// Creation Date : Wed May 14 21:56:00 1997
// Last Modified : Wed May 28 20:06:33 1997
// $Id$

#ifndef _MNG_H
#define _MNG_H

#include <stdio.h>
#include <sys/ipc.h>
#include <sys/shm.h>
#include <sys/sem.h>
#include <errno.h>
//------------- Shared memories -----------------
//Note: This is not a _dynamical_ shared memory manager, it only manages
//      _static_ shared memory blocks, which are alloced at start and
//      destroyed altogether at the end.

//`ShmAlloc':alloc a chunk of shared memory
//     `nblk':    number of memory in blocks
//     `blksize': size of block (e.g. sizeof(double), sizeof(int), etc)
//The returned pointer will be aligned to the boundary of blksize
char *ShmAlloc(int nblk, int blksize);
//`ShmDestroy': destroy any shared memory alloced before.
#define ShmDestroy() ((void)ShmAlloc(-1,0))

//------------- Semaphores -----------------
//`SemInit':initalize the semaphore array, first `nMutex' semaphores will
//          behave as mutices (initally have value 1), and the rest are
//          general purpose semaphores (with inital value 0).
void SemInit(int n, int nMutex);
//`SemOp': semaphore operation (cf. `man semop')
void SemOp(int i,int n);
//`SemDestroy': destroy any semphores initialized.
#define SemDestroy() SemInit(-1,0);
//`SemUnlock/SemLock':mutex operation.
#define SemUnlock(i) SemOp(i,1)
#define SemLock(i) SemOp(i,-1)

#endif // _MNG_H