C++ queue_pop函数代码示例

static int proceed(h2o_http2_scheduler_node_t *node, h2o_http2_scheduler_run_cb cb, void *cb_arg)
{
Redo:
    if (node->_queue == NULL)
        return 0;

    h2o_http2_scheduler_queue_node_t *drr_node = queue_pop(node->_queue);
    if (drr_node == NULL)
        return 0;

    h2o_http2_scheduler_openref_t *ref = H2O_STRUCT_FROM_MEMBER(h2o_http2_scheduler_openref_t, _queue_node, drr_node);

    if (!ref->_self_is_active) {
        /* run the children (manually-unrolled tail recursion) */
        queue_set(node->_queue, &ref->_queue_node, ref->weight);
        node = &ref->node;
        goto Redo;
    }
    assert(ref->_active_cnt != 0);

    /* call the callbacks */
    int still_is_active, bail_out = cb(ref, &still_is_active, cb_arg);
    if (still_is_active) {
        queue_set(node->_queue, &ref->_queue_node, ref->weight);
    } else {
        ref->_self_is_active = 0;
        if (--ref->_active_cnt != 0) {
            queue_set(node->_queue, &ref->_queue_node, ref->weight);
        } else if (ref->node._parent != NULL) {
            decr_active_cnt(ref->node._parent);
        }
    }

    return bail_out;
}

void sched_handler_try_steal(scheduler_t* scheduler, int steal_attempts) {
	if (schedulers_nr > 1) {
		unsigned int seed = 42;
		srand(time(NULL));
		long victim_id = 0;
		int attempt = 0;
		task_t* stolen = NULL;

		while (stolen == NULL && attempt < steal_attempts) {
			do {
				victim_id = rand_r(&seed) % schedulers_nr;
			} while (victim_id == scheduler->id);

			scheduler_t* victim = &schedulers[victim_id];
			stolen = queue_pop(&victim->ready);
			if (stolen) {
				debug("%d - yay", scheduler->id);
			}
			attempt+=1;
		}
		if (stolen) {
			debug("%d - Succesfully stolen task %d from victim %d", scheduler->id, stolen->id, (int) victim_id);
			scheduler->action = YIELD;
			scheduler->current_task = stolen;
		} else {
			//debug("%d - Failed to steal from victim %d", scheduler->id, (int) victim_id);
		}		
	}
}

/* Push element x onto stack */
void stackPush(Stack *stack, int element) {
    while(!queue_empty(&stack->q[stack->cur])) {
        int x = queue_pop(&stack->q[stack->cur]);
        queue_push(&stack->q[(stack->cur+1)%2], x);
    }
    queue_push(&stack->q[stack->cur], element);
}

/**
 * @brief     This thread represents a print spooler which directly talks to a single printer
 * @param     param
 *                 The PRINT_SPOOL_PARAM this printer should pull its jobs from, casted to a void*
 * @return    NULL
 *
 * This function should loop forever.  The basic process is as follows:
 * 1) pop a print job from this threads queue
 * 2) if it is NULL return
 * 3) print to the log file that printing of the job is starting
 * 4) call the print method on the printer object of the param and check the return
 * 5) handel errors correctly
 * 6) destroy the print job and get the next
 */
void *spooler(void* param)
{
	struct PRINTER_SPOOLER_PARAM* params =  malloc(sizeof(struct PRINTER_SPOOLER_PARAM));
	params = (struct PRINTER_SPOOLER_PARAM*)param;
	queue_t queue = params->print_queue_list;
	printer_t printer = params->printer_driver;
	struct arguments arguments = params->arguments;

	queue_ends_t q_ends = QUEUE_HEAD;
	print_job_t* popped;
	FILE *file;
	char *str;
	while(1){
		popped = queue_pop(queue,  q_ends);
		if (popped == NULL){	
			printer_uninstall(printer);
			return NULL;
		}
	
		file = fopen(arguments.log_file_name, "a");

		if(file == NULL){
			fprintf(stderr, "%s: error opening log file\n", __func__);	
			exit(-1);
		}
		asprintf(&str, "Starting to print job %s\n", popped->job_name);
		fputs(str,file);
		fclose(file);
		printer_print(printer, popped);
	}
}

bool esta_bien_armada() {
	/*Esta correctamente armada si tiene todos los ingredientes,
		 *  y los tiene definidos en el orden dado por el enum t_Ingredientes*/

	for (int i = 0; (((t_Ingredientes) i) <= PANSUPERIOR); i++) {
		t_Ingredientes ingrediente_correcto = (t_Ingredientes) i;
		t_Ingredientes ingrediente_hamburguesa;

		pthread_mutex_lock(&mutex);
		int* ingrediente = queue_pop(hamburguesa.ingredientes);
		pthread_mutex_unlock(&mutex);

		if (ingrediente == NULL) {
			printf("Faltaron ingredientes!\n");
			return false;
		}

		ingrediente_hamburguesa = (t_Ingredientes) *ingrediente;
		if (ingrediente_hamburguesa != ingrediente_correcto) {
			printf("Ingrediente incorrecto debia ser %s y era %s\n",
					ingrediente_to_string(ingrediente_correcto),
					ingrediente_to_string(ingrediente_hamburguesa));

			free(ingrediente);
			return false;
		}
	}

	return true;
}

void* ResThreads(void* empty)
{
	char* outhostname; //hostname you pop off the queue
	char firstipstring[INET6_ADDRSTRLEN];
	
