API + Model: Add blocks and checks for various load requests

Add a sequential lock and wait until jobs are completed before executing
any loading requests that directly alter the model. However, we also
need to block any new requests that come in until the load is finished,
so add a condition that triggers once the lock is free.

Signed-off-by: kingbri <bdashore3@proton.me>

common/concurrency.py

@@ -1,12 +1,8 @@
 """Concurrency handling"""
 
 import asyncio
-import inspect
 from fastapi.concurrency import run_in_threadpool  # noqa
-from functools import partialmethod
-from typing import AsyncGenerator, Generator, Union
-
-generate_semaphore = asyncio.Semaphore(1)
+from typing import AsyncGenerator, Generator
 
 
 # Originally from https://github.com/encode/starlette/blob/master/starlette/concurrency.py
@@ -34,24 +30,3 @@ async def iterate_in_threadpool(generator: Generator) -> AsyncGenerator:
             yield await asyncio.to_thread(gen_next, generator)
         except _StopIteration:
             break
-
-
-async def generate_with_semaphore(generator: Union[AsyncGenerator, Generator]):
-    """Generate with a semaphore."""
-
-    async with generate_semaphore:
-        if not inspect.isasyncgenfunction:
-            generator = iterate_in_threadpool(generator())
-
-        async for result in generator():
-            yield result
-
-
-async def call_with_semaphore(callback: partialmethod):
-    """Call with a semaphore."""
-
-    async with generate_semaphore:
-        if not inspect.iscoroutinefunction:
-            callback = run_in_threadpool(callback)
-
-        return await callback()