graph.c

// Copyright 2016-2017 Open Source Robotics Foundation, Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
 
#ifdef __cplusplus
extern "C"
{
#endif
 
#include <stddef.h>
 
#include "rcl/graph.h"
#include "rcl/error_handling.h"
#include "rcl/guard_condition.h"
#include "rcl/wait.h"
 
#include "rcutils/allocator.h"
#include "rcutils/error_handling.h"
#include "rcutils/macros.h"
#include "rcutils/time.h"
#include "rcutils/types.h"
 
#include "rmw/error_handling.h"
#include "rmw/get_node_info_and_types.h"
#include "rmw/get_service_endpoint_info.h"
#include "rmw/get_service_names_and_types.h"
#include "rmw/get_topic_endpoint_info.h"
#include "rmw/get_topic_names_and_types.h"
#include "rmw/names_and_types.h"
#include "rmw/rmw.h"
#include "rmw/service_endpoint_info_array.h"
#include "rmw/topic_endpoint_info_array.h"
#include "rmw/validate_namespace.h"
#include "rmw/validate_node_name.h"
 
#include "./common.h"
 
rcl_ret_t
__validate_node_name_and_namespace(
  const char * node_name,
  const char * node_namespace)
{
  int validation_result = 0;
  rmw_ret_t rmw_ret = rmw_validate_namespace(node_namespace, &validation_result, NULL);
 
  if (RMW_RET_OK != rmw_ret) {
    RCL_SET_ERROR_MSG(rmw_get_error_string().str);
    return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
  }
  if (validation_result != RMW_NAMESPACE_VALID) {
    const char * msg = rmw_namespace_validation_result_string(validation_result);
    RCL_SET_ERROR_MSG_WITH_FORMAT_STRING("%s, result: %d", msg, validation_result);
    return RCL_RET_NODE_INVALID_NAMESPACE;
  }
 
  validation_result = 0;
  rmw_ret = rmw_validate_node_name(node_name, &validation_result, NULL);
  if (RMW_RET_OK != rmw_ret) {
    RCL_SET_ERROR_MSG(rmw_get_error_string().str);
    return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
  }
  if (RMW_NODE_NAME_VALID != validation_result) {
    const char * msg = rmw_node_name_validation_result_string(validation_result);
    RCL_SET_ERROR_MSG_WITH_FORMAT_STRING("%s, result: %d", msg, validation_result);
    return RCL_RET_NODE_INVALID_NAME;
  }
 
  return RCL_RET_OK;
}
 
rcl_ret_t
rcl_get_publisher_names_and_types_by_node(
  const rcl_node_t * node,
  rcl_allocator_t * allocator,
  bool no_demangle,
  const char * node_name,
  const char * node_namespace,
  rcl_names_and_types_t * topic_names_and_types)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;
  }
  RCL_CHECK_ALLOCATOR_WITH_MSG(allocator, "invalid allocator", return RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(node_name, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(node_namespace, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(topic_names_and_types, RCL_RET_INVALID_ARGUMENT);
 
  const char * valid_namespace = "/";
  if (strlen(node_namespace) > 0) {
    valid_namespace = node_namespace;
  }
  rmw_ret_t rmw_ret = rmw_names_and_types_check_zero(topic_names_and_types);
  if (RMW_RET_OK != rmw_ret) {
    return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
  }
  rcl_ret_t rcl_ret = __validate_node_name_and_namespace(node_name, valid_namespace);
  if (RCL_RET_OK != rcl_ret) {
    return rcl_ret;
  }
  rcutils_allocator_t rcutils_allocator = *allocator;
  rmw_ret = rmw_get_publisher_names_and_types_by_node(
    rcl_node_get_rmw_handle(node),
    &rcutils_allocator,
    node_name,
    valid_namespace,
    no_demangle,
    topic_names_and_types
  );
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
rcl_ret_t
rcl_get_subscriber_names_and_types_by_node(
  const rcl_node_t * node,
  rcl_allocator_t * allocator,
  bool no_demangle,
  const char * node_name,
  const char * node_namespace,
  rcl_names_and_types_t * topic_names_and_types)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;
  }
  RCL_CHECK_ALLOCATOR_WITH_MSG(allocator, "invalid allocator", return RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(node_name, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(node_namespace, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(topic_names_and_types, RCL_RET_INVALID_ARGUMENT);
 
