rclpy wakes the executor unconditionally. We should probably document it here. For example: if the future comes from a ROS client request, the executor will wake up when you receive the response (and that's when the future is completed). Map -> Odom tf moving causing obstacles in localcostmap to move with robot. Is it possible to wait on a bunch of conditions at once - sort of like select()? When I use the function to call the service B from the code it works, the problems comes when this function is called from a service. We and our partners use cookies to Store and/or access information on a device.We and our partners use data for Personalised ads and content, ad and content measurement, audience insights and product development.An example of data being processed may be a unique identifier stored in a cookie. floor: 3 You can rate examples to help us improve the quality of examples. Then, the program spins until the response has been received with the rclpy.spin_until_future_complete() function. The future could be set by anything, including a thread created by the user. ROS2ROS2@. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. I have a node which create a service A. I don't have any ideas here. To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. Of course, after writing that, I realize that this is core problem. The python spin_until_future_complete example is extracted from the most popular open source projects, you can refer to the following example for usage. Programming Language: Python. The following are 29 code examples of rclpy.spin_once () . . It's responsibility of the user to make sure that whatever sets the future does that through the executor. to your account. Manage SettingsContinue with Recommended Cookies. Rate and sleep function in RCLPY library for ROS2, ROS2 Performance: rclpy is 30x-100x slower than rclcpp, ROS2 add_on_set_parameters_callback not trigger with open loop. To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. privacy statement. ever since it has been red and . I'm getting this to work by replacing the rclpy.spin_until_future_complete() with my own using rclpy.spin_once(), but that seems like an unintended workaround. so naturally i changed it to regular ring i had in my collection. """ # # # # Take an observation rclpy.spin_once(self.node) obs_message = self._observation_msg # Check that the observation is not prior to the action # obs_message = self._observation_msg while obs_message is None or int(str(self._observation_msg.header.stamp.sec)+(str(self._observation_msg . ros2 service call /send_lift_to_floor kone_open_opc_interfaces/SendLiftToFloor "site: 'a' The TF listener uses a seaparate callback group (https://github.com/ros2/geometry2/blo) - so using this approach will make the TF callback being handled by a separate thread. While what I said is true, it also means that the executor will prevent the function from returning until it times out (if it times out). I made it work using rclpy.spin_once()instead. If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page. The following are 21 code examples of rclpy.ok().You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. Please start posting anonymously - your entry will be published after you log in or create a new account. spin_until_future_complete is just a fancy way of saying: do a while loop where you spin_some and check the future in between spins. Already on GitHub? ros2 run kone_open_opc_server_simu kone_simu I'm having trouble with the node stopping execution, due to the rclpy.spin_until_future_complete unregistering the node in the SingleThreadedExecutor, making it stop. ROS2 Galactic Universal Robots Driver Controller Error [closed]. You can find the full file here : https://github.com/MarcTestier/kone_o You can run the full thing by running : The function send_request() defines a variable called self.future which receives the response from the Service Server. The consent submitted will only be used for data processing originating from this website. EDIT 4: Actually, I get stuck when trying to rclpy.spin_once(self) in the callback function of a subscriber in the node. I'm not sure if this is intentional, or if I'm doing something unappropriate here. In ros2/demos#558 I made another std::async call just to wait on the future and wake the executor. I'm writing a ROS2 rclpy node (using Galactic and Ubuntu 20.04LTS) that is executed using rclpy.spin, but also uses arclpy.spin_until_future_complete for waiting for a TF transform to become available. wait = self.client.call_async(self.request) rclpy.spin_until_future_complete(self, wait . Some of our partners may process your data as a part of their legitimate business interest without asking for consent. The service B does answer but the service A still get stuck on rclpy.spin_until_future_complete (self, future). These are the top rated real world Python examples of rclpy.spin_once extracted from open source projects. Here are the examples of the python api rclpy.Parameter taken from open source projects. you can see a solution here: [https://answers.ros.org/question/3020]. Sign in class MyNode(Node): def __init__(self): super().