Pragma Disable_Atomic_Synchronization (GNAT Reference Manual) (original) (raw)

2.50 Pragma Disable_Atomic_Synchronization ¶

Syntax:

pragma Disable_Atomic_Synchronization [(Entity)];

pragma Enable_Atomic_Synchronization [(Entity)];

Ada requires that accesses (reads or writes) of an atomic variable be regarded as synchronization points in the case of multiple tasks. Particularly in the case of multi-processors this may require special handling, e.g. the generation of memory barriers. This synchronization is performed by default, but can be turned off using pragmaDisable_Atomic_Synchronization. The Enable_Atomic_Synchronization pragma turns it back on.

The placement and scope rules for these pragmas are the same as those for pragma Suppress. In particular they can be used as configuration pragmas, or in a declaration sequence where they apply until the end of the scope. If an Entity argument is present, the action applies only to that entity.