#include <cyg/kernel/kapi.h>
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void cyg_mempool_var_create(void* base, cyg_uint32 size, cyg_handle_t* varpool, cyg_mempool_var* var);
void cyg_mempool_var_delete(cyg_handle_t varpool);
void* cyg_mempool_var_alloc(cyg_handle_t varpool, cyg_uint32 size);
void* cyg_mempool_var_timed_alloc(cyg_handle_t varpool, cyg_uint32 size, cyg_tick_count_t abstime);
void* cyg_mempool_var_try_alloc(cyg_handle_t varpool, cyg_uint32 size);
void cyg_mempool_var_free(cyg_handle_t varpool, void* p);
cyg_bool_t cyg_mempool_var_waiting(cyg_handle_t varpool);
void cyg_mempool_var_get_info(cyg_handle_t varpool, cyg_mempool_info* info);
The variable size memory pool functions are used for allocating
blocks of any size. Before memory can be allocated the pool must
first be created by calling
cyg_mempool_var_create(). The parameter
base is a point to the bottom of the
memory area to be used by the pool and
size is the size of the memory area in
bytes. It also takes a pointer to a
cyg_mempool_var data structure which is
typically statically allocated, and may be part of a larger data
structure. It should be noted that some memory is take from the
pool for book keeping purposes. If a memory pool is no longer
required and there are not threads waiting to allocate memory
from it, it can be destroyed with
cyg_mempool_var_delete().
Memory can be allocated from the pool using a number of
functions. They all take the
paramtersvarpoolwhich indicates which
pool should be used and the sizewhich
indicates who big a memory area should be
allocated. cyg_mempool_var_alloc() will
block until the memory becomes
available. cyg_mempool_tryalloc()will try
not block if no memory is available and will return
NULL. Otherwise a pointer to the allocated
memory will be returned.
cyg_mempool_var_timed_alloc() will block if
memory is not available and wait for memory to become available
until the timeabstime is reached. It will
then return NULL.
Allocated memory can be freed using the function cyg_mempool_var_free().
Lastly it is possible to query information about the pool using
the function
cyg_mempool_var_get_info(). This takes a
pointer to the structure cyg_mempool_info which is:
typedef struct {
cyg_int32 totalmem;
cyg_int32 freemem;
void *base;
cyg_int32 size;
cyg_int32 blocksize;
cyg_int32 maxfree;
} cyg_mempool_info;
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