diff options
Diffstat (limited to 'nexgb/xgb.go')
| -rw-r--r-- | nexgb/xgb.go | 259 |
1 files changed, 86 insertions, 173 deletions
diff --git a/nexgb/xgb.go b/nexgb/xgb.go index 0dd8163..1a4ada1 100644 --- a/nexgb/xgb.go +++ b/nexgb/xgb.go @@ -12,7 +12,6 @@ import ( "io" "net" "os" - "strconv" "strings" "sync" ) @@ -23,11 +22,9 @@ const ( ) // A Conn represents a connection to an X server. -// Only one goroutine should use a Conn's methods at a time. type Conn struct { host string conn net.Conn - nextId Id nextCookie uint16 cookies map[uint16]*Cookie events queue @@ -44,6 +41,7 @@ type Conn struct { eventChan chan bool errorChan chan bool + xidChan chan xid newIdLock sync.Mutex writeLock sync.Mutex dequeueLock sync.Mutex @@ -51,6 +49,51 @@ type Conn struct { extLock sync.Mutex } +// NewConn creates a new connection instance. It initializes locks, data +// structures, and performs the initial handshake. (The code for the handshake +// has been relegated to conn.go.) +func NewConn() (*Conn, error) { + return NewConnDisplay("") +} + +// NewConnDisplay is just like NewConn, but allows a specific DISPLAY +// string to be used. +// If 'display' is empty it will be taken from os.Getenv("DISPLAY"). +// +// Examples: +// NewConn(":1") -> net.Dial("unix", "", "/tmp/.X11-unix/X1") +// NewConn("/tmp/launch-123/:0") -> net.Dial("unix", "", "/tmp/launch-123/:0") +// NewConn("hostname:2.1") -> net.Dial("tcp", "", "hostname:6002") +// NewConn("tcp/hostname:1.0") -> net.Dial("tcp", "", "hostname:6001") +func NewConnDisplay(display string) (*Conn, error) { + conn := &Conn{} + + // First connect. This reads authority, checks DISPLAY environment + // variable, and loads the initial Setup info. + err := conn.connect(display) + if err != nil { + return nil, err + } + + conn.xidChan = make(chan xid, 5) + go conn.generateXids() + + conn.nextCookie = 1 + conn.cookies = make(map[uint16]*Cookie) + conn.events = queue{make([][]byte, 100), 0, 0} + conn.extensions = make(map[string]byte) + + conn.newReadChannels() + conn.newRequestChannels() + + return conn, nil +} + +// Close closes the connection to the X server. +func (c *Conn) Close() { + c.conn.Close() +} + // Id is used for all X identifiers, such as windows, pixmaps, and GCs. type Id uint32 @@ -111,14 +154,46 @@ type Error interface { var newErrorFuncs = map[int]func(buf []byte) Error{} // NewID generates a new unused ID for use with requests like CreateWindow. -func (c *Conn) NewId() Id { - c.newIdLock.Lock() - defer c.newIdLock.Unlock() - - id := c.nextId - // TODO: handle ID overflow - c.nextId++ - return id +// If no new ids can be generated, the id returned is 0 and error is non-nil. +func (c *Conn) NewId() (Id, error) { + xid := <-c.xidChan + if xid.err != nil { + return 0, xid.err + } + return xid.id, nil +} + +// xid encapsulates a resource identifier being sent over the Conn.xidChan +// channel. If no new resource id can be generated, id is set to -1 and a +// non-nil error is set in xid.err. +type xid struct { + id Id + err error +} + +// generateXids sends new Ids down the channel for NewId to use. +// This needs to be updated to use the XC Misc extension once we run out of +// new ids. +func (conn *Conn) generateXids() { + inc := conn.Setup.ResourceIdMask & -conn.Setup.ResourceIdMask + max := conn.Setup.ResourceIdMask + last := uint32(0) + for { + // TODO: Use the XC Misc extension to look for released ids. + if last > 0 && last >= max - inc + 1 { + conn.xidChan <- xid{ + id: Id(0), + err: errors.New("There are no more available resource" + + "identifiers."), + } + } + + last += inc + conn.xidChan <- xid{ + id: Id(last | conn.Setup.ResourceIdBase), + err: nil, + } + } } // RegisterExtension adds the respective extension's major op code to @@ -328,165 +403,3 @@ func (c *Conn) PollForEvent() (Event, error) { return nil, nil } -// Dial connects to the X server given in the 'display' string. -// If 'display' is empty it will be taken from os.Getenv("DISPLAY"). -// -// Examples: -// Dial(":1") // connect to net.Dial("unix", "", "/tmp/.X11-unix/X1") -// Dial("/tmp/launch-123/:0") // connect to net.Dial("unix", "", "/tmp/launch-123/:0") -// Dial("hostname:2.1") // connect to net.Dial("tcp", "", "hostname:6002") -// Dial("tcp/hostname:1.0") // connect to net.Dial("tcp", "", "hostname:6001") -func Dial(display string) (*Conn, error) { - c, err := connect(display) - if err != nil { - return nil, err - } - - // Get authentication data - authName, authData, err := readAuthority(c.host, c.display) - noauth := false - if err != nil { - fmt.Fprintf(os.Stderr, "Could not get authority info: %v\n", err) - fmt.Fprintf(os.Stderr, "Trying connection without authority info...