The following constants identify the standard Media Foundation work queues.
Applications should use MFASYNC_CALLBACK_QUEUE_MULTITHREADED or use a work queue obtained from MFLockSharedWorkQueue if they want to control the execution priority. Note that the default platform work queue priorities can dynamically change when an application calls MFRegisterPlatformWithMMCSS. For more information about work queues, see Work Queues.
| Constant/value | Description |
|---|---|
| MFASYNC_CALLBACK_QUEUE_STANDARD | In most cases, applications should use MFASYNC_CALLBACK_QUEUE_MULTITHREADED. This work queue is used for synchronous operations. Using the standard work queue may run the risk of deadlocking. Applications can create a private synchronous queue on top of the multithreaded queue by using MFAllocateSerialWorkQueue. |
| MFASYNC_CALLBACK_QUEUE_RT | Not for general application use. |
| MFASYNC_CALLBACK_QUEUE_IO | Not for general application use. This work queue is used internally for I/O operations such as reading files and reading from the network. |
| MFASYNC_CALLBACK_QUEUE_TIMER | Not for general application use. This work queue is used for periodic callbacks and scheduled work items. The following functions put work items in this queue:
|
| MFASYNC_CALLBACK_QUEUE_MULTITHREADED | This multithreaded work queue should be used in most cases. This work queue is used for asynchronous operations throughout Media Foundation. |
| MFASYNC_CALLBACK_QUEUE_LONG_FUNCTION | Not for general application use. Applications should instead use MFASYNC_CALLBACK_QUEUE_MULTITHREADED. |
In addition, the following constants are used in connection with work queues.
| Constant/value | Description |
|---|---|
| MFASYNC_CALLBACK_QUEUE_UNDEFINED | Undefined work queue. |
| MFASYNC_CALLBACK_QUEUE_PRIVATE_MASK | Bit mask to distinguish platform work queues from those created by calling MFAllocateWorkQueue (Desktop only). For a work queue created by MFAllocateWorkQueue (Desktop only), the following value is nonzero: (identifier & MFASYNC_CALLBACK_QUEUE_PRIVATE_MASK) |
| MFASYNC_CALLBACK_QUEUE_ALL | All platform work queues. |
Header: Declared in mfobjects.h (include mfidl.h).