	//while the search is incomplete or the queue is not empty
	while (!queue_is_empty(requesterQ) || !SearchComplete)
	{
		//if queue is empty wait
		while (queue_is_empty(requesterQ)){
			if(SearchComplete)
			{
				free(outhostname);
				return 0;
			}
		}
		//if there is an item in the queue, pop 
		pthread_mutex_lock(&Q_lock);//lock to have exclusion
		outhostname = queue_pop(requesterQ); //hostname 
		pthread_mutex_unlock(&Q_lock);
		
		//Lookup hostname and get IP string
		if(dnslookup(outhostname, firstipstring, sizeof(firstipstring)) == UTIL_FAILURE)
		{
			fprintf(stderr, "dnslookup error: %s\n", outhostname);
			strncpy(firstipstring, "", sizeof(firstipstring));
		}
		//Write to output file
		pthread_mutex_lock( &Out_lock ); //Lock the outputfile so you only put one thing at a time in it
		fprintf(outputfp, "%s,%s\n", outhostname, firstipstring);
		free(outhostname);
		pthread_mutex_unlock( &Out_lock );
	}
	return 0;
}

void queue_destroy(queue *Q)
{
    while(!queue_empty(Q))
    {
        queue_pop(Q);
    }
}

void threadDispositivo(stDispositivo* unDispositivo) {
	int error = 0;
	t_queue *colaRafaga;
	stRafaga *unaRafaga;
	stPCB *unPCB;

	colaRafaga = unDispositivo->rafagas;

	while (!error) {
		while (unDispositivo->numInq == 0)
			pthread_mutex_lock(&unDispositivo->empty);
		pthread_mutex_lock(&unDispositivo->mutex);		// Se lockea el acceso a la cola
		unaRafaga = queue_pop(colaRafaga);
		unDispositivo->numInq--;
		pthread_mutex_unlock(&unDispositivo->mutex);	// Se desbloquea el acceso a la cola

		log_info("Pedido I/O - Retardo de dispositivo [%s] con [%d].",unDispositivo->nombre,atoi(unDispositivo->retardo));
		usleep(atoi(unDispositivo->retardo)*unaRafaga->unidades*1000);

		/*Busqueda del pcb en la lista de pcb bloqueados*/
		int _es_el_pcb(stPCB *p) {
			return p->pid == unaRafaga->pid;
		}
		pthread_mutex_lock(&mutex_listaBlock);
		unPCB = list_remove_by_condition(listaBlock, (void*) _es_el_pcb);
		pthread_mutex_unlock(&mutex_listaBlock);

		/*Ponemos en la cola de Ready para que lo vuelva a ejecutar un CPU*/
		ready_productor(unPCB);
		log_info("El PCB [PID - %d] cambia de estado BLOCK a READY\n", unPCB->pid);
		free(unaRafaga);

	}
}

static void
command(struct skynet_context *ctx, struct package *P, int session, uint32_t source, const char *msg, size_t sz) {
	switch (msg[0]) {
	case 'R':
		// request a package
		if (P->closed) {
			skynet_send(ctx, 0, source, PTYPE_ERROR, session, NULL, 0);
			break;
		}
		if (!queue_empty(&P->response)) {
			assert(queue_empty(&P->request));
			struct response resp;
			queue_pop(&P->response, &resp);
			skynet_send(ctx, 0, source, PTYPE_RESPONSE | PTYPE_TAG_DONTCOPY, session, resp.msg, resp.sz);
		} else {
			struct request req;
			req.source = source;
			req.session = session;
			queue_push(&P->request, &req);
		}
		break;
	case 'K':
		// shutdown the connection
		skynet_socket_shutdown(ctx, P->fd);
		break;
	case 'I':
		report_info(ctx, P, session, source);
		break;
	default:
		// invalid command
		skynet_error(ctx, "Invalid command %.*s", (int)sz, msg);
		skynet_send(ctx, 0, source, PTYPE_ERROR, session, NULL, 0);
		break;
	};
}

si_t application_exec()
{
    /**
     * parse the application before execute
     **/
    application_parse();

	event_listener_add_read_event(&global_application.app_event_listener, &global_application.uds, NULL, application_event_handler, NULL);

	while(!queue_empty(&global_application.message_queue))
	{
		union message* msg = queue_front(&global_application.message_queue);
		application_handle_message(msg);
		queue_pop(&global_application.message_queue);
	}

	global_application.exec_flag = 1;
	if(0 != event_listener_exec(&global_application.app_event_listener))
	{
		EGUI_PRINT_ERROR("failed to run event_listener.");
		return -1;
	}
	global_application.exec_flag = 0;

    return 0;
}

si_t application_event_handler(struct egui_uds* uds_ptr, addr_t arg)
{
	union message msg;
    NOT_USED(arg);

	if(0 != comm_recv_msg(uds_ptr, &msg))
	{
		EGUI_PRINT_ERROR("failed to recv msg");
		return SELECTER_RETURN_TYPE_CONTINUE;
	}

	application_handle_message(&msg);

