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# Common Mode Flag

A run loop pseudo-mode that manages objects monitored in the “common” modes.

## Discussion

Run loops never run in this mode. This pseudo-mode is used only as a special set of sources, timers, and observers that is shared by other modes. See Managing Observers for more details.

## Topics

### Constants

[`static let commonModes: CFRunLoopMode!`](/documentation/CoreFoundation/CFRunLoopMode/commonModes)

Objects added to a run loop using this value as the mode are monitored by all run loop modes that have been declared as a member of the set of “common” modes with [`CFRunLoopAddCommonMode(_:_:)`](/documentation/CoreFoundation/CFRunLoopAddCommonMode(_:_:)).


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