  const char * valid_namespace = "/";
  if (strlen(node_namespace) > 0) {
    valid_namespace = node_namespace;
  }
  rmw_ret_t rmw_ret;
  rmw_ret = rmw_names_and_types_check_zero(topic_names_and_types);
  if (rmw_ret != RMW_RET_OK) {
    return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
  }
  rcutils_allocator_t rcutils_allocator = *allocator;
  rcl_ret_t rcl_ret = __validate_node_name_and_namespace(node_name, valid_namespace);
  if (RCL_RET_OK != rcl_ret) {
    return rcl_ret;
  }
  rmw_ret = rmw_get_subscriber_names_and_types_by_node(
    rcl_node_get_rmw_handle(node),
    &rcutils_allocator,
    node_name,
    valid_namespace,
    no_demangle,
    topic_names_and_types
  );
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
rcl_ret_t
rcl_get_service_names_and_types_by_node(
  const rcl_node_t * node,
  rcl_allocator_t * allocator,
  const char * node_name,
  const char * node_namespace,
  rcl_names_and_types_t * service_names_and_types)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;
  }
  RCL_CHECK_ALLOCATOR_WITH_MSG(allocator, "invalid allocator", return RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(node_name, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(node_namespace, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(service_names_and_types, RCL_RET_INVALID_ARGUMENT);
 
  const char * valid_namespace = "/";
  if (strlen(node_namespace) > 0) {
    valid_namespace = node_namespace;
  }
  rmw_ret_t rmw_ret;
  rmw_ret = rmw_names_and_types_check_zero(service_names_and_types);
  if (rmw_ret != RMW_RET_OK) {
    return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
  }
  rcl_ret_t rcl_ret = __validate_node_name_and_namespace(node_name, valid_namespace);
  if (RCL_RET_OK != rcl_ret) {
    return rcl_ret;
  }
  rcutils_allocator_t rcutils_allocator = *allocator;
  rmw_ret = rmw_get_service_names_and_types_by_node(
    rcl_node_get_rmw_handle(node),
    &rcutils_allocator,
    node_name,
    valid_namespace,
    service_names_and_types
  );
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
rcl_ret_t
rcl_get_client_names_and_types_by_node(
  const rcl_node_t * node,
  rcl_allocator_t * allocator,
  const char * node_name,
  const char * node_namespace,
  rcl_names_and_types_t * service_names_and_types)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;
  }
  RCL_CHECK_ALLOCATOR_WITH_MSG(allocator, "invalid allocator", return RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(node_name, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(node_namespace, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(service_names_and_types, RCL_RET_INVALID_ARGUMENT);
 
  const char * valid_namespace = "/";
  if (strlen(node_namespace) > 0) {
    valid_namespace = node_namespace;
  }
  rmw_ret_t rmw_ret;
  rmw_ret = rmw_names_and_types_check_zero(service_names_and_types);
  if (rmw_ret != RMW_RET_OK) {
    return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
  }
  rcl_ret_t rcl_ret = __validate_node_name_and_namespace(node_name, valid_namespace);
  if (RCL_RET_OK != rcl_ret) {
    return rcl_ret;
  }
  rcutils_allocator_t rcutils_allocator = *allocator;
  rmw_ret = rmw_get_client_names_and_types_by_node(
    rcl_node_get_rmw_handle(node),
    &rcutils_allocator,
    node_name,
    valid_namespace,
    service_names_and_types
  );
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
rcl_ret_t
rcl_get_topic_names_and_types(
  const rcl_node_t * node,
  rcl_allocator_t * allocator,
  bool no_demangle,
  rcl_names_and_types_t * topic_names_and_types)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;  // error already set
  }
  RCL_CHECK_ALLOCATOR_WITH_MSG(allocator, "invalid allocator", return RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(topic_names_and_types, RCL_RET_INVALID_ARGUMENT);
  rmw_ret_t rmw_ret;
  rmw_ret = rmw_names_and_types_check_zero(topic_names_and_types);
  if (rmw_ret != RMW_RET_OK) {
    return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
  }
  rcutils_allocator_t rcutils_allocator = *allocator;
  rmw_ret = rmw_get_topic_names_and_types(
    rcl_node_get_rmw_handle(node),
    &rcutils_allocator,
    no_demangle,
    topic_names_and_types
  );
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
rcl_ret_t
rcl_get_service_names_and_types(
  const rcl_node_t * node,
  rcl_allocator_t * allocator,
  rcl_names_and_types_t * service_names_and_types)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;  // error already set
  }
  RCL_CHECK_ALLOCATOR_WITH_MSG(allocator, "invalid allocator", return RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(service_names_and_types, RCL_RET_INVALID_ARGUMENT);
  rmw_ret_t rmw_ret;
  rmw_ret = rmw_names_and_types_check_zero(service_names_and_types);
  if (rmw_ret != RMW_RET_OK) {
    return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
  }
  rcutils_allocator_t rcutils_allocator = *allocator;
  rmw_ret = rmw_get_service_names_and_types(
    rcl_node_get_rmw_handle(node),
    &rcutils_allocator,
    service_names_and_types
  );
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
rcl_ret_t
rcl_names_and_types_init(
  rcl_names_and_types_t * names_and_types,
  size_t size,
  rcl_allocator_t * allocator)
{
  RCUTILS_CAN_RETURN_WITH_ERROR_OF(RCL_RET_INVALID_ARGUMENT);
 
