mirror of /home/gitosis/repositories/libowfat.git
Mirror of :pserver:cvs@cvs.fefe.de:/cvs libowfat
https://www.fefe.de/libowfat/
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
52 lines
1.7 KiB
52 lines
1.7 KiB
/* this header file comes from libowfat, http://www.fefe.de/libowfat/ */
|
|
#ifndef IARRAY_H
|
|
#define IARRAY_H
|
|
|
|
/* This header defines an indirect array for use with the io_* routines.
|
|
* Assumptions:
|
|
* - the elements are small (many fit on one page),
|
|
* - the platform has an atomic compare-and-swap instruction
|
|
* - the compiler supports it via __sync_val_compare_and_swap
|
|
*/
|
|
|
|
#include <libowfat/uint64.h>
|
|
#include <stddef.h>
|
|
#ifdef _WIN32
|
|
#include <windows.h>
|
|
#else
|
|
#include <pthread.h>
|
|
#endif
|
|
|
|
/* The basic data structure is a static array of pointers to pages.
|
|
* Each page also contains a next pointer to form a linked list.
|
|
* To get to element n, you take n % the number of elements in the
|
|
* static array (iarray->pages) to get to the list of pages that
|
|
* contains it. Then keep going to the next page until you are on the
|
|
* right page.
|
|
* Note: The elements on each page are not contiguous. If the fanout is
|
|
* 16, the indices on page 0 are 0, 16, 32, ...
|
|
* To get to element 0, you'd go to iarray->pages[0].data,
|
|
* to get to element 1, you'd go to iarray->pages[1].data,
|
|
* to get to element 16, you'd go to iarray->pages[0].data+iarray->elemsize.
|
|
*/
|
|
typedef struct _iarray_page {
|
|
struct _iarray_page* next;
|
|
char data[];
|
|
} iarray_page;
|
|
|
|
typedef struct {
|
|
iarray_page* pages[16];
|
|
size_t elemsize,elemperpage,bytesperpage,len;
|
|
} iarray;
|
|
|
|
void iarray_init(iarray* ia,size_t elemsize);
|
|
void* iarray_get(iarray* ia,size_t pos);
|
|
void* iarray_allocate(iarray* ia,size_t pos);
|
|
size_t iarray_length(iarray* ia);
|
|
|
|
/* WARNING: do not use the array during or after iarray_free, make sure
|
|
* no threads are potentially doing anything with the iarray while it is
|
|
* being freed! */
|
|
void iarray_free(iarray* ia);
|
|
|
|
#endif
|
|
|