[BugFix] openbb-cboe: Fix cache lock so that concurrent callers in separate processes don't hang (#7796)

* fix cboe's cache lock so that concurrent callers in separate processes don't hang

* fix test coverage and ty check

* more test failure

* more test failure

* more Windows Python 3.10 test failure

* Move lint path filter into a job so required checks always report

lint-openbb-platform.yml used `on.pull_request.paths` to skip PRs that only
touch api/extensions/providers/obbject_extensions. A workflow skipped by a
trigger filter never reports its checks, so the required "General Code
Linting" and "Markdown Linting" checks stayed pending forever on those PRs.

Detect relevant changes in a `changes` job instead and gate the lint jobs with
a job-level `if:`. Skipped jobs report success, so required checks resolve.
The gate fails closed: if detection fails, the lint jobs still run.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: dlee-bq <325002271+dlee-bq@users.noreply.github.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

.github/workflows/lint-openbb-platform.yml

@@ -6,15 +6,6 @@ env:
 on:
   pull_request:
     types: [opened, synchronize, edited]
-    paths:
-      - 'openbb_platform/**'
-      - '!openbb_platform/api/**'
-      - '!openbb_platform/extensions/**'
-      - '!openbb_platform/providers/**'
-      - '!openbb_platform/obbject_extensions/**'
-      - '.github/workflows/lint-openbb-platform.yml'
-      - '.github/codeql/**'
-      - '.github/workflows/codeql.yml'
   merge_group:
     types: [checks_requested]
 
@@ -23,8 +14,46 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
+  changes:
+    name: Detect Changes
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: read
+    outputs:
+      platform: ${{ steps.filter.outputs.platform }}
+    steps:
+      - name: Check for shared platform changes
+        id: filter
+        env:
+          GH_TOKEN: ${{ github.token }}
+          EVENT_NAME: ${{ github.event_name }}
+          REPO: ${{ github.repository }}
+          PR_NUMBER: ${{ github.event.pull_request.number }}
+        run: |
+          # Path filtering lives here instead of `on.pull_request.paths`: a workflow
+          # skipped by a trigger filter never reports its checks, which leaves the
+          # required "General Code Linting" and "Markdown Linting" checks pending
+          # forever. Jobs skipped by a job-level `if:` report success instead.
+          if [ "$EVENT_NAME" != "pull_request" ]; then
+            echo "platform=true" >> "$GITHUB_OUTPUT"
+            exit 0
+          fi
+          gh api --paginate "repos/${REPO}/pulls/${PR_NUMBER}/files" --jq '.[].filename' > changed_files.txt
+          if awk '
+            /^\.github\/(workflows\/(lint-openbb-platform|codeql)\.yml$|codeql\/)/ { found = 1 }
+            /^openbb_platform\// && !/^openbb_platform\/(api|extensions|providers|obbject_extensions)\// { found = 1 }
+            END { exit !found }
+          ' changed_files.txt; then
+            echo "platform=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "platform=false" >> "$GITHUB_OUTPUT"
+          fi
+
   code-linting:
     name: General Code Linting
+    needs: changes
+    # Fail closed: run unless change detection explicitly found nothing relevant.
+    if: ${{ !cancelled() && needs.changes.outputs.platform != 'false' }}
     runs-on: ubuntu-latest
     env:
       UV_CACHE_DIR: ${{ github.workspace }}/.uv-cache
@@ -122,6 +151,8 @@ jobs:
 
   markdown-link-check:
     name: Markdown Linting
+    needs: changes
+    if: ${{ !cancelled() && needs.changes.outputs.platform != 'false' }}
     runs-on: ubuntu-latest
     permissions:
       contents: read
@@ -136,6 +167,8 @@ jobs:
 
   json-yaml-validate:
     name: JSON Check
+    needs: changes
+    if: ${{ !cancelled() && needs.changes.outputs.platform != 'false' }}
     runs-on: ubuntu-latest
     permissions:
       contents: read

openbb_platform/providers/cboe/openbb_cboe/utils/helpers.py

@@ -3,6 +3,10 @@
 from __future__ import annotations
 
 import logging
+import os
+import sqlite3
+import threading
+from contextlib import asynccontextmanager
 from datetime import (
     date as dateType,
     datetime,
@@ -149,10 +153,17 @@ async def response_callback(response, _) -> Any:
     return await response.read()
 
