GoToSocial/vendor/modernc.org/libc/etc.go
kim ed46224573
Add SQLite support, fix un-thread-safe DB caches, small performance f… (#172)
* Add SQLite support, fix un-thread-safe DB caches, small performance fixes

Signed-off-by: kim (grufwub) <grufwub@gmail.com>

* add SQLite licenses to README

Signed-off-by: kim (grufwub) <grufwub@gmail.com>

* appease the linter, and fix my dumbass-ery

Signed-off-by: kim (grufwub) <grufwub@gmail.com>

* make requested changes

Signed-off-by: kim (grufwub) <grufwub@gmail.com>

* add back comment

Signed-off-by: kim (grufwub) <grufwub@gmail.com>
2021-08-29 16:41:41 +02:00

915 lines
18 KiB
Go

// Copyright 2020 The Libc 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 libc // import "modernc.org/libc"
import (
"fmt"
"io"
"os"
"path/filepath"
"runtime"
"runtime/debug"
"sort"
"strconv"
"strings"
"sync"
"sync/atomic"
"syscall"
"time"
"unsafe"
"modernc.org/libc/errno"
"modernc.org/libc/signal"
"modernc.org/libc/sys/types"
)
const (
allocatorPageOverhead = 4 * unsafe.Sizeof(int(0))
stackHeaderSize = unsafe.Sizeof(stackHeader{})
stackSegmentSize = 1<<12 - allocatorPageOverhead
uintptrSize = unsafe.Sizeof(uintptr(0))
)
var (
Covered = map[uintptr]struct{}{}
CoveredC = map[string]struct{}{}
fToken uintptr
tid int32
atExit []func()
atExitMu sync.Mutex
signals [signal.NSIG]uintptr
signalsMu sync.Mutex
objectMu sync.Mutex
objects = map[uintptr]interface{}{}
tlsBalance int32
_ = origin
_ = trc
)
func init() {
if n := stackHeaderSize; n%16 != 0 {
panic(fmt.Errorf("internal error: stackHeaderSize %v == %v (mod 16)", n, n%16))
}
}
func origin(skip int) string {
pc, fn, fl, _ := runtime.Caller(skip)
f := runtime.FuncForPC(pc)
var fns string
if f != nil {
fns = f.Name()
if x := strings.LastIndex(fns, "."); x > 0 {
fns = fns[x+1:]
}
}
return fmt.Sprintf("%s:%d:%s", filepath.Base(fn), fl, fns)
}
func trc(s string, args ...interface{}) string { //TODO-
switch {
case s == "":
s = fmt.Sprintf(strings.Repeat("%v ", len(args)), args...)
default:
s = fmt.Sprintf(s, args...)
}
r := fmt.Sprintf("%s: TRC %s", origin(2), s)
fmt.Fprintf(os.Stdout, "%s\n", r)
os.Stdout.Sync()
return r
}
func todo(s string, args ...interface{}) string { //TODO-
switch {
case s == "":
s = fmt.Sprintf(strings.Repeat("%v ", len(args)), args...)
default:
s = fmt.Sprintf(s, args...)
}
r := fmt.Sprintf("%s: TODOTODO %s", origin(2), s) //TODOOK
if dmesgs {
dmesg("%s", r)
}
fmt.Fprintf(os.Stdout, "%s\n", r)
fmt.Fprintf(os.Stdout, "%s\n", debug.Stack()) //TODO-
os.Stdout.Sync()
os.Exit(1)
panic("unrechable")
}
var coverPCs [1]uintptr //TODO not concurrent safe
func Cover() {
runtime.Callers(2, coverPCs[:])
Covered[coverPCs[0]] = struct{}{}
}
func CoverReport(w io.Writer) error {
var a []string
pcs := make([]uintptr, 1)
for pc := range Covered {
pcs[0] = pc
frame, _ := runtime.CallersFrames(pcs).Next()
a = append(a, fmt.Sprintf("%s:%07d:%s", filepath.Base(frame.File), frame.Line, frame.Func.Name()))
}
