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#define NO_ALLOCATOR 1 /* useful for debugging; valgrind checks writing past the end of a malloc, but that won't work with an allocator */
/* number of bytes a page hold, not including the header */
#define PAGE_BYTES (16384 - sizeof(Page))
#define PAGE_MAX_ALIGNS (PAGE_BYTES / sizeof(max_align_t))
static void allocr_create(Allocator *a) {
a->first = a->last = NULL;
}
static void *allocr_malloc(Allocator *a, size_t bytes) {
assert(bytes);
#if NO_ALLOCATOR
(void)a;
return err_malloc(bytes);
#else
/* position in this page to return */
size_t pos = PAGE_MAX_ALIGNS;
if (a->last)
pos = a->last->used;
size_t max_aligns = (bytes + sizeof(max_align_t) - 1) / sizeof(max_align_t);
if (pos + max_aligns > PAGE_MAX_ALIGNS) {
/* make a new page for this data */
Page *page = err_malloc(sizeof *page + (bytes > PAGE_BYTES ? bytes : PAGE_BYTES));
page->next = NULL;
page->used = max_aligns;
if (a->last)
a->last->next = page;
else
a->first = page;
a->last = page;
return page->data;
} else {
a->last->used += max_aligns;
return &a->last->data[pos];
}
#endif
}
static void *allocr_calloc(Allocator *a, size_t n, size_t sz) {
#if NO_ALLOCATOR
(void)a;
return err_calloc(n, sz);
#else
/* OPTIM: use calloc */
size_t bytes = n * sz;
void *data = allocr_malloc(a, bytes);
memset(data, 0, bytes);
return data;
#endif
}
/* OPTIM */
static void *allocr_realloc(Allocator *a, void *data, size_t old_size, size_t new_size) {
#if NO_ALLOCATOR
(void)a;
(void)old_size;
return err_realloc(data, new_size);
#else
void *ret = allocr_malloc(a, new_size);
memcpy(ret, data, old_size);
return ret;
#endif
}
static void allocr_free_all(Allocator *a) {
for (Page *page = a->first; page;) {
Page *next = page->next;
free(page);
page = next;
}
}
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