With every connection on its own thread (previous commit), the process-wide V8
lock served no safety purpose across connections yet forced all of them to
serialize on one mutex, so throughput did not scale with concurrency. Move the
lock into CdpContext so each connection has its own: a connection's nav task and
command dispatch still coordinate on one page's isolate at a time on its thread,
but different connections no longer block each other. Delete the now-unused
process-wide obscura_js::v8_lock.
Measured on a local CPU-bound fixture, page throughput stays flat (~75/s from
concurrency 1 to 8) with the global lock and scales to about 2.5x at concurrency
8 with the per-connection lock, with no crash at any concurrency. Obstacle
course 33/33, obscura-cdp 76/76.
Refs #430.
A hung page (a runaway Runtime.evaluate, a synchronous DOM op) holds the
process-wide V8 lock and wedges every other session forever. The one-shot CLI has
a process-level hard deadline for this; the long-running server cannot force-exit,
so terminate just the offending isolate instead.
dispatch() arms a watchdog on the session page's isolate after taking the V8 lock
and disarms it after the handler; on overrun it terminates the isolate and clears
the termination flag so the session keeps working. OBSCURA_CDP_COMMAND_TIMEOUT_MS
tunes the bound (default 60s, 0 disables); navigation already self-bounds well
under it.
The watchdog is a single long-lived shared thread (cdp_watchdog), not a thread
per command: the V8 lock serializes commands so at most one is ever armed, and
arm/disarm are a mutex plus notify with no measurable per-command cost. Also
fixes a lost-wakeup in the per-call watchdog (spawn_watchdog) where disarming a
fast call before the watchdog thread started blocked for the full budget.
Verified: a hung Runtime.evaluate is terminated at the budget and the session
recovers; CDP integration 37/37, obstacle course 33/33; per-command latency
unchanged (watchdog on equals off within noise).
* feat(cli): add --v8-flags plumbing to configure V8 at startup (#130)
Obscura had no way to pass flags to V8, so users hitting OOM on pages
larger than ~5MB had no escape hatch. Adds a generic passthrough rather
than a one-off heap knob, so future V8 tuning needs no new code.
- New `obscura_js::set_v8_flags` (Once-guarded, empty-string no-op).
- Global `--v8-flags <FLAGS>` arg with `allow_hyphen_values = true`,
applied once in `main` before any isolate is created.
- Usage: `obscura --v8-flags "--max-old-space-size=4096" fetch <url>`.
Closes#130.
* test(cli): expand --v8-flags coverage with normalize helper
Extract normalize_v8_flags() from main() so the trim/empty-check logic
is unit-testable without needing to invoke V8. Adds parse-coverage tests
for --v8-flags with serve/scrape subcommands and empty-string values,
plus pure-function tests for the normalizer.
Surfaces the existing LP.getMarkdown CDP machinery as a CLI flag so
text-pipeline users (LLM agents, scrapers feeding markdown to other
tools) don't need a separate HTML-to-markdown converter step.
obscura fetch --dump markdown 'https://example.com'
Layout:
- crates/obscura-js/src/markdown.rs holds HTML_TO_MARKDOWN_JS as a
pub const so every layer can share the same DOM-walker. obscura-js
is at the bottom of the dep DAG (obscura-browser -> obscura-js,
obscura-cdp -> obscura-js, obscura-cli -> obscura-js) so a single
source of truth works without a circular dependency.
- crates/obscura-browser/src/lib.rs re-exports it for ergonomics.
- crates/obscura-cdp/src/domains/lp.rs drops its inline duplicate
and calls the shared const.
- crates/obscura-cli/src/main.rs adds the `Markdown` DumpFormat
variant + dump_markdown(&mut Page) which page.evaluate's the
shared script and prints the result.
Net diff: a new 75-line markdown.rs, a 70+ line deletion in lp.rs
that's reborn as 3 lines, and ~10 lines added across the other four
files. No behavior change for `--dump html|text|links`, and
LP.getMarkdown over CDP keeps the exact same JSON shape.
Four new unit tests in obscura-js cover headings, inline emphasis +
links, ordered/unordered lists, and that <script> / <style> contents
do not leak into the output.
Generated by Ora Studio
Vibe coded by ousamabenyounes
Co-authored-by: Ora Studio <[email protected]>
* fix(#19): serialize V8 work across pages with process-wide async lock
Concurrent CDP clients (≥5) trip V8's
`heap->isolate() == Isolate::TryGetCurrent()` invariant and abort the
process via V8_Fatal — no Rust panic, just abort(3). Each Page owns its
own JsRuntime/Isolate and they all run on a single OS thread via
LocalSet+spawn_local; when two pages' V8-touching futures interleave
across an .await, V8 trips the check.
