How can I manage resource across multiple tool calls during one session?

Description

I was messing around multiple agents running in parallel, and suffered from some kind of race condition. I had to write a lock for them.

It looks like each agent has their own session, but I don't have any idea to handle how they create and terminate.

The code can be like below, assuming it is a streamable-http app:

import asyncio

import mcp
from mcp.server.fastmthemcp import Context
import mcp.events # some mcp protocol events, maybe session creation or termination.

mcp_server = mcp.server.FastMCP("demo-locking")
lock = None

async def acquire_lock(ctx: Context):
    # assume ctx.session.session_id = mcp-session-id acquired from headers, however not defined in this field.
    while lock is not None and lock != ctx.session.session_id:
        await asyncio.sleep(1)
        ctx.info("Waiting for the lock")
    lock = ctx.session.session_id


@mcp_server.tool()
async def tool1(ctx: Context):
    await acquire_lock(ctx)
    # ... do tool things

@mcp_server.tool()
async def tool2(ctx: Context):
    await acquire_lock(ctx)
    # ... do tool things

async def release_lock(ctx: Context):
    if lock == ctx.session.session_id:
        lock = None

mcp_server.add_handler(mcp.events.SESSION_TERMINATE, release_lock) # should be something like this to register a session cleanup.

app = mcp_server.streamable_http_app()

import uvicorn
uvicorn.run(app, host="0.0.0.0", port=8000)

References

No response

先閱讀 streamable_http_app() 進入點以及範例中的 Context/session 參照，然後檢查 add_handler() 和 SESSION_TERMINATE 目前是如何定義的。該 issue 未指出現有的檔案或測試。若要視為完成，就需要決定並記錄一種協調工具呼叫之間資源以及處理工作階段清理的方法。