sort.Strings(a)
_, err := fmt.Fprintf(w, "%s\n", strings.Join(a, "\n"))
return err
}
func CoverC(s string) {
CoveredC[s] = struct{}{}
}
func CoverCReport(w io.Writer) error {
var a []string
for k := range CoveredC {
a = append(a, k)
}
sort.Strings(a)
_, err := fmt.Fprintf(w, "%s\n", strings.Join(a, "\n"))
return err
}
func token() uintptr { return atomic.AddUintptr(&fToken, 1) }
func addObject(o interface{}) uintptr {
t := token()
objectMu.Lock()
objects[t] = o
objectMu.Unlock()
return t
}
func getObject(t uintptr) interface{} {
objectMu.Lock()
o := objects[t]
if o == nil {
panic(todo("", t))
}
objectMu.Unlock()
return o
}
func removeObject(t uintptr) {
objectMu.Lock()
if _, ok := objects[t]; !ok {
panic(todo(""))
}
delete(objects, t)
objectMu.Unlock()
}
func (t *TLS) setErrno(err interface{}) {
if memgrind {
if atomic.SwapInt32(&t.reentryGuard, 1) != 0 {
panic(todo("concurrent use of TLS instance %p", t))
}
defer func() {
if atomic.SwapInt32(&t.reentryGuard, 0) != 1 {
panic(todo("concurrent use of TLS instance %p", t))
}
}()
}
// if dmesgs {
// dmesg("%v: %T(%v)\n%s", origin(1), err, err, debug.Stack())
// }
again:
switch x := err.(type) {
case int:
*(*int32)(unsafe.Pointer(t.errnop)) = int32(x)
case int32:
*(*int32)(unsafe.Pointer(t.errnop)) = x
case *os.PathError:
err = x.Err
goto again
case syscall.Errno:
*(*int32)(unsafe.Pointer(t.errnop)) = int32(x)
case *os.SyscallError:
err = x.Err
goto again
default:
panic(todo("%T", x))
}
}
// Close frees the resources of t.
func (t *TLS) Close() {
t.Free(int(unsafe.Sizeof(int32(0))))
if memgrind {
if t.stackHeaderBalance != 0 {
panic(todo("non zero stack header balance: %d", t.stackHeaderBalance))
}
atomic.AddInt32(&tlsBalance, -1)
}
}
// Alloc allocates n bytes of thread-local storage. It must be paired with a
// call to t.Free(n), using the same n. The order matters. This is ok:
//
// t.Alloc(11)
// t.Alloc(22)
// t.Free(22)
// t.Free(11)
//
// This is not correct:
//
// t.Alloc(11)
// t.Alloc(22)
// t.Free(11)
// t.Free(22)
func (t *TLS) Alloc(n int) (r uintptr) {
if memgrind {
if atomic.SwapInt32(&t.reentryGuard, 1) != 0 {
panic(todo("concurrent use of TLS instance %p", t))
}
defer func() {
if atomic.SwapInt32(&t.reentryGuard, 0) != 1 {
panic(todo("concurrent use of TLS instance %p", t))
}
}()
}
n += 15
n &^= 15
if t.stack.free >= n {
r = t.stack.sp
t.stack.free -= n
t.stack.sp += uintptr(n)
return r
}
//if we have a next stack
if nstack := t.stack.next; nstack != 0 {
if (*stackHeader)(unsafe.Pointer(nstack)).free >= n {
*(*stackHeader)(unsafe.Pointer(t.stack.page)) = t.stack
t.stack = *(*stackHeader)(unsafe.Pointer(nstack))
r = t.stack.sp
t.stack.free -= n
t.stack.sp += uintptr(n)
return r
}
nstack := *(*stackHeader)(unsafe.Pointer(t.stack.next))
for ; ; nstack = *(*stackHeader)(unsafe.Pointer(nstack.next)) {
if memgrind {
if atomic.AddInt32(&t.stackHeaderBalance, -1) < 0 {
panic(todo("negative stack header balance"))
}
}
