System.Generics.Collections.TThreadedQueue.PopItem
Delphi
function PopItem: T; overload;
function PopItem(var AQueueSize: Integer): T; overload;
function PopItem(var AQueueSize: Integer; var AItem: T): TWaitResult; overload;
function PopItem(var AItem: T): TWaitResult; overload;
C++
T __fastcall PopItem(void)/* overload */;
T __fastcall PopItem(int &AQueueSize)/* overload */;
System::Types::TWaitResult __fastcall PopItem(int &AQueueSize, T &AItem)/* overload */;
System::Types::TWaitResult __fastcall PopItem(T &AItem)/* overload */;
Properties
Type | Visibility | Source | Unit | Parent |
---|---|---|---|---|
function | public | System.Generics.Collections.pas System.Generics.Collections.hpp |
System.Generics.Collections | TThreadedQueue |
Description
Pops an item from the queue.
Use PushItem to pop an item from the queue according to the First In, First Out data management.
There are 4 overloaded PopItem methods:
- Without parameters -- this method returns the popped item.
- With a
AQueueSize
parameter -- this method also returns the popped item.
- With two parameters:
AQueueSize
andAItem
.AQueueSize
specifies the position of theAItem
item.
- With an
AItem
parameter.
The last two methods return a TWaitResult. If the queue is empty, then the monitor waits for it to push an element. If no element is pushed in PopTimeout, the method returns wrTimeout; otherwise, the method returns wrSignaled.
Use the last two methods when you need to know whether the pop was successfully completed.