Thanks. First destroy_*() methods free memory. I don't know why it would not have the effect you wanted. Sign in It maybe that Valgrind isn't smart enough to recognize the garbage collector in python. You can disable These are the top rated real world Python examples of rclpy.create_node extracted from open source projects. First, if you don't really know where to put your code: create a ROS2 Python package, and place the Python file inside the folder that has the same name as the package. Since it had a generator before, it would exit, returing None. We can either fix it, add it to known bugs, or mark the issue as help wanted. Can you please report this in the ros2 repository or the appropriate middleware repository? You signed in with another tab or window. I couldn't reproduce the problem with the FastRTPS middleware. Permissive License, Build not available. rclpy.spin(node) We have a node, but if we do nothing else the program will exit. Namespace/Package Name: rclpy. This is the only function which must be overridden by a custom executor. This is definitely a bug in I call the gc.collect() method at the end of spin_node. I can't think of a case where it getting StopIteration from _wait_for_ready_callbacks() is normal behaviour. It is not, but the client libraries should be. The rclpy implementation has only been implemented well in places. You may also want to check out all available functions/classes of the module rclpy , or try the search function . The following are 29 code examples of rclpy.spin_once().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. After experimenting a bunch more, I found that invoking the garbage collector fixes the issue (I think). But we have to attach the rcrclcpp::Clock (RCL_ROS_TIME) to one ros node (and furthor one executor) to be able subscibe to topic /clock and update simulated time stored in RCL_ROS_TIME clock instance. Example #1 Their memory is free'd by the garbage collector, but they also have close() to stop using the resource right away. Valgrind may show some unexpected results when PyMalloc is used. to your account. Following up, it turns out that other destroy_* methods are not thread-safe, including destroy_node, and destroy_timer. http://en.cppreference.com/w/cpp/utility/program/quick_exit, http://pythonsweetness.tumblr.com/post/151938194807/debugging-c-extension-memory-safety-with-valgrind, http://svn.python.org/projects/python/trunk/Misc/README.valgrind, add function to destroy waitset and call it in spin_once, add abilitiy to destroy guard conditions and destroy the sigint guard condition in spin_once. I've sent TwinOaks some information on the problem. Each level requires you to . Probably what happened is spin_once() got called after shutdown. Based on your comment it looks like the problem is not only related to Python. Here are the examples of the python api rclpy.time.Duration taken from open source projects. It doesn't matter what the second argument of spin_once is. Maybe that's not the fix then? Disabling the pygame audio fixed it. Could you provide a reproducible and independent examples for the CPU consumption and the memory leak ? By clicking Sign up for GitHub, you agree to our terms of service and We can look at it closer when reviewing your pr if you open one. If running out of memory because the garbage collector may never run was a real concern then it would also justify "foobar".destroy_string(). I suppose rmw is not designed to be threadsafe. $ cd ~/ros2_ws/src/. Sign up for a free GitHub account to open an issue and contact its maintainers and the community. privacy statement. Reporting back: I don't see the leak any more. Already on GitHub? Since the memory leak has been addressed I will change the title of this ticket. Just a cursory look at the Internet seems to confirm our theories about CPython and valgrind: We see already valgrind is reporting memory has been leaked. You may also want to check out all available functions/classes of the module rclpy , or try the search function . What I mean is that this is still a bug in Dashing (where the bug is being reported). Well occasionally send you account related emails. rclpy.destroy_node() rclpy.shutdown() By voting up you can indicate which examples are most useful and appropriate. Can you please try the patch from #109 which should fix the leaking of the waitset in the spin_once call. @BrannonKing what you are seeing (the increasing memory usage) is not a memory leak. This ends in the result that I get the client output twice: [INFO] [minimal_client_async]: Result of add_two_ints: for 41 + 1 = 42 [INFO] [minimal_client_async]: Result of add_two_ints: for 41 + 1 = 42. I think we are going to do a large refactoring of rclpy in the near future; what that happens, we should explicitly make sure to try and free this memory. Minimal example here https://github.com/brawner/crashing_subscription_destroyer, Change the code in subscriber.py to see an example that does not crash, Node continues to spin and subscription is ended, Locking/or thread management is required to safely destroy a subscription. rclpy, but it might be related to using QThread (since it also has C When you run the script without this patch it shows a memory leak in the order of iterations of the loop referencing the code in _rclpy.c which creates and initializes the wait set. Valgrind still shows that there's a memory leak, but monitoring the ram on htop shows that the leak is plugged. Now let's create a package named py_srvcli. With this patch the memory leak is gone. The three code . See the test