The GQUEUE modules provides implementations of different queues and buffers.
The API reference of the GQUEUE module can be found here.
A pool of buffers can be allocated using
gfxBufferAlloc(num, size) where num is the number of buffers and size the size per buffer. The created buffer pool is global. It is not possible to have more than one buffer pool.
Memory once dedicated to become a buffer cannot be freed anymore. Therefore, the number and size of the buffers allocated should be chosen carefully.
gfxBufferGet() will return a pointer to a free buffer in the buffer pool (if any). The buffer is marked as used until it has been released using
Note that some modules like the GAUDIO module that take a buffer as a parameter usually release the buffer automatically.
gfxBufferGet() takes a timeout parameter, this function polls until either a free buffer is available or the timeout is exceeded. To avoid this,
gfxBufferIsAvailable() can be used to check if there is a free buffer before hand.
The GAUDIO play back demo shows how to use buffers.
Although the queues provided by the GQUEUE module are mainly used internally, these features are still accessible for the user. The user can use the queue by creating a struct and using gfxQueueASyncItem as the first struct member.
There are three types of queues available:
|ASync||Fully asynchronous queue. Queue operations do never block|
|GSync||Get synchronous queue. The put operations are still asynchronous.|
|FSync||Fully synchronous queue. Both, the put and the get operations are synchronous.|
Although there are three types of queues, the API is fully compatible between them. Only the function name changes (ASync, GSync, FSync).
The following queue operations are available:
Please refer to the API reference for further information.