Thread safety in the main client

[preritdas]

Implement Thread Safety in BigDBMClient to Prevent Race Conditions

Description

The current implementation of BigDBMClient is not thread-safe, particularly in its access token management. This can lead to race conditions when the class is used in concurrent scenarios, potentially causing unexpected behavior or errors.

Current Behavior

• Access token management methods (_update_token, _access_token_valid) are not protected against concurrent access.
• Multiple threads could attempt to update or check the token simultaneously, leading to inconsistent state.

Proposed Solution

Implement thread-safe mechanisms to protect critical sections of the BigDBMClient class, focusing on access token management.

Steps:

1. Add a threading lock to the class.
2. Use the lock to protect access to token-related methods.
3. Consider using thread-local storage for high-concurrency scenarios.

Example Implementation

from threading import Lock

class BigDBMClient:
    def __init__(self, client_id: str, client_secret: str, logging: bool = DEFAULT_LOGGING) -> None:
        # ... existing code ...
        self._token_lock = Lock()

    def _update_token(self) -> None:
        with self._token_lock:
            # ... existing token update code ...

    def _access_token_valid(self) -> bool:
        with self._token_lock:
            # ... existing token validation code ...

    def __request(self, request: Request) -> dict:
        with self._token_lock:
            if not self._access_token_valid():
                self._update_token()
        # ... rest of the method ...

Additional Considerations

• Evaluate the thread-safety of the logging mechanism (logfire).
• Review other methods for potential thread-safety issues.
• Add clear documentation about thread-safety and usage in concurrent environments.

Expected Outcome

• BigDBMClient can be safely used in multi-threaded environments without risk of race conditions.
• Improved reliability and predictability of the class in concurrent scenarios.

Testing

• Implement unit tests to verify thread-safe behavior.
• Conduct stress tests with multiple threads accessing the client simultaneously.

Questions

• Are there any other areas of the class that might be susceptible to race conditions?
• Should we consider using a thread-safe caching mechanism for the access token?