diff options
Diffstat (limited to 'src/malloc/malloc.c')
-rw-r--r-- | src/malloc/malloc.c | 548 |
1 files changed, 0 insertions, 548 deletions
diff --git a/src/malloc/malloc.c b/src/malloc/malloc.c deleted file mode 100644 index 96982596..00000000 --- a/src/malloc/malloc.c +++ /dev/null @@ -1,548 +0,0 @@ -#define _GNU_SOURCE -#include <stdlib.h> -#include <string.h> -#include <limits.h> -#include <stdint.h> -#include <errno.h> -#include <sys/mman.h> -#include "libc.h" -#include "atomic.h" -#include "pthread_impl.h" -#include "malloc_impl.h" - -#if defined(__GNUC__) && defined(__PