---
title: "--terminate"
description: "Stops runs at their time limit the way competitions do, so they still give their best answer."
---

> Documentation Index
> Fetch the complete documentation index at: https://docs.cpbenchy.com/llms.txt
> Use this file to discover all available pages before exploring further.

# --terminate

## What it does

By default, a solver is told how much time it has, and it is killed if it is still running a grace
period after that; a killed run has no answer. Competitions stop solvers differently: at the time
limit, the solver gets SIGTERM and must print the best solution it found, and a second later it gets
SIGKILL. `--terminate` makes runs behave like that.

At its time limit (wall or CPU), or on SIGTERM, a run reports the last solution its solver found:
competition output gets its `s` and `v` lines, [`CheckSolutions`](/library/check-solutions/) checks it,
and the run ends as `feasible` with that objective, or as `timeout` without one.

## Use it

```python
import cpbenchy
from cpbenchy import observers

cpbenchy.run("instances/", solvers=["ortools"], time_limit=60, plugins=[observers.PBOutput()],
             args=["--terminate", "--grace", "1"])
```

```sh
cpbenchy run instances/ -s ortools -t 60 --terminate --grace 1 -p cpbenchy.observers:PBOutput
```

Rules switch it on with `terminate = true`, and [`cpbenchy solve`](/library/solve/) always has it.

## What it records

| What the run had | `status` | `termination` |
|---|---|---|
| a solution of an optimization problem | `feasible`, with its objective | `walltime`, `cputime` or `signal` |
| no solution | `timeout` | same |

## Notes

- The solutions are those the solver reports through its solution callback; satisfaction problems and
  solvers without one have nothing to report until they finish.
- Keeping each solution costs a little time per solution, as it does for competition solvers.
- A watcher thread stops the run, so a solver that holds Python's GIL while it searches can't be
  stopped this way; native solvers release it. Others are killed after the grace period.

[Measurement and limits](/guides/limits/#stopping-runs-at-their-limit) has the details.

## Implementation

Source: https://docs.cpbenchy.com/library/terminate/index.mdx