Using the CPOOL macro

The cell pool macro (CPOOL) provides programs with another way of obtaining virtual storage. This macro provides centralized, high-performance cell management services.

What is a cell pool? A cell pool is a block of virtual storage that is divided into smaller, fixed-size blocks of storage, called cells. You specify the size of the cells. You then can request cells of storage from this cell pool as you need them. If the request for cells exceeds the storage available in the cell pool, you can increase the size of the cell pool.

The CPOOL macro allows you to:

Create a cell pool (BUILD), where all cells have the size you specify
Obtain a cell from a cell pool if storage is available (GET,COND)
Obtain a cell from a cell pool and extend the cell pool if storage is not available (GET,UNCOND)
Return a cell to the cell pool (FREE)
Free all storage for a cell pool (DELETE)
Place the starting and ending addresses of the cell pool extents in a buffer (LIST)

You can also create and manage cell pools by using callable cell pool services. These services offer advantages over using CPOOL in some cases. Callable cell pool services describes these services. Comparison of CPOOL macro and callable cell pool services can help you decide whether to use the callable cell pool services or the CPOOL macro.