C++ pthread_rwlock_init函数代码示例

    void run() {
/**
 * note: this test will deadlock if the code breaks
 */

#if defined(__linux__) || defined(__APPLE__)

        // create
        pthread_rwlock_t lk;
        verify(pthread_rwlock_init(&lk, 0) == 0);

        // read lock
        verify(pthread_rwlock_rdlock(&lk) == 0);

        AtomicUInt32 x1(0);
        stdx::thread t1(stdx::bind(worker1, &lk, &x1));
        while (!x1.load())
            ;
        verify(x1.load() == 1);
        sleepmillis(500);
        verify(x1.load() == 1);

        AtomicUInt32 x2(0);

        stdx::thread t2(stdx::bind(worker2, &lk, &x2));
        t2.join();
        verify(x2.load() == 1);

        pthread_rwlock_unlock(&lk);

        for (int i = 0; i < 2000; i++) {
            if (x1.load() == 2)
                break;
            sleepmillis(1);
        }

        verify(x1.load() == 2);
        t1.join();
#endif
    }

Region::Region(Palette* p, int i) {

	spritelist = new SpriteList();

	id = i;
	name = "";
	SetTypeAndSid(UNKNOWN, 0, 0);

	_loop = NULL;
	_disableNotes = false;

	palette = p;
	_lastScheduled = -1;
	_chording = false;
	_looping = DEFAULT_LOOPING;

	NosuchLockInit(&_region_mutex,"region");
	// spritelist_rwlock = PTHREAD_RWLOCK_INITIALIZER;
	cursorlist_rwlock = PTHREAD_RWLOCK_INITIALIZER;
	// int rc1 = pthread_rwlock_init(&spritelist_rwlock, NULL);
	int rc = pthread_rwlock_init(&cursorlist_rwlock, NULL);
	if ( rc ) {
		NosuchDebug("Failure on pthread_rwlock_init!? rc=%d",rc);
	}

	_latestNoteTime = 0;
	x_min = 0.00f;
	y_min = 0.00f;
	x_max = 1.0f;
	y_max = 1.0f;
	_channel = -1;

	PaletteHost* ph = p->paletteHost();
	_graphicBehaviour = ph->makeGraphicBehaviour(this);
	_musicBehaviour = ph->makeMusicBehaviour(this);

	_noteBehaviour = new NoteBehaviourDefault(this);

	initParams();
}

TEST(sfrlock, uncontended_write_cost) {
  double t;
  double r;
  pthread_mutex_t mutex;
  pthread_rwlock_t rwlock;
  sfrlock_t sfrlock;

  sfrlock_init(&sfrlock);
  pthread_rwlock_init(&rwlock, nullptr);
  pthread_mutex_init(&mutex, nullptr);

  r = measure_time([&] () {
        for (unsigned cnt = repeat; cnt; cnt--) {
          sfrlock_wrlock(&sfrlock);
          sfrlock_wrunlock(&sfrlock);
        }
      });
  printf("sfrlock_t time: %lf ms\n", r / 1e6);

  t = measure_time([&] () {
        for (unsigned cnt = repeat; cnt; cnt--) {
          pthread_rwlock_wrlock(&rwlock);
          pthread_rwlock_unlock(&rwlock);
        }
      });
  printf("pthread_rwlock_t time: %lf ms (%+.2lf%%)\n", t / 1e6,
         -(1 - (t / r)) * 100);

  t = measure_time([&] () {
        for (unsigned cnt = repeat; cnt; cnt--) {
          pthread_mutex_lock(&mutex);
          pthread_mutex_unlock(&mutex);
        }
      });
  printf("pthread_mutex_t time: %lf ms (%+.2lf%%)\n", t / 1e6,
         -(1 - (t / r)) * 100);

  pthread_rwlock_destroy(&rwlock);
  pthread_mutex_destroy(&mutex);
}

ESFReadWriteLock::ESFReadWriteLock() :
    _magic(0) {
#ifdef HAVE_PTHREAD_RWLOCK_INIT

    if (0 == pthread_rwlock_init(&_lock, 0)) {
        _magic = ESF_MAGIC;
    }

#elif defined HAVE_PTHREAD_MUTEX_INIT && defined HAVE_PTHREAD_COND_INIT && \
      defined HAVE_PTHREAD_MUTEX_DESTROY && defined HAVE_PTHREAD_COND_DESTROY

    if ( 0 != pthread_mutex_init( &_lock._mutex, 0 ) )
    {
        return;
    }

    if ( 0 != pthread_cond_init( &_lock._readSignal, 0 ) )
    {
        pthread_mutex_destroy( &_lock._mutex );
        return;
    }

    if ( 0 != pthread_cond_init( &_lock._writeSignal, 0 ) )
    {
        pthread_mutex_destroy( &_lock._mutex );
        pthread_cond_destroy( &_lock._readSignal );
        return;
    }