 
-_cache: Any = None
+# Every cached request shares one SQLite connection, which lives on an event loop
+# of its own (see ``_get_cache_loop``). ``_cache_lock`` guards the state below that
+# threads outside that loop also touch; ``_stores`` and ``_swept`` belong to it, and
+# ``_cache_guard`` lets one thing at a time open, use or close the connection.
+_cache_lock = threading.Lock()
 _cache_loop: Any = None
-_swept = False
+_cache_guard: Any = None
 _cache_users = 0
+_stores: Any = None
+_swept = False
+_inherited: list = []
 
 
 def cache_path() -> str:
@@ -175,6 +186,30 @@ async def _oldest(backend: Any, count: int) -> set:
     return keys
 
 
+async def _pragma(connection: Any, statement: str) -> Any:
+    """Run a PRAGMA and return its row, leaving no statement open behind it."""
+    cursor = await connection.execute(statement)
+
+    try:
+        return await cursor.fetchone()
+    finally:
+        await cursor.close()
+
+
+async def _size(backend: Any) -> int:
+    """Return how big the cache file is, counting what is still in its log.
+
+    The file on disk cannot say. After a ``VACUUM`` in write-ahead mode the new
+    pages wait in the log until it is checkpointed, and the file keeps its old
+    size until then.
+    """
+    async with backend.responses.get_connection() as connection:
+        (pages,) = await _pragma(connection, "PRAGMA page_count")
+        (page_size,) = await _pragma(connection, "PRAGMA page_size")
+
+    return pages * page_size
+
+
 async def _sweep(backend: Any) -> None:
     """Drop what has expired, then the oldest of what is left if still too big.
 
@@ -184,18 +219,17 @@ async def _sweep(backend: Any) -> None:
     of the file that overshoots it, which is one rewrite of the file rather than
     one per entry.
     """
-    from pathlib import Path
-
     await backend.delete_expired_responses()
     await _vacuum(backend)
-    stored = Path(f"{cache_path()}.sqlite")
 
     for _ in range(CACHE_SWEEP_PASSES):
-        if not stored.exists() or stored.stat().st_size <= CACHE_MAX_BYTES:
+        size = await _size(backend)
+
+        if size <= CACHE_MAX_BYTES:
             return
 
         held = await backend.responses.size()
-        overshoot = 1 - CACHE_MAX_BYTES / stored.stat().st_size
+        overshoot = 1 - CACHE_MAX_BYTES / size
         dropped = await _oldest(backend, max(1, round(held * overshoot)))
 
         if not dropped:
@@ -206,74 +240,297 @@ async def _sweep(backend: Any) -> None:
 
 
 async def _vacuum(backend: Any) -> None:
-    """Give back the pages the deleted responses were held in."""
+    """Give back the pages the deleted responses were held in, if there are any.
+
+    A ``VACUUM`` rewrites the whole file while holding it, and every process
+    sweeps as it starts, so one that has nothing to give back must not run it.
+    """
     async with backend.responses.get_connection(commit=True) as connection:
+        (unused,) = await _pragma(connection, "PRAGMA freelist_count")
+
+        if not unused:
+            return
+
         await connection.execute("VACUUM")
+        # In write-ahead mode the vacuumed file reaches the disk, and gives its
+        # space back, only when the log is checkpointed.
+        await _pragma(connection, "PRAGMA wal_checkpoint(TRUNCATE)")
 
 
-async def close_cache_backend(backend: Any) -> None:
+async def _use_wal(stores: Any) -> None:
-    """Close the shared cache and forget it, so the next caller builds a fresh one.
+    """Put the cache file in write-ahead logging, where readers and a writer coexist.
 
