app.py

"""
Parallel execution test for gr.Workflow.

Open in two browser tabs, type different prompts, click Run in both within
a second of each other. Check the printed timestamps:

  BEFORE fix: tab 2's slow_fn starts exactly when tab 1's slow_fn ends (~16s total)
  AFTER fix:  both run concurrently (~8s total), timestamps overlap
"""
import time
from datetime import UTC, datetime

import gradio as gr


def _now() -> str:
    return datetime.now(UTC).strftime("%H:%M:%S.%f")[:-3]


def slow_fn(text: str) -> str:
    start = _now()
    time.sleep(5)
    return f"slow | start={start} end={_now()} | input={text!r}"


def fast_fn(text: str) -> str:
    start = _now()
    time.sleep(2)
    return f"fast | start={start} end={_now()}\n{text}"


demo = gr.Workflow(bind={"slow_fn": slow_fn, "fast_fn": fast_fn})

if __name__ == "__main__":
    demo.launch()