C++ pthread_rwlock_rdlock函数代码示例

/** command "show logging" */
int _dessert_cli_cmd_logging(struct cli_def* cli, char* command, char* argv[], int argc) {
    pthread_rwlock_rdlock(&_dessert_logrbuf_len_lock);
    int i = 0;
    int max = _dessert_logrbuf_len - 1;
    char* line;

    if(_dessert_logrbuf_len < 1) {
        cli_print(
            cli,
            "logging to ringbuffer is disabled - use \"logging ringbuffer [int]\" in config-mode first");
        pthread_rwlock_unlock(&_dessert_logrbuf_len_lock);
        return CLI_ERROR;
    }

    if(argc == 1) {
        int max2 = (int) strtol(argv[0], NULL, 10);

        if(max2 > 0) {
            max = max2;
        }
    }

    /* where to start and print? */
    if(max > _dessert_logrbuf_used) {
        max = _dessert_logrbuf_used;
    }

    i = _dessert_logrbuf_cur - max - 1;

    if(i < 0) {
        i += _dessert_logrbuf_len;
    }

    while(max > 0) {
        i++;
        max--;

        if(i == _dessert_logrbuf_len) {
            i = 0;
        }

        line = _dessert_logrbuf + (DESSERT_LOGLINE_MAX * i);
        cli_print(cli, "%s", line);
    }

    pthread_rwlock_unlock(&_dessert_logrbuf_len_lock);

    return CLI_OK;
}

void rw_lock_read_lock(rw_lock_t* lock)
{
#ifdef __MINGW32__
	EnterCriticalSection(&lock->readlock);

	EnterCriticalSection(&lock->lock);
	lock->readers++;
	ResetEvent(lock->writelock);
	LeaveCriticalSection(&lock->lock);

	LeaveCriticalSection(&lock->readlock);
#else
	pthread_rwlock_rdlock(lock);
#endif
}

void * writer() {
    for (int i = 0; i < 5; i++) {
        pthread_rwlock_rdlock(&rwlock);

        pthread_rwlock_trywrlock(&rwlock);

        value += 1;

        pthread_rwlock_unlock(&rwlock);

        sleep(i);
    }

    pthread_exit(NULL);
}

struct list * list_lookup(int lookup_id)
{
   struct list *curr;
   int rv;
   rv=pthread_rwlock_rdlock(&rw);   // 只讀表，因此以讀模式申請讀寫鎖 
   check_error(rv, "lookup: read lock");
   for (curr=list_head; curr !=NULL; curr=curr->next) // 查詢記錄位置 
         if (curr->id >= lookup_id) 
            break;
   if (curr != NULL && curr->id != lookup_id)
      curr = (struct list *)NULL;    // 沒有找到
   rv = pthread_rwlock_unlock(&rw);   // 釋放讀寫鎖 
   check_error(rv, "add: write unlock");
   return (curr);
}

static int cache_get(lua_State * L) {
	size_t len1,len2;
	const char * key_l=lua_tolstring(L,1,&len1);
	char * val=NULL;
	pthread_rwlock_rdlock(&rwlock);
	val=hashtable_get(ht,key_l,&len2);
	//printf("%p %s %u\n",val,val,len2);
	if(val==NULL) {
		pthread_rwlock_unlock(&rwlock);
		return 0;
	}
	lua_pushlstring(L,val,len2);
	pthread_rwlock_unlock(&rwlock);
	return 1;
}

struct gate_info *gate_info_manager_t::get_best_gate_incref(uint64_t uid)
{
    struct gate_info *info = NULL;

    pthread_rwlock_rdlock(&rwlock);
    size_t sz = gate_infos.size();
    if (sz > 0) {
        int idx = (int)(uid % (uint64_t)sz);
        info = gate_infos[idx];
        gate_info_incref(info);
    }
    pthread_rwlock_unlock(&rwlock);

    return info;
}

void runpath_list_fprintf(runpath_list_type * list ) {
  pthread_rwlock_rdlock( &list->lock );
  {
    FILE * stream = util_mkdir_fopen( list->export_file , "w");
    const char * line_fmt = runpath_list_get_line_fmt( list );
    int index;
    vector_sort( list->list , runpath_node_cmp );
    for (index =0; index < vector_get_size( list->list ); index++) {
      const runpath_node_type * node = runpath_list_iget_node__( list , index );
      runpath_node_fprintf( node , line_fmt , stream );
    }
    fclose( stream );
  }
  pthread_rwlock_unlock( &list->lock );
}

