🩹 [Patch]: Prevent Concurrent Access Token Refresh with Mutex Lock

[MariusStorhaug]

Describe the change

Problem:

When multiple runspaces concurrently call functions utilizing Invoke-GitHubAPI, there's a risk of triggering multiple simultaneous refresh attempts of the same context's GitHub access token. This concurrency leads to race conditions, redundant token refreshes, and potential conflicts or errors.

Desired Behavior:

Only a single refresh operation per context should occur at a time. Subsequent calls needing the refreshed token should wait until the ongoing refresh completes, ensuring consistency and preventing conflicts.

Proposed Solution:

Implement synchronization using the System.Threading.Mutex class:

• When a context initiates a token refresh, it creates and acquires a mutex lock specific to that context.
• Other parallel runspaces attempting to refresh the same context should detect the mutex lock and wait until it's released.
• Upon successful token refresh, release and remove the mutex.
• Any waiting processes will then reload the updated context without attempting another redundant refresh.

Implementation Considerations:

• Ensure mutex names are unique per context.
• Use proper try/finally blocks to guarantee mutex release.
• Dispose of mutex objects appropriately after use.

This solution will eliminate concurrent token refresh attempts and enhance stability and reliability for parallelized GitHub API calls.