msgQNLib.h

#ifndef _MSG_QN_LIB_H_
#define _MSG_QN_LIB_H_

#define MSG_Q_DIR               "/tmp"
#define MSG_Q_MAXQUEUES         256


#define WAIT_FOREVER            (-1)
#define NO_WAIT                 0
#define S_objLib_OBJ_TIMEOUT    EAGAIN


#define MSG_Q_LOCK_NONE         0
#define MSG_Q_LOCK              1
#define MSG_Q_LOCK_EXPECT       2


#define MSG_Q_TIMEOUT           (-1)
#define MSG_Q_ERROR             (-2)    // OS-specific error i.e. write returns -1
#define MSG_Q_NOTASK            (-3)    // "no task present" error 

struct msgQNStruct {
        int desc ;
        int len ;
        int locked ;
        int task ;
} ;


#define MSG_Q_ID        int



extern MSG_Q_ID msgQNCreate(int task, int msglen, int lock = MSG_Q_LOCK_NONE) ;
extern int msgQNSend(MSG_Q_ID task, char *what, int size, int timeout = WAIT_FOREVER, int prio = 0) ;
extern int msgQNReceive(MSG_Q_ID task, char *where, int size, int timeout = WAIT_FOREVER) ;
extern int msgQNDelete(MSG_Q_ID task) ;
extern int msgQNLocking(MSG_Q_ID task, int lock) ;
extern int msgQNSize(MSG_Q_ID task, int size) ;
extern int msgQNCheck(MSG_Q_ID task) ;

#endif