include/isc/mutex.h

	mutex.h revision d1dc805692ff816e28849396577affa9b4890e41
/*
 * Copyright (C) 1998-2000  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: mutex.h,v 1.22 2001/01/08 19:47:30 gson Exp $ */

#ifndef ISC_MUTEX_H
#define ISC_MUTEX_H 1

#include <pthread.h>
#include <stdio.h>

#include <isc/result.h>     /* for ISC_R_ codes */

/*
 * Supply mutex attributes that enable deadlock detection
 * (helpful when debugging).  This is system dependent and
 * currently only supported on NetBSD.
 */
#if ISC_MUTEX_DEBUG && defined(__NetBSD__) && defined(PTHREAD_MUTEX_ERRORCHECK)
extern pthread_mutexattr_t isc__mutex_attrs;
#define ISC__MUTEX_ATTRS &isc__mutex_attrs
#else
#define ISC__MUTEX_ATTRS NULL
#endif

/* XXX We could do fancier error handling... */

/*
 * Define ISC_MUTEX_PROFILE to turn on profiling of mutexes by line.  When
 * enabled, isc_mutex_stats() can be used to print a table showing the
 * number of times each type of mutex was locked and the amount of time
 * waiting to obtain the lock.
 */
#ifndef ISC_MUTEX_PROFILE
#define ISC_MUTEX_PROFILE 0
#endif

#if ISC_MUTEX_PROFILE
typedef struct isc_mutexstats isc_mutexstats_t;

typedef struct {
    pthread_mutex_t     mutex;  /* The actual mutex. */
    isc_mutexstats_t *  stats;  /* Mutex statistics. */
} isc_mutex_t;
#else
typedef pthread_mutex_t isc_mutex_t;
#endif


#if ISC_MUTEX_PROFILE
#define isc_mutex_init(mp) \
    isc_mutex_init_profile((mp), __FILE__, __LINE__)
#else
#define isc_mutex_init(mp) \
    ((pthread_mutex_init((mp), ISC__MUTEX_ATTRS) == 0) ? \
     ISC_R_SUCCESS : ISC_R_UNEXPECTED)
#endif

#if ISC_MUTEX_PROFILE
#define isc_mutex_lock(mp) \
    isc_mutex_lock_profile((mp), __FILE__, __LINE__)
#else
#define isc_mutex_lock(mp) \
    ((pthread_mutex_lock((mp)) == 0) ? \
     ISC_R_SUCCESS : ISC_R_UNEXPECTED)
#endif

#if ISC_MUTEX_PROFILE
#define isc_mutex_unlock(mp) \
    isc_mutex_unlock_profile((mp), __FILE__, __LINE__)
#else
#define isc_mutex_unlock(mp) \
    ((pthread_mutex_unlock((mp)) == 0) ? \
     ISC_R_SUCCESS : ISC_R_UNEXPECTED)
#endif

#if ISC_MUTEX_PROFILE
#define isc_mutex_trylock(mp) \
    ((pthread_mutex_trylock((&(mp)->mutex)) == 0) ? \
     ISC_R_SUCCESS : ISC_R_LOCKBUSY)
#else
#define isc_mutex_trylock(mp) \
    ((pthread_mutex_trylock((mp)) == 0) ? \
     ISC_R_SUCCESS : ISC_R_LOCKBUSY)
#endif

#if ISC_MUTEX_PROFILE
#define isc_mutex_destroy(mp) \
    ((pthread_mutex_destroy((&(mp)->mutex)) == 0) ? \
     ISC_R_SUCCESS : ISC_R_UNEXPECTED)
#else
#define isc_mutex_destroy(mp) \
    ((pthread_mutex_destroy((mp)) == 0) ? \
     ISC_R_SUCCESS : ISC_R_UNEXPECTED)
#endif

#if ISC_MUTEX_PROFILE
#define isc_mutex_stats(fp) isc_mutex_statsprofile(fp);
#else
#define isc_mutex_stats(fp)
#endif

#if ISC_MUTEX_PROFILE

isc_result_t
isc_mutex_init_profile(isc_mutex_t *mp, const char * _file, int _line);
isc_result_t
isc_mutex_lock_profile(isc_mutex_t *mp, const char * _file, int _line);
isc_result_t
isc_mutex_unlock_profile(isc_mutex_t *mp, const char * _file, int _line);

void
isc_mutex_statsprofile(FILE *fp);

#endif /* ISC_MUTEX_PROFILE */

#endif /* ISC_MUTEX_H */