/*
 * Find a job for the given thread ID.
 */
struct job *
job_find(struct queue *qp, pthread_t id)
{
  struct job *jp;

  if (pthread_rwlock_rdlock(&qp->q_lock) != 0)
    return NULL;

  for (jp = qp->q_head; jp != NULL; jp = jp->j_next)
    if (pthread_equal(jp->j_id, id))
      break;

  pthread_rwlock_unlock(&qp->q_lock);
  return jp;
}

//---------------------------------------------------------------------------------------------------------------------
int pmip_cache_iterate(int (*func) (void *, void *), void *arg)
{
    int err;
    int mutex_return_code;
    mutex_return_code = pthread_rwlock_rdlock(&pmip_lock);
    if (mutex_return_code != 0) {
        dbg("pthread_rwlock_rdlock(&pmip_lock) %s\n", strerror(mutex_return_code));
    }
    err = pmip_hash_iterate(&g_pmip_hash, func, arg);
    mutex_return_code = pthread_rwlock_unlock(&pmip_lock);
    if (mutex_return_code != 0) {
        dbg("pthread_rwlock_unlock(&pmip_lock) %s\n", strerror(mutex_return_code));
    }
    return err;
}

  void RateLimiter::Release(int counter_index, const char * key, uint64_t amount) {
    TSReleaseAssert(!pthread_rwlock_rdlock(&rwlock_keymap_));

    std::map<const char *,LimiterState *>::iterator it = keymap_.find(key);

    TSReleaseAssert(!pthread_rwlock_unlock(&rwlock_keymap_));
    TSReleaseAssert( it != keymap_.end() );
    LimiterState * state = it->second;


    TSMutexLock(update_mutex_);
    state->set_taken(counter_index, state->taken(counter_index) - amount);
    dbg("released amount, currently taken %f", state->taken(counter_index));
    TSMutexUnlock(update_mutex_);
  }

//---------------------------------------------------------------------------------------------------------------------
pmip_entry_t *pmip_cache_get(const struct in6_addr * our_addr, const struct in6_addr * peer_addr)
{
	pmip_entry_t *bce;
	assert(peer_addr && our_addr);
	pthread_rwlock_rdlock(&pmip_lock);
	bce = hash_get(&g_pmip_hash, our_addr, peer_addr);
	if (bce) {
		pthread_rwlock_wrlock(&bce->lock);
		//dbg("PMIP cache entry is found for: %x:%x:%x:%x:%x:%x:%x:%x with type %d\n", NIP6ADDR(&bce->mn_hw_address), (bce->type));
	} else {
		pthread_rwlock_unlock(&pmip_lock);
		//dbg("PMIP cache entry is NOT found for %x:%x:%x:%x:%x:%x:%x:%x <-> %x:%x:%x:%x:%x:%x:%x:%x\n", NIP6ADDR(our_addr), NIP6ADDR(peer_addr));
	}
	return bce;
}

/* Looks for the photoset specified in the argument.
 * Returns pointer to the stored cached_information
 * or 0 if not found.
 */
cached_information *photoset_lookup(const char *photoset) {
    cached_photoset *cps;
    cached_information *ci_copy = NULL;

    pthread_rwlock_rdlock(&cache_lock);
    if(check_cache())
        goto fail;

    cps = g_hash_table_lookup(photoset_ht, photoset);
    if(cps)
        ci_copy = copy_cached_info(&(cps->ci));

fail: pthread_rwlock_unlock(&cache_lock);
    return ci_copy;
}

/**
 * \brief Bind to a variable
 *
 * Subscribe to the give variable and automatically populate its value in the float whose reference is passed
 *
 * \param name Name of the variable to subscribe to
 * \param store_to Pointer to a float to store the value of the variable when it is updated
 * \return 0 on success
 */
int Var_bind(char* name, float* store_to) {
    Subscription* s;

    Var_subscribe(name);

    pthread_rwlock_rdlock(&subscriptions_lock); {
        s = Dictionary_get(subscriptions, name);
        s->writeback = store_to;
    }
    pthread_rwlock_unlock(&subscriptions_lock);

    (*s->writeback) = s->current;
    
    return 0;
}

static void
__dcethread_child_fork(void)
{
    unsigned int i;

    pthread_rwlock_rdlock(&atfork_lock);

    for (i = 0; i < atfork_handlers_len; i++)
    {
	if (atfork_handlers[i].child_fork)
	    atfork_handlers[i].child_fork(atfork_handlers[i].user_state);
    }

    pthread_rwlock_unlock(&atfork_lock);
}

/* Force log context acquisition through a function */
static rpmlogCtx rpmlogCtxAcquire(int write)
{
    static struct rpmlogCtx_s _globalCtx = { PTHREAD_RWLOCK_INITIALIZER,
					     RPMLOG_UPTO(RPMLOG_NOTICE),
					     0, NULL, NULL, NULL, NULL };
    rpmlogCtx ctx = &_globalCtx;

    /* XXX: errors should be handled */
    if (write)
	pthread_rwlock_wrlock(&ctx->lock);
    else
	pthread_rwlock_rdlock(&ctx->lock);

    return ctx;
}