-    ``SQLiteBackend.close()`` clears the connection object the backend was
+    Otherwise a process writing to the file makes every other process wait to
-    constructed with and never rebuilds it, so a closed backend is permanently
+    read it, and a process reading it makes the writer wait to commit; one that
-    unusable - every later request through it dies on ``NoneType has no
+    holds the file for longer than SQLite will wait makes the request fail with
-    attribute '_connection'``. Dropping the module reference is what makes the
+    ``database is locked``. The mode belongs to the file, so it holds for every
-    close recoverable.
+    process that opens it from now on. A file that cannot be switched - another
+    process is part way through a write, or the file system cannot keep the shared
+    memory the mode needs - keeps working in its default mode.
 
     Parameters
     ----------
-    backend : Any
+    stores : SQLiteBackend
-        The backend to close; ignored if it is no longer the shared one.
+        The stores whose file is switched.
     """
-    global _cache, _cache_loop  # noqa: PLW0603
+    try:
+        async with stores.responses.get_connection() as connection:
+            row = await _pragma(connection, "PRAGMA journal_mode=WAL")
+    except Exception:  # noqa: BLE001
+        _logger.exception("Could not put the Cboe response cache in WAL mode")
 
-    if _cache is backend:
+        return
-        _cache = None
-        _cache_loop = None
 
+    if not row or str(row[0]).lower() != "wal":
+        _logger.warning("The Cboe response cache is staying in %s mode", row)
+
+
+class _CacheConnection(sqlite3.Connection):
+    """A connection set up for a cache that many processes share.
+
+    It commits each statement as it runs. By default a write opens a transaction,
+    takes the file's write lock, and only gives it up when a second call, made
+    after the event loop has had its turn, commits it. Other processes wait out
+    that gap, however long a busy machine makes it, and a write cancelled inside
+    it leaves the lock held until something else commits.
+
+    It does not wait for the disk after each commit either (``synchronous`` is
+    ``NORMAL``). A commit that waits holds the write lock for as long as the disk
+    takes, which on a slow one is long enough for every other process to give up
+    on the lock; what the wait buys is surviving a power cut, and a response that
+    is lost is fetched again.
+
+    Both have to be set by the thread the connection lives on, and the library
+    drops ``isolation_level=None`` along with every other ``None`` argument, so
+    they are set here, where the library hands a connection ``factory`` its
+    arguments.
+    """
+
+    def __init__(self, *args: Any, **kwargs: Any) -> None:
+        super().__init__(*args, **kwargs)
+        self.isolation_level = None
+        self.execute("PRAGMA synchronous = NORMAL")
+
+
+def _new_backend() -> Any:
+    """Build the SQLite stores of the response cache."""
+    from aiohttp_client_cache import SQLiteBackend
+
+    return SQLiteBackend(cache_path(), autoclose=False, factory=_CacheConnection)
+
+
+async def _sweep_file() -> None:
+    """Sweep the cache file on a connection of its own, closed when it is done.
+
+    The sweep can stop part way - on a row that cannot be read back, say - with a
+    read still open. It runs before the requests' connection exists, and on a
+    connection that is closed whatever happens, so nothing of it is left holding
+    the file once it is over.
+    """
+    backend = _new_backend()
+
+    try:
+        await _sweep(backend)
+    except Exception:  # noqa: BLE001
+        _logger.exception("Sweeping the Cboe response cache failed")
+    finally:
         try:
             await backend.close()
         except Exception:  # noqa: BLE001
-        _logger.exception("Closing the Cboe response cache failed")
+            _logger.exception("Closing the Cboe sweep connection failed")
 