  RCL_CHECK_ARGUMENT_FOR_NULL(names_and_types, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ALLOCATOR(allocator, return RCL_RET_INVALID_ARGUMENT);
  rmw_ret_t rmw_ret = rmw_names_and_types_init(names_and_types, size, allocator);
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
rcl_ret_t
rcl_names_and_types_fini(rcl_names_and_types_t * topic_names_and_types)
{
  RCUTILS_CAN_RETURN_WITH_ERROR_OF(RCL_RET_INVALID_ARGUMENT);
 
  RCL_CHECK_ARGUMENT_FOR_NULL(topic_names_and_types, RCL_RET_INVALID_ARGUMENT);
  rmw_ret_t rmw_ret = rmw_names_and_types_fini(topic_names_and_types);
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
rcl_ret_t
rcl_get_node_names(
  const rcl_node_t * node,
  rcl_allocator_t allocator,
  rcutils_string_array_t * node_names,
  rcutils_string_array_t * node_namespaces)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;  // error already set
  }
  RCL_CHECK_ARGUMENT_FOR_NULL(node_names, RCL_RET_INVALID_ARGUMENT);
  if (node_names->size != 0) {
    RCL_SET_ERROR_MSG("node_names size is not zero");
    return RCL_RET_INVALID_ARGUMENT;
  }
  if (node_names->data) {
    RCL_SET_ERROR_MSG("node_names is not null");
    return RCL_RET_INVALID_ARGUMENT;
  }
  RCL_CHECK_ARGUMENT_FOR_NULL(node_namespaces, RCL_RET_INVALID_ARGUMENT);
  if (node_namespaces->size != 0) {
    RCL_SET_ERROR_MSG("node_namespaces size is not zero");
    return RCL_RET_INVALID_ARGUMENT;
  }
  if (node_namespaces->data) {
    RCL_SET_ERROR_MSG("node_namespaces is not null");
    return RCL_RET_INVALID_ARGUMENT;
  }
  (void)allocator;  // to be used in rmw_get_node_names in the future
  rmw_ret_t rmw_ret = rmw_get_node_names(
    rcl_node_get_rmw_handle(node),
    node_names,
    node_namespaces);
 
  if (RMW_RET_OK != rmw_ret) {
    return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
  }
 
  // Check that none of the node names are NULL or empty
  for (size_t i = 0u; i < node_names->size; ++i) {
    if (!node_names->data[i]) {
      RCL_SET_ERROR_MSG("NULL node name returned by the RMW layer");
      return RCL_RET_NODE_INVALID_NAME;
    }
    if (!strcmp(node_names->data[i], "")) {
      RCL_SET_ERROR_MSG("empty node name returned by the RMW layer");
      return RCL_RET_NODE_INVALID_NAME;
    }
  }
  // Check that none of the node namespaces are NULL
  for (size_t i = 0u; i < node_namespaces->size; ++i) {
    if (!node_namespaces->data[i]) {
      RCL_SET_ERROR_MSG("NULL node namespace returned by the RMW layer");
      return RCL_RET_NODE_INVALID_NAMESPACE;
    }
  }
  return RCL_RET_OK;
}
 