__init__('my_node_name') Here we create a class which inherits from the rclpy Node class. Initially I tried just looking up the transform using lookup_transform with a timeout, but this blocks the executor in whole making the TF transform callbacks not being served - therefore I'm attempting to use the wait_for_transform_async function instead. We may need to iterate on #1874 more, if this is required too. Even if the API had a way to pair the future with a condition variable or something similar that would wake up the executor, how would it know if this is needed or not? You may also want to check out all available functions/classes of the module rclpy , or try the search function . [ROS2] What's the best way to wait for a new message? rclpy provides the canonical Python API for interacting with ROS 2. Any PID-based "controller_interface::ControllerInterface" implementations/examples for ROS2? Examples at hotexamples.com: 26. Previously, work could come either from get_next_timer, which would always return a ready timer, even if it were not previously ready; or from the wait_for_work method, which was called when no work was currently ready, regardless of whether . Actually that's not technically a requirement. 7Pythonrclpy. :return: state. recently i had a dangely piercing in for almost year Until I came home about a week ago and realized half of the dangely part had fallen off. I'm having trouble with the node stopping execution, due to the rclpy.spin_until_future_complete unregistering the node in the SingleThreadedExecutor, making it stop. But it's still true that something that runs outside of the executor could complete the future, but it would have to also ensure the executor is interrupted. Well occasionally send you account related emails. spin_until_future_complete is just a fancy way of saying: do a while loop where you spin_some and check the future in between spins. group: 'c' Namespace/Package Name: rclpy. We call. It's probably better to use a MultiThreadedExecutor instead, and let the thread block until the transform becomes available. I'm not sure if this is intentional, or if I'm doing something unappropriate here. About Examples API Initialization, Shutdown, and Spinning Node Topics Publisher Subscription Services Client Service Actions Action Client Action Server Timer Parameters Parameter Parameter Service Logging Context Execution and Callbacks Executors Callback Groups Utilities Running the node, I get the following output: Not really. This will be even more complicated in the new API - proposed in #1874 (Accepted, pending for Humble to branch the release out of master). I would expect the future being completed would cause spin_until_future_complete() to return, and the program would shutdown without the timer callback running. By voting up you can indicate which examples are most useful and appropriate. Did you ever figure out how to call a service from inside a service callback? Maybe I will try to come up with some idea during this weekend on how this could be solved. I'm not sure if we should change this behavior as it may also be non-trivial. The executor adds a done callback to the future to wake itself. The callback from this service A calls a function which calls another service B from another node. and then call the service : Some of our partners may process your data as a part of their legitimate business interest without asking for consent. Are locks redundant for mutually exclusive callback groups? I thinkspin_until_future_complete() only returns immediately after completion if the future is completed in the callback of the same executor. This limitation is why the demo for lifecycle_service_client doesn't exit (related issue ros2/demos#504). rclpy.spin_until_future_complete (node, future, executor=None, timeout_sec=None) Execute work until the future is complete. [ROS2] Can't see nodes, topics, on PC when using container. By voting up you can indicate which examples are most useful and appropriate. So, I'd actually be inclined to mark this as "won't fix", because that's expected behavior for this function. If you would like to change your settings or withdraw consent at any time, the link to do so is in our privacy policy accessible from our home page. This structure will allow you to write all your node's code in the class you created. rclpy avoids this by having it's own Future class with callbacks that get called after the result on the future is set. Programming language: Python Namespace/package name: rclpy Example#1 File: action_client_py.py Project: ros2/system_tests def send_goals(node, action_type, tests): import rclpy Even if the API had a way to pair the future with a condition variable or something similar that would wake up the executor, how would it know if this is needed or not? I didn't wake the executor at the end of callee_script because I think it would be a race condition between the executor spinning again and the shared_future being updated at the end of the function call. location: 'b' This seems unnecessarily complicated. The goal of this change is to allow spin_some to only queue work items once at the start of an execution, without adversely affecting other spin methods. Callbacks and other work will be executed by