 
-async def cache_backend() -> Any:
+def _get_cache_loop() -> Any:
-    """Return the shared cache for the running event loop, swept on first use.
+    """Return the event loop the cache's connection lives on, starting it if needed.
+
+    An aiosqlite connection, and the lock beside it, only work on the loop that
+    first used them. Requests run on whatever loop their caller has - core's
+    ``run_async`` gives every synchronous call a thread and a loop of its own -
+    so a connection per loop would be one writer per loop on a single file, and
+    one connection shared between loops would fail with ``bound to a different
+    event loop`` or wait on a wake-up that never reaches its loop. One loop, on a
+    thread of its own, owns the single connection, and requests reach it from
+    wherever they run.
+
+    Returns
+    -------
+    AbstractEventLoop
+        The loop, running on a daemon thread, that every cache operation uses.
+    """
+    global _cache_loop, _cache_guard  # noqa: PLW0603
+
+    from asyncio import Lock, new_event_loop
+
+    with _cache_lock:
+        if _cache_loop is None:
+            loop = new_event_loop()
+            threading.Thread(
+                target=loop.run_forever, name="cboe-cache", daemon=True
+            ).start()
+            _cache_guard = Lock()
+            _cache_loop = loop
+
+        return _cache_loop
+
+
+async def _on_cache_loop(operation: Any) -> Any:
+    """Run a coroutine on the cache loop and wait for it from the running one."""
+    from asyncio import run_coroutine_threadsafe, wrap_future
+
+    return await wrap_future(run_coroutine_threadsafe(operation, _get_cache_loop()))
+
+
+async def _store_call(table: str, method: str, *args: Any) -> Any:
+    """Run a method of one of the cache's stores where its connection is.
+
+    One at a time. A read leaves its statement open until it is collected, so a
+    connection that starts a write while another request's read is still open
+    holds the file for reading as it asks to write. Another process committing at
+    that moment makes SQLite refuse the write at once, as ``database is locked``,
+    where it would otherwise have waited. A connection that finishes each
+    operation before it starts the next never asks for both.
+
+    Parameters
+    ----------
+    table : str
+        ``responses`` or ``redirects``.
+    method : str
+        The store's method.
+    *args : Any
+        The method's arguments.
 
     Returns
     -------
     Any
-        The ``SQLiteBackend`` every cached request on the running loop shares.
+        What the method returns; a method that yields returns the list it yielded.
     """
-    global _cache, _cache_loop, _swept, _cache_users  # noqa: PLW0603
 
-    from asyncio import get_running_loop
+    async def call() -> Any:
+        async with _cache_guard:
+            result = getattr(getattr(_stores, table), method)(*args)
 
-    from aiohttp_client_cache import SQLiteBackend
+            if hasattr(result, "__aiter__"):
+                return [item async for item in result]
 
-    loop = get_running_loop()
+            return await result
 
-    if _cache is None or (_cache_loop is not loop and _cache_users == 0):
+    return await _on_cache_loop(call())
-        _cache = SQLiteBackend(
+
-            cache_path(),
+
+async def _open() -> None:
+    """Open the stores if they are not open, sweeping the file first the first time.
+
+    Runs on the cache loop. The sweep finishes before the stores exist, so no
+    request is ever in the middle of the file while it is vacuumed.
+    """
+    global _stores, _swept  # noqa: PLW0603
+
+    async with _cache_guard:
+        if _stores is not None:
+            return
+
+        if not _swept:
+            await _sweep_file()
+            _swept = True
+
+        _stores = _new_backend()
+        await _use_wal(_stores)
+
+
+async def _close() -> None:
+    """Close the stores if no request is using them any more.
+
+    ``SQLiteBackend.close()`` clears the connection object the backend was built
+    with and never rebuilds it, so a closed backend cannot be used again. The next
+    request opens a fresh one.
+    """
+    global _stores  # noqa: PLW0603
+
+    async with _cache_guard:
+        with _cache_lock:
+            idle = _cache_users == 0
+
+        if _stores is None or not idle:
+            return
+
+        stores, _stores = _stores, None
+
+        try:
+            await stores.close()
+        except Exception:  # noqa: BLE001
+            _logger.exception("Closing the Cboe response cache failed")
+
+
+@asynccontextmanager
+async def cache_backend():
+    """Provide the response cache for the length of one request.
+
+    Every request, on every loop and thread, is backed by the same connection.
+    It is opened for the first request to need it and closed after the last has
+    finished, so an idle process holds no connection open.
+
+    Yields
+    ------
+    SharedCache
+        The ``aiohttp_client_cache`` backend to build a ``CachedSession`` on.
+    """
+    global _cache_users  # noqa: PLW0603
+
+    from asyncio import run_coroutine_threadsafe, shield, wrap_future
+
+    from openbb_cboe.utils.shared_cache import SharedCache
+
+    with _cache_lock:
+        _cache_users += 1
+
+    try:
+        await _on_cache_loop(_open())
+
+        yield SharedCache(
+            _store_call,
+            cache_name=CACHE_NAME,
             expire_after=CACHE_TTL["*"],
             urls_expire_after=CACHE_TTL,
             autoclose=False,
         )
-        _cache_loop = loop
-
-    if not _swept:
-        _swept = True
-        _cache_users += 1
-
-        try:
-            await _sweep(_cache)
-        except Exception:  # noqa: BLE001
-            _logger.exception("Sweeping the Cboe response cache failed")
     finally:
+        with _cache_lock:
             _cache_users -= 1
 
