doc: Edit microkernel_memory_pools.rst for consistency in structure.

Much of this doc is comparable to memory_maps, so edits make the overall
language and structure consistent among files. Added heading syntax to
APIs, make imperative verbs on API notes, as discussed in code reviews and
on previous edits.

Change-Id: I8e14b44007acdf5422d75810dde78aef1a9c653a
Signed-off-by: L.S. Cook <leonax.cook@intel.com>

doc/kernel/microkernel/microkernel_memory_pools.rst

@@ -6,64 +6,62 @@ Memory Pools
 Concepts
 ********
 
-The microkernel's memory pool objects provide dynamic allocation and
+The microkernel's :dfn:`memory pool` objects provide dynamic allocation and
 release of variable-size memory blocks.
 
-Unlike a memory map, which only supports memory blocks of a single size,
-a memory pool has the ability to support multiple memory block sizes.
-It does this by subdividing blocks into smaller chunks whenever possible
-to more closely match the actual needs of the requesting task.
+Unlike :ref:`memory map <microkernel_memory_map>` objects, which support
+memory blocks of only a *single* size, a memory pool can support memory blocks
+of *various* sizes. The memory pool does this by subdividing blocks into smaller
+chunks, where possible, to more closely match the actual needs of a requesting
+task.
 
-Any number of memory pools can be defined in a microkernel system.
-Each memory pool has a name that uniquely identifies it.
-In addition, a memory pool defines minimum and maximum memory block sizes
-in bytes and the number of maximum size blocks that the memory pool
-contains.
+Any number of memory pools can be defined in a microkernel system. Each memory
+pool has:
 
-A task that needs to use a memory block simply allocates it from a
-memory pool. If a block of the desired size is unavailable, the task
-may choose to wait for one to become available. Following a successful
-allocation the :c:data:`pointer_to_data` field of the block descriptor
-supplied by the task indicates the starting address of the memory block.
-When the task is finished with a memory block, it must release the block
-back to the memory pool that allocated it so that the block can be
-reused.
+* A **name** that uniquely identifies it.
+* A **minimum** and **maximum** block size, in bytes, of memory blocks
+  within the pool.
+* The **number of maximum-size memory blocks** initially available.
 
-Any number of tasks may wait on a memory pool simultaneously;
-when a memory block becomes available it is given to the highest
-priority task that has waited the longest.
+A task that needs to use a memory block simply allocates it from a memory
+pool. When a block of the desired size is unavailable, the task can wait
+for one to become available. Following a successful allocation, the
+:c:data:`pointer_to_data` field of the block descriptor supplied by the
+task indicates the starting address of the memory block. When the task is
+finished with a memory block, it must release the block back to the memory
+pool that allocated it so that the block can be reused.
+
+Any number of tasks can wait on a memory pool simultaneously; when a
+memory block becomes available, it is given to the highest-priority task
+that has waited the longest.
 
 When a request for memory is sufficiently smaller than an available
-memory pool block, the memory pool will automatically split the
-block into 4 smaller blocks. The resulting smaller
-blocks can also be split repeatedly, until a block just larger
-than the needed size is available, or the minimum block size,
-as specified in the MDEF, is reached.
+memory pool block, the memory pool will automatically split the block into
+4 smaller blocks. The resulting smaller blocks can also be split repeatedly,
+until a block just larger than the needed size is available, or the minimum
+block size, as specified in the MDEF, is reached.
 
-If the memory pool is unable to find an available block
-that is at least the requested size, it will attempt to create
-one by merging adjacent free blocks; if it is unable to create
-a suitable block the request fails.
+If the memory pool cannot find an available block that is at least
+the requested size, it will attempt to create one by merging adjacent
+free blocks. If a suitable block can't be created, the request fails.
 
-Although a memory pool uses efficient algorithms to manage its
-blocks, splitting available blocks and merging free blocks
-takes time and increases the overhead involved in allocating
-a block. The larger the allowable number of splits, the larger
-the overhead. The minimum and maximum block size parameters
-specified for a pool can be used to control the amount of
-splitting, and thus the amount of overhead.
+Although a memory pool uses efficient algorithms to manage its blocks,
+the splitting of available blocks and merging of free blocks takes time
+and increases overhead block allocation. The larger the allowable
+number of splits, the larger the overhead. However, the minimum and maximum
+block-size parameters specified for a pool can be used to control the amount
+of splitting, and thus the amount of overhead.
 
-Unlike a heap, more than one memory pool can be defined, if
-needed. For example, different applications can utilize
-different memory pools so that one application does not
-allocate all of the available blocks.
+Unlike a heap, more than one memory pool can be defined, if needed. For
+example, different applications can utilize different memory pools; this
+can help prevent one application from hijacking resources to allocate all
+of the available blocks.
 
 Purpose
 *******
 Use memory pools to allocate memory in variable-size blocks.
 
-Use memory pool blocks when sending data to a mailbox
-asynchronously.
+Use memory pool blocks when sending data to a mailbox asynchronously.
 
 Usage
 *****
@@ -77,7 +75,7 @@ The following parameters must be defined:
           This specifies a unique name for the memory pool.
 
    *min_block_size*
-          This specifies the minimimum memory block size in bytes.
+          This specifies the minimum memory block size in bytes.
           It should be a multiple of the processor's word size.
 
    *max_block_size*
@@ -92,7 +90,7 @@ The following parameters must be defined:
 Public Memory Pool
 ------------------
 
-Define the memory pool in the application's MDEF using the following
+Define the memory pool in the application's MDEF with the following
 syntax:
 
 .. code-block:: console
@@ -146,7 +144,7 @@ in that time.
       printf('Memory allocation timeout');
   }
 
-Example: Requesting a Memory Block from a Pool with a No Blocking Condition
+Example: Requesting a Memory Block from a Pool with a No-Blocking Condition
 ===========================================================================
 
 This code gives an immediate warning when it can not satisfy the request for
@@ -180,9 +178,9 @@ Example: Manually Defragmenting a Memory Pool
 
 This code instructs the memory pool to concatenate any unused memory blocks
 that can be merged. Doing a full defragmentation of the entire memory pool
-before allocating a number of memory blocks may be more efficient
-than having to do an implicit partial defragmentation of the memory pool
-each time a memory block allocation occurs.
+before allocating a number of memory blocks may be more efficient than doing
+an implicit partial defragmentation of the memory pool each time a memory
+block allocation occurs.
 
 .. code-block:: c
 
@@ -191,14 +189,15 @@ each time a memory block allocation occurs.
 APIs
 ****
 
-The following Memory Pools APIs are provided by :file:`microkernel.h`:
+Memory Pools APIs provided by :file:`microkernel.h`
+===================================================
 
 :cpp:func:`task_mem_pool_alloc()`
-   Waits for a block of memory for the time period defined by the time-out
+   Wait for a block of memory; wait the period of time defined by the time-out
    parameter.
 
 :cpp:func:`task_mem_pool_free()`
-   Returns a block of memory to a memory pool.
+   Return a block of memory to a memory pool.
 
 :cpp:func:`task_mem_pool_defragment()`
-   Defragments a memory pool.
+   Defragment a memory pool.