the provided executor until future.done () returns True or the context associated with the executor is shutdown. This should definitely be indicated in the API documentation. Have a question about this project? We and our partners use cookies to Store and/or access information on a device.We and our partners use data for Personalised ads and content, ad and content measurement, audience insights and product development.An example of data being processed may be a unique identifier stored in a cookie. A similar limitation exists in rclpy. It would be needed in your example, but not if the future comes from a ROS client. Installation type: From source Version or commit hash: Foxy DDS implementation: Fast-RTPS Client library (if applicable): rclpy Publish a message from one node (with latching_qos) In another node, subscribe to the topic with a callback that sets the result of the future Start both nodes in a MuliThreadedExecutor Spin until future complete I thought about using GuardCondition callbacks as a way to get the executor to do work, but there seems to be a bug where when a guard condition has a callback, it doesn't call the rcl method that would have woken the executor. Any ideas to make this easier? The callback from this service A calls a function which calls another service B from another node. After the future completes, spin_until_future_complete() blocks for another 5 seconds until the timer callback is run. When I use the function to call the service B from the code it works, the problems comes when this function is called from a service. Actually, I get stuck when trying to rclpy.spin_once(self) in the callback function of a subscriber in the node. The service B does answer but the service A still get stuck on rclpy.spin_until_future_complete(self, future). Any suggestion on how I could call a service from another service without getting stuck ? rclpy.spin_until_future_complete() removes node from executor added by rclpy.spin(), Creative Commons Attribution Share Alike 3.0. ROS2 service only sometimes present in python, Define custom messages in python package (ROS2), Incorrect Security Information - Docker GUI, ROS2 service : spin_until_future_complete blocking when calling a service that calls another service [closed], Creative Commons Attribution Share Alike 3.0. Example #1. I'm using ROS2 Bouncy, built from source on Ubuntu 18.04. GuardConditon would need to also wake up any condition that can be invoked - considering that the special Future class for rclcpp makes no sense anymore. ros2 run kone_open_opc_client kone_client Method/Function: spin_once. If that exists maybe a dedicated thread could wait on all known conditions and call executor.cancel() when any one of them completes. def take_observation(self): """ Take observation from the environment and return it. lift: 'd' Sign up for a free GitHub account to open an issue and contact its maintainers and the community. Manage SettingsContinue with Recommended Cookies. Example #1 rclpy spin until future complete i got my belly button pierced atleast three years ago, maybe four. That can be tricky. The consent submitted will only be used for data processing originating from this website. rclcpp/rclcpp/src/rclcpp/guard_condition.cpp. Here is just the interesting part of the function called by service A : EDIT : same problem when trying to use : EDIT 2 : Same thing when using self.read_agv_cmd.call(req), EDIT 3: I tried to change Service A to a Subscriber and the result is the same, the callback stay stuck on rclpy.spin_until_future_complete(self, future). By clicking Sign up for GitHub, you agree to our terms of service and In this function, you need to specify which variable contains the received response. It's responsibility of the user to make sure that whatever sets the future does that through the executor. Each ROS2 Python node that you'll write will be a superset of "rclpy.node.Node". We then create an instance of the Server class in the main function and allow it to spin forever. It's responsibility of the user to make sure that whatever sets the future does that through the executor. You signed in with another tab or window. . Is it how it's supposed to work ? Parameters How can I build deb packages from ROS2 Bouncy Bolson packages? The text was updated successfully, but these errors were encountered: Yes. I tried to change Service A to a Subscriber and the result is the same, the callback stay stuck on rclpy.spin_until_future_complete(self, future). Make lifecycle demo automatically exit when done, with callbacks that get called after the result on the future is set, adds a done callback to the future to wake itself, GuardCondition should have a callback that gets handled by the executor, Add support for spin_until_timeout (#1821). door_side: 1". Here are the examples of the python api rclpy.Parameter taken from open source projects. then I also left a suggest here to how to better solve the original problem: https://github.com/ros2/demos/pull/558/files#r871940510, spin_until_future_complete may block forever if nothing wakes the executor after the future completes, ./rclcpp_spin_until_future_complete_blocked. 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