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// Copyright 2014 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"
"internal/goarch"
"runtime/internal/atomic"
"unsafe"
)
const (
_SS_DISABLE = 4
_SIG_BLOCK = 1
_SIG_UNBLOCK = 2
_SIG_SETMASK = 3
_NSIG = 33
_SI_USER = 0
// From NetBSD's <sys/ucontext.h>
_UC_SIGMASK = 0x01
_UC_CPU = 0x04
// From <sys/lwp.h>
_LWP_DETACHED = 0x00000040
)
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 sigprocmask(how int32, new, old *sigset)
//go:noescape
func sysctl(mib *uint32, miblen uint32, out *byte, size *uintptr, dst *byte, ndst uintptr) int32
func lwp_tramp()
func raiseproc(sig uint32)
func lwp_kill(tid int32, sig int)
//go:noescape
func getcontext(ctxt unsafe.Pointer)
//go:noescape
func lwp_create(ctxt unsafe.Pointer, flags uintptr, lwpid unsafe.Pointer) int32
//go:noescape
func lwp_park(clockid, flags int32, ts *timespec, unpark int32, hint, unparkhint unsafe.Pointer) int32
//go:noescape
func lwp_unpark(lwp int32, hint unsafe.Pointer) int32
func lwp_self() int32
func osyield()
//go:nosplit
func osyield_no_g() {
osyield()
}
func kqueue() int32
//go:noescape
func kevent(kq int32, ch *keventt, nch int32, ev *keventt, nev int32, ts *timespec) int32
func pipe2(flags int32) (r, w int32, errno int32)
func closeonexec(fd int32)
const (
_ESRCH = 3
_ETIMEDOUT = 60
// From NetBSD's <sys/time.h>
_CLOCK_REALTIME = 0
_CLOCK_VIRTUAL = 1
_CLOCK_PROF = 2
_CLOCK_MONOTONIC = 3
_TIMER_RELTIME = 0
_TIMER_ABSTIME = 1
)
var sigset_all = sigset{[4]uint32{^uint32(0), ^uint32(0), ^uint32(0), ^uint32(0)}}
// From NetBSD's <sys/sysctl.h>
const (
_CTL_KERN = 1
_KERN_OSREV = 3
_CTL_HW = 6
_HW_NCPU = 3
_HW_PAGESIZE = 7
_HW_NCPUONLINE = 16
)
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 {
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 {
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 {
return uintptr(out)
}
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 {
gp := getg()
var deadline int64
if ns >= 0 {
deadline = nanotime() + ns
}
for {
v := atomic.Load(&gp.m.waitsemacount)
if v > 0 {
if atomic.Cas(&gp.m.waitsemacount, v, v-1) {
return 0 // semaphore acquired
}
continue
}
// Sleep until unparked by semawakeup or timeout.
var tsp *timespec
var ts timespec
if ns >= 0 {
wait := deadline - nanotime()
if wait <= 0 {
return -1
}
ts.setNsec(wait)
tsp = &ts
}
ret := lwp_park(_CLOCK_MONOTONIC, _TIMER_RELTIME, tsp, 0, unsafe.Pointer(&gp.m.waitsemacount), nil)
if ret == _ETIMEDOUT {
return -1
}
}
}
//go:nosplit
func semawakeup(mp *m) {
atomic.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(mp.g0.stack.hi)
if false {
print("newosproc stk=", stk, " m=", mp, " g=", mp.g0, " id=", mp.id, " ostk=", &mp, "\n")
}
var uc ucontextt
getcontext(unsafe.Pointer(&uc))
// _UC_SIGMASK does not seem to work here.
// It would be nice if _UC_SIGMASK and _UC_STACK
// worked so that we could do all the work setting
// the sigmask and the stack here, instead of setting
// the mask here and the stack in netbsdMstart.