functions in test_destroy_node_while_spin_once(), test_destroy_publisher_while_spin_once(), test_destroy_subscriptions_out_of_thread(), https://github.com/brawner/rclpy/blob/test_destruction_outside_thread/rclpy/test/test_destruction_outside_thread.py, It looks like this is a related issue with similar discussion #192. It looks like this is what ROS 1 rospy did: see Subscriber.unregister(), and Service.shutdown(). This is not yet resolved with #114 still pending. I think there might be some issues about these shortfalls already: I thought there was one for adding a proper spin function to rclpy too, but I can't find that one. The "increasing memory" you mention is just too much. We also have big issues with CPU performance problems in the middleware wait methods -- a place where I would never expect high CPU usage. This is normal, as there are a variety of small structures allocated by CPython at startup that it never frees, usually because doing so would be too difficult. I suspect we will see at least the same test failures as we did in Eloquent after addressing the merge conflicts in Dashing. node.destroy_subscription() is the only way to remove a subscription from the node graph without waiting for the garbage collector. The concern is there is no guarantee the garbage collector will ever run. Still not leaking for me. The process does have an increasing memory usage but once it finishes valgrind does report no incremental leaks for me (only three tiny leaks of a few kb). That's very likely imo. @sloretz may have better insight into what should be done here or if the design of rclpy should be changed in some way. It would be a lot of work to add APIs to all the rmw implementations. Block forever if None. So I reopened it for now. <, executor.spin_once crashes after destroy_subscription called in separate thread. If you don't have time to try doing the backport @audrow, feel free to assign me and I will try doing it or mark the issue as help wanted if I fail to do so. Since the memory leak is being fixed by #109 I will go ahead an merge that PR. Operating System: Ubuntu 18.04; Installation type: ubuntu packages; Version or commit hash: Dashing; Client library (if applicable): rclpy; When developping a node that has a timer and Action clients, and having a MultiThreadExecutor manage the callbacks, I encoutered the following issue when trying to shutdown the executor from the timer callback: Would you mind adding a reproducible example? Per this comment ros-visualization/rqt#181 (comment) I suppose rmw is not designed to be threadsafe. As a workaround, it seems you can make the timeout anything greater than 0.0, and the memory will at least leak slowly (possibly not at all?). Examples at hotexamples.com: 30. Reply to this email directly, view it on GitHub Are you sure it is getting called from Python? Increasing memory usage when only using spin_once. If any other value or the default infinite timeout is chosen, everything works fine. Even after integrating the PR's I was still losing large amounts of memory. -- http://pythonsweetness.tumblr.com/post/151938194807/debugging-c-extension-memory-safety-with-valgrind, Yes, there is also a README for using python with valgrind - http://svn.python.org/projects/python/trunk/Misc/README.valgrind. That would be great, it does sound like we should be destroying the waitset in the spin_once(). First, part of the reason that rclpy.spin_once(node, timeout_sec=None) never leaks memory is that it blocks forever. I will close this ticket for now but if there are still reproducible examples left which need fixing it can be reopened. The program below leaks massive amounts of memory even with the fix. I then made a simple publisher with integers of similar size and end up with the same result. The text was updated successfully, but these errors were encountered: To reproduce the crash it is important that node.destroy_node() is not called immediately after node.destroy_subscription(), which is why the subscriber.py sleeps for a second afterward. Your package named py_srvcli has now been created. Unfortunately, the fix doesn't seem to help my program. But I don't think that marking the ticket as solved is correct. I'll assign you. It maybe that Valgrind isn't smart enough to recognize the garbage collector in python. I spent some time investigating this leak today, figuring it would be a good chance to dip my toe into ros2.It does seem there is a memory leak here, and as far as I can tell there is something funny happening beneath the rmw_wait() function whenever you pass in timeout_sec=0.0 into rclpy.spin_once(), as you did in your example code, @ArkturusMengsk. Programming Language: Python Namespace/Package Name: rclpy Method/Function: create_node Examples at hotexamples.com: 30 Example #1 0 Show file Inside the generator _wait_for_ready_callbacks() it saw self._is_shutdown and didn't enter the loop. Your added function looks right to me, and I think it should be necessary (through the current rclpy implementation is fast and loose with "on shutdown" cleanup). That would be helpful for testing. Coin Master Pet Xp Hack QtqV5G Where Can I Get Free Spin In Coin Master [ Updated : December 12, 2022] Users Online: 1221 In Coin Master, villages serve as levels. # Shutdown the executor since there's nothing left to execute. I think I see what happened. So, I did a bit more research into this problem. . thanks @ArkturusMengsk @IanTheEngineer and @srsidd for the initial report and investigation. Yes it is getting called from Python. to your account. rclpy.spin(node) will pause the program execution here, waiting for you to request to kill the node (for example CTRL+C in the terminal). When developping a node that has a timer and Action clients, and having a MultiThreadExecutor manage the callbacks, I encoutered the following issue when trying to shutdown the executor from the timer callback: The text was updated successfully, but these errors were encountered: Thanks for the bug report! Sign in Well occasionally send you account related emails. You signed in with another tab or window. 