//
// Transform the list socketList such that the only sockets left are those
// with a file descriptor contained in the array "fileDescriptorArray"
//
private static int SelectFileDescriptor(IList socketList, FileDescriptorSet fileDescriptorSet) {
//
// Walk the list in order
// Note that the counter is not necessarily incremented at each step;
// when the socket is removed, advancing occurs automatically as the
// other elements are shifted down.
//
Socket socket;
int currentSocket, currentFileDescriptor;
if (socketList==null) {
return 0;
}
if (fileDescriptorSet.Count==0) {
//
// no socket present, will never find it, remove all sockets
//
socketList.Clear();
}
if (socketList.Count==0) {
//
// list is already empty
//
return 0;
}
lock (socketList) {
for (currentSocket = 0; currentSocket < socketList.Count; currentSocket++) {
//
// parameter validation: only Socket should be here
//
if (!(socketList[currentSocket] is Socket)) {
throw new ArgumentException("socketList");
}
socket = (Socket)socketList[currentSocket];
//
// Look for the file descriptor in the array
//
for (currentFileDescriptor = 0; currentFileDescriptor < fileDescriptorSet.Count; currentFileDescriptor++) {
if (fileDescriptorSet.Array[currentFileDescriptor]==socket.m_Handle) {
break;
}
}
if (currentFileDescriptor==fileDescriptorSet.Count) {
//
// descriptor not found: remove the current socket and start again
//
socketList.RemoveAt(currentSocket--);
}
}
}
return socketList.Count;
}
private static FileDescriptorSet SocketListToFileDescriptorSet(IList socketList) {
if (socketList==null || socketList.Count==0) {
return FileDescriptorSet.Empty;
}
if (socketList.Count>FileDescriptorSet.Size) {
throw new ArgumentOutOfRangeException("socketList.Count");
}
FileDescriptorSet fileDescriptorSet = new FileDescriptorSet(socketList.Count);
for (int current = 0; current < fileDescriptorSet.Count; current++) {
if (!(socketList[current] is Socket)) {
throw new ArgumentException(SR.GetString(SR.net_sockets_select, socketList[current].GetType().FullName, typeof(System.Net.Sockets.Socket).FullName));
}
fileDescriptorSet.Array[current] = ((Socket)socketList[current]).m_Handle;
}
return fileDescriptorSet;
}
/*
* This function servers to isolate the Select/Poll functionality
* from the representation used by the FileDescriptorSet structure by converting
* into a flat array of integers.
* Assumption: the descriptors in the set are always placed as a contigious
* block at the beginning of the file descriptor array.
*/
private static IntPtr[] FileDescriptorSetToFileDescriptorArray(FileDescriptorSet fileDescriptorSet) {
if (fileDescriptorSet.Count==0) {
return null;
}
IntPtr[] fileDescriptorArray = new IntPtr[fileDescriptorSet.Count];
for (int current = 0; current < fileDescriptorSet.Count; current++) {
fileDescriptorArray[current] = fileDescriptorSet.Array[current];
}
return fileDescriptorArray;
}
/// <include file='doc\Socket.uex' path='docs/doc[@for="Socket.Poll"]/*' />
/// <devdoc>
/// <para>
/// Determines the status of the socket.
/// </para>
/// </devdoc>
public bool Poll(int microSeconds, SelectMode mode) {
if (CleanedUp) {
throw new ObjectDisposedException(this.GetType().FullName);
}
FileDescriptorSet fileDescriptorSet = new FileDescriptorSet(1);
fileDescriptorSet.Array[0] = m_Handle;
TimeValue IOwait = new TimeValue();
//
// negative timeout value implies indefinite wait
//
if (microSeconds>=0) {
MicrosecondsToTimeValue(microSeconds, ref IOwait);
}
int errorCode;
switch (mode) {
case SelectMode.SelectRead:
errorCode = (microSeconds>=0)
? UnsafeNclNativeMethods.OSSOCK.select(
0,
ref fileDescriptorSet,
IntPtr.Zero,
IntPtr.Zero,
ref IOwait)
: UnsafeNclNativeMethods.OSSOCK.select(
0,
ref fileDescriptorSet,
IntPtr.Zero,
IntPtr.Zero,
IntPtr.Zero);
break;
case SelectMode.SelectWrite:
errorCode = (microSeconds>=0)
? UnsafeNclNativeMethods.OSSOCK.select(
0,
IntPtr.Zero,
ref fileDescriptorSet,
IntPtr.Zero,
ref IOwait)
: UnsafeNclNativeMethods.OSSOCK.select(
0,
IntPtr.Zero,
ref fileDescriptorSet,
IntPtr.Zero,
IntPtr.Zero);
break;
case SelectMode.SelectError:
errorCode = (microSeconds>=0)
? UnsafeNclNativeMethods.OSSOCK.select(
0,
IntPtr.Zero,
IntPtr.Zero,
ref fileDescriptorSet,
ref IOwait)
: UnsafeNclNativeMethods.OSSOCK.select(
0,
IntPtr.Zero,
IntPtr.Zero,
ref fileDescriptorSet,
IntPtr.Zero);
break;
default:
throw new NotSupportedException(SR.GetString(SR.net_SelectModeNotSupportedException, mode.ToString()));
};
//
// if the native call fails we'll throw a SocketException
//
if (errorCode==SocketErrors.SocketError) {
//
// update our internal state after this socket error and throw
//
SocketException socketException = new SocketException();
UpdateStatusAfterSocketError();
throw socketException;
}
if (fileDescriptorSet.Count==0) {
return false;
}
//return (fileDescriptorSet.Count!=0);
return fileDescriptorSet.Array[0]==m_Handle;
}
