Running Judge Programs

Seele provides two action tasks for performing judge-related tasks. They are used by specifying seele/run-judge/compile@1 and seele/run-judge/run@1 for the action. The former is mainly for compiling some source files and saving the generated files, and the latter is for running the program to be evaluated.

Compilation tasks and execution tasks build sandboxes using Linux container technology to ensure that the programs to be run are executed in an isolated environment. This not only prevents interference between different judge tasks but also prevents malicious programs from damaging the system while limiting the resources the program can use. To properly use compilation tasks and execution tasks, you may need to master some knowledge about Linux containers.

Compilation Task

The compilation task is usually combined with the Add File task, adding the files from the latter to the container for the compilation program to use. After the compilation program runs successfully, the compilation task will copy the specified files from the container to the root folder.

Parameter List

The parameters accepted by the compilation task are as follows:

cache Property

Seele supports caching for compilation tasks through the cache property. Its parameters are as follows:

The compilation task calculates the SHA-256 hash value using the values listed below in order to determine whether the cache is hit. When the cache is hit, the compilation task will skip running the container and directly reuse the files specified in saves from the cache.

1. The value of command.
2. Each string in extra.
3. Each string in saves, sorted in dictionary order.
4. Each string in sources, sorted in dictionary order.
5. The content of the file pointed to by each string in sources.

Example

The example below adds a main.c file to the root folder in the prepare step, mounts this main.c file to the container and runs the gcc program in the container for compilation in the compile step, and finally saves the output main program to the root folder for use in subsequent steps.

steps:
  prepare:
    action: "seele/add-file@1"
    files:
      - path: "main.c"
        plain: |
          #include <stdio.h>
          int main(void) {
            printf("Hello, world!\n");
            return 0;
          }
 
  compile:
    action: "seele/run-judge/compile@1"
    image: "gcc:11-bullseye"
    command: "gcc -O2 -Wall main.c -o main"
    sources: ["main.c"]
    saves: ["main"]

Execution Tasks

Execution tasks are generally used to run programs that need to be judged. Users often need to limit the runtime, memory usage, etc., of the programs being judged.

Parameter List

The parameter list accepted by the execution task is shown in the table below:

Example

The example below adds a main executable file to the root folder in the prepare step, and then runs the program in the run step.

steps:
  prepare:
    action: "seele/add-file@1"
    files:
      - path: "main"
        url: "http://darkyzhou.net/main"
 
  compile:
    action: "seele/run-judge/run@1"
    image: "gcc:11-bullseye"
    command: "main"
    files: ["main:exec"]

Common Configurations

ContainerConfig

Some parameters shared by compilation tasks and execution tasks for building sandboxes are as follows:

fd Configuration

The fd configuration can redirect the standard input, output, and error streams of the judge program to files in the root folder. Its parameters are as follows:

limits Configuration

The limits configuration can limit the resources used by the judge program. The sandbox will terminate the program when it uses resources beyond the limit.

Its parameters are as follows:

Judge Report

The judge report returned by compilation tasks and execution tasks contains the following properties:

status attribute

Indicates the reason for the program termination. Its values are as shown in the table below: