@ -451,10 +451,9 @@ func Accept(fd int) (nfd int, sa Sockaddr, err error) {
//sys recvmsg(s int, msg *Msghdr, flags int) (n int, err error) = libsocket.__xnet_recvmsg
func Recvmsg ( fd int , p , oob [ ] byte , flags int ( n , oobn int , recvflags int , from Sockaddr , err error ) {
func recvmsgRaw ( fd int , p , oob [ ] byte , flags int , rsa * RawSockaddrAny ) ( n , oobn int , recvflags int , err error ) {
var msg Msghdr
var rsa RawSockaddrAny
msg . Name = ( * byte ) ( unsafe . Pointer ( & rsa ) )
msg . Name = ( * byte ) ( unsafe . Pointer ( rsa ) )
msg . Namelen = uint32 ( SizeofSockaddrAny )
var iov Iovec
if len ( p ) > 0 {
@ -476,29 +475,12 @@ func Recvmsg(fd int, p, oob []byte, flags int) (n, oobn int, recvflags int, from
return
}
oobn = int ( msg . Accrightslen )
// source address is only specified if the socket is unconnected
if rsa . Addr . Family != AF_UNSPEC {
from , err = anyToSockaddr ( fd , & rsa )
}
return
}
func Sendmsg ( fd int , p , oob [ ] byte , to Sockaddr , flags int ) ( err error ) {
_ , err = SendmsgN ( fd , p , oob , to , flags )
return
}
//sys sendmsg(s int, msg *Msghdr, flags int) (n int, err error) = libsocket.__xnet_sendmsg
func SendmsgN ( fd int , p , oob [ ] byte , to Sockaddr , flags int ) ( n int , err error ) {
var ptr unsafe . Pointer
var salen _Socklen
if to != nil {
ptr , salen , err = to . sockaddr ( )
if err != nil {
return 0 , err
}
}
func sendmsgN ( fd int , p , oob [ ] byte , ptr unsafe . Pointer , salen _Socklen , flags int ) ( n int , err error ) {
var msg Msghdr
msg . Name = ( * byte ) ( unsafe . Pointer ( ptr ) )
msg . Namelen = uint32 ( salen )
@ -661,8 +643,8 @@ func Sendfile(outfd int, infd int, offset *int64, count int) (written int, err e
//sys Openat(dirfd int, path string, flags int, mode uint32) (fd int, err error)
//sys Pathconf(path string, name int) (val int, err error)
//sys Pause() (err error)
//sys P read(fd int, p []byte, offset int64) (n int, err error)
//sys P write(fd int, p []byte, offset int64) (n int, err error)
//sys p read(fd int, p []byte, offset int64) (n int, err error)
//sys p write(fd int, p []byte, offset int64) (n int, err error)
//sys read(fd int, p []byte) (n int, err error)
//sys Readlink(path string, buf []byte) (n int, err error)
//sys Rename(from string, to string) (err error)
@ -755,8 +737,20 @@ type fileObjCookie struct {
type EventPort struct {
port int
mu sync . Mutex
fds map [ uintptr ] interface { }
fds map [ uintptr ] * fileObjCookie
paths map [ string ] * fileObjCookie
// The user cookie presents an interesting challenge from a memory management perspective.
// There are two paths by which we can discover that it is no longer in use:
// 1. The user calls port_dissociate before any events fire
// 2. An event fires and we return it to the user
// The tricky situation is if the event has fired in the kernel but
// the user hasn't requested/received it yet.
// If the user wants to port_dissociate before the event has been processed,
// we should handle things gracefully. To do so, we need to keep an extra
// reference to the cookie around until the event is processed
// thus the otherwise seemingly extraneous "cookies" map
// The key of this map is a pointer to the corresponding &fCookie.cookie
cookies map [ * interface { } ] * fileObjCookie
}
// PortEvent is an abstraction of the port_event C struct.
@ -780,9 +774,10 @@ func NewEventPort() (*EventPort, error) {
return nil , err
}
e := & EventPort {
port : port ,
fds : make ( map [ uintptr ] interface { } ) ,
paths : make ( map [ string ] * fileObjCookie ) ,
port : port ,
fds : make ( map [ uintptr ] * fileObjCookie ) ,
paths : make ( map [ string ] * fileObjCookie ) ,
cookies : make ( map [ * interface { } ] * fileObjCookie ) ,
}
return e , nil
}
@ -797,9 +792,13 @@ func NewEventPort() (*EventPort, error) {
func ( e * EventPort ) Close ( ) error {
e . mu . Lock ( )
defer e . mu . Unlock ( )
err := Close ( e . port )
if err != nil {
return err
}
e . fds = nil
e . paths = nil
return Close ( e . port )
return nil
}
// PathIsWatched checks to see if path is associated with this EventPort.
@ -836,6 +835,7 @@ func (e *EventPort) AssociatePath(path string, stat os.FileInfo, events int, coo
return err
}
e . paths [ path ] = fCookie
e . cookies [ & fCookie . cookie ] = fCookie
return nil
}
@ -848,11 +848,19 @@ func (e *EventPort) DissociatePath(path string) error {
return fmt . Errorf ( "%v is not associated with this Event Port" , path )
}
_ , err := port_dissociate ( e . port , PORT_SOURCE_FILE , uintptr ( unsafe . Pointer ( f . fobj ) ) )
if err != nil {
// If the path is no longer associated with this event port (ENOENT)
// we should delete it from our map. We can still return ENOENT to the caller.
// But we need to save the cookie
if err != nil && err != ENOENT {
return err
}
if err == nil {
// dissociate was successful, safe to delete the cookie
fCookie := e . paths [ path ]
delete ( e . cookies , & fCookie . cookie )
}
delete ( e . paths , path )
return nil
return err
}
// AssociateFd wraps calls to port_associate(3c) on file descriptors.
