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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 "unsafe"
const (
_ESRCH = 3
_ETIMEDOUT = 60
// From NetBSD's <sys/time.h>
_CLOCK_REALTIME = 0
_CLOCK_VIRTUAL = 1
_CLOCK_PROF = 2
_CLOCK_MONOTONIC = 3
)
var sigset_all = sigset{[4]uint32{^uint32(0), ^uint32(0), ^uint32(0), ^uint32(0)}}
// From NetBSD's <sys/sysctl.h>
const (
_CTL_HW = 6
_HW_NCPU = 3
)
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 semacreate() uintptr {
return 1
}
//go:nosplit
func semasleep(ns int64) int32 {
_g_ := getg()
// Compute sleep deadline.
var tsp *timespec
if ns >= 0 {
var ts timespec
var nsec int32
ns += nanotime()
ts.set_sec(timediv(ns, 1000000000, &nsec))
ts.set_nsec(nsec)
tsp = &ts
}
for {
v := atomicload(&_g_.m.waitsemacount)
if v > 0 {
if cas(&_g_.m.waitsemacount, v, v-1) {
return 0 // semaphore acquired
}
continue
}
// Sleep until unparked by semawakeup or timeout.
ret := lwp_park(tsp, 0, unsafe.Pointer(&_g_.m.waitsemacount), nil)
if ret == _ETIMEDOUT {
return -1
}
}
}
//go:nosplit
func semawakeup(mp *m) {
xadd(&mp.waitsemacount, 1)
// From NetBSD's _lwp_unpark(2) manual:
// "If the target LWP is not currently waiting, it will return
// immediately upon the next call to _lwp_park()."
ret := lwp_unpark(int32(mp.procid), unsafe.Pointer(&mp.waitsemacount))
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) {
if false {
print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " id=", mp.id, "/", int32(mp.tls[0]), " ostk=", &mp, "\n")
}
mp.tls[0] = uintptr(mp.id) // so 386 asm can find it
var uc ucontextt
getcontext(unsafe.Pointer(&uc))
uc.uc_flags = _UC_SIGMASK | _UC_CPU
uc.uc_link = nil
uc.uc_sigmask = sigset_all
lwp_mcontext_init(&uc.uc_mcontext, stk, mp, mp.g0, funcPC(mstart))
ret := lwp_create(unsafe.Pointer(&uc), 0, unsafe.Pointer(&mp.procid))
if ret < 0 {
print("runtime: failed to create new OS thread (have ", mcount()-1, " already; errno=", -ret, ")\n")
throw("runtime.newosproc")
}
}
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
}
func msigsave(mp *m) {
smask := (*sigset)(unsafe.Pointer(&mp.sigmask))
if unsafe.Sizeof(*smask) > unsafe.Sizeof(mp.sigmask) {
throw("insufficient storage for signal mask")
}
sigprocmask(_SIG_SETMASK, nil, smask)
}
// Called to initialize a new m (including the bootstrap m).
// Called on the new thread, can not allocate memory.
func minit() {
_g_ := getg()
_g_.m.procid = uint64(lwp_self())
// Initialize signal handling
signalstack(&_g_.m.gsignal.stack)
// restore signal mask from m.sigmask and unblock essential signals
nmask := *(*sigset)(unsafe.Pointer(&_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.
func unminit() {
_g_ := getg()
smask := (*sigset)(unsafe.Pointer(&_g_.m.sigmask))
sigprocmask(_SIG_SETMASK, smask, nil)
signalstack(nil)
}
func memlimit() uintptr {
return 0
}
func sigtramp()
type sigactiont struct {
sa_sigaction uintptr
sa_mask sigset
sa_flags int32
}
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)
}
func setsigstack(i int32) {
throw("setsigstack")
}
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
}
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)
}
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)
}
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