    _lock._readersActive = 0;
    _lock._readersWaiting = 0;
    _lock._writersActive = 0;
    _lock._writersWaiting = 0;

    _magic = ESF_MAGIC;

#else
#error "Platform has no rw lock initializer"
#endif
}

void dt_control_init(dt_control_t *s)
{
  memset(s->vimkey, 0, sizeof(s->vimkey));
  s->vimkey_cnt = 0;

  // same thread as init
  s->gui_thread = pthread_self();

  // initialize static mutex
  dt_pthread_mutex_init(&_control_gdk_lock_threads_mutex, NULL);

  // s->last_expose_time = dt_get_wtime();
  s->key_accelerators_on = 1;
  s->log_pos = s->log_ack = 0;
  s->log_busy = 0;
  s->log_message_timeout_id = 0;
  dt_pthread_mutex_init(&(s->log_mutex), NULL);
  s->progress = 200.0f;

  dt_conf_set_int("ui_last/view", DT_MODE_NONE);

  pthread_cond_init(&s->cond, NULL);
  dt_pthread_mutex_init(&s->cond_mutex, NULL);
  dt_pthread_mutex_init(&s->queue_mutex, NULL);
  dt_pthread_mutex_init(&s->run_mutex, NULL);
  pthread_rwlock_init(&s->xprofile_lock, NULL);
  dt_pthread_mutex_init(&(s->global_mutex), NULL);
  dt_pthread_mutex_init(&(s->progress_system.mutex), NULL);

  // start threads
  dt_control_jobs_init(s);

  s->button_down = 0;
  s->button_down_which = 0;
  s->mouse_over_id = -1;
  s->dev_closeup = 0;
  s->dev_zoom_x = 0;
  s->dev_zoom_y = 0;
  s->dev_zoom = DT_ZOOM_FIT;
}

/* init function (must be called once) */
rsRetVal
dnscacheInit(void)
{
    DEFiRet;
    if((dnsCache.ht = create_hashtable(100, hash_from_key_fn, key_equals_fn,
                                       (void(*)(void*))entryDestruct)) == NULL) {
        DBGPRINTF("dnscache: error creating hash table!\n");
        ABORT_FINALIZE(RS_RET_ERR); // TODO: make this degrade, but run!
    }
    dnsCache.nEntries = 0;
    pthread_rwlock_init(&dnsCache.rwlock, NULL);
    CHKiRet(objGetObjInterface(&obj)); /* this provides the root pointer for all other queries */
    CHKiRet(objUse(glbl, CORE_COMPONENT));
    CHKiRet(objUse(errmsg, CORE_COMPONENT));
    CHKiRet(objUse(prop, CORE_COMPONENT));

    prop.Construct(&staticErrValue);
    prop.SetString(staticErrValue, (uchar*)"???", 3);
    prop.ConstructFinalize(staticErrValue);
finalize_it:
    RETiRet;
}

DICTIONARY *dictionary_create(uint32_t flags) {
	debug(D_DICTIONARY, "Creating dictionary.");

	DICTIONARY *dict = calloc(1, sizeof(DICTIONARY));
	if(unlikely(!dict)) fatal("Cannot allocate DICTIONARY");

	if(flags & DICTIONARY_FLAG_WITH_STATISTICS) {
		dict->stats = calloc(1, sizeof(struct dictionary_stats));
		if(!dict->stats) fatal("Cannot allocate statistics for DICTIONARY");
	}

	if(!(flags & DICTIONARY_FLAG_SINGLE_THREADED)) {
		dict->rwlock = calloc(1, sizeof(pthread_rwlock_t));
		if(!dict->rwlock) fatal("Cannot allocate pthread_rwlock_t for DICTIONARY");
		pthread_rwlock_init(dict->rwlock, NULL);
	}