\n") - authName = "" - authData = []byte{} - noauth = true - } - - // Assume that the authentication protocol is "MIT-MAGIC-COOKIE-1". - if !noauth && (authName != "MIT-MAGIC-COOKIE-1" || len(authData) != 16) { - return nil, errors.New("unsupported auth protocol " + authName) - } - - buf := make([]byte, 12+pad(len(authName))+pad(len(authData))) - buf[0] = 0x6c - buf[1] = 0 - Put16(buf[2:], 11) - Put16(buf[4:], 0) - Put16(buf[6:], uint16(len(authName))) - Put16(buf[8:], uint16(len(authData))) - Put16(buf[10:], 0) - copy(buf[12:], []byte(authName)) - copy(buf[12+pad(len(authName)):], authData) - if _, err = c.conn.Write(buf); err != nil { - return nil, err - } - - head := make([]byte, 8) - if _, err = io.ReadFull(c.conn, head[0:8]); err != nil { - return nil, err - } - code := head[0] - reasonLen := head[1] - major := Get16(head[2:]) - minor := Get16(head[4:]) - dataLen := Get16(head[6:]) - - if major != 11 || minor != 0 { - return nil, errors.New(fmt.Sprintf("x protocol version mismatch: %d.%d", major, minor)) - } - - buf = make([]byte, int(dataLen)*4+8, int(dataLen)*4+8) - copy(buf, head) - if _, err = io.ReadFull(c.conn, buf[8:]); err != nil { - return nil, err - } - - if code == 0 { - reason := buf[8 : 8+reasonLen] - return nil, errors.New(fmt.Sprintf("x protocol authentication refused: %s", string(reason))) - } - - ReadSetupInfo(buf, &c.Setup) - - if c.defaultScreen >= len(c.Setup.Roots) { - c.defaultScreen = 0 - } - - c.nextId = Id(c.Setup.ResourceIdBase) - c.nextCookie = 1 - c.cookies = make(map[uint16]*Cookie) - c.events = queue{make([][]byte, 100), 0, 0} - c.extensions = make(map[string]byte) - - c.newReadChannels() - c.newRequestChannels() - return c, nil -} - -// Close closes the connection to the X server. -func (c *Conn) Close() { c.conn.Close() } - -func connect(display string) (*Conn, error) { - if len(display) == 0 { - display = os.Getenv("DISPLAY") - } - - display0 := display - if len(display) == 0 { - return nil, errors.New("empty display string") - } - - colonIdx := strings.LastIndex(display, ":") - if colonIdx < 0 { - return nil, errors.New("bad display string: " + display0) - } - - var protocol, socket string - c := new(Conn) - - if display[0] == '/' { - socket = display[0:colonIdx] - } else { - slashIdx := strings.LastIndex(display, "/") - if slashIdx >= 0 { - protocol = display[0:slashIdx] - c.host = display[slashIdx+1 : colonIdx] - } else { - c.host = display[0:colonIdx] - } - } - - display = display[colonIdx+1 : len(display)] - if len(display) == 0 { - return nil, errors.New("bad display string: " + display0) - } - - var scr string - dotIdx := strings.LastIndex(display, ".") - if dotIdx < 0 { - c.display = display[0:] - } else { - c.display = display[0:dotIdx] - scr = display[dotIdx+1:] - } - - dispnum, err := strconv.Atoi(c.display) - if err != nil || dispnum < 0 { - return nil, errors.New("bad display string: " + display0) - } - - if len(scr) != 0 { - c.defaultScreen, err = strconv.Atoi(scr) - if err != nil { - return nil, errors.New("bad display string: " + display0) - } - } - - // Connect to server - if len(socket) != 0 { - c.conn, err = net.Dial("unix", socket+":"+c.display) - } else if len(c.host) != 0 { - if protocol == "" { - protocol = "tcp" - } - c.conn, err = net.Dial(protocol, c.host+":"+strconv.Itoa(6000+dispnum)) - } else { - c.conn, err = net.Dial("unix", "/tmp/.X11-unix/X"+c.display) - } - - if err != nil { - return nil, errors.New("cannot connect to " + display0 + ": " + err.Error()) - } - return c, nil -} |