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

首先阅读 streamable_http_app() 入口点以及示例中的 Context/session 引用，然后检查 add_handler() 和 SESSION_TERMINATE 当前是如何定义的。该 issue 未指出现有的文件或测试。要视为完成，需要确定并记录一种协调工具调用之间资源以及处理会话清理的方法。