	avl_init(&dict->values_index, name_value_compare);
	dict->flags = flags;

	return dict;
}

int main(int argc, char *argv[])
{
    L = atol(argv[1]);
    K = atol(argv[2]);
    M = atol(argv[3]);

    if (signal(SIGINT, exit_server) == SIG_ERR)
        syserr("Error in signal (SIGINT)");

    init_queues();

    int thr_err;
    pthread_t thread_id;
    make_attr_detached();
    if (thr_err = pthread_rwlock_init(&rwlock, NULL))
        syserr_ext(thr_err, "Error in function pthread_rwlock_init");

    Mesg mesg;
    int bytes_rcvd;
    while (1)
    {
        if ((bytes_rcvd = msgrcv(msg_rcv_id, &mesg, MAX_BUFF, 0, 0)) <= 0)
            syserr("Error in msgrcv (receiving type(pid))");
        mesg.mesg_data[bytes_rcvd] = '\0';

        if (mesg.mesg_type == READ_TYPE_KOM)
        {
            if ((thr_err = pthread_create(&thread_id, &attr, serve_committee, &mesg.mesg_data)) != 0)
                syserr_ext(thr_err, "Error in pthread_create (for serve_committee)");
        }
        else
        {
            if ((thr_err = pthread_create(&thread_id, &attr, serve_report, &mesg.mesg_data)) != 0)
                syserr_ext(thr_err, "Error in pthread_create (for serve_report)");
        }
    }

    exit_server(0);
}

static void
init_read_write_lock(pthread_rwlock_t* lock)
{
    pthread_rwlockattr_t* pattr;
#if defined(YOG_HAVE_PTHREAD_RWLOCKATTR_INIT)
    pthread_rwlockattr_t attr;
    pthread_rwlockattr_init(&attr);
#   if defined(YOG_HAVE_PTHREAD_RWLOCKATTR_SETKIND_NP)
    pthread_rwlockattr_setkind_np(&attr, PTHREAD_RWLOCK_PREFER_WRITER_NP);
#   endif
    pattr = &attr;
#else
    pattr = NULL;
#endif
    int err;
    if ((err = pthread_rwlock_init(lock, pattr)) != 0) {
        YOG_BUG(NULL, "pthread_rwlock_init failed: %s", strerror(err));
    }
#if defined(YOG_HAVE_PTHREAD_RWLOCKATTR_INIT) && defined(YOG_HAVE_PTHREAD_RWLOCKATTR_DESTROY)
    pthread_rwlockattr_destroy(&attr);
#endif
}

/* The user must define this function if she wants to use the node
   cache.  Create and initialize a node.  */
error_t
diskfs_user_make_node (struct node **npp, struct lookup_context *ctx)
{
  struct node *np;
  struct disknode *dn;

  /* Create the new node.  */
  np = diskfs_make_node_alloc (sizeof *dn);
  if (np == NULL)
    return ENOMEM;

  /* Format specific data for the new node.  */
  dn = diskfs_node_disknode (np);
  dn->dirents = 0;
  dn->dir_idx = 0;
  dn->pager = 0;
  pthread_rwlock_init (&dn->alloc_lock, NULL);
  pokel_init (&dn->indir_pokel, diskfs_disk_pager, disk_cache);

  *npp = np;
  return 0;
}

int main(int argc, char** argv)
{
  pthread_t thread1;
  pthread_t thread2;

#if 0

  VALGRIND_DO_CLIENT_REQUEST_STMT(VG_USERREQ__DRD_TRACE_ADDR,
                                  &s_racy, 0, 0, 0, 0, 0);
#endif

  pthread_rwlock_init(&s_rwlock, 0);
  pthread_create(&thread1, 0, thread_func, 0);
  pthread_create(&thread2, 0, thread_func, 0);
  pthread_join(thread1, 0);
  pthread_join(thread2, 0);
  pthread_rwlock_destroy(&s_rwlock);

  fprintf(stderr, "Result: %d\n", s_racy);

  return 0;
}

int main(int argc, char **argv)
{
	int retval, i;

	pthread_t writer_id, reader_id;
	pthread_attr_t attr;
	int nreadercount = 1, nwritercount = 1;

	if (argc != 2) {
		fprintf(stderr, "usage, <%s threadcount>", argv[0]);
		return -1;
	}
	retval = pthread_rwlock_init(&rwlock, NULL);
	if (retval) {
		fprintf(stderr, "init lock failed\n");
		return retval;
	}
	pthread_attr_init(&attr);
	//pthread_attr_setdetachstate用来设置线程的分离状态
	//也就是说一个线程怎么样终止自己，状态设置为PTHREAD_CREATE_DETACHED
	//表示以分离状态启动线程
	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
	
