}
}
// May run with m.p==nil, so write barriers are not allowed.
//go:nowritebarrier
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")
}
// Stack pointer must point inside stack area (as marked with MAP_STACK),
// rather than at the top of it.
param := tforkt{
tf_tcb: unsafe.Pointer(&mp.tls[0]),
tf_tid: nil, // minit will record tid
tf_stack: uintptr(stk) - sys.PtrSize,
}
var oset sigset
sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
ret := tfork(&param, unsafe.Sizeof(param), mp, mp.g0, funcPC(mstart))
sigprocmask(_SIG_SETMASK, &oset, nil)
if ret < 0 {
print("runtime: failed to create new OS thread (have ", mcount()-1, " already; errno=", -ret, ")\n")
if ret == -_EAGAIN {
println("runtime: may need to increase max user processes (ulimit -p)")
}
throw("runtime.newosproc")
}
}
func osinit() {
ncpu = getncpu()
physPageSize = getPageSize()
haveMapStack = getOSRev() >= 201805 // OpenBSD 6.3
}
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) {
gsignalSize := int32(32 * 1024)
if GOARCH == "mips64" {
gsignalSize = int32(64 * 1024)
}
mp.gsignal = malg(gsignalSize)
mp.gsignal.m = mp
}
// Called to initialize a new m (including the bootstrap m).
// Called on the new thread, can not allocate memory.
func minit() {
getg().m.procid = uint64(getthrid())
minitSignals()
}
// Called from dropm to undo the effect of an minit.
//go:nosplit
func unminit() {
unminitSignals()
}
func sigtramp()
type sigactiont struct {
sa_sigaction uintptr
sa_mask uint32
sa_flags int32
}
//go:nosplit
//go:nowritebarrierrec
func setsig(i uint32, fn uintptr) {
var sa sigactiont
sa.sa_flags = _SA_SIGINFO | _SA_ONSTACK | _SA_RESTART
sa.sa_mask = uint32(sigset_all)
if fn == funcPC(sighandler) {
fn = funcPC(sigtramp)
}
sa.sa_sigaction = fn
sigaction(i, &sa, nil)
}
//go:nosplit
//go:nowritebarrierrec
func setsigstack(i uint32) {
throw("setsigstack")
}
//go:nosplit
//go:nowritebarrierrec
func getsig(i uint32) uintptr {
var sa sigactiont
sigaction(i, nil, &sa)
return sa.sa_sigaction
}
// setSignaltstackSP sets the ss_sp field of a stackt.
//go:nosplit
func setSignalstackSP(s *stackt, sp uintptr) {
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:nosplit
func (c *sigctxt) fixsigcode(sig uint32) {
}
var haveMapStack = false
func osStackAlloc(s *mspan) {
// OpenBSD 6.4+ requires that stacks be mapped with MAP_STACK.
// It will check this on entry to system calls, traps, and
// when switching to the alternate system stack.
//
// This function is called before s is used for any data, so
// it's safe to simply re-map it.
osStackRemap(s, _MAP_STACK)
}
func osStackFree(s *mspan) {
// Undo MAP_STACK.
osStackRemap(s, 0)
}
func osStackRemap(s *mspan, flags int32) {
if !haveMapStack {
// OpenBSD prior to 6.3 did not have MAP_STACK and so
// the following mmap will fail. But it also didn't
// require MAP_STACK (obviously), so there's no need
// to do the mmap.
return
}
a, err := mmap(unsafe.Pointer(s.base()), s.npages*pageSize, _PROT_READ|_PROT_WRITE, _MAP_PRIVATE|_MAP_ANON|_MAP_FIXED|flags, -1, 0)
if err != 0 || uintptr(a) != s.base() {
print("runtime: remapping stack memory ", hex(s.base()), " ", s.npages*pageSize, " a=", a, " err=", err, "\n")
throw("remapping stack memory failed")
}
}
//go:nosplit
func raise(sig uint32) {
thrkill(getthrid(), int(sig))
}
func signalM(mp *m, sig int) {
thrkill(int32(mp.procid), sig)
}