Buffer States

At this time, Buffer states are defined for purposes of discussion. The states described in this section are not exposed through the API (can not be queried, or be set directly), and the state description used in the implementation might differ from this.

A Buffer is considered to be in one of the following States, with respect to all Sources:

• UNUSED: the Buffer is no included in any queue for any Source. In particular, the Buffer is neither pending nor current for any Source. The Buffer name can be deleted at this time.

• PROCESSED: the Buffer is listed in the queue of at least one Source, but is neither pending nor current for any Source. The Buffer can be deleted as soon as it has been unqueued for all Sources it is queued with.

• PENDING: there is at least one Source for which the Buffer has been queued, for which the Buffer data has not yet been dereferenced. The Buffer can only be unqueued for those Sources which have dereferenced the data in the Buffer in its entirety, and can not be deleted or changed.

The Buffer state is dependent on the state of all Sources that is has been queued for. A single queue occurrence of a Buffer propagates the Buffer state (over all Sources) from UNUSED to PROCESSED or higher. Sources that are STOPPED or INITIAL still have queue entries that cause Buffers to be PROCESSED.

A single queue entry with a single Source for which the Buffer is not yet PROCESSED propagates the buffer's queueing state to PENDING.

Buffers that are PROCESSED for a given Source can be unqueued from that Source's queue. Buffers that have been unqueued from all Sources are UNUSED. Buffers that are UNUSED can be deleted, or changed by BufferData commands.