rcl_ret_t
rcl_get_node_names_with_enclaves(
  const rcl_node_t * node,
  rcl_allocator_t allocator,
  rcutils_string_array_t * node_names,
  rcutils_string_array_t * node_namespaces,
  rcutils_string_array_t * enclaves)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;  // error already set
  }
  RCL_CHECK_ARGUMENT_FOR_NULL(node_names, RCL_RET_INVALID_ARGUMENT);
  if (node_names->size != 0) {
    RCL_SET_ERROR_MSG("node_names size is not zero");
    return RCL_RET_INVALID_ARGUMENT;
  }
  if (node_names->data) {
    RCL_SET_ERROR_MSG("node_names is not null");
    return RCL_RET_INVALID_ARGUMENT;
  }
  RCL_CHECK_ARGUMENT_FOR_NULL(node_namespaces, RCL_RET_INVALID_ARGUMENT);
  if (node_namespaces->size != 0) {
    RCL_SET_ERROR_MSG("node_namespaces size is not zero");
    return RCL_RET_INVALID_ARGUMENT;
  }
  if (node_namespaces->data) {
    RCL_SET_ERROR_MSG("node_namespaces is not null");
    return RCL_RET_INVALID_ARGUMENT;
  }
  RCL_CHECK_ARGUMENT_FOR_NULL(enclaves, RCL_RET_INVALID_ARGUMENT);
  if (enclaves->size != 0) {
    RCL_SET_ERROR_MSG("enclaves size is not zero");
    return RCL_RET_INVALID_ARGUMENT;
  }
  if (enclaves->data) {
    RCL_SET_ERROR_MSG("enclaves is not null");
    return RCL_RET_INVALID_ARGUMENT;
  }
  (void)allocator;  // to be used in rmw_get_node_names in the future
  rmw_ret_t rmw_ret = rmw_get_node_names_with_enclaves(
    rcl_node_get_rmw_handle(node),
    node_names,
    node_namespaces,
    enclaves);
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
rcl_ret_t
rcl_count_publishers(
  const rcl_node_t * node,
  const char * topic_name,
  size_t * count)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;  // error already set
  }
  const rcl_node_options_t * node_options = rcl_node_get_options(node);
  if (!node_options) {
    return RCL_RET_NODE_INVALID;  // shouldn't happen, but error is already set if so
  }
  RCL_CHECK_ARGUMENT_FOR_NULL(topic_name, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(count, RCL_RET_INVALID_ARGUMENT);
  rmw_ret_t rmw_ret = rmw_count_publishers(rcl_node_get_rmw_handle(node), topic_name, count);
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
rcl_ret_t
rcl_count_subscribers(
  const rcl_node_t * node,
  const char * topic_name,
  size_t * count)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;  // error already set
  }
  const rcl_node_options_t * node_options = rcl_node_get_options(node);
  if (!node_options) {
    return RCL_RET_NODE_INVALID;  // shouldn't happen, but error is already set if so
  }
  RCL_CHECK_ARGUMENT_FOR_NULL(topic_name, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(count, RCL_RET_INVALID_ARGUMENT);
  rmw_ret_t rmw_ret = rmw_count_subscribers(rcl_node_get_rmw_handle(node), topic_name, count);
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
rcl_ret_t
rcl_count_clients(
  const rcl_node_t * node,
  const char * service_name,
  size_t * count)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;  // error already set
  }
  const rcl_node_options_t * node_options = rcl_node_get_options(node);
  if (!node_options) {
    return RCL_RET_NODE_INVALID;  // shouldn't happen, but error is already set if so
  }
  RCL_CHECK_ARGUMENT_FOR_NULL(service_name, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(count, RCL_RET_INVALID_ARGUMENT);
  rmw_ret_t rmw_ret = rmw_count_clients(rcl_node_get_rmw_handle(node), service_name, count);
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
rcl_ret_t
rcl_count_services(
  const rcl_node_t * node,
  const char * service_name,
  size_t * count)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;  // error already set
  }
  const rcl_node_options_t * node_options = rcl_node_get_options(node);
  if (!node_options) {
    return RCL_RET_NODE_INVALID;  // shouldn't happen, but error is already set if so
  }
  RCL_CHECK_ARGUMENT_FOR_NULL(service_name, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(count, RCL_RET_INVALID_ARGUMENT);
  rmw_ret_t rmw_ret = rmw_count_services(rcl_node_get_rmw_handle(node), service_name, count);
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
typedef rcl_ret_t (* count_entities_func_t)(
  const rcl_node_t * node,
  const char * topic_name,
  size_t * count);
 