-    return _cache
+        # Handed to the cache loop here and now, not by a task that could be
+        # cancelled, or whose loop could end, before it ever started: a close
+        # that is lost leaves the connection, and its thread, open for good.
+        closing = run_coroutine_threadsafe(_close(), _get_cache_loop())
+        await shield(wrap_future(closing))
+
+
+def _forget_cache_loop() -> None:
+    """Start over in a forked child, whose cache loop's thread did not survive.
+
+    The child would otherwise wait for ever on a loop that is not running. The
+    parent's connection is kept, never closed or collected, because closing an
+    SQLite connection in the process it was not opened in can undo the parent's
+    work on the file.
+    """
+    global _cache_lock, _cache_loop, _cache_guard, _cache_users, _stores  # noqa: PLW0603
+
+    if _stores is not None:
+        _inherited.append(_stores)
+
+    _cache_lock = threading.Lock()
+    _cache_loop = None
+    _cache_guard = None
+    _cache_users = 0
+    _stores = None
+
+
+def _forget_after_fork() -> None:
+    """Have a forked child start over, on the platforms that can fork."""
+    if hasattr(os, "register_at_fork"):
+        os.register_at_fork(after_in_child=_forget_cache_loop)
+
+
+_forget_after_fork()
 
 
 async def get_cboe_data(url: str, use_cache: bool = True, **kwargs) -> Any:
@@ -292,26 +549,15 @@ async def get_cboe_data(url: str, use_cache: bool = True, **kwargs) -> Any:
     Any
         The deserialized response.
     """
-    global _cache_users  # noqa: PLW0603
-
     from aiohttp_client_cache.session import CachedSession
 
     if use_cache is not True:
         return await amake_request(url, response_callback=response_callback, **kwargs)
 
-    backend = await cache_backend()
+    async with cache_backend() as backend, CachedSession(cache=backend) as session:
-    _cache_users += 1
-
-    try:
-        async with CachedSession(cache=backend) as session:
         response = await session.get(url, timeout=10, **kwargs)
 
         return await response_callback(response, None)
-    finally:
-        _cache_users -= 1
-
-        if _cache_users == 0:
-            await close_cache_backend(backend)
 
 
 async def get_company_directory(use_cache: bool = True, **kwargs) -> DataFrame:

openbb_platform/providers/cboe/openbb_cboe/utils/options/create_surface.py

@@ -146,7 +146,7 @@ def create_surface(
         "open_interest",
         "volume",
     ]
-    df = df[[c for c in dict.fromkeys(columns) if c in df.columns]]
+    df = df[[c for c in dict.fromkeys(columns) if c in df.columns]].copy()
     metric_title = METRIC_TITLES.get(metric, metric.replace("_", " ").title())
     label = f"{symbol} {OPTION_TYPE_LABELS[option_type]} {metric_title} Surface"
 