This adds a process-wide tokio::sync::Mutex (obscura_js::v8_lock) that
is acquired:
- At the top of obscura_cdp::dispatch::dispatch (covers every CDP
handler that may call into a JsRuntime).
- In server.rs's process_with_interception spawn_local that runs
page.navigate_with_wait + execute_preload_script (this path
bypasses dispatch).
The guard keeps each V8-touching block contiguous on the thread: V8
fully exits one Isolate before another page is allowed in. Trade-off:
non-V8 handlers (Browser.*, Storage.*, Emulation.*) also serialize,
but those are cheap and the safety win dominates.
The properly concurrent fix is to pin each JsRuntime to its own OS
thread and message-pass; tracked as the larger #19 follow-up.
Adds an opt-in smoke test (`--ignored`) that boots the CDP server and
runs 5 parallel clients through createTarget+navigate. Note: the
deterministic abort needs subresource-fetch yields (page.rs:285
join_all) which data: URLs skip — full repro requires JS-heavy real
traffic (issue author used scrapegraphai.com).
* fix(#19): suspend other Isolates and defer foreign CDP during interception nav
Address maintainer feedback on PR #36 (comment 4328238087): the V8 fatal
still reproduces with `Fetch.enable patterns:["*"]` + 5 concurrent
`Page.navigate`s. The `obscura_js::v8_lock` mutex was insufficient
because V8's actual invariant is "only one Isolate may be entered per
OS thread", and the mutex can't enforce that across `.await` points
inside V8 ops.
Two distinct paths violated the invariant:
1. Foreign CDP messages dispatched while a nav task was running.
`process_with_interception`'s `select!` routed every non-Fetch
message through `process_cdp_message → dispatch → page::handle::*`.
`get_session_page_mut` then `suspend_js`'es other pages (drops
their `JsRuntime` → `Isolate::Exit`) while the spawned nav task is
parked at `op_fetch_url`'s `resolve_rx.await` with its Isolate
still entered. Drop trips
`heap->isolate() == Isolate::TryGetCurrent()`.
2. Subsequent navs through `process_with_interception` did not
suspend prior pages. After nav-1 completes (page-1's JsRuntime
stays alive in `ctx.pages`), nav-2's `init_js` constructs
Isolate-2 while Isolate-1 is still current. The next V8 scope
unwind aborts via `Context::Exit`.
Fix (3 changes in `crates/obscura-cdp/src/server.rs`):
- `cdp_processor`: add a `VecDeque<ServerMessage> deferred` drained
before each new `rx.recv()`, so deferred messages are processed
with no nav task in flight.
- `process_with_interception` `select!`: only handle `NewConnection`
and `Fetch.{continue,fulfill,fail}Request` inline (safe — no V8
enter on this side); push everything else into `deferred`.
- `process_with_interception` entry: explicitly `suspend_js()` every
other page in `ctx.pages` before spawning the nav task, mirroring
the invariant the regular dispatch path already enforces via
`get_session_page_mut`.
Verification:
- New test `crates/obscura-cdp/tests/concurrent_navigations_with_fetch.rs`
is the maintainer's exact repro (5 clients, `Fetch.enable patterns:["*"]`,
concurrent `Page.navigate` to https://example.com, auto-reply
`Fetch.continueRequest`). Aborts on PR #36 head, passes after fix
(5/5 stable runs, ~1.2s each).
- Existing data-URL smoke test (`concurrent_navigations`) still passes.
- Full workspace test suite (90 tests) still passes.
Run with:
cargo test -p obscura-cdp --test concurrent_navigations_with_fetch \
-- --nocapture --ignored
Honest caveat. This is still the lock/serialize approach — it converts
the abort into latency. The properly concurrent fix (Option 2 in
issue #19: pin each `JsRuntime` to its own OS thread and message-pass)
remains the right long-term direction.
* fix(cdp): bound deferred message queue to prevent OOM during stalled navigation
PR #36 comment 4341743194: process_with_interception deferred foreign
CDP messages into an unbounded VecDeque while a navigation task was in
flight. A stalled navigation (e.g. waiting for Fetch interception
resolution) could accumulate arbitrary queued messages and OOM the
process.
Add MAX_DEFERRED_MESSAGES = 256. When the cap is reached, return an
explicit CDP error (-32000) to the client instead of silently dropping
or growing without bound.
All 90 workspace tests pass.
sycatle