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. Programming Language: Python Namespace/Package Name: rclpy Method/Function: spin_once Examples at hotexamples.com: 26 Example #1 0 If this seems the right thing to do, I can create a PR with this change.. At ASI we've had a lot of issues with large messages causing leaked (er, gushing) memory both in CPP and Python. You may also want to check out all available functions/classes of the module rclpy , or try the search function . The following are 21 code examples of rclpy.ok () . Follow-up PRs fixing memory leaks outside of spin_once are pending. First destroy_*() methods free memory. The function wait_for_ready_callbacks would have gotten StopIteration. The middleware seems to exit without releasing the zero-initialized wait_set memory, guard_condition, and timer_ready_list that it allocates. I tried using Valgrind, based on someone's recommendation but this is my first time using it so I couldn't make much sense of what I saw. I killed it at that point; something is clearly leaking a lot of memory pretty quickly. . The backport won't be trivial, as I noted in #574 (comment): the fix breaks tests in Eloquent (#584) and doesn't merge cleanly into Dashing. The high CPU issue in Python3 was actually cause by a pygame Alsa bug. I first stumbled upon this while publishing and subscribing to images (~250kB). privacy statement. I'd have to read deeper into the code. Also, I'm not sure if where you said you're calling it from (at the end of spin_once()) is the right place. With all the referenced PRs merged I can run the infinite spin_once loop as well as the large publisher (and a corresponding subscriber) with constant memory usage. In C++ you just let the subscription go out of scope, then the executor continues to hold ownership until it wakes up at which point it will release its lock too and the subscription can be destroyed. Programming Language: Python. Example #1.Controls 50 listed common lawn weeds including dandelion, clover and chickweed. https://github.com/brawner/crashing_subscription_destroyer, ros2: rqt --list-plugins sometimes segfaults, https://github.com/notifications/unsubscribe-auth/AA_x-oVkPnUBJssqsmLCluSO5q8qTO9iks5u6q_0gaJpZM4ZbAgM, Segfault when destroying node while it is spinning in other thread, Fix crash at shutdown of rqt_console plugin. We fixed several memory leaks recently but are welcoming any contribution to patch the remaining ones. File objects in python seem like good model to follow. 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. Not sure what this means exactly but if someone can help me out with this, it'd be great! It should probably raise a RuntimeError in that case. Here are the examples of the python api rclpy.init taken from open source projects. There seem to be two issues. I don't know if this is related, but I found a huge memory leak when I publish large amounts of data. I was hoping to have a fix to accompany this write up, but I've yet to uncover the underlying issue. Python spin_once - 26 examples found. Maybe @mikaelarguedas has an idea off-hand. Second, wait_for_ready_callbacks() should make sure it never returns None. It could also be that Python is not garbage collecting when it knows it is shutting down, and just lets the OS handling reclaiming the memory. I suppose rmw is not designed to be threadsafe. I tried adding a method in _rclpy.c and call this method at the end of spin_once in rclpy/__init__.py. When use_sim_time is enabled, RCL_ROS_TIME type clock will use time source from topic /clock. The concern is there is no guarantee the garbage collector will ever run. If the timeout in spin_once is set to zero (see snippet below) the program will continuously allocate new memory. Already on GitHub? These are the top rated real world Python examples of rclpy.spin_once extracted from open source projects. This issue is exacerbated by the while loop continually spinning without a pause. to your account. If you mark it as help wanted, perhaps I'll give it another try in the future. Instead of running forever you should add an upper bound to the loop as in my example above which makes the script terminate after a deterministic number of iterations. The backport won't be trivial, as I noted in #574 (comment): the fix breaks tests in Eloquent (#584) and doesn't merge cleanly into Dashing. During this time, any thread/timer you've created in the node will continue to be executed. that will be useful for further benchmarking of python extensions. I updated the example The following are 30 code examples of rclpy.node () . The following are 29 code examples of rclpy.spin_once () . Second, if I change the timeout_sec to a value other than 0 (in this case, I tried 0.01), the program still leaks memory, just at a slower rate. By clicking Sign up for GitHub, you agree to our terms of service and I don't think this matters though because nothing makes the memory used by rclpy special. rclpy.spin_once()1 . We've cut corners in lots of others because we simply haven't had time. PyMalloc