Xfree(t, nstack.page)
if nstack.next == 0 {
break
}
}
t.stack.next = 0
}
if t.stack.page != 0 {
*(*stackHeader)(unsafe.Pointer(t.stack.page)) = t.stack
}
rq := n + int(stackHeaderSize)
if rq%int(stackSegmentSize) != 0 {
rq -= rq % int(stackSegmentSize)
rq += int(stackSegmentSize)
}
t.stack.free = rq - int(stackHeaderSize)
t.stack.prev = t.stack.page
rq += 15
rq &^= 15
t.stack.page = Xmalloc(t, types.Size_t(rq))
if t.stack.page == 0 {
panic("OOM")
}
if memgrind {
atomic.AddInt32(&t.stackHeaderBalance, 1)
}
t.stack.sp = t.stack.page + stackHeaderSize
r = t.stack.sp
t.stack.free -= n
t.stack.sp += uintptr(n)
if t.stack.prev != 0 {
(*stackHeader)(unsafe.Pointer(t.stack.prev)).next = t.stack.page
}
return r
}
//this declares how many stack frames are kept alive before being freed
const stackFrameKeepalive = 2
// Free deallocates n bytes of thread-local storage. See TLS.Alloc for details
// on correct usage.
func (t *TLS) Free(n int) {
if memgrind {
if atomic.SwapInt32(&t.reentryGuard, 1) != 0 {
panic(todo("concurrent use of TLS instance %p", t))
}
defer func() {
if atomic.SwapInt32(&t.reentryGuard, 0) != 1 {
panic(todo("concurrent use of TLS instance %p", t))
}
}()
}
n += 15
n &^= 15
t.stack.free += n
t.stack.sp -= uintptr(n)
if t.stack.sp != t.stack.page+stackHeaderSize {
return
}
nstack := t.stack
//if we are the first one, just free all of them
if t.stack.prev == 0 {
for ; ; nstack = *(*stackHeader)(unsafe.Pointer(nstack.next)) {
if memgrind {
if atomic.AddInt32(&t.stackHeaderBalance, -1) < 0 {
panic(todo("negative stack header balance"))
}
}
Xfree(t, nstack.page)
if nstack.next == 0 {
break
}
}
t.stack = stackHeader{}
return
}
//look if we are in the last n stackframes (n=stackFrameKeepalive)
//if we find something just return and set the current stack pointer to the previous one
for i := 0; i < stackFrameKeepalive; i++ {
if nstack.next == 0 {
*((*stackHeader)(unsafe.Pointer(t.stack.page))) = t.stack
t.stack = *(*stackHeader)(unsafe.Pointer(t.stack.prev))
return
}
nstack = *(*stackHeader)(unsafe.Pointer(nstack.next))
}
//else only free the last
if memgrind {
if atomic.AddInt32(&t.stackHeaderBalance, -1) < 0 {
panic(todo("negative stack header balance"))
}
}
Xfree(t, nstack.page)
(*stackHeader)(unsafe.Pointer(nstack.prev)).next = 0
*(*stackHeader)(unsafe.Pointer(t.stack.page)) = t.stack
t.stack = *(*stackHeader)(unsafe.Pointer(t.stack.prev))
}
type stackHeader struct {
free int // bytes left in page
page uintptr // stack page
prev uintptr // prev stack page = prev stack header
next uintptr // next stack page = next stack header
sp uintptr // next allocation address
_ stackHeaderPadding
}
func cString(t *TLS, s string) uintptr { //TODO-
n := len(s)
p := Xmalloc(t, types.Size_t(n)+1)
if p == 0 {
panic("OOM")
}
copy((*RawMem)(unsafe.Pointer(p))[:n:n], s)
*(*byte)(unsafe.Pointer(p + uintptr(n))) = 0
return p
}
// VaList fills a varargs list at p with args and returns p. The list must