openbb_platform/providers/cboe/openbb_cboe/utils/shared_cache.py

@@ -0,0 +1,103 @@
+"""Response cache whose storage is reached through another event loop.
+
+An aiosqlite connection, and the lock that guards it, only work on the event
+loop that first used them. Cboe requests run on whichever loop their caller
+has - core's ``run_async`` gives every synchronous call a thread and a loop of
+its own - so the one connection they all share has to live on a loop of its
+own, and each request reaches it from wherever it is running. These classes are
+that reach: they implement the storage interface ``aiohttp_client_cache`` asks
+of a custom backend and leave the work to a ``call`` function.
+"""
+
+from __future__ import annotations
+
+from collections.abc import AsyncIterator, Awaitable, Callable
+from typing import Any
+
+from aiohttp_client_cache import CacheBackend
+from aiohttp_client_cache.backends import BaseCache
+
+StoreCall = Callable[..., Awaitable[Any]]
+"""``call(table, method, *args)`` runs a store's method where its connection is.
+
+A method that yields, like ``keys``, comes back as the list of what it yielded.
+"""
+
+
+class SharedStore(BaseCache):
+    """One table of the shared cache, usable from any event loop.
+
+    Parameters
+    ----------
+    table : str
+        The name of the backend's store this stands for, ``responses`` or
+        ``redirects``.
+    call : StoreCall
+        Runs a method of that store where the connection is.
+    """
+
+    def __init__(self, table: str, call: StoreCall) -> None:
+        super().__init__()
+        self._table = table
+        self._call = call
+
+    async def contains(self, key: str) -> bool:
+        """Check if a key is stored in the cache."""
+        return await self._call(self._table, "contains", key)
+
+    async def clear(self) -> None:
+        """Delete all items from the cache."""
+        await self._call(self._table, "clear")
+
+    async def close(self) -> None:
+        """Leave the connection open: other requests are still using it."""
+
+    async def delete(self, key: str) -> None:
+        """Delete an item from the cache."""
+        await self._call(self._table, "delete", key)
+
+    async def bulk_delete(self, keys: set) -> None:
+        """Delete items from the cache."""
+        await self._call(self._table, "bulk_delete", keys)
+
+    async def keys(self) -> AsyncIterator[str]:  # type: ignore[override]
+        """Yield all keys stored in the cache."""
+        for key in await self._call(self._table, "keys"):
+            yield key
+
+    async def read(self, key: str) -> Any:
+        """Read an item from the cache; ``None`` if it is missing."""
+        return await self._call(self._table, "read", key)
+
+    async def size(self) -> int:
+        """Get the number of items in the cache."""
+        return await self._call(self._table, "size")
+
+    async def values(self) -> AsyncIterator[Any]:  # type: ignore[override]
+        """Yield all values stored in the cache."""
+        for value in await self._call(self._table, "values"):
+            yield value
+
+    async def write(self, key: str, item: Any) -> None:
+        """Write an item to the cache."""
+        await self._call(self._table, "write", key, item)
+
+
+class SharedCache(CacheBackend):
+    """A response cache that keeps what it stores through ``call``.
+
+    Expiry, keys and redirects are decided here, on the caller's loop, as they
+    are for any backend; only reading and writing leave it.
+
+    Parameters
+    ----------
+    call : StoreCall
+        Runs a store's method where the connection is.
+    **kwargs
+        The settings of ``aiohttp_client_cache.CacheBackend``.
+    """
+
+    def __init__(self, call: StoreCall, **kwargs: Any) -> None:
+        super().__init__(**kwargs)
+        self.responses = SharedStore("responses", call)
+        self.redirects = SharedStore("redirects", call)

openbb_platform/providers/cboe/pyproject.toml

@@ -79,6 +79,18 @@ exclude = ["tests", "integration"]
 [tool.ty.rules]
 unresolved-import = "warn"
 
