Common Layer Characteristics (Windows Embedded CE 6.0)
1/6/2010
Internally, every layer maintains a list of object owners or contexts, which are defined as clients of the stack. Their activity leads to the creation of a particular object. Associated with this context is a table of events and callbacks used to route an up-call, filters for incoming connections, and other information.
Every layer maintains a list of calls or tasks that are data structures describing actions that are currently pending in the system. These structures serve as call contexts for lower layers. For example, when an L2CAP connection is being created, the L2CAP layer creates a context that describes establishing a baseband connection to a peer Bluetooth device and calls the HCI connection creation function to request that a connection be created. When the function completes or aborts, this context is passed back to the L2CAP as a context. The system matches this context to the list of existing contexts to ensure integrity. It sees the connection has been created, retires that context, and creates another one that describes the creation of a logical connection, which is then passed down as context for a write request for a signaling package.
The following topics discuss common layer characteristics in more detail:
- Internal Representation for Bluetooth Address
- Shared Thread Pool
- Memory Utilization
- IO Control and Other Common Stack Functions
- Sharing Responsibilities
- Debug/Auxiliary