rcl_ret_t
_rcl_wait_for_entities(
  const rcl_node_t * node,
  rcl_allocator_t * allocator,
  const char * topic_name,
  const size_t expected_count,
  rcutils_duration_value_t timeout,
  bool * success,
  count_entities_func_t count_entities_func)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;
  }
  RCL_CHECK_ALLOCATOR_WITH_MSG(allocator, "invalid allocator", return RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(topic_name, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(success, RCL_RET_INVALID_ARGUMENT);
 
  rcl_ret_t ret = RCL_RET_OK;
  *success = false;
 
  // We can avoid waiting if there are already the expected number of entities
  size_t count = 0u;
  ret = count_entities_func(node, topic_name, &count);
  if (ret != RCL_RET_OK) {
    // Error message already set
    return ret;
  }
  if (expected_count <= count) {
    *success = true;
    return RCL_RET_OK;
  }
 
  // Create a wait set and add the node graph guard condition to it
  rcl_wait_set_t wait_set = rcl_get_zero_initialized_wait_set();
  ret = rcl_wait_set_init(
    &wait_set, 0, 1, 0, 0, 0, 0, node->context, *allocator);
  if (ret != RCL_RET_OK) {
    // Error message already set
    return ret;
  }
 
  const rcl_guard_condition_t * guard_condition = rcl_node_get_graph_guard_condition(node);
  if (!guard_condition) {
    // Error message already set
    ret = RCL_RET_ERROR;
    goto cleanup;
  }
 
  // Add it to the wait set
  ret = rcl_wait_set_add_guard_condition(&wait_set, guard_condition, NULL);
  if (ret != RCL_RET_OK) {
    // Error message already set
    goto cleanup;
  }
 
  // Get current time
  // We use system time to be consistent with the clock used by rcl_wait()
  rcutils_time_point_value_t start;
  rcutils_ret_t time_ret = rcutils_system_time_now(&start);
  if (time_ret != RCUTILS_RET_OK) {
    rcutils_error_string_t error = rcutils_get_error_string();
    rcutils_reset_error();
    RCL_SET_ERROR_MSG(error.str);
    ret = RCL_RET_ERROR;
    goto cleanup;
  }
 
  // Wait for expected count or timeout
  rcl_ret_t wait_ret;
  while (true) {
    // Use separate 'wait_ret' code to avoid returning spurious TIMEOUT value
    wait_ret = rcl_wait(&wait_set, timeout);
    if (wait_ret != RCL_RET_OK && wait_ret != RCL_RET_TIMEOUT) {
      // Error message already set
      ret = wait_ret;
      break;
    }
 
    // Check count
    ret = count_entities_func(node, topic_name, &count);
    if (ret != RCL_RET_OK) {
      // Error already set
      break;
    }
    if (expected_count <= count) {
      *success = true;
      break;
    }
 
    // If we're not waiting indefinitely, compute time remaining
    if (timeout >= 0) {
      rcutils_time_point_value_t now;
      time_ret = rcutils_system_time_now(&now);
      if (time_ret != RCUTILS_RET_OK) {
        rcutils_error_string_t error = rcutils_get_error_string();
        rcutils_reset_error();
        RCL_SET_ERROR_MSG(error.str);
        ret = RCL_RET_ERROR;
        break;
      }
      timeout = timeout - (now - start);
      if (timeout <= 0) {
        ret = RCL_RET_TIMEOUT;
        break;
      }
    }
 