// have been allocated by caller and it must not be in Go managed memory, ie.
// it must be pinned. Caller is responsible for freeing the list.
//
// Individual arguments must be one of int, uint, int32, uint32, int64, uint64,
// float64, uintptr or Intptr. Other types will panic.
//
// This function supports code generated by ccgo/v3. For manually constructed
// var args it's recommended to use the NewVaList function instead.
//
// Note: The C translated to Go varargs ABI alignment for all types is 8 on all
// architectures.
func VaList(p uintptr, args ...interface{}) (r uintptr) {
if p&7 != 0 {
panic("internal error")
}
r = p
for _, v := range args {
switch x := v.(type) {
case int:
*(*int64)(unsafe.Pointer(p)) = int64(x)
case int32:
*(*int64)(unsafe.Pointer(p)) = int64(x)
case int64:
*(*int64)(unsafe.Pointer(p)) = x
case uint:
*(*uint64)(unsafe.Pointer(p)) = uint64(x)
case uint16:
*(*uint64)(unsafe.Pointer(p)) = uint64(x)
case uint32:
*(*uint64)(unsafe.Pointer(p)) = uint64(x)
case uint64:
*(*uint64)(unsafe.Pointer(p)) = x
case float64:
*(*float64)(unsafe.Pointer(p)) = x
case uintptr:
*(*uintptr)(unsafe.Pointer(p)) = x
default:
panic(todo("invalid VaList argument type: %T", x))
}
p += 8
}
return r
}
// NewVaListN returns a newly allocated va_list for n items. The caller of
// NewVaListN is responsible for freeing the va_list.
func NewVaListN(n int) (va_list uintptr) {
return Xmalloc(nil, types.Size_t(8*n))
}
// NewVaList is like VaList but automatically allocates the correct amount of
// memory for all of the items in args.
//
// The va_list return value is used to pass the constructed var args to var
// args accepting functions. The caller of NewVaList is responsible for freeing
// the va_list.
func NewVaList(args ...interface{}) (va_list uintptr) {
return VaList(NewVaListN(len(args)), args...)
}
func VaInt32(app *uintptr) int32 {
ap := *(*uintptr)(unsafe.Pointer(app))
if ap == 0 {
return 0
}
ap = roundup(ap, 8)
v := int32(*(*int64)(unsafe.Pointer(ap)))
ap += 8
*(*uintptr)(unsafe.Pointer(app)) = ap
return v
}
func VaUint32(app *uintptr) uint32 {
ap := *(*uintptr)(unsafe.Pointer(app))
if ap == 0 {
return 0
}
ap = roundup(ap, 8)
v := uint32(*(*uint64)(unsafe.Pointer(ap)))
ap += 8
*(*uintptr)(unsafe.Pointer(app)) = ap
return v
}
func VaInt64(app *uintptr) int64 {
ap := *(*uintptr)(unsafe.Pointer(app))
if ap == 0 {
return 0
}
ap = roundup(ap, 8)
v := *(*int64)(unsafe.Pointer(ap))
ap += 8
*(*uintptr)(unsafe.Pointer(app)) = ap
return v
}
func VaUint64(app *uintptr) uint64 {
ap := *(*uintptr)(unsafe.Pointer(app))
if ap == 0 {
return 0
}
ap = roundup(ap, 8)
v := *(*uint64)(unsafe.Pointer(ap))
ap += 8
*(*uintptr)(unsafe.Pointer(app)) = ap
return v
}
func VaFloat32(app *uintptr) float32 {
ap := *(*uintptr)(unsafe.Pointer(app))
if ap == 0 {
return 0
}
ap = roundup(ap, 8)
v := *(*float64)(unsafe.Pointer(ap))
ap += 8
*(*uintptr)(unsafe.Pointer(app)) = ap
return float32(v)
}
func VaFloat64(app *uintptr) float64 {
