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Matlab and Robotic System Toolbox: java.lang.​OutOfMemor​yError: GC overhead limit exceeded

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Hello everyone,
I am using the Robotic System Toolbox of Matlab 2015a and most of the time reading a single rosbag produces an error with the following message:
java.lang.OutOfMemoryError: GC overhead limit exceeded
at java.util.zip.ZipCoder.getBytes(Unknown Source)
at java.util.zip.ZipFile.getEntry(Unknown Source)
at java.util.jar.JarFile.getEntry(Unknown Source)
at java.util.jar.JarFile.getJarEntry(Unknown Source)
at sun.misc.URLClassPath$JarLoader.getResource(Unknown Source)
at sun.misc.URLClassPath.getResource(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at com.mathworks.jmi.OpaqueJavaInterface.getExceptionMessage(OpaqueJavaInterface.java:1016)
Error using org.ros.internal.message.DefaultMessageDeserializer/deserialize
Failed to retrieve Exception Message
Error in robotics.ros.BagSelection/deserializeMessages (line 444)
msg{i,1} =
robotics.ros.msg.internal.MessageFactory.newFromJava(msgType,
des.deserialize(cbuffer));
Error in robotics.ros.BagSelection/readMessages (line 194)
msgs = obj.deserializeMessages(obj.MessageList, rows);
Error in LoadMeasurements (line 47)
msgs = readMessages(bag);
The bag I am reading with
msgs = readMessages(bag);
contains some nested custom messages I compiled with Robotics System Toolbox Support Package and has a size of 44267 kB. Sometimes the error does not appear, but then Matlab gets REALLY slow after reading the bag, so no further computation is possible.
Whats wrong here?
Thank you for your help in advance!
  6 Comments
MathWorks Robotics and Autonomous Systems Team
I am glad to hear that this worked for you. I will post my workarounds as an answer and it would be great if you can "Accept this answer"

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Accepted Answer

MathWorks Robotics and Autonomous Systems Team
Depending on your MATLAB configuration and other running code, the Java heap space might be limited. This can lead to the error that you are describing when reading a lot of ROS messages into memory at the same time.
Have you tried increasing the Java heap memory that is at MATLAB's disposal? See this documentation page . The default value is 384 MB, but you might want to increase it to a larger value.
Alternatively, you could try loading only a subset of messages (the second argument to readMessages specifies the messages to read, e.g. 1:1000) or using the timeseries function to directly extract the numeric values without creating message objects.

More Answers (2)

GBorghesan
GBorghesan on 29 Jun 2017
Since i had problem in using the timeseries and extracting the data, i wrote the following function
function [ time,images ] = getCameraFromBag( bag )
%getCameraFromBag Gives back the time and the images in a strucure vector
topic='/STEREO_CAM/STEREO_CAM_RAW_DATA' ;
[ts,~] = timeseries(select(bag,'Topic',topic));
time=ts.Time;
n_messages=length(time);
bagselect=select(bag,'Topic',topic);
images=[];
for i=1:n_messages
msgs = readMessages(bagselect,i);
images(i).left=readImage(msgs{1}.Left);
images(i).right=readImage(msgs{1}.Right);
end
end
reading one message at time limited the problem of memory. Cheers, Gianni.

Seyed Mostafa Mousavi Kahaki
On the Home tab, in the Environment section, click Preferences. Select MATLAB > General > Java Heap Memory. Select a Java heap size value using the slider or spin box. Note. ... Click OK. Restart MATLAB.

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