    // Clear wait set for next iteration
    ret = rcl_wait_set_clear(&wait_set);
    if (ret != RCL_RET_OK) {
      // Error message already set
      break;
    }
  }
 
  rcl_ret_t cleanup_ret;
cleanup:
  // Cleanup
  cleanup_ret = rcl_wait_set_fini(&wait_set);
  if (cleanup_ret != RCL_RET_OK) {
    // If we got two unexpected errors, return the earlier error
    if (ret != RCL_RET_OK && ret != RCL_RET_TIMEOUT) {
      // Error message already set
      ret = cleanup_ret;
    }
  }
 
  return ret;
}
 
rcl_ret_t
rcl_wait_for_publishers(
  const rcl_node_t * node,
  rcl_allocator_t * allocator,
  const char * topic_name,
  const size_t expected_count,
  rcutils_duration_value_t timeout,
  bool * success)
{
  return _rcl_wait_for_entities(
    node,
    allocator,
    topic_name,
    expected_count,
    timeout,
    success,
    rcl_count_publishers);
}
 
rcl_ret_t
rcl_wait_for_subscribers(
  const rcl_node_t * node,
  rcl_allocator_t * allocator,
  const char * topic_name,
  const size_t expected_count,
  rcutils_duration_value_t timeout,
  bool * success)
{
  return _rcl_wait_for_entities(
    node,
    allocator,
    topic_name,
    expected_count,
    timeout,
    success,
    rcl_count_subscribers);
}
 
 
rcl_ret_t
rcl_wait_for_clients(
  const rcl_node_t * node,
  rcl_allocator_t * allocator,
  const char * service_name,
  const size_t expected_count,
  rcutils_duration_value_t timeout,
  bool * success)
{
  return _rcl_wait_for_entities(
    node,
    allocator,
    service_name,
    expected_count,
    timeout,
    success,
    rcl_count_clients);
}
 
rcl_ret_t
rcl_wait_for_servers(
  const rcl_node_t * node,
  rcl_allocator_t * allocator,
  const char * service_name,
  const size_t expected_count,
  rcutils_duration_value_t timeout,
  bool * success)
{
  return _rcl_wait_for_entities(
    node,
    allocator,
    service_name,
    expected_count,
    timeout,
    success,
    rcl_count_services);
}
 
typedef rmw_ret_t (* get_topic_endpoint_info_func_t)(
  const rmw_node_t * node,
  rcutils_allocator_t * allocator,
  const char * topic_name,
  bool no_mangle,
  rmw_topic_endpoint_info_array_t * info_array);
 
rcl_ret_t
__rcl_get_info_by_topic(
  const rcl_node_t * node,
  rcutils_allocator_t * allocator,
  const char * topic_name,
  bool no_mangle,
  rmw_topic_endpoint_info_array_t * info_array,
  get_topic_endpoint_info_func_t get_topic_endpoint_info)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;  // error already set.
  }
  const rcl_node_options_t * node_options = rcl_node_get_options(node);
  if (!node_options) {
    return RCL_RET_NODE_INVALID;  // shouldn't happen, but error is already set if so
  }
  RCL_CHECK_ALLOCATOR_WITH_MSG(allocator, "invalid allocator", return RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(topic_name, RCL_RET_INVALID_ARGUMENT);
  rmw_error_string_t error_string;
  rmw_ret_t rmw_ret = rmw_topic_endpoint_info_array_check_zero(info_array);
  if (rmw_ret != RMW_RET_OK) {
    error_string = rmw_get_error_string();
    rmw_reset_error();
    RCL_SET_ERROR_MSG_WITH_FORMAT_STRING(
      "rmw_topic_endpoint_info_array_t must be zero initialized: %s,\n"
      "Use rmw_get_zero_initialized_topic_endpoint_info_array",
      error_string.str);
    return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
  }
  rmw_ret = get_topic_endpoint_info(
    rcl_node_get_rmw_handle(node),
    allocator,
    topic_name,
    no_mangle,
    info_array);
  if (rmw_ret != RMW_RET_OK) {
    error_string = rmw_get_error_string();
    rmw_reset_error();
    RCL_SET_ERROR_MSG(error_string.str);
  }
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
rcl_ret_t
rcl_get_publishers_info_by_topic(
  const rcl_node_t * node,
  rcutils_allocator_t * allocator,
  const char * topic_name,
  bool no_mangle,
  rmw_topic_endpoint_info_array_t * publishers_info)
{
  return __rcl_get_info_by_topic(
    node,
    allocator,
    topic_name,
    no_mangle,
    publishers_info,
    rmw_get_publishers_info_by_topic);
}
 
