XAsyncOp

Represents an operation code for an asynchronous provider.

Syntax

enum class XAsyncOp  : uint32_t  
{  
    Begin,  
    DoWork,  
    GetResult,  
    Cancel,  
    Cleanup  
}  

Constants

Constant	Description
Begin	The asynchronous provider is invoked with this operation code when XAsyncBegin is invoked. If this operation code is implemented, the asynchronous provider should start their asynchronous work, by either calling XAsyncSchedule or starting an external asynchronous process such as overlapped I/O. NOTE Asynchronous work performed for this operation code must not block the thread.
DoWork	The asynchronous provider is invoked with this operation code when XAsyncSchedule has been called to schedule work. If this operation code is implemented, the asynchronous provider should perform their asynchronous work and then call XAsyncComplete, specifying the data payload size in requiredBufferSize. If additional work needs to be done the asynchronous provider can schedule it and then call XAsyncComplete, specifying the error code E_PENDING in result.
GetResult	The asynchronous provider is invoked with this operation code after an asynchronous call completes and the user needs to get the resulting data payload. The values for the buffer and bufferSize fields of XAsyncProviderData have been validated.
Cancel	The asynchronous provider is invoked with this operation code when the asynchronous work should be canceled. The asynchronous provider should cancel all asynchronous work and then call XAsyncComplete, specifying the error code E_ABORT in result.
Cleanup	The asynchronous provider is invoked with this operation code when the asynchronous call is either completed or canceled and data in the context can be cleaned up.

Remarks

The XAsyncProvider callback function for an asynchronous provider is called repeatedly, and what that asynchronous provider should do for each call is determined by the operation code specified for each call. XAsyncOp represents the operation codes that can be implemented by an asynchronous provider.
An asynchronous provider should implement only those operation codes from XAsyncOp needed to perform asynchronous work. For example, an asynchronous provider that performs non-cancelable asynchronous I/O work which doesn't require cleanup only needs to implement XAsyncOp::GetResult.

For an example of an asynchronous provider that implements the DoWork, GetResult, and Cleanup operation codes from XAsyncOp, see the "Async Library" section in Asynchronous Programming Model.

Requirements

Header: XAsyncProvider.h

Supported platforms: Windows, Xbox One family consoles and Xbox Series consoles

See also

XAsyncProviderData
XAsyncProvider Members
Asynchronous Programming Model