ap := *(*uintptr)(unsafe.Pointer(app))
if ap == 0 {
return 0
}
ap = roundup(ap, 8)
v := *(*float64)(unsafe.Pointer(ap))
ap += 8
*(*uintptr)(unsafe.Pointer(app)) = ap
return v
}
func VaUintptr(app *uintptr) uintptr {
ap := *(*uintptr)(unsafe.Pointer(app))
if ap == 0 {
return 0
}
ap = roundup(ap, 8)
v := *(*uintptr)(unsafe.Pointer(ap))
ap += 8
*(*uintptr)(unsafe.Pointer(app)) = ap
return v
}
func roundup(n, to uintptr) uintptr {
if r := n % to; r != 0 {
return n + to - r
}
return n
}
func GoString(s uintptr) string {
if s == 0 {
return ""
}
var buf []byte
for {
b := *(*byte)(unsafe.Pointer(s))
if b == 0 {
return string(buf)
}
buf = append(buf, b)
s++
}
}
// GoBytes returns a byte slice from a C char* having length len bytes.
func GoBytes(s uintptr, len int) []byte {
if len == 0 {
return nil
}
return (*RawMem)(unsafe.Pointer(s))[:len:len]
}
func Bool32(b bool) int32 {
if b {
return 1
}
return 0
}
func Bool64(b bool) int64 {
if b {
return 1
}
return 0
}
type sorter struct {
len int
base uintptr
sz uintptr
f func(*TLS, uintptr, uintptr) int32
t *TLS
}
func (s *sorter) Len() int { return s.len }
func (s *sorter) Less(i, j int) bool {
return s.f(s.t, s.base+uintptr(i)*s.sz, s.base+uintptr(j)*s.sz) < 0
}
func (s *sorter) Swap(i, j int) {
p := uintptr(s.base + uintptr(i)*s.sz)
q := uintptr(s.base + uintptr(j)*s.sz)
for i := 0; i < int(s.sz); i++ {
*(*byte)(unsafe.Pointer(p)), *(*byte)(unsafe.Pointer(q)) = *(*byte)(unsafe.Pointer(q)), *(*byte)(unsafe.Pointer(p))
p++
q++
}
}
func CString(s string) (uintptr, error) {
n := len(s)
p := Xmalloc(nil, types.Size_t(n)+1)
if p == 0 {
return 0, fmt.Errorf("CString: cannot allocate %d bytes", n+1)
}
copy((*RawMem)(unsafe.Pointer(p))[:n:n], s)
*(*byte)(unsafe.Pointer(p + uintptr(n))) = 0
return p, nil
}
func GetEnviron() (r []string) {
for p := Environ(); ; p += unsafe.Sizeof(p) {
q := *(*uintptr)(unsafe.Pointer(p))
if q == 0 {
return r
}
r = append(r, GoString(q))
}
}
func strToUint64(t *TLS, s uintptr, base int32) (seenDigits, neg bool, next uintptr, n uint64, err int32) {
var c byte
out:
for {
c = *(*byte)(unsafe.Pointer(s))
switch c {
case ' ', '\t', '\n', '\r', '\v', '\f':
s++
case '+':
s++
break out
case '-':
s++
neg = true
break out
default:
break out
}
}
for {
c = *(*byte)(unsafe.Pointer(s))
var digit uint64
switch base {
case 10:
switch {
case c >= '0' && c <= '9':
seenDigits = true
digit = uint64(c) - '0'
default:
return seenDigits, neg, s, n, 0
}
case 16:
if c >= 'A' && c <= 'F' {
c = c + ('a' - 'A')
}
switch {
case c >= '0' && c <= '9':
seenDigits = true
digit = uint64(c) - '0'
case c >= 'a' && c <= 'f':
seenDigits = true
digit = uint64(c) - 'a' + 10
default:
return seenDigits, neg, s, n, 0
}
default:
panic(todo("", base))
}
n0 := n
n = uint64(base)*n + digit
if n < n0 { // overflow
return seenDigits, neg, s, n0, errno.ERANGE
}
s++
}
}
func strToFloatt64(t *TLS, s uintptr, bits int) (n float64, errno int32) {
var b []byte
var neg bool
