System.AtomicDecrement
Delphi
function AtomicDecrement(var Target: Integer; Decrement: Integer): Integer; overload;
function AtomicDecrement(var Target: Int64; Decrement: Int64): Int64; overload;
Properties
Type | Visibility | Source | Unit | Parent |
---|---|---|---|---|
function | public | System.pas | System | System |
Description
Atomic intrinsic Decrement function for use with Delphi mobile compilers. Decrements the specified number (Target
) by the specified number (Decrement
) or 1 if the Decrement
parameter is not specified. Returns the new value of Target
.
Because the Delphi mobile compilers do not support a built-in assembler, the System unit provides four atomic intrinsic functions that provide a way to atomically exchange, compare and exchange, increment, and decrement memory values.
AtomicDecrement is used for decrementing memory values.
Atomic operations are used to:
- Implement multi-threaded locking primitives
- Provide the primitives necessary for implementing so-called "lock-free" structures