02.10.06 — The Playwright actor: one owner thread

Mon, 01 Jun 2026 00:00:00 +0000

02.10.06 — The Playwright actor: one owner thread#

Source folder: src/ocarina/infra/playwright/

The Playwright adapter mirrors the Selenium one file for file (create_driver, create_drivers_pool, create_screenshotter, driver_healthcheck, mixins), with one extra file: driver.py. That file deserves a chapter of its own. It is what reconciles Playwright’s sync API — inherently bound to one thread — with Ocarina’s threaded model (pool, warmup, Watcher). The model has been stressed and stabilized; it holds.

The problem: Playwright’s sync API is thread-affine#

Playwright’s sync API binds every object it hands out — Playwright, Browser, BrowserContext, Page, Locator, … — to the thread that called sync_playwright().start(). Under the hood it is a greenlet pinned to that thread. Touching any of them from another thread raises:

Concurrency on Ocarina — manual

02.10.06 — The Playwright actor: one owner thread

02.10.06 — The Playwright actor: one owner thread#

The problem: Playwright’s sync API is thread-affine#