There is not limit of the message size of SHM?

[h2cw2l]

1、I use fastdds versioon 3.1
2、I use the example delivery_mechanisms and use SHM
./delivery_mechanisms publisher -m SHM
./delivery_mechanisms subscriber -m SHM
3、I change the message size to 5000000 in the DeliveryMechanisms.idl

change the size in DeliveryMechanisms.hpp to 5000000

change the max_samples to 5 in Publisher.cpp and Subscriber.cpp

so the segment size is 3xx

use data_ to write data


4、the message size is large than the segment size, whey it can write and the Subsciber can receive the message? There is no limit?

[cferreiragonz]

Hello @h2cw2l,

The size of the payload or message you are sending is independent of the segment size configured for SHM. If the payload is bigger than the max_msg_size allowed, RTPS Fragmentation will be accomplished, which is defined in section 8.4.14.1 of the RTPS standard.

Any limits will mainly be imposed by your hardware.