rcl_ret_t
rcl_get_subscriptions_info_by_topic(
  const rcl_node_t * node,
  rcutils_allocator_t * allocator,
  const char * topic_name,
  bool no_mangle,
  rmw_topic_endpoint_info_array_t * subscriptions_info)
{
  return __rcl_get_info_by_topic(
    node,
    allocator,
    topic_name,
    no_mangle,
    subscriptions_info,
    rmw_get_subscriptions_info_by_topic);
}
 
typedef rmw_ret_t (* get_service_endpoint_info_func_t)(
  const rmw_node_t * node,
  rcutils_allocator_t * allocator,
  const char * service_name,
  bool no_mangle,
  rmw_service_endpoint_info_array_t * info_array);
 
rcl_ret_t
__rcl_get_info_by_service(
  const rcl_node_t * node,
  rcutils_allocator_t * allocator,
  const char * service_name,
  bool no_mangle,
  rmw_service_endpoint_info_array_t * info_array,
  get_service_endpoint_info_func_t get_service_endpoint_info)
{
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;  // error already set.
  }
  const rcl_node_options_t * node_options = rcl_node_get_options(node);
  if (!node_options) {
    return RCL_RET_NODE_INVALID;  // shouldn't happen, but error is already set if so
  }
  RCL_CHECK_ALLOCATOR_WITH_MSG(allocator, "invalid allocator", return RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(service_name, RCL_RET_INVALID_ARGUMENT);
  rmw_error_string_t error_string;
  rmw_ret_t rmw_ret = rmw_service_endpoint_info_array_check_zero(info_array);
  if (rmw_ret != RMW_RET_OK) {
    error_string = rmw_get_error_string();
    rmw_reset_error();
    RCL_SET_ERROR_MSG_WITH_FORMAT_STRING(
      "rmw_service_endpoint_info_array_t must be zero initialized: %s,\n"
      "Use rmw_get_zero_initialized_service_endpoint_info_array",
      error_string.str);
    return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
  }
  rmw_ret = get_service_endpoint_info(
    rcl_node_get_rmw_handle(node),
    allocator,
    service_name,
    no_mangle,
    info_array);
  if (rmw_ret != RMW_RET_OK) {
    error_string = rmw_get_error_string();
    rmw_reset_error();
    RCL_SET_ERROR_MSG(error_string.str);
  }
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
rcl_ret_t
rcl_get_clients_info_by_service(
  const rcl_node_t * node,
  rcutils_allocator_t * allocator,
  const char * service_name,
  bool no_mangle,
  rmw_service_endpoint_info_array_t * clients_info)
{
  return __rcl_get_info_by_service(
    node,
    allocator,
    service_name,
    no_mangle,
    clients_info,
    rmw_get_clients_info_by_service);
}
 
rcl_ret_t
rcl_get_servers_info_by_service(
  const rcl_node_t * node,
  rcutils_allocator_t * allocator,
  const char * service_name,
  bool no_mangle,
  rmw_service_endpoint_info_array_t * servers_info)
{
  return __rcl_get_info_by_service(
    node,
    allocator,
    service_name,
    no_mangle,
    servers_info,
    rmw_get_servers_info_by_service);
}
 
rcl_ret_t
rcl_service_server_is_available(
  const rcl_node_t * node,
  const rcl_client_t * client,
  bool * is_available)
{
  RCUTILS_CAN_RETURN_WITH_ERROR_OF(RCL_RET_INVALID_ARGUMENT);
  RCUTILS_CAN_RETURN_WITH_ERROR_OF(RCL_RET_NODE_INVALID);
 
  if (!rcl_node_is_valid(node)) {
    return RCL_RET_NODE_INVALID;  // error already set
  }
  const rcl_node_options_t * node_options = rcl_node_get_options(node);
  if (!node_options) {
    return RCL_RET_NODE_INVALID;  // shouldn't happen, but error is already set if so
  }
  RCL_CHECK_ARGUMENT_FOR_NULL(client, RCL_RET_INVALID_ARGUMENT);
  RCL_CHECK_ARGUMENT_FOR_NULL(is_available, RCL_RET_INVALID_ARGUMENT);
  rmw_ret_t rmw_ret = rmw_service_server_is_available(
    rcl_node_get_rmw_handle(node),
    rcl_client_get_rmw_handle(client),
    is_available
  );
  return rcl_convert_rmw_ret_to_rcl_ret(rmw_ret);
}
 
#ifdef __cplusplus
}
#endif