when configuring python by adding the --without-pymalloc option. I can try that and see if it helps. Sounds good. On Wed, Dec 19, 2018 at 1:30 PM William Woodall ***@***. Executor spin_once must check wait_for_ready_callbacks returns None. By clicking Sign up for GitHub, you agree to our terms of service and Looking at the rclcpp implementation, the wait set is initialized once and hence forth used as a member of the Executor class. Create a Package. @BrannonKing thanks for following up on it. I don't think this matters though because nothing makes the memory used by rclpy special. kandi ratings - Low support, No Bugs, No Vulnerabilities. After that the increasing memory usage still needs to be investigated and addressed. :param timeout_sec: Seconds to wait. Well occasionally send you account related emails. This way the loop is called multiple times and should print the service response multiple times as well. Successfully merging a pull request may close this issue. And the service server output appears . Some of our partners may process your data as a part of their legitimate business interest without asking for consent. Unfortunately, rmw and rcl don't have a separation between stopping a subscriber/publisher/service/timer/etc and freeing the memory used by them. The issue with large messages causing a memory leak (and running slow) appears to be a CoreDX-only thing. Question: Does this test use the disabling of PyMalloc suggested in #74 (comment) ? To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. Second, these methods unsubscribe, stop timers, stop service servers, stop clients, etc. There will also be a follow up PR (#110) to fix the memory leaks coming from the other entities (beside the wait set). It's difficult to track because the profilers show the problem to be in the middleware, but it may not be the middleware's fault if the cleanup methods aren't getting called. You can rate examples to help us improve the quality of examples. You can also make this file executable. The following are 21 code examples of rclpy .ok(). This is definitely a bug in rclpy, but it might be related to using QThread (since it also has C extension code), can this be done with just threading.Thread? This is a follow up from ros-visualization/rqt#182. def spin_once(self, timeout_sec=None): """ Execute a single callback, then return. Either it should yield work, or it should raise an exception. I had a question - Why does spin_once create the wait_set every time it's called. I did some more digging on the memory leaks and high CPU I was seeing. Destroying subscriptions is not thread safe. Here are the examples of the python api rclpy.shutdown taken from open source projects. @ivanpauno Are you sure that we need to backport #574 to Dashing? By voting up you can indicate which examples are most useful and appropriate. Example #1 You can put a gc.collect() call into the while loop; the memory still increases but the rate is less. Builds strong, deep roots. Since it wasn't a timeout, the generator returned None instead of yielding work. Have a question about this project? If running out of memory because the garbage collector may never run was a real concern then it . Its job is to start executing one callback, then return. Here are snippets from the valgrind run -. You signed in with another tab or window. to remove the PyQt5 dependence. Marking this as a bug. I think at least part of the problem stems from _rclpy.c using PyMem_Malloc() without ever calling PyMem_Free(). Starting with Python 2.3, PyMalloc is used by default. But the conclusions kind of confirmed a memory leak. It does seem there is a memory leak here, and as far as I can tell there is something funny happening beneath the rmw_wait() function whenever you pass in timeout_sec=0.0 into rclpy.spin_once(), as you did in your example code, @ArkturusMengsk. You can confirm that by running the script with valgrind --leak-check=full which python3 your_script.py. Of course if another thread is in rcl_wait() when this is called, then the rmw implementation will use memory after it was free'd when checking if a subscription has data. That is, since this is a simple test program, it just sits inside spin_once() forever, and since nothing is happening, it never does anything further. Sign in Good jorb. Example #1 IIUC the node.destroy_*() methods are there to avoid relying on the python garbage collector. Manage Settings Allow Necessary Cookies & ContinueContinue with Recommended Cookies, 6 Python code examples are found related to ", Learning-Robotics-using-Python-Second-Edition. Given the low number of iteration it's not seeable, can you try the same test with another 3 orders of magnitude ? You can rate examples to help us improve the quality of examples. You can rate examples to help us improve the quality of examples. @BrannonKing feel free to comment here if this is not fixed for you or to open another ticket if you face issues unrelated to spin_once. Reopening until a fix gets backported in Dashing. Hope this is helpful to those debugging this :). 