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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
_EAGAIN = 35
_EWOULDBLOCK = _EAGAIN
_ENOTSUP = 91
// From OpenBSD's sys/time.h
_CLOCK_REALTIME = 0
_CLOCK_VIRTUAL = 1
_CLOCK_PROF = 2
_CLOCK_MONOTONIC = 3
)
var sigset_none = uint32(0)
var sigset_all = ^sigset_none
// From OpenBSD'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)
// Fetch hw.ncpu via sysctl.
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(int64(timediv(ns, 1000000000, &nsec)))
ts.set_nsec(nsec)
tsp = &ts
}
for {
// spin-mutex lock
for {
if xchg(&_g_.m.waitsemalock, 1) == 0 {
break
}
osyield()
}
if _g_.m.waitsemacount != 0 {
// semaphore is available.
_g_.m.waitsemacount--
// spin-mutex unlock
atomicstore(&_g_.m.waitsemalock, 0)
return 0 // semaphore acquired
}
// sleep until semaphore != 0 or timeout.
// thrsleep unlocks m.waitsemalock.
ret := thrsleep(uintptr(unsafe.Pointer(&_g_.m.waitsemacount)), _CLOCK_MONOTONIC, tsp, uintptr(unsafe.Pointer(&_g_.m.waitsemalock)), (*int32)(unsafe.Pointer(&_g_.m.waitsemacount)))
if ret == _EWOULDBLOCK {
return -1
}
}
}
//go:nosplit
func semawakeup(mp *m) {
// spin-mutex lock
for {
if xchg(&mp.waitsemalock, 1) == 0 {
break
}
osyield()
}
mp.waitsemacount++
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")
})
}
// spin-mutex unlock
atomicstore(&mp.waitsemalock, 0)
}
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
param := tforkt{
tf_tcb: unsafe.Pointer(&mp.tls[0]),
tf_tid: (*int32)(unsafe.Pointer(&mp.procid)),
tf_stack: uintptr(stk),
}
oset := sigprocmask(_SIG_SETMASK, sigset_all)
ret := tfork(&param, unsafe.Sizeof(param), mp, mp.g0, funcPC(mstart))
sigprocmask(_SIG_SETMASK, oset)
if ret < 0 {
print("runtime: failed to create new OS thread (have ", mcount()-1, " already; errno=", -ret, ")\n")
if ret == -_ENOTSUP {
print("runtime: is kern.rthreads disabled?\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)))
close(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
}
// Called to initialize a new m (including the bootstrap m).
// Called on the new thread, can not allocate memory.
func minit() {
_g_ := getg()
// m.procid is a uint64, but tfork writes an int32. Fix it up.
_g_.m.procid = uint64(*(*int32)(unsafe.Pointer(&_g_.m.procid)))
// Initialize signal handling
signalstack((*byte)(unsafe.Pointer(_g_.m.gsignal.stack.lo)), 32*1024)
sigprocmask(_SIG_SETMASK, sigset_none)
}
// Called from dropm to undo the effect of an minit.
func unminit() {
signalstack(nil, 0)
}
func memlimit() uintptr {
return 0
}
func sigtramp()
type sigactiont struct {
sa_sigaction uintptr
sa_mask uint32
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(p *byte, n int32) {
var st stackt
st.ss_sp = uintptr(unsafe.Pointer(p))
st.ss_size = uintptr(n)
st.ss_flags = 0
if p == nil {
st.ss_flags = _SS_DISABLE
}
sigaltstack(&st, nil)
}
func unblocksignals() {
sigprocmask(_SIG_SETMASK, sigset_none)
}