[foreign-jextract] Segmentation fault from generated code

[Maurizio Cimadamore]

Thanks - unfortunately libucx seems to be unavailable for Ubuntu 
20.04/18.04 - I'll try to build the library from scratch and reproduce 
your issue.

Cheers
Maurizio

On 18/12/2020 12:56, Filip Krakowski wrote:
> Hi,
>
> the same code is running well inside a Docker container (Debian 11). I 
> use Debian as the base image because it provides packages for the ucx 
> development headers. For reference, here is my Dockerfile.
>
>     FROM debian:bullseye
>
>     # Use bash shell
>     SHELL ["/bin/bash", "-c"]
>
>     # Install packages
>     RUN apt update && apt install -y libucx0 libucx-dev curl unzip zip
>     wget llvm-9
>
>     # Install SDKMAN!
>     RUN curl -s "https://get.sdkman.io" | bash
>
>     # Initialize SDKMAN!
>     RUN source "$HOME/.sdkman/bin/sdkman-init.sh"
>
>     # Install latest OpenJDK Panama nightly
>     RUN curl -s "https://coconucos.cs.hhu.de/forschung/jdk/install" | bash
>
>
> Inside the built container I switch to the Panama JDK using "sdk 
> default java panama", jextract the ucp headers using "jextract -l ucp 
> -d . -t org.openucx /usr/include/ucp/api/ucp.h" and run a simple 
> programm using "java -Dforeign.restricted=permit --add-modules 
> jdk.incubator.foreign Main.java".
>
>     import org.openucx.ucx_h.ucp_params_t;
>
>     public class Main {
>
>         public static void main(String[] args) {
>             var layout = ucp_params_t.$LAYOUT();
>             System.out.println(layout);
>         }
>     }
>
>
> The only difference I make with the other method (leading to a 
> segfault) is that I run jextract locally on my machine (Arch Linux), 
> compile the code afterwards and upload it to our cluster (CentOS). 
> Both machines have the same version (1.9) of ucx installed.
>
> Best regards
> Filip
>
> On 12/18/20 12:12 PM, Filip Krakowski wrote:
>> Hi,
>>
>> I ran the code on Linux (CentOS Linux release 8.1.1911) after 
>> installing the "ucx" package (version 1.9). I will create a Docker 
>> container with the environment to reproduce this issue for easier 
>> debugging.
>>
>> Best regards
>> Filip
>>
>> On 12/17/20 10:49 PM, Maurizio Cimadamore wrote:
>>> Hi,
>>> I haven't seen this particular one.
>>>
>>> What platform are you on? What do you need to reproduce?
>>>
>>> Thanks
>>> Maurizio
>>>
>>> On 17/12/2020 18:43, Filip Krakowski wrote:
>>>> Hi,
>>>>
>>>> I work on a simple wrapper for ucx (https://github.com/openucx/ucx) 
>>>> and am experiencing a segmentation fault when calling any generated 
>>>> method. The strange thing is that the segmentation fault disappears 
>>>> as soon as I attach a (remote) debugger and manually step through 
>>>> the code.
>>>>
>>>>   * Screenshot - https://i.imgur.com/okl3epv.png
>>>>
>>>> My code does only access a struct's layout. I don't create any 
>>>> additional threads.
>>>>
>>>>    log.info("Starting");
>>>>    var layout = ucp_params_t.$LAYOUT();
>>>>    log.info("{}", layout);
>>>>
>>>> The generated layout looks like this.
>>>>
>>>>    static final MemoryLayout ucp_params$struct$LAYOUT_ =
>>>>    MemoryLayout.ofStruct(
>>>>             C_LONG.withName("field_mask"),
>>>>             C_LONG.withName("features"),
>>>>             C_LONG.withName("request_size"),
>>>>             C_POINTER.withName("request_init"),
>>>>             C_POINTER.withName("request_cleanup"),
>>>>             C_LONG.withName("tag_sender_mask"),
>>>>             C_INT.withName("mt_workers_shared"),
>>>>             MemoryLayout.ofPaddingBits(32),
>>>>             C_LONG.withName("estimated_num_eps"),
>>>>             C_LONG.withName("estimated_num_ppn")
>>>>    ).withName("ucp_params");
>>>>
>>>>
>>>> Is this a known Issue? I use the latest build from last night.
>>>>
>>>> Best regards
>>>> Filip
>>
>