Does iceoryx support Android NDK?

[mertonmeng]

Hi there,

I am considering to use iceoryx as IPC library for a cross-platform project. It will need to support Android, Arm Linux 64 and X86 Linux. Arm Linux 64 and X86 Linux seems already supported. I am wondering if iceoryx support Android NDK?

Thanks!

[mossmaurice]

Hi @mertonmeng

Thanks for starting this discussion!

Android support has been requested before, see here. However, there was no final decision if this feature will be supported, also AFAIK no one started to work on it yet. The iceoryx maintainers will not work on it in the near future.

Of course, your contribution of this feature would be much appreciated! 😊 You can find more details on a port for a new platform over here.

If you plan to work on this feature it would probably best to discuss it beforehand in the developer meetup. The next one is today at 17:00 CET.

[elfenpiff]

@mertonmeng @mossmaurice This is not entirely true. I started exploring android in the beginning of last year an it seems that the only thing which is not working right out of the box is the shared memory.
Maybe it is easier than we think when this is the only issue. In the end it is just a linux system.

@mertonmeng What kind of project do you have in mind you need iceoryx for?

[mertonmeng]

Thanks for the quick reply @elfenpiff @mossmaurice !
Let me deep dive a little on how I can port them.
Due to confidentiality of the project, I cannot disclose any details. Sorry about that.

[elfenpiff]

@mertonmeng If you like you could start creating a new platform by following this article: https://github.com/eclipse-iceoryx/iceoryx/blob/master/doc/website/advanced/custom-iceoryx-platform.md

I think it may can be done quickly. Just copy the linux platform folder to a folder called android and try to compile everything. I assume that shm_*** inside iox_shm_** will maybe cause some issues. If this is the case you can remove the implementation (forwarding) in the platform so that you have just an empty function. If everything compiles you can forward the shared memory function to the android pendant.

If this is done, execute the iceoryx_hoofs unit tests. If they pass then iceoryx should work, if something fails you have to look at the platform again and fix the posix construct which is causing the problem.

And of course if you need support with any of the steps please do not hesitate to ask us here.

[mertonmeng]

Thanks a lot for the instructions! @elfenpiff
I think maybe shm_open can be replaced by the ashmem_create in here: https://elinux.org/Android_Kernel_Features
But not sure about shm_unlink
I will follow your steps first and see if there is anything missing.

[mertonmeng]

Hi @elfenpiff @mossmaurice
I have tried your suggestion, basically just copy the linux posix functions to android, and removed shm_*** to replace with the dummy value. So I am setting up cmake with NDK and all:
cmake -Bbuild -Hiceoryx_meta -DIOX_PLATFORM_PATH=/home/iceoryx/iceoryx/iceoryx_platform/android \ -DCMAKE_TOOLCHAIN_FILE=/opt/android-ndk-r21b/build/cmake/android.toolchain.cmake \ -DANDROID_ABI=arm64-v8a \ -DANDROID_NATIVE_API_LEVEL=24
But got the error:

-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /opt/android-ndk-r21b/toolchains/llvm/prebuilt/linux-x86_64/bin/clang - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /opt/android-ndk-r21b/toolchains/llvm/prebuilt/linux-x86_64/bin/clang++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- The package 'iceoryx_platform' is used in source code version.
-- [i] <<<<<<<<<<<<< Start iceoryx_hoofs configuration: >>>>>>>>>>>>>
-- [i] IOX_MINIMAL_LOG_LEVEL: TRACE
-- [i] <<<<<<<<<<<<<< End iceoryx_hoofs configuration: >>>>>>>>>>>>>>
-- The package 'iceoryx_hoofs' is used in source code version.
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Failed
-- Looking for pthread_create in pthreads
-- Looking for pthread_create in pthreads - not found
-- Looking for pthread_create in pthread
-- Looking for pthread_create in pthread - not found
-- Check if compiler accepts -pthread
-- Check if compiler accepts -pthread - yes
-- Found Threads: TRUE
-- The package 'iceoryx_dust' is used in source code version.
-- Configuring done
-- Generating done
-- Build files have been written to: /home/iceoryx/iceoryx/build/dependencies/cpptoml/download
[ 11%] Creating directories for 'ext_cpptoml'
[ 22%] Performing download step (git clone) for 'ext_cpptoml'
Cloning into 'src'...
HEAD is now at fededad one-char typo
Submodule 'deps/meta-cmake' (https://github.com/meta-toolkit/meta-cmake.git) registered for path 'deps/meta-cmake'
Cloning into '/home/iceoryx/iceoryx/build/dependencies/cpptoml/src/deps/meta-cmake'...
Submodule path 'deps/meta-cmake': checked out 'db7ff976c430a6cb6cbd03ae691be04cfaac0a07'
[ 33%] Performing update step for 'ext_cpptoml'
[ 44%] No patch step for 'ext_cpptoml'
[ 55%] No configure step for 'ext_cpptoml'
[ 66%] No build step for 'ext_cpptoml'
[ 77%] No install step for 'ext_cpptoml'
[ 88%] No test step for 'ext_cpptoml'
[100%] Completed 'ext_cpptoml'
[100%] Built target ext_cpptoml
-- ANDROID_PLATFORM not set. Defaulting to minimum supported version
16.
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /opt/android-ndk-r21b/toolchains/llvm/prebuilt/linux-x86_64/bin/clang - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /opt/android-ndk-r21b/toolchains/llvm/prebuilt/linux-x86_64/bin/clang++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Could NOT find Doxygen (missing: DOXYGEN_EXECUTABLE)
-- Configuring done
-- Generating done
-- Build files have been written to: /home/iceoryx/iceoryx/build/dependencies/cpptoml/build
Install the project...
-- Install configuration: ""
-- Installing: /home/iceoryx/iceoryx/build/dependencies/install/include/cpptoml.h
-- Installing: /home/iceoryx/iceoryx/build/dependencies/install/lib/cmake/cpptoml/cpptomlTargets.cmake
-- Installing: /home/iceoryx/iceoryx/build/dependencies/install/lib/cmake/cpptoml/cpptomlConfigVersion.cmake
-- Installing: /home/iceoryx/iceoryx/build/dependencies/install/lib/cmake/cpptoml/cpptomlConfig.cmake
CMake Error at /home/iceoryx/iceoryx/iceoryx_posh/CMakeLists.txt:37 (find_package):
Could not find a configuration file for package "cpptoml" that is
compatible with requested version "".
The following configuration files were considered but not accepted:
/home/iceoryx/iceoryx/build/dependencies/install/lib/cmake/cpptoml/cpptomlConfig.cmake, version: 0.4.0 (32bit)
-- Configuring incomplete, errors occurred!
See also "/home/iceoryx/iceoryx/build/CMakeFiles/CMakeOutput.log".
See also "/home/iceoryx/iceoryx/build/CMakeFiles/CMakeError.log".