+# The models extend the platform's standard models by overriding their fields:
+# a query parameter narrowed to a ``Literal`` (core derives the parameter's choices
+# from it), or a field the provider may leave empty. ty treats both as unsound
+# overrides of a mutable attribute. The check is off for the model modules, where
+# that is how a provider is written, and stays on everywhere else.
+[[tool.ty.overrides]]
+include = ["openbb_cboe/models/**"]
+
+[tool.ty.overrides.rules]
+invalid-attribute-override = "ignore"
+invalid-mutable-override = "ignore"
+
 [tool.coverage.report]
 exclude_lines = ["pragma: no cover", "if TYPE_CHECKING:", "raise NotImplementedError", "@overload"]
 

openbb_platform/providers/cboe/tests/cache_worker.py

@@ -0,0 +1,73 @@
+"""One OS process making cached requests, for the tests that share a cache file.
+
+Run as ``cache_worker.py URL CACHE_FILE ROUNDS REQUESTS_PER_ROUND THREADS``. Each
+thread runs bursts of concurrent requests on an event loop of its own, over a few
+dozen URLs the other processes ask for too, and the last line printed is a JSON
+summary of how many succeeded and what the failures were.
+"""
+
+import asyncio
+import collections
+import json
+import logging
+import sys
+import threading
+import traceback
+from pathlib import Path
+
+from openbb_cboe.utils import helpers
+
+URL, CACHE_FILE, ROUNDS, PER_ROUND, THREADS = sys.argv[1:6]
+URLS = 40
+# Requests in flight per event loop. A test server can only queue so many
+# connections at once (128 on macOS); this keeps the workers' total under it, so
+# what the test measures is the cache and not the server's accept queue.
+IN_FLIGHT = 2
+
+logging.disable(logging.CRITICAL)
+helpers.cache_path = lambda: CACHE_FILE
+succeeded = 0
+failures: collections.Counter = collections.Counter()
+
+
+async def request(number, turn):
+    """Request one URL, recording how it went."""
+    global succeeded  # noqa: PLW0603
+
+    try:
+        async with turn:
+            await asyncio.wait_for(
+                helpers.get_cboe_data(f"{URL}/{number % URLS}.json"), timeout=30
+            )
+
+        succeeded += 1
+    except Exception as error:  # noqa: BLE001
+        frames = traceback.extract_tb(error.__traceback__)[-4:]
+        where = " <- ".join(
+            f"{Path(frame.filename).name}:{frame.lineno} {frame.name}"
+            for frame in reversed(frames)
+        )
+        failures[f"{type(error).__name__}: {error} (at {where})"] += 1
+
+
+def work(thread):
+    """Run the bursts of one thread, each on a new event loop."""
+
+    async def burst(first):
+        turn = asyncio.Semaphore(IN_FLIGHT)
+
+        await asyncio.gather(*(request(first + n, turn) for n in range(int(PER_ROUND))))
+
+    for round_number in range(int(ROUNDS)):
+        asyncio.run(burst(round_number * int(PER_ROUND) + thread * 7))
+
+
+threads = [threading.Thread(target=work, args=(n,)) for n in range(int(THREADS))]
+
+for thread in threads:
+    thread.start()
+
+for thread in threads:
+    thread.join()
+
+sys.stdout.write(json.dumps({"succeeded": succeeded, "failures": failures}) + "\n")

openbb_platform/providers/cboe/tests/test_options_analysis.py

@@ -189,6 +189,10 @@ class TestStats:
         assert output.chart.content["data"]
 
 
+# pandas warns that way when a frame that is a view of another is written to. The
+# class it uses is not in every version, so it is matched by what it says, and the
+# message starts on a new line, hence the flag that lets ``.`` match one.
+@pytest.mark.filterwarnings("error:(?s).*trying to be set on a copy of a slice")
 class TestSurface:
     """3-D surface builder."""
 