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. Successfully merging a pull request may close this issue. It is not, but the client libraries should be. If yes, can you post the invocation here? Since the memory leak and memory usage increase has been fixed in #112 and #113 I'm going to close this. Implement rclpy with how-to, Q&A, fixes, code snippets. @ArkturusMengsk @IanTheEngineer @srsidd @BrannonKing please give the current state a try and report back how your experience is. But that didn't really help. Can someone comment on whether this is correct? Maybe there's a way to make destroy_*() methods wake the executor so the rcl types can be safely fini'd? The text was updated successfully, but these errors were encountered: I spent some time investigating this leak today, figuring it would be a good chance to dip my toe into ros2. Type this command: ros2 pkg create --build-type ament_python py_srvcli --dependencies rclpy example_interfaces. I've never had good luck with Valgrind for Python memory leaks. It seems that the middle ware exits without releasing the zero-initialized wait_set memory as pointed by @IanTheEngineer . privacy statement. I suspect we will see at least the same test failures as we did in Eloquent after addressing the merge conflicts in Dashing. Method/Function: create_node. I felt the memory leak is because waitset is created every time spin once is called, hence added the rcl_wait_set_fini method. @srsidd it probably should. The consent submitted will only be used for data processing originating from this website. Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community. Sign up for a free GitHub account to open an issue and contact its maintainers and the community. 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. IIUC the node.destroy_*() methods are there to avoid relying on the python garbage collector. It uses the method `wait_for_ready_callbacks` to get work to execute. First _wait_for_ready_callbacks() should raise ShutdownException instead of returning None. triangle with exclamation point volkswagen tiguan, the executioner and her way of life opening song. After looking at the c implementation, it seems that rcl_wait_set_fini() function (Member of rcl/src/rcl/wait.c) destroys the wait_set? This is a major issue -- please focus on it! Already on GitHub? Running valgrind on this gave the following output -. spin_once () is typically used to integrate with another thing that needs the same thread (like if ROS and Qt need the main thread, they can take turns "spinning" to share the time), but can be used to do what you're doing. You are receiving this because you authored the thread. . ***> wrote: If I run the same program, but leave timeout_sec as None (the default), no memory is leaked at all. I'm not sure destroying the subscription is the right thing to do. $ ros2 pkg create ros2_tutorials_py --build-type ament_python --dependencies rclpy. rospy.spin() and ros::spin() both block the main thread from exiting until ROS invokes a shutdown - via a Ctrl + C for example. Have a question about this project? 13 Examples 3 View Source File : mara.py License : Apache License 2.0 Project Creator : AcutronicRobotics. extension code), can this be done with just threading.Thread? 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 is still a bug in the distribution it was reported, and backporting the fix applied on master doesn't seem trivial. Okay I was able to do some more debugging on this, and it seems that the PR from #79 and #80 are not the only problems. No, I didn't rebuild Python and all of that (which that document suggests). I fired up the test program from the first comment, and after about 30 seconds of running, I'm now up to 3g resident memory (confirmed using top). This suggests that we have something more fundamental going on. They are written as the last line of code of the main thread of the program. There is a way to disable to PyMalloc errors although I haven't tried it myself -. Declare params with rclpy Here's a minimal ROS2 Python node which declares 3 parameters (with no default value, we'll see later how to do that): import rclpy from rclpy.node import Node class TestParams(Node): def __init__(self): super().__init__('test_params_rclpy') self.declare_parameter('my_str') self.declare_parameter('my_int') Of course I waited a while to post this after not finding an answer and now I have it. I just needed to use a multi-threaded executor and spin that instead of spinning the nodes individually: import threading import rclpy rclpy.init() node = rclpy.create_node('simple_node') node2 = rclpy.create_node('simpler_node') executor = rclpy.executors . Sort of like http://en.cppreference.com/w/cpp/utility/program/quick_exit. If this seems the right thing to do, I can create a PR with this change. # All done with timer, better destroy it right? I think we need a different way to track these. For ROS Python, rospy.spin() can be replaced by a while loop, so it is not mandatory to use it when working with subscribers. I can also reproduce the issue with threading.Thread. Open a new terminal window, and navigate to the src directory of your workspace: cd ~/dev_ws/src. Right, I'd assume the best way forward would be to create a class for node within the __init__.py script and use the existing api to make calls to the node class? This page implies that memory allocated with PyMem_Malloc() must be explicitly freed, and I see no calls in _rclpy.c to do that (please correct me if I'm wrong, here). It would be very helpful for overall stability if there was a thread management solution in the client libraries. @ivanpauno Are you sure that we need to backport #574 to Dashing? Doing a quick test here, I still see the memory leak from the original report. Output with #time.sleep(0.01) commented in the loop: Output with time.sleep(0.01) un-commented in the loop: All this really shows is the sources of memory allocation, and that the faster the spin_once function is called, the more memory is lost. 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