Any suggestions?

[elfenpiff]

@mertonmeng You can disable tom file config support by calling cmake with the additional switch -DTOML_CONFIG=OFF.

Do you have a branch where you are working on? If something else comes up you could just provide the link to it here to make things easier.

[uupks]

It can't access shared memory by file name with Ashmem on Android platform.

I have cross compiled iceoryx and run iox-roudi successfully on Android, but failed to map created shared memory into process when running icehello publisher example.

2023-04-13 19:43:18.010 [Warn ]: IPC channel still there, doing an unlink of iox-cpp-publisher-helloworld
fd : 6
2023-04-13 19:43:18.011 [Error]: /home/r10051/01_code/iceoryx/iceoryx_hoofs/source/posix_wrapper/shared_memory_object/memory_map.cpp:33 { expected<iox::posix::MemoryMap, iox::posix::MemoryMapError> iox::posix::MemoryMapBuilder::create() -> mmap }  :::  [ 22 ]  Invalid argument
2023-04-13 19:43:18.011 [Error]: Unable to map memory with the following properties [ baseAddressHint = 0x0, length = 66611176, fileDescriptor = 6, access mode = AccessMode::READ_WRITE, flags = 00000000000000000000000000000001, offset = 0x0 ]
2023-04-13 19:43:18.011 [Error]: One or more of the following failures happened:
  1. The address, length or the offset is not aligned on a page boundary.
  2. The provided length is 0.
  3. One of the flags of MAP_PRIVATE, MAP_SHARED or MAP_SHARED_VALIDATE is missing.
2023-04-13 19:43:18.011 [Error]: Unable to create a shared memory object with the following properties [ name = iceoryx_mgmt, sizeInBytes = 66611176, access mode = AccessMode::READ_WRITE, open mode = OpenMode::OPEN_EXISTING, baseAddressHint =  (no hint set), permissions = 0o660 ]
2023-04-13 19:43:18.011 [Error]: Failed to map created shared memory into process!
2023-04-13 19:43:18.011 [Error]: ICEORYX error! POSH__SHM_APP_MAPP_ERR
terminating
Aborted 

[elBoberido]

Did you check this sources?
https://stackoverflow.com/questions/53058077/multiprocess-by-using-android-ndk-sharedmemory-h/53062250#53062250
https://devarea.com/android-creating-shared-memory-using-ashmem/

[uupks]

you can check my public branch mentioned above.

int iox_shm_open(const char* name, int oflag, mode_t mode)
{
    int fd, ret;
    fd = open(ASHMEM_DEVICE, O_RDWR);
    if (fd < 0) {
        return fd;
    }

    if (name) {
        char buf[ASHMEM_NAME_LEN] = {0};

        strlcpy(buf, name, sizeof(buf));
        ret = ioctl(fd, ASHMEM_SET_NAME, buf);
        if (ret < 0) {
            goto error;
        }
    }

    return fd;

error:
    close(fd);
    return ret;
}

use ioctl to control the shared memory size.

int ftruncate(int fildes, off_t length)
{
    return ioctl(fildes, ASHMEM_SET_SIZE, length);
}

I think the problem is it can only access shared memory by transport the fd to another process on Android system.

We can't access the shared memory region by opening the same device name like /dev/ashmem/name

[elBoberido]

The first link I posted suggested to use ASharedMemory_create. Did you try that?

I have no experience with Android, so it might indeed not work and exchanging FDs via binder might be necessary. If this is the case, it still might be possible to do this behind the scene in the platform abstraction but it will definitely become ugly.

[uupks]

ASharedMemory_create is actually a wrapper of what i have done ...

https://github.com/termux/libandroid-shmem

https://github.com/green-green-avk/libwrapdroid

There two repos use unix domain socket to emulate SystemV and POSIX shared memory on Android using ashmem.

Can we also do this in iox-roudi?

[elBoberido]

It might be possible but I'm not sure how ugly it will become to do all of this in the platform layer. I guess it is worth a try.