defer func() {
var err error
if n, err = strconv.ParseFloat(string(b), bits); err != nil {
panic(todo(""))
}
if neg {
n = -n
}
}()
var c byte
out:
for {
c = *(*byte)(unsafe.Pointer(s))
switch c {
case ' ', '\t', '\n', '\r', '\v', '\f':
s++
case '+':
s++
break out
case '-':
s++
neg = true
break out
default:
break out
}
}
for {
c = *(*byte)(unsafe.Pointer(s))
switch {
case c >= '0' && c <= '9':
b = append(b, c)
case c == '.':
b = append(b, c)
s++
for {
c = *(*byte)(unsafe.Pointer(s))
switch {
case c >= '0' && c <= '9':
b = append(b, c)
case c == 'e' || c == 'E':
b = append(b, c)
s++
for {
c = *(*byte)(unsafe.Pointer(s))
switch {
case c == '+' || c == '-':
b = append(b, c)
s++
for {
c = *(*byte)(unsafe.Pointer(s))
switch {
case c >= '0' && c <= '9':
b = append(b, c)
default:
return
}
s++
}
default:
panic(todo("%q %q", b, string(c)))
}
}
default:
return
}
s++
}
default:
panic(todo("%q %q", b, string(c)))
}
s++
}
}
func parseZone(s string) (name string, off int) {
_, name, off, _ = parseZoneOffset(s, false)
return name, off
}
func parseZoneOffset(s string, offOpt bool) (string, string, int, bool) {
s0 := s
name := s
for len(s) != 0 {
switch c := s[0]; {
case c >= 'A' && c <= 'Z', c >= 'a' && c <= 'z', c == '_', c == '/':
s = s[1:]
default:
name = name[:len(name)-len(s)]
if len(name) < 3 {
panic(todo("%q", s0))
}
if offOpt {
if len(s) == 0 {
return "", name, 0, false
}
if c := s[0]; (c < '0' || c > '9') && c != '+' && c != '-' {
return s, name, 0, false
}
}
s, off := parseOffset(s)
return s, name, off, true
}
}
return "", s0, 0, true
}
// [+|-]hh[:mm[:ss]]
func parseOffset(s string) (string, int) {
if len(s) == 0 {
panic(todo(""))
}
k := 1
switch s[0] {
case '+':
// nop
s = s[1:]
case '-':
k = -1
s = s[1:]
}
s, hh, ok := parseUint(s)
if !ok {
panic(todo(""))
}
n := hh * 3600
if len(s) == 0 || s[0] != ':' {
return s, k * n
}
s = s[1:] // ':'
if len(s) == 0 {
panic(todo(""))
}
s, mm, ok := parseUint(s)
if !ok {
panic(todo(""))
}
n += mm * 60
if len(s) == 0 || s[0] != ':' {
return s, k * n
}
s = s[1:] // ':'
if len(s) == 0 {
panic(todo(""))
}
s, ss, _ := parseUint(s)
return s, k * (n + ss)
}
func parseUint(s string) (string, int, bool) {
var ok bool
var r int
for len(s) != 0 {
switch c := s[0]; {
case c >= '0' && c <= '9':
ok = true
r0 := r
r = 10*r + int(c) - '0'
if r < r0 {
panic(todo(""))
}
s = s[1:]
default:
return s, r, ok
}
}
return s, r, ok
}
// https://stackoverflow.com/a/53052382
//
// isTimeDST returns true if time t occurs within daylight saving time
// for its time zone.
func isTimeDST(t time.Time) bool {
// If the most recent (within the last year) clock change
// was forward then assume the change was from std to dst.
hh, mm, _ := t.UTC().Clock()
tClock := hh*60 + mm
for m := -1; m > -12; m-- {
// assume dst lasts for at least one month
hh, mm, _ := t.AddDate(0, m, 0).UTC().Clock()
clock := hh*60 + mm
if clock != tClock {
return clock > tClock
}
}
// assume no dst
return false
}