/
syscall.go
178 lines (153 loc) · 3.5 KB
/
syscall.go
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//go:build linux
package uring
import (
"math"
"os"
"syscall"
"unsafe"
)
const (
sysRingSetup uintptr = 425
sysRingEnter uintptr = 426
sysRingRegister uintptr = 427
//copied from signal_unix.numSig
numSig = 65
)
// sqRing ring flags
const (
sqNeedWakeup uint32 = 1 << 0 // needs io_uring_enter wakeup
sqCQOverflow uint32 = 1 << 1 // cq ring is overflown
)
// io_uring_enter flags
const (
sysRingEnterGetEvents uint32 = 1 << 0
sysRingEnterSQWakeup uint32 = 1 << 1
sysRingEnterSQWait uint32 = 1 << 2
sysRingEnterExtArg uint32 = 1 << 3
)
// SQE flags
const (
SqeFixedFileFlag uint8 = 1 << 0
SqeIODrainFlag uint8 = 1 << 1
SqeIOLinkFlag uint8 = 1 << 2
SqeIOHardLinkFlag uint8 = 1 << 3
SqeAsyncFlag uint8 = 1 << 4
SqeBufferSelectFlag uint8 = 1 << 5
)
const (
libUserDataTimeout = math.MaxUint64
)
func sysEnter(ringFD int, toSubmit uint32, minComplete uint32, flags uint32, sig unsafe.Pointer, raw bool) (uint, error) {
return sysEnter2(ringFD, toSubmit, minComplete, flags, sig, numSig/8, raw)
}
func sysEnter2(ringFD int, toSubmit uint32, minComplete uint32, flags uint32, sig unsafe.Pointer, sz int, raw bool) (uint, error) {
var consumed uintptr
var errno syscall.Errno
if raw {
consumed, _, errno = syscall.RawSyscall6(
sysRingEnter,
uintptr(ringFD),
uintptr(toSubmit),
uintptr(minComplete),
uintptr(flags),
uintptr(sig),
uintptr(sz),
)
} else {
consumed, _, errno = syscall.Syscall6(
sysRingEnter,
uintptr(ringFD),
uintptr(toSubmit),
uintptr(minComplete),
uintptr(flags),
uintptr(sig),
uintptr(sz),
)
}
if errno != 0 {
return 0, os.NewSyscallError("io_uring_enter", errno)
}
return uint(consumed), nil
}
func sysSetup(entries uint32, params *ringParams) (int, error) {
fd, _, errno := syscall.Syscall(sysRingSetup, uintptr(entries), uintptr(unsafe.Pointer(params)), 0)
if errno != 0 {
return int(fd), os.NewSyscallError("io_uring_setup", errno)
}
return int(fd), nil
}
func sysRegister(ringFD int, op int, arg unsafe.Pointer, nrArgs int) error {
_, _, errno := syscall.Syscall6(
sysRingRegister,
uintptr(ringFD),
uintptr(op),
uintptr(arg),
uintptr(nrArgs),
0,
0,
)
if errno != 0 {
return os.NewSyscallError("io_uring_register", errno)
}
return nil
}
type SQEntry struct {
OpCode uint8
Flags uint8
IoPrio uint16
Fd int32
Off uint64
Addr uint64
Len uint32
OpcodeFlags uint32
UserData uint64
BufIG uint16
Personality uint16
SpliceFdIn int32
_pad2 [2]uint64
}
//go:uintptrescapes
func (sqe *SQEntry) fill(op OpCode, fd int32, addr uintptr, len uint32, offset uint64) {
sqe.OpCode = uint8(op)
sqe.Flags = 0
sqe.IoPrio = 0
sqe.Fd = fd
sqe.Off = offset
setAddr(sqe, addr)
sqe.Len = len
sqe.OpcodeFlags = 0
sqe.UserData = 0
sqe.BufIG = 0
sqe.Personality = 0
sqe.SpliceFdIn = 0
sqe._pad2[0] = 0
sqe._pad2[1] = 0
}
func (sqe *SQEntry) setUserData(ud uint64) {
sqe.UserData = ud
}
//go:uintptrescapes
func setAddr(sqe *SQEntry, addr uintptr) {
sqe.Addr = uint64(addr)
}
type CQEvent struct {
UserData uint64
Res int32
Flags uint32
}
func (cqe *CQEvent) Error() error {
if cqe.Res < 0 {
return syscall.Errno(uintptr(-cqe.Res))
}
return nil
}
type getEventsArg struct {
sigMask uintptr
sigMaskSz uint32
_pad uint32
ts uintptr
}
//go:uintptrescapes
func newGetEventsArg(sigMask uintptr, sigMaskSz uint32, ts uintptr) *getEventsArg {
return &getEventsArg{sigMask: sigMask, sigMaskSz: sigMaskSz, ts: ts}
}