@ -862,12 +870,13 @@ func (e *EventPort) AssociateFd(fd uintptr, events int, cookie interface{}) erro
if _ , found := e . fds [ fd ] ; found {
return fmt . Errorf ( "%v is already associated with this Event Port" , fd )
}
pcookie := & cookie
_ , err := port_associate ( e . port , PORT_SOURCE_FD , fd , events , ( * byte ) ( unsafe . Pointer ( p ) ) )
fCookie := & fileObjCookie { nil , cookie }
_ , err := port_associate ( e . port , PORT_SOURCE_FD , fd , events , ( * byte ) ( unsafe . Pointer ( & fCookie . ) ) )
if err != nil {
return err
}
e . fds [ fd ] = pcookie
e . fds [ fd ] = fCookie
e . cookies [ & fCookie . cookie ] = fCookie
return nil
}
@ -880,11 +889,16 @@ func (e *EventPort) DissociateFd(fd uintptr) error {
return fmt . Errorf ( "%v is not associated with this Event Port" , fd )
}
_ , err := port_dissociate ( e . port , PORT_SOURCE_FD , fd )
if err != nil {
if err != nil && err != ENOENT {
return err
}
if err == nil {
// dissociate was successful, safe to delete the cookie
fCookie := e . fds [ fd ]
delete ( e . cookies , & fCookie . cookie )
}
delete ( e . fds , fd )
return nil
return err
}
func createFileObj ( name string , stat os . FileInfo ) ( * fileObj , error ) {
@ -912,24 +926,46 @@ func (e *EventPort) GetOne(t *Timespec) (*PortEvent, error) {
return nil , err
}
p := new ( PortEvent )
p . Events = pe . Events
p . Source = pe . Source
e . mu . Lock ( )
defer e . mu . Unlock ( )
switch pe . Source {
e . peIntToExt ( pe , p )
return p , nil
}
// peIntToExt converts a cgo portEvent struct into the friendlier PortEvent
// NOTE: Always call this function while holding the e.mu mutex
func ( e * EventPort ) peIntToExt ( peInt * portEvent , peExt * PortEvent ) {
peExt . Events = peInt . Events
peExt . Source = peInt . Source
cookie := ( * interface { } ) ( unsafe . Pointer ( peInt . User ) )
peExt . Cookie = * cookie
switch peInt . Source {
case PORT_SOURCE_FD :
p . Fd = uintptr ( pe . Object )
cookie := ( * interface { } ) ( unsafe . Pointer ( pe . User ) )
p . Cookie = * cookie
delete ( e . fds , p . Fd )
delete ( e . cookies , cookie )
peExt . Fd = uintptr ( peInt . Object )
// Only remove the fds entry if it exists and this cookie matches
if fobj , ok := e . fds [ peExt . Fd ] ; ok {
if & fobj . cookie == cookie {
delete ( e . fds , peExt . Fd )
}
}
case PORT_SOURCE_FILE :
p . fobj = ( * fileObj ) ( unsafe . Pointer ( uintptr ( pe . Object ) ) )
p . Path = BytePtrToString ( ( * byte ) ( unsafe . Pointer ( p . fobj . Name ) ) )
cookie := ( * interface { } ) ( unsafe . Pointer ( pe . User ) )
p . Cookie = * cookie
delete ( e . paths , p . Path )
if fCookie , ok := e . cookies [ cookie ] ; ok && uintptr ( unsafe . Pointer ( fCookie . fobj ) ) == uintptr ( peInt . Object ) {
// Use our stashed reference rather than using unsafe on what we got back
// the unsafe version would be (*fileObj)(unsafe.Pointer(uintptr(peInt.Object)))
peExt . fobj = fCookie . fobj
} else {
panic ( "mismanaged memory" )
}
delete ( e . cookies , cookie )
peExt . Path = BytePtrToString ( ( * byte ) ( unsafe . Pointer ( peExt . fobj . Name ) ) )
// Only remove the paths entry if it exists and this cookie matches
if fobj , ok := e . paths [ peExt . Path ] ; ok {
if & fobj . cookie == cookie {
delete ( e . paths , peExt . Path )
}
}
}
return p , nil
}
// Pending wraps port_getn(3c) and returns how many events are pending.
@ -962,21 +998,7 @@ func (e *EventPort) Get(s []PortEvent, min int, timeout *Timespec) (int, error)
e . mu . Lock ( )
defer e . mu . Unlock ( )
for i := 0 ; i < int ( got ) ; i ++ {
s [ i ] . Events = ps [ i ] . Events
s [ i ] . Source = ps [ i ] . Source
switch ps [ i ] . Source {
case PORT_SOURCE_FD :
s [ i ] . Fd = uintptr ( ps [ i ] . Object )
cookie := ( * interface { } ) ( unsafe . Pointer ( ps [ i ] . User ) )
s [ i ] . Cookie = * cookie
delete ( e . fds , s [ i ] . Fd )
case PORT_SOURCE_FILE :
s [ i ] . fobj = ( * fileObj ) ( unsafe . Pointer ( uintptr ( ps [ i ] . Object ) ) )
s [ i ] . Path = BytePtrToString ( ( * byte ) ( unsafe . Pointer ( s [ i ] . fobj . Name ) ) )
cookie := ( * interface { } ) ( unsafe . Pointer ( ps [ i ] . User ) )
s [ i ] . Cookie = * cookie
delete ( e . paths , s [ i ] . Path )
}
e . peIntToExt ( & ps [ i ] , & s [ i ] )
}
return int ( got ) , err
}
Justin Chadwell
3 years ago