fix(memory): serialize concurrent writes in AsyncSQLAlchemyMemory

[umerkhan95]

AgentScope Version

1.0.18

Description

Fixes #1381 — AsyncSQLAlchemyMemory raises IntegrityError when ReActAgent runs with parallel_tool_calls=True because multiple _acting() coroutines call memory.add() concurrently on a shared AsyncSession.

This PR adds an asyncio.Lock wrapped in a _write_session() async context manager that serializes all mutating session operations (add, clear, delete, delete_by_mark, update_messages_mark) with automatic commit/rollback. Internal helpers remain lock-free since they're only called from within _write_session(). Read-only methods are left unlocked.

Includes test_concurrent_add that fires 20 concurrent asyncio.gather-based add() calls and verifies message count and index contiguity.

Checklist

• Code has been formatted with pre-commit run --all-files command
• All tests are passing
• Docstrings are in Google style
• Related documentation has been updated (e.g. links, examples, etc.)
• Code is ready for review

[cla-assistant]

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[qbc2016]

Please sign our CLA and merge the latest main branch to pass the unittests.

[umerkhan95]

I am not able to authenticate the license agreement, its really buggy and does not authenticate through my Github account, I tried multiple times but the trigger to authentication is not hitting.

The error: upstream connect error or disconnect/reset before headers. reset reason: connection termination

This error comes after I authenticate to the license agreement.