	/**
	 * 处理器消息过程中，应用程序需要发送一些请求，等待回应的过程中，窗口管理器可能会发送消息。
	 * 因此当请求处理完毕之后，再逐一处理消息。
	 **/
	while(!queue_empty(&global_application.message_queue))
	{
		union message* msg = queue_front(&global_application.message_queue);
		application_handle_message(msg);
		queue_pop(&global_application.message_queue);
	}

	return SELECTER_RETURN_TYPE_CONTINUE;
}

void queue_clear(orders_queue *q)
{
    order_t tmp_order;
    assert(q != NULL);
    while(!queue_empty(q))
        queue_pop(q, &tmp_order);
}

void dijkstra_distance_target(grid *distances, grid *target, const pos *targets, int count, int neighbors, cost_function_t cost_function, void *userdata){
    grid_fill(distances, distances->x0, distances->y0, distances->width, distances->height, DBL_MAX);
    if(target != NULL) grid_fill(target, target->x0, target->y0, target->width, target->height, -1);

    queue open_set = queue_create(sizeof(pos));

    for(int i = 0;i<count;++i) {
        grid_set(distances, targets[i].x, targets[i].y, 0.0);
        if(target != NULL) grid_set(target, targets[i].x, targets[i].y, i);
        queue_push(&open_set, targets+i);
    }

    while(!queue_empty(&open_set)) {
        pos cur = *(pos*)queue_front(&open_set);
        double curdist = grid_get(distances, cur.x, cur.y);
        queue_pop(&open_set);
        for(int i = 0;i<neighbors;++i) {
            pos neigh = {cur.x+offsets[i].x, cur.y+offsets[i].y};

            if(!grid_contains(distances, neigh.x, neigh.y)) continue;

            double neighdist = grid_get(distances, neigh.x, neigh.y);

            double cost = cost_function(cur.x, cur.y, neigh.x, neigh.y, userdata);
            if(neighdist > curdist + cost) {
                grid_set(distances, neigh.x, neigh.y, curdist + cost);
                if(target != NULL) grid_set(target, neigh.x, neigh.y, grid_get(target, cur.x, cur.y));
                queue_push(&open_set, &neigh);
            }
        }
    }

    queue_destroy(open_set);
}

/* Release the event handle returned by framework_event_query.
 * In the ASYNC model we must remove the event handle from the FIFO request
 * queue. */
void framework_release_handle(naf_handle handle)
{
    queue_entry* entry;

    if (!handle) {
        return;
    }
    if (queue_empty()) {
        /* Why do the application try to release a handle on an empty queue? */
        NABTO_LOG_FATAL(("SW error: Calling framework_release_handle on an empty queue"));
        return;
    }

    /* Find the entry containing the handle */
    entry = queue_find_entry(handle);
    /* The given handle must belong to the queue */
    UNABTO_ASSERT(entry);

    entry->state = APPREQ_FREE;
    LOG_APPREQ_WHERE("framework_release_handle", entry);

    /* Remove top entry from FIFO queue - and remove all consecutive
     * entries that have expired/finished in the mean time. */
    while (!queue_empty()) {
        if (queue_top()->state != APPREQ_FREE)
            break;
        queue_pop();
    }

    LOG_APPREQ_QUEUE();
}

static void
update_frame_v1(struct accuraterip_v1 *v1,
                unsigned total_pcm_frames,
                unsigned start_offset,
                unsigned end_offset,
                unsigned value)
{
    /*calculate initial checksum*/
    if ((v1->index >= start_offset) && (v1->index <= end_offset)) {
        v1->checksums[0] += (value * v1->index);
        v1->values_sum += value;
    }

    /*store the first (pcm_frame_range - 1) values in initial_values*/
    if ((v1->index >= start_offset) && (!queue_full(v1->initial_values))) {
        queue_push(v1->initial_values, value);
    }

    /*store the trailing (pcm_frame_range - 1) values in final_values*/
    if ((v1->index > end_offset) && (!queue_full(v1->final_values))) {
        queue_push(v1->final_values, value);
    }

    /*calculate incremental checksums*/
    if (v1->index > total_pcm_frames) {
        const uint32_t initial_value = queue_pop(v1->initial_values);

        const uint32_t final_value = queue_pop(v1->final_values);

        const uint32_t initial_value_product =
            (uint32_t)(start_offset - 1) * initial_value;

        const uint32_t final_value_product =
            (uint32_t)end_offset * final_value;

        v1->checksums[v1->index - total_pcm_frames] =
            v1->checksums[v1->index - total_pcm_frames - 1] +
            final_value_product -
            v1->values_sum -
            initial_value_product;

        v1->values_sum -= initial_value;
        v1->values_sum += final_value;
    }

    v1->index++;
}