openbb_platform/providers/cboe/tests/test_shared_cache.py

@@ -0,0 +1,108 @@
+"""Tests for openbb_cboe.utils.shared_cache."""
+
+import asyncio
+from unittest.mock import AsyncMock
+
+import pytest
+
+from openbb_cboe.utils.shared_cache import SharedCache, SharedStore
+
+
+async def _gather(iterable):
+    """Collect everything an async iterable yields."""
+    return [item async for item in iterable]
+
+
+class TestSharedStore:
+    """A store hands every operation to ``call``, whichever loop it is used on."""
+
+    @pytest.mark.parametrize(
+        ("method", "args", "returned"),
+        [
+            ("contains", ("key",), True),
+            ("read", ("key",), "item"),
+            ("size", (), 7),
+            ("write", ("key", "item"), None),
+            ("delete", ("key",), None),
+            ("bulk_delete", ({"key"},), None),
+            ("clear", (), None),
+        ],
+    )
+    def test_an_operation_is_run_where_the_connection_is(self, method, args, returned):
+        """The table, the method and its arguments go over, and the result comes back."""
+        call = AsyncMock(return_value=returned)
+        store = SharedStore("responses", call)
+
+        result = asyncio.run(getattr(store, method)(*args))
+
+        assert result == returned
+        call.assert_awaited_once_with("responses", method, *args)
+
+    @pytest.mark.parametrize("method", ["keys", "values"])
+    def test_what_is_yielded_is_yielded_here(self, method):
+        """Keys and values arrive gathered, and are yielded on the caller's loop."""
+        call = AsyncMock(return_value=["a", "b"])
+        store = SharedStore("redirects", call)
+
+        assert asyncio.run(_gather(getattr(store, method)())) == ["a", "b"]
+        call.assert_awaited_once_with("redirects", method)
+
+    def test_closing_leaves_the_connection_to_the_cache(self):
+        """Other requests are still using the connection, so a session may not close it."""
+        call = AsyncMock()
+
+        asyncio.run(SharedStore("responses", call).close())
+
+        call.assert_not_awaited()
+
+    def test_pop_reads_then_deletes(self):
+        """The base class's ``pop`` works through the same two operations."""
+        call = AsyncMock(side_effect=lambda table, method, *args: "item")
+
+        assert asyncio.run(SharedStore("responses", call).pop("key")) == "item"
+        assert [step.args[1] for step in call.await_args_list] == ["read", "delete"]
+
+    def test_an_error_where_the_connection_is_reaches_the_caller(self):
+        """A failed read is the failure of the request that made it."""
+        call = AsyncMock(side_effect=OSError("disk"))
+
+        with pytest.raises(OSError):
+            asyncio.run(SharedStore("responses", call).read("key"))
+
+
+class TestSharedCache:
+    """The backend decides expiry and keys itself, and stores through ``call``."""
+
+    def test_its_tables_are_the_responses_and_the_redirects(self):
+        """Each table of the backend is a store of the same name."""
+        call = AsyncMock()
+        cache = SharedCache(call)
+
+        asyncio.run(cache.responses.write("key", "item"))
+        asyncio.run(cache.redirects.write("alias", "key"))
+
+        assert [step.args[:2] for step in call.await_args_list] == [
+            ("responses", "write"),
+            ("redirects", "write"),
+        ]
+
+    def test_it_keeps_the_settings_it_is_given(self):
+        """Expiry is applied on the caller's loop, from the backend's own settings."""
+        cache = SharedCache(
+            AsyncMock(),
+            expire_after=60,
+            urls_expire_after={"*/book/*": 5},
+            autoclose=False,
+        )
+
+        assert cache.expire_after == 60
+        assert cache.urls_expire_after == {"*/book/*": 5}
+        assert cache.autoclose is False
+
+    def test_closing_it_does_not_close_the_shared_connection(self):
+        """Closing the backend is not closing the connection other requests use."""
+        call = AsyncMock()
+
+        asyncio.run(SharedCache(call).close())
+
+        call.assert_not_awaited()