Swift2, Call swift function in CFSocketCallBack - EXEC_BAD_ACCESS - swift

Question

I'm trying to write a socket server app for Mac OSX with Xcode:7.2.1 in Swift2.1.1. referring to CocoaEcho sample code.
But I cannot call a swift function in the socketCallBack function.
My code is here. I'm passing the self based on the answer at Swift 2 - UnsafeMutablePointer to object. And I think the part of the code is 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 with 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 back
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 at the code server.acceptConnection(tempData).
Debugger shows same pointer for both info and server, which should mean info(self) is properly assigned to server.
But EXEC_BAD_ACCESS seems to mean self is no longer available.
I'm struggling to find a solution. If anyone could give me any advise,
it'd be very much appreciated.
Thanks in advance for your help.

Answer 1

I'll admit I don't know much about using these lower level C conventions, but since the callback function is part of your class, can't just say self.acceptConnection(tempData)?