// For now do the blocking manually.
uc.uc_flags = _UC_SIGMASK | _UC_CPU
uc.uc_link = nil
uc.uc_sigmask = sigset_all
var oset sigset
sigprocmask(_SIG_SETMASK, &sigset_all, &oset)
lwp_mcontext_init(&uc.uc_mcontext, stk, mp, mp.g0, abi.FuncPCABI0(netbsdMstart))
ret := retryOnEAGAIN(func() int32 {
errno := lwp_create(unsafe.Pointer(&uc), _LWP_DETACHED, unsafe.Pointer(&mp.procid))
// lwp_create returns negative errno
return -errno
})
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")
}
}
// mstart is the entry-point for new Ms.
// It is written in assembly, uses ABI0, is marked TOPFRAME, and calls netbsdMstart0.
func netbsdMstart()
// netbsdMStart0 is the function call that starts executing a newly
// created thread. On NetBSD, a new thread inherits the signal stack
// of the creating thread. That confuses minit, so we remove that
// signal stack here before calling the regular mstart. It's a bit
// baroque to remove a signal stack here only to add one in minit, but
// it's a simple change that keeps NetBSD working like other OS's.
// At this point all signals are blocked, so there is no race.
//
//go:nosplit
func netbsdMstart0() {
st := stackt{ss_flags: _SS_DISABLE}
sigaltstack(&st, nil)
mstart0()
}
func osinit() {
ncpu = getncpu()
if physPageSize == 0 {
physPageSize = getPageSize()
}
needSysmonWorkaround = getOSRev() < 902000000 // NetBSD 9.2
}
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
}
// Called to initialize a new m (including the bootstrap m).
// Called on the new thread, cannot allocate memory.
func minit() {
gp := getg()
gp.m.procid = uint64(lwp_self())
// On NetBSD a thread created by pthread_create inherits the
// signal stack of the creating thread. We always create a
// new signal stack here, to avoid having two Go threads using
// the same signal stack. This breaks the case of a thread
// created in C that calls sigaltstack and then calls a Go
// function, because we will lose track of the C code's
// sigaltstack, but it's the best we can do.
signalstack(&gp.m.gsignal.stack)
gp.m.newSigstack = true
minitSignalMask()
}
// Called from dropm to undo the effect of an minit.
//
//go:nosplit
func unminit() {
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) {
}
func sigtramp()
type sigactiont struct {
sa_sigaction uintptr
sa_mask sigset
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 = sigset_all
if fn == abi.FuncPCABIInternal(sighandler) { // abi.FuncPCABIInternal(sighandler) matches the callers in signal_unix.go
fn = abi.FuncPCABI0(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
}
// setSignalstackSP 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.__bits[(i-1)/32] |= 1 << ((uint32(i) - 1) & 31)
}
func sigdelset(mask *sigset, i int) {
mask.__bits[(i-1)/32] &^= 1 << ((uint32(i) - 1) & 31)
}
//go:nosplit
func (c *sigctxt) fixsigcode(sig uint32) {
}
func setProcessCPUProfiler(hz int32) {
setProcessCPUProfilerTimer(hz)
}
func setThreadCPUProfiler(hz int32) {
setThreadCPUProfilerHz(hz)
}
//go:nosplit
func validSIGPROF(mp *m, c *sigctxt) bool {
return true
}
func sysargs(argc int32, argv **byte) {
n := argc + 1
// skip over argv, envp to get to auxv
for argv_index(argv, n) != nil {
n++
}
// skip NULL separator
n++
// now argv+n is auxv
auxv := (*[1 << 28]uintptr)(add(unsafe.Pointer(argv), uintptr(n)*goarch.PtrSize))
sysauxv(auxv[:])
}
const (
_AT_NULL = 0 // Terminates the vector
_AT_PAGESZ = 6 // Page size in bytes
)
func sysauxv(auxv []uintptr) {
for i := 0; auxv[i] != _AT_NULL; i += 2 {
tag, val := auxv[i], auxv[i+1]
switch tag {
case _AT_PAGESZ:
physPageSize = val
}
}
}
// raise sends signal to the calling thread.
//
// It must be nosplit because it is used by the signal handler before
// it definitely has a Go stack.
//
//go:nosplit
func raise(sig uint32) {
lwp_kill(lwp_self(), int(sig))
}
func signalM(mp *m, sig int) {
lwp_kill(int32(mp.procid), 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")
}