Reduced contention on CallEndpoint::commonMutex() when getting current or last peer ID.
Added a variable and separate mutex for the last peer ID, also used as cache for current one.


git-svn-id: http://yate.null.ro/svn/yate/trunk@5702 acf43c95-373e-0410-b603-e72c3f656dc1
Added and Engine congestion counter and call accept status override.
Send alarms when entering or exiting congestion state.
The Driver now refuses to route calls while engine is congested or rejecting calls.


git-svn-id: http://yate.null.ro/svn/yate/trunk@5703 acf43c95-373e-0410-b603-e72c3f656dc1
Retry taking the lock on CallEndpoint mutex keeping the Engine congested.
This should allow recovering from performance problems as new calls are blocked.


git-svn-id: http://yate.null.ro/svn/yate/trunk@5704 acf43c95-373e-0410-b603-e72c3f656dc1