/*
        Copyright 1999-2001, Be Incorporated.   All Rights Reserved.
        This file may be used under the terms of the Be Sample Code License.
*/

#ifndef _LOCK_H
#define _LOCK_H

#include <BeBuild.h>

#include <OS.h>

#ifndef _IMPEXP_KERNEL
#define _IMPEXP_KERNEL
#endif

#ifdef __cplusplus
        extern "C" {
#else
        typedef struct lock lock;
        typedef struct mlock mlock;
#endif


struct lock {
        sem_id          s;
        long            c;
};

struct mlock {
        sem_id          s;
};

extern _IMPEXP_KERNEL int       new_lock(lock *l, const char *name);
extern _IMPEXP_KERNEL int       free_lock(lock *l);

#ifdef LOCK
#undef LOCK
#endif

#define LOCK(l)         if (atomic_add(&l.c, -1) <= 0) acquire_sem(l.s);
#define UNLOCK(l)       if (atomic_add(&l.c, 1) < 0) release_sem(l.s);

extern _IMPEXP_KERNEL int       new_mlock(mlock *l, long c, const char *name);
extern _IMPEXP_KERNEL int       free_mlock(mlock *l);

#define         LOCKM(l,cnt)    acquire_sem_etc(l.s, cnt, 0, 0)
#define         UNLOCKM(l,cnt)  release_sem_etc(l.s, cnt, 0)


#ifdef __cplusplus
  } // extern "C"
#endif

#endif