fix: attempted to exit cancel scope in a different task (mcp)

[phact]

This pull request introduces several changes to improve the cleanup process and error handling in the MCPStdioClient and MCPSseClient classes in the src/backend/base/langflow/base/mcp/util.py file. Additionally, it adds context management methods to the MCPComponent class in the src/backend/base/langflow/components/tools/mcp_component.py file.

Improvements to Cleanup Process and Error Handling:

• Added a _cleanup_lock and _is_cleaning flag to both MCPStdioClient and MCPSseClient classes to ensure that cleanup operations are not executed concurrently. [1] [2]
• Introduced a cleanup method in both MCPStdioClient and MCPSseClient classes to handle the cleanup of sessions and exit stacks. This method is called before establishing new connections and in case of exceptions during the connection process. [1] [2]
• Enhanced error handling in the connect_to_server methods by adding specific exception handling for asyncio.CancelledError, GeneratorExit, and general exceptions to ensure proper cleanup and provide informative error messages. [1] [2]

Context Management:

• Added __aenter__ and __aexit__ methods to the MCPComponent class to support asynchronous context management, ensuring that cleanup operations are performed when the component is no longer needed.
• Introduced a cleanup method in the MCPComponent class to explicitly handle the cleanup of stdio_client and sse_client instances.

These changes enhance the stability and reliability of the MCP clients by ensuring that resources are properly managed and cleaned up, reducing the risk of resource leaks and improving error diagnostics.

[Cristhianzl]

lgtm

[codspeed-hq]

CodSpeed Performance Report

Merging #7268 will degrade performances by 19.57%

_{Comparing cancel-task-mcp (cb7769a) with main (58e0d42)}

Summary

❌ 1 regressions
✅ 18 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
❌	test_cancel_nonexistent_build	7.7 ms	9.6 ms	-19.57%