#include <sys/types.h>
#include <inttypes.h>
-enum pa_memblock_type { PA_MEMBLOCK_FIXED, PA_MEMBLOCK_APPENDED, PA_MEMBLOCK_DYNAMIC, PA_MEMBLOCK_USER };
+/* A pa_memblock is a reference counted memory block. Polypaudio
+ * passed references to pa_memblocks around instead of copying
+ * data. See pa_memchunk for a structure that describes parts of
+ * memory blocks. */
+/* The type of memory this block points to */
+enum pa_memblock_type {
+ PA_MEMBLOCK_FIXED, /* data is a pointer to fixed memory that needs not to be freed */
+ PA_MEMBLOCK_APPENDED, /* The most common kind: the data is appended to the memory block */
+ PA_MEMBLOCK_DYNAMIC, /* data is a pointer to some memory allocated with pa_xmalloc() */
+ PA_MEMBLOCK_USER /* User supplied memory, to be freed with free_cb */
+};
+
+/* A structure of keeping memory block statistics */
struct pa_memblock_stat;
struct pa_memblock {
enum pa_memblock_type type;
- unsigned ref;
- int read_only;
+ unsigned ref; /* the reference counter */
+ int read_only; /* boolean */
size_t length;
void *data;
- void (*free_cb)(void *p);
+ void (*free_cb)(void *p); /* If type == PA_MEMBLOCK_USER this points to a function for freeing this memory block */
struct pa_memblock_stat *stat;
};
+/* Allocate a new memory block of type PA_MEMBLOCK_APPENDED */
struct pa_memblock *pa_memblock_new(size_t length, struct pa_memblock_stat*s);
+
+/* Allocate a new memory block of type PA_MEMBLOCK_DYNAMIC. The pointer data is to be maintained be the memory block */
struct pa_memblock *pa_memblock_new_dynamic(void *data, size_t length, struct pa_memblock_stat*s);
+
+/* Allocate a new memory block of type PA_MEMBLOCK_FIXED */
struct pa_memblock *pa_memblock_new_fixed(void *data, size_t length, int read_only, struct pa_memblock_stat*s);
+
+/* Allocate a new memory block of type PA_MEMBLOCK_USER */
struct pa_memblock *pa_memblock_new_user(void *data, size_t length, void (*free_cb)(void *p), int read_only, struct pa_memblock_stat*s);
void pa_memblock_unref(struct pa_memblock*b);
struct pa_memblock* pa_memblock_ref(struct pa_memblock*b);
+/* This special unref function has to be called by the owner of the
+memory of a static memory block when he wants to release all
+references to the memory. This causes the memory to be copied and
+converted into a PA_MEMBLOCK_DYNAMIC type memory block */
void pa_memblock_unref_fixed(struct pa_memblock*b);
+/* Matinatins statistics about memory blocks */
struct pa_memblock_stat {
int ref;
unsigned total;