pointers - Swift2, Call swift function in CFSocketCallBack - EXEC_BAD_ACCESS -

i'm trying write socket server app mac osx xcode:7.2.1 in swift2.1.1. referring cocoaecho sample code. cannot call swift function in socketcallback function.
code here. i'm passing self based on answer @ swift 2 - unsafemutablepointer object. , think part of code working ok.

class myserver: nsobject {    // sockets   private var socketipv4: cfsocket!   private var socketipv6: cfsocket!    // connections   var connections = set<spfconnection>()    func start(address: string) -> bool {      var sockctxt = cfsocketcontext(version: 0, info: nil, retain: nil, release: nil, copydescription: nil)     sockctxt.info = unsafemutablepointer(unsafeaddressof(self))      // create socket cfsocketcreate     socketipv4 = cfsocketcreate(         kcfallocatordefault,         pf_inet,         sock_stream,         ipproto_tcp,         kcfsocketautomaticallyreenableacceptcallback,         socketcallback,         &sockctxt)      // ipv4     var sin = sockaddr_in()  // = initstruct()     let server_addr_size = socklen_t(inet_addrstrlen)     sin.sin_len = uint8(server_addr_size)     sin.sin_family = sa_family_t(af_inet)     sin.sin_port = uint16(9999).bigendian     sin.sin_addr.s_addr = inet_addr(address)      let sindata = nsdata(bytes: &sin, length: sizeof(sockaddr_in))     let ptr = unsafepointer<uint8>(sindata.bytes)      let sincfd = cfdatacreate(kcfallocatordefault, ptr, sizeof(sockaddr_in))      let ipv4socketerror: cfsocketerror = cfsocketsetaddress(socketipv4, sincfd)     switch ipv4socketerror {     case .success:         print("ipv4 success")     default:         print("ipv4 error = \(ipv4socketerror.rawvalue)")         return false     }      let socketsource = cfsocketcreaterunloopsource(kcfallocatordefault, socketipv4, 0)     cfrunloopaddsource(cfrunloopgetcurrent(), socketsource, kcfrunloopdefaultmode)      return true   }    // cfsocket call   var socketcallback : @convention(c)(cfsocket!, cfsocketcallbacktype, cfdata!, unsafepointer<void>, unsafemutablepointer<void>) -> void = {     (socketref, callbacktype, address, data, info) in      print("acceptconnection callback-ed") // \(socketref), \(callbacktype), \(address), \(data),\(info)")      var tempdata: cfsocketnativehandle = 0     var annsdata:nsdata = nsdata(bytes: data, length: sizeofvalue(data))     annsdata.getbytes(&tempdata, length: sizeof(cfsocketnativehandle))      var tempary = [unsafemutablepointer<void>]()     tempary.append(info)     if callbacktype == cfsocketcallbacktype.acceptcallback {         let server = unsafebitcast(info, myserver.self)         // **** exec_bad_access, code=2 ***** //         server.acceptconnection(tempdata)     } else {         print("callbacktype = \(callbacktype.rawvalue)")     }   }     func acceptconnection(data: cfsocketnativehandle) {     print("acceptconnection called")     var readstream: unmanaged<cfreadstream>?     var writestream: unmanaged<cfwritestream>?      cfstreamcreatepairwithsocket(kcfallocatordefault, data, &readstream, &writestream)     if readstream != nil && writestream != nil {         cfreadstreamsetproperty(readstream!.takeunretainedvalue(), kcfstreampropertyshouldclosenativesocket, kcfbooleantrue)         cfwritestreamsetproperty(writestream!.takeunretainedvalue(), kcfstreampropertyshouldclosenativesocket, kcfbooleantrue)          let connection = spfconnection()         connection.inputstream = readstream!.takeretainedvalue()         connection.outputstream = writestream!.takeretainedvalue()          if connection.open() {             connections.insert(connection)         }     }   } } 

i'm getting exec_bad_access code=2 @ code server.acceptconnection(tempdata).
debugger shows same pointer both info , server, should mean info(self) assigned server. exec_bad_access seems mean self no longer available. i'm struggling find solution. if give me advise, it'd appreciated. in advance help.

i'll admit don't know using these lower level c conventions, since callback function part of class, can't self.acceptconnection(tempdata)?