We would like to offer the capability to have memory pool heap data
structures that are usable from user mode threads. The current
k_mem_pool implementation uses IRQ locking and system-wide membership
lists that make it incompatible with user mode constraints.
However, much of the existing memory pool code can be abstracted to some
common functions that are used by both k_mem_pool and the new
sys_mem_pool implementations.
The sys_mem_pool implementation has the following differences:
* The alloc/free APIs work directly with pointers, no internal memory
block structures are exposed to the end user. A pointer to the source
pool is provided for allocation, but freeing memory just requires the
pointer and nothing else.
* k_mem_pool uses IRQ locks and required very fine-grained locking in
order to not affect system latency. sys_mem_pools just use a semaphore
to protect the pool data structures at the API level, since there aren't
implications for system responsiveness with this kind of concurrency
control.
* sys_mem_pools do not support the notion of timeouts for requesting
memory.
* sys_mem_pools are specified at compile time with macros, just like
kernel memory pools. Alternative forms of specification at runtime
will be a later enhancement.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Andrew Boie