[Question] About the usage of shared memory in docker

@dataclass
class MainCameraImage(IdlStruct):
    img: array[uint8, 4147200]
    shape: array[uint64, 3]

    @classmethod
    def from_numpy(cls, img):
        assert len(img.shape) == 3
        seq_img = img.tobytes()
        return MainCameraImage(seq_img, tuple(img.shape))


    def to_numpy(self):
        shape = self.shape
        return np.frombuffer(self.img, dtype=np.uint8).reshape(shape)

import cv2
import time
import numpy as np

import fire

from cyclonedds.core import Listener, Qos, Policy
from cyclonedds.util import duration
from cyclonedds.internal import dds_infinity
from cyclonedds.domain import DomainParticipant
from cyclonedds.topic import Topic
from cyclonedds.pub import DataWriter


from dds_data_structures import MainCameraImage, Image, CameraState,DeviceState


def stream(dev=0, resize_to=None, output_topic_names=['camera_images', 'camera_images_vis', 'camera_images_clr'],
            data_type='MainCameraImage', cap_gstreamer=True):
    data_type = MainCameraImage
    participant = DomainParticipant(0)

    writers = []

    # unknown, disabled, enabled, error
    qos = Qos(
        # livelines: automatic
        # deadline: dds_infinity
        # reliability: reliable
        # durability: volatile
        # history: keep last
        Policy.Liveliness.Automatic(lease_duration=duration(seconds=10)),
        Policy.Deadline(deadline=dds_infinity),
        Policy.Reliability.Reliable(max_blocking_time=duration(seconds=1)),
        Policy.Durability.Volatile,
        Policy.History.KeepLast(1)
    )

    for topic_name in output_topic_names:
        topic_out = Topic(participant, topic_name, data_type)
        writers.append(DataWriter(participant, topic_out, qos))

    frame = np.random.randint(0, 256, (1280, 1080, 3), dtype=np.uint8)
    print(frame.shape, frame.dtype)

    while True:
        time_start = time.time()
        ret, frame = 1, frame
        if not ret:
            print('Error: Unable to read frame')
            
            break
        if resize_to is not None:
            frame = cv2.resize(frame, resize_to[::-1])
        for writer in writers:
            writer.write(data_type.from_numpy(frame))
        
        loop_time = time.time() - time_start
        print(f'Streaming Camera with topic {output_topic_names[0]}, {loop_time=}', end='\r')


if __name__ == '__main__':
    fire.Fire(stream)

import cv2
import time
import numpy as np

import fire

from cyclonedds.core import Listener, Qos, Policy
from cyclonedds.util import duration
from cyclonedds.internal import dds_infinity
from cyclonedds.domain import DomainParticipant
from cyclonedds.topic import Topic
from cyclonedds.sub import DataReader


from dds_data_structures import MainCameraImage


def receive(topic_name='camera_images'):
    data_type = MainCameraImage
    participant = DomainParticipant(0)

    qos = Qos(
        # livelines: automatic
        # deadline: dds_infinity
        # reliability: reliable
        # durability: volatile
        # history: keep last
        Policy.Liveliness.Automatic(lease_duration=duration(seconds=10)),
        Policy.Deadline(deadline=dds_infinity),
        Policy.Reliability.Reliable(max_blocking_time=duration(seconds=1)),
        Policy.Durability.Volatile,
        Policy.History.KeepLast(1)
    )

    topic_in = Topic(participant, topic_name, data_type)
    reader = DataReader(participant, topic_in, qos)

    while True:
        time_start = time.time()
        img = reader.read()
        if len(img) == 0:
            continue
        img = img[0].to_numpy()
        loop_time = time.time() - time_start
        print(f'Received img {img.shape=}, {loop_time=}', end='\r')


if __name__ == '__main__':
    fire.Fire(receive)

<?xml version="1.0" encoding="UTF-8" ?>
<CycloneDDS xmlns="https://cdds.io/config" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="https://cdds.io/config https://raw.githubusercontent.com/eclipse-cyclonedds/cyclonedds/master/etc/cyclonedds.xsd">
    <Domain Id="any">
        <General>
            <Interfaces>
                <NetworkInterface autodetermine="true" priority="default" multicast="default" />
            </Interfaces>
            <AllowMulticast>default</AllowMulticast>
        </General>
        <SharedMemory>
            <Enable>true</Enable>
            <LogLevel>info</LogLevel>
        </SharedMemory>
    </Domain>
</CycloneDDS>