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#include "config.h"
#include <stdio.h>
#include <string.h>
/**
* antithread/alloc - memory allocator routines
*
* The alloc module implements a simple allocator which you can use to
* dynamically allocate space within a region of memory. This can be useful
* for suballocations within a given region, or a memory-mapped file.
*
* All metadata is kept within the memory handed to the allocator: you only
* need hand the pointer and the size of the memory to each call.
*
* The region contents is always in offsets, so it can be mapped in different
* places, but is not endian-safe.
*
* Example:
* #include <sys/mman.h>
* #include <unistd.h>
* #include <sys/types.h>
* #include <err.h>
* #include <sys/stat.h>
* #include <fcntl.h>
* #include <string.h>
* #include <stdlib.h>
* #include <ccan/antithread/alloc/alloc.h>
*
* static void usage(const char *name)
* {
* errx(1, "Usage: %s --create <mapfile>\n"
* " %s --check <mapfile>\n"
* " %s --alloc <mapfile>\n"
* " %s --free=<offset> <mapfile>\n", name, name, name, name);
* }
*
* // Create a memory mapped file, and allocate from within it
* int main(int argc, char *argv[])
* {
* void *a, *p;
* int fd;
* enum { CREATE, CHECK, ALLOC, FREE } cmd;
*
* if (argc != 3)
* usage(argv[0]);
*
* if (strcmp(argv[1], "--create") == 0)
* cmd = CREATE;
* else if (strcmp(argv[1], "--check") == 0)
* cmd = CHECK;
* else if (strcmp(argv[1], "--alloc") == 0)
* cmd = ALLOC;
* else if (strncmp(argv[1], "--free=", strlen("--free=")) == 0)
* cmd = FREE;
* else
* usage(argv[0]);
*
* if (cmd == CREATE) {
* fd = open(argv[2], O_RDWR|O_CREAT|O_EXCL, 0600);
* if (fd < 0)
* err(1, "Could not create %s", argv[2]);
* if (ftruncate(fd, 1048576) != 0)
* err(1, "Could not set length on %s", argv[2]);
* } else {
* fd = open(argv[2], O_RDWR);
* if (fd < 0)
* err(1, "Could not open %s", argv[2]);
* }
*
* a = mmap(NULL, 1048576, PROT_READ|PROT_WRITE, MAP_SHARED, fd,0);
* if (a == MAP_FAILED)
* err(1, "Could not map %s", argv[2]);
*
* switch (cmd) {
* case CREATE:
* alloc_init(a, 1048576);
* break;
* case CHECK:
* if (!alloc_check(a, 1048576))
* err(1, "Region is corrupt");
* break;
* case ALLOC:
* p = alloc_get(a, 1048576, 1024, 16);
* if (!p)
* errx(1, "Could not allocate");
* printf("%zu\n", (char *)p - (char *)a);
* break;
* case FREE:
* p = (char *)a + atol(argv[1] + strlen("--free="));
* alloc_free(a, 1048576, p);
* break;
* }
* return 0;
* }
*
* License: LGPL (v2.1 or any later version)
* Author: Rusty Russell <rusty@rustcorp.com.au>
*/
int main(int argc, char *argv[])
{
if (argc != 2)
return 1;
if (strcmp(argv[1], "depends") == 0) {
printf("ccan/alignof\n");
printf("ccan/build_assert\n");
printf("ccan/compiler\n");
printf("ccan/ilog\n");
printf("ccan/likely\n");
printf("ccan/short_types\n");
return 0;
}
return 1;
}
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