jj-parallelize

Parallelize given revisions

$ jj parallelize [revsets]

jj-parallelize [OPTIONS] [COMMAND_TEMPLATE [ARGUMENT_PLACEHOLDER...]]
Or
jj-parallelize [OPTIONS] < JOB_LIST_FILE
Or
generate_jobs | jj-parallelize [OPTIONS]

-j , --jobs
    Specifies the maximum number of commands to run concurrently. Defaults to the number of CPU cores.

-s , --separator
    Defines the input record separator when reading jobs from stdin or a file. Default is newline.

-k, --keep-output-order
    Ensures that the output of the commands is printed in the same order as their input, buffering output if necessary.

-q, --quiet
    Suppresses command output, only showing errors or summaries.

--dry-run
    Prints the commands that would be executed without actually running them.

--retries
    Number of times to retry a failed command before giving up.

--fail-fast
    Exits immediately upon the first command failure, stopping all ongoing and pending jobs.

-v, --verbose
    Enables verbose output, showing more details about command execution and progress.

jj-parallelize is conceptually designed as a utility to execute a set of commands or jobs in parallel, managing the concurrency level to efficiently utilize system resources. It aims to streamline workflows where multiple independent tasks need to be processed simultaneously. While its name suggests a link to the just command runner (often aliased jj), it is not a standard subcommand or a widely distributed tool within the just ecosystem or common Linux distributions. If it were to exist, it would likely function similarly to tools like xargs -P or GNU parallel, taking a list of commands or arguments and executing them up to a specified maximum number of concurrent processes. Its primary benefit would be accelerating operations by leveraging multi-core processors.

jj-parallelize is NOT a standard, widely distributed Linux command or a core feature of the just command runner. This analysis describes a hypothetical command based on its name, assuming it would provide parallel execution capabilities similar to tools like xargs -P or GNU parallel. If you encounter this command, it is likely a custom script, an internal tool, or a misinterpretation. For general-purpose parallel task execution on Linux, consider using xargs -P or GNU parallel. For parallelizing recipes within the just command runner, you typically use the -j or --jobs option with just itself (e.g., just -j 4 recipe), or structure your Justfile to call parallelizable external commands.

While jj-parallelize is not a standalone command, the just command runner (jj) natively supports parallel execution of its recipes. Users can run multiple recipes concurrently by invoking just with the -j or --jobs option (e.g., just -j 8 build_all). This allows just to execute independent recipes or steps in parallel, significantly speeding up build or task execution times. The specific implementation of parallelization depends on the external commands called by the recipes.

For general shell scripting, common patterns for parallelization involve:
1. Using xargs -P to run a command with multiple arguments in parallel.
2. Employing GNU parallel for more advanced scenarios, including reading input from various sources, handling complex command structures, and managing output.
3. Backgrounding processes with & and waiting for them with wait in a shell script, often combined with a job slot counter to limit concurrency.

As jj-parallelize is not a standard or widely documented Linux command, there is no public history of its development or usage. Its name suggests a potential connection to the just command runner (often aliased jj) and the concept of parallelization. It may exist as a custom script in specific environments or have been an experimental concept that was not broadly adopted.

xargs(1), parallel(1), just(1)