Add clarification to docs on ASYNC_free_pool()

ASYNC_init_pool(). If the user application is multi-threaded, then this should

ASYNC_init_pool(). If the user application is multi-threaded, then this should

be done for each thread that will initiate asynchronous jobs. Before user code

be done for each thread that will initiate asynchronous jobs. Before user code

exits it should free the pool up (for each thread where a pool was initialised)

exits it should free the pool up (for each thread where a pool was initialised)

using ASYNC_free_pool(). The B<max_size> argument limits the number of

using ASYNC_free_pool(). No asynchronous jobs must be outstanding for the thread

ASYNC_JOBs that will be held in the pool. If B<max_size> is set to 0 then no

when ASYNC_free_pool() is called. Failing to ensure this will result in memory

upper limit is set. When an ASYNC_JOB is needed but there are none available in

leaks.

the pool already then one will be automatically created, as long as the total

of ASYNC_JOBs managed by the pool does not exceed B<max_size>. When the pool is

The B<max_size> argument limits the number of ASYNC_JOBs that will be held in

first initialised B<init_size> ASYNC_JOBs will be created immediately. If

the pool. If B<max_size> is set to 0 then no upper limit is set. When an

ASYNC_init_pool() is not called before the pool is first used then it will be

ASYNC_JOB is needed but there are none available in the pool already then one

called automatically with a B<max_size> of 0 (no upper limit) and an

will be automatically created, as long as the total of ASYNC_JOBs managed by the

B<init_size> of 0 (no ASYNC_JOBs created up front). If a pool is created in this

pool does not exceed B<max_size>. When the pool is first initialised

way it must still be cleaned up with an explicit call to ASYNC_free_pool().

B<init_size> ASYNC_JOBs will be created immediately. If ASYNC_init_pool() is not

called before the pool is first used then it will be called automatically with a

B<max_size> of 0 (no upper limit) and an B<init_size> of 0 (no ASYNC_JOBs

created up front). If a pool is created in this way it must still be cleaned up

with an explicit call to ASYNC_free_pool().

An asynchronous job is started by calling the ASYNC_start_job() function.

An asynchronous job is started by calling the ASYNC_start_job() function.

Initially B<*job> should be NULL. B<ret> should point to a location where the

Initially B<*job> should be NULL. B<ret> should point to a location where the