The document defines a Network class that handles sending and receiving packets over a network. The Network class constructor takes in parameters like the network address, reliability, and callback functions. Member functions of the Network class allow sending and receiving packets with header and data fields, as well as checking for packet availability and send completion. The class also defines a PacketHeader structure to store packet header details like destination, source, and length. Private members store network-specific details like the address, socket, and flags to track send/receive status.

1. Network.h

2. #ifndef NETWORK_H
#define NETWORK_H
#include "copyright.h"
#include "utility.h“
When using ifndef conditional we mean the specialist to
see if a macro identifier is defined or not.

3. class Network {
public:
Network(NetworkAddress addr, double reliability,
VoidFunctionPtr readAvail, VoidFunctionPtr
writeDone, int callArg);
~Network(); // De-allocate the network driver
data
void Send(PacketHeader hdr, char* data);
PacketHeader Receive(char* data);
void SendDone();
void CheckPktAvail();

4. typedef int NetworkAddress;
class PacketHeader {
public:
NetworkAddress to; // Destination machine ID
NetworkAddress from; // source machine ID
unsigned length; // bytes of packet data
};
#define MaxWireSize 64 // largest packet that can
go out on the wire.
#define MaxPacketSize

5. private:
NetworkAddress ident; // This machine's network
address
double chanceToWork; // Likelihood packet will be
dropped
int sock; // UNIX socket number for incoming
packets
char sockName[32];
VoidFunctionPtr writeHandler;
VoidFunctionPtr readHandler;

6. int handlerArg; // Argument to be passed to
interrupt handler
bool sendBusy;
bool packetAvail;
// network
PacketHeader inHdr;
char inbox[MaxPacketSize];
};
#endif