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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"
)
type mOS struct{}
//go:noescape
//extern _umtx_op
func sys_umtx_op(addr *uint32, mode int32, val uint32, uaddr1 uinptr, ts *umtx_time) int32
//go:noescape
//extern sysctl
func sysctl(*uint32, uint32, *byte, *uintptr, *byte, uintptr) int32
const (
_CTL_MAXNAME = 24
_CPU_LEVEL_WHICH = 3
_CPU_WHICH_PID = 2
)
// From FreeBSD's <sys/sysctl.h>
const (
_CTL_HW = 6
_HW_PAGESIZE = 7
)
// Undocumented numbers from FreeBSD's lib/libc/gen/sysctlnametomib.c.
const (
_CTL_QUERY = 0
_CTL_QUERY_MIB = 3
)
// sysctlnametomib fill mib with dynamically assigned sysctl entries of name,
// return count of effected mib slots, return 0 on error.
func sysctlnametomib(name []byte, mib *[_CTL_MAXNAME]uint32) uint32 {
oid := [2]uint32{_CTL_QUERY, _CTL_QUERY_MIB}
miblen := uintptr(_CTL_MAXNAME)
if sysctl(&oid[0], 2, (*byte)(unsafe.Pointer(mib)), &miblen, (*byte)(unsafe.Pointer(&name[0])), (uintptr)(len(name))) < 0 {
return 0
}
miblen /= unsafe.Sizeof(uint32(0))
if miblen <= 0 {
return 0
}
return uint32(miblen)
}
const (
_CPU_CURRENT_PID = -1 // Current process ID.
)
//go:noescape
//extern cpuset_getaffinity
func cpuset_getaffinity(level int32, which int32, id int64, size uintptr, mask *byte) int32
//go:systemstack
func getncpu() int32 {
// Use a large buffer for the CPU mask. We're on the system
// stack, so this is fine, and we can't allocate memory for a
// dynamically-sized buffer at this point.
const maxCPUs = 64 * 1024
var mask [maxCPUs / 8]byte
var mib [_CTL_MAXNAME]uint32
// According to FreeBSD's /usr/src/sys/kern/kern_cpuset.c,
// cpuset_getaffinity return ERANGE when provided buffer size exceed the limits in kernel.
// Querying kern.smp.maxcpus to calculate maximum buffer size.
// See https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=200802
// Variable kern.smp.maxcpus introduced at Dec 23 2003, revision 123766,
// with dynamically assigned sysctl entries.
miblen := sysctlnametomib([]byte("kern.smp.maxcpus"), &mib)
if miblen == 0 {
return 1
}
// Query kern.smp.maxcpus.
dstsize := uintptr(4)
maxcpus := uint32(0)
if sysctl(&mib[0], miblen, (*byte)(unsafe.Pointer(&maxcpus)), &dstsize, nil, 0) != 0 {
return 1
}
maskSize := uintptr(int(maxcpus+7) / 8)
if maskSize < sys.PtrSize {
maskSize = sys.PtrSize
}
if maskSize > uintptr(len(mask)) {
maskSize = uintptr(len(mask))
}
if cpuset_getaffinity(_CPU_LEVEL_WHICH, _CPU_WHICH_PID, _CPU_CURRENT_PID,
maskSize, (*byte)(unsafe.Pointer(&mask[0]))) != 0 {
return 1
}
n := int32(0)
for _, v := range mask[:maskSize] {
for v != 0 {
n += int32(v & 1)
v >>= 1
}
}
if n == 0 {
return 1
}
return n
}
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
}
// FreeBSD's umtx_op syscall is effectively the same as Linux's futex, and
// thus the code is largely similar. See Linux implementation
// and lock_futex.go for comments.
//go:nosplit
func futexsleep(addr *uint32, val uint32, ns int64) {
systemstack(func() {
futexsleep1(addr, val, ns)
})
}
func futexsleep1(addr *uint32, val uint32, ns int64) {
var utp *umtx_time
if ns >= 0 {
var ut umtx_time
ut._clockid = _CLOCK_MONOTONIC
ut._timeout.setNsec(ns)
utp = &ut
}
ret := sys_umtx_op(addr, _UMTX_OP_WAIT_UINT_PRIVATE, val, unsafe.Sizeof(*utp), utp)
if ret >= 0 || ret == -_EINTR || ret == -_ETIMEDOUT {
return
}
print("umtx_wait addr=", addr, " val=", val, " ret=", ret, "\n")
*(*int32)(unsafe.Pointer(uintptr(0x1005))) = 0x1005
}
//go:nosplit
func futexwakeup(addr *uint32, cnt uint32) {
ret := sys_umtx_op(addr, _UMTX_OP_WAKE_PRIVATE, cnt, 0, nil)
if ret >= 0 {
return
}
systemstack(func() {
print("umtx_wake_addr=", addr, " ret=", ret, "\n")
})
}
func osinit() {
ncpu = getncpu()
if physPageSize == 0 {
physPageSize = getPageSize()
}
}
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)*sys.PtrSize))
sysauxv(auxv[:])
}
const (
_AT_NULL = 0 // Terminates the vector
_AT_PAGESZ = 6 // Page size in bytes
_AT_TIMEKEEP = 22 // Pointer to timehands.
_AT_HWCAP = 25 // CPU feature flags
_AT_HWCAP2 = 26 // CPU feature flags 2
)
func sysauxv(auxv []uintptr) {
for i := 0; auxv[i] != _AT_NULL; i += 2 {
tag, val := auxv[i], auxv[i+1]
switch tag {
// _AT_NCPUS from auxv shouldn't be used due to golang.org/issue/15206
case _AT_PAGESZ:
physPageSize = val
case _AT_TIMEKEEP:
timekeepSharedPage = (*vdsoTimekeep)(unsafe.Pointer(val))
}
archauxv(tag, val)
}
}