	//分别在main函数中对读出者和写入者加锁，得到的处理结果是不一样的
	pthread_rwlock_wrlock(&rwlock);
//	pthread_rwlock_rdlock(&rwlock);
	for (i = 0; i < atoi(argv[1]); i++) {
		if (random() % 2) {
			pthread_create(&reader_id, &attr, readers, (void *)nreadercount);
			printf("create reader %d\n", nreadercount++);
		} else {
			pthread_create(&writer_id, &attr, writers, (void *)nwritercount);
			printf("create writer %d\n", nwritercount++);
		}
	}
	pthread_rwlock_unlock(&rwlock);
	sleep(20);//sleep是为了等待另外的线程的执行
	return 0;	
}

int init_mapping()
{
	int i;
	for (i = 0; i < MAP_TABLE_SIZE; i++) {
		memset(&(ip_map_table[i]), 0, sizeof(struct ip_map_table_node));
		if (pthread_rwlock_init(&(ip_map_table[i].rwlock), NULL) != 0) {
			fprintf(stderr, "Error initialize mutex for map-table\n");
			return(1);
		}
	}
	for (i = 0; i < HASH_TABLE_SIZE; i++) {
		memset(&(hash_table[i]), 0, sizeof(struct hash_table_array_node));
		if (pthread_mutex_init(&(hash_table[i].mutex), NULL) != 0) {
			fprintf(stderr, "Error initialize mutex for hash-table\n");
			return(1);
		}
	}
	for (i = 0; i < VSERVER_MAXSIZE; i++) {
		memset(&(vserver_list[i]), 0, sizeof(struct vserver_list_node));
	}
	return(0);
}

// create a file handle from an fs_entry
struct fs_file_handle* fs_file_handle_create( struct fs_core* core, struct fs_entry* ent, char const* opened_path, uint64_t parent_id, char const* parent_name ) {
    struct fs_file_handle* fh = SG_CALLOC( struct fs_file_handle, 1 );
    fh->flags = 0;
    fh->open_count = 0;
    fh->fent = ent;
    fh->volume = ent->volume;
    fh->file_id = ent->file_id;
    fh->path = strdup( opened_path );
    fh->parent_name = strdup( parent_name );
    fh->parent_id = parent_id;
    fh->transfer_timeout_ms = (core->conf->transfer_timeout) * 1000L;
    fh->dirty = false;

    uint64_t gateway_type = ms_client_get_gateway_type( core->ms, ent->coordinator );
    if( gateway_type == SYNDICATE_AG ) {
        fh->is_AG = true;
    }

    pthread_rwlock_init( &fh->lock, NULL );

    return fh;
}

/* Initialize TPCLog LOG to use the provided DIRNAME to store its associated
 * entries. Sets LOG's NEXTID field based on the entries that currently exist
 * in DIRNAME. */
int tpclog_init(tpclog_t *log, char *dirname) {
  struct stat st;
  unsigned long nextid = 0;
  char filename[MAX_FILENAME];
  if (stat(dirname, &st) == -1) {
    if (mkdir(dirname, 0700) == -1)
      return errno;
  }
  log->dirname = malloc(strlen(dirname) + 1);
  if (!log->dirname)
    fatal_malloc();
  strcpy(log->dirname, dirname);
  pthread_rwlock_init(&log->lock, NULL);

  /* Iterate through entries to determine next available ID, since this log may
   * be recovering from a crash. */
  sprintf(filename, "%s/%lu%s", log->dirname, nextid++, TPCLOG_FILETYPE);
  while (stat(filename, &st) != -1)
    sprintf(filename, "%s/%lu%s", log->dirname, nextid++, TPCLOG_FILETYPE);
  log->nextid = nextid - 1;
  return 0;
}