Getting Started with QNX Neutrino - QNX Software Systems

© 2009, QNX Software Systems GmbH & Co. KG. time1.c
time1.c
For more information about this program, see “Server-maintained timeouts” in the
Clocks, Timers, and Getting a Kick Every So Often chapter.
/*
* time1.c
*
* Example of a server that receives periodic messages from
* a timer, and regular messages from a client.
*
* Illustrates using the timer functions with a pulse.
*/
#include
#include
#include
#include
#include
#include
#include
#include
// message send definitions
// messages
#define MT_WAIT_DATA 2 // message from client
#define MT_SEND_DATA 3 // message from client
// pulses
#define CODE_TIMER 1 // pulse from timer
// message reply definitions
#define MT_OK 0 // message to client
#define MT_TIMEDOUT 1 // message to client
// message structure
typedef struct
{
int messageType;
int messageData;
} ClientMessageT;
// contains both message to and from client
// optional data, depending upon message
typedef union
{
ClientMessageT msg; // a message can be either from a client, or
struct _pulse pulse; // a pulse
} MessageT;
// client table
#define MAX_CLIENT 16
// maximum number of simultaneous clients
struct
{
int in_use;
// is this client entry in use?
int rcvid;
// receive ID of client
int timeout;
// timeout left for client
} clients [MAX_CLIENT]; // client table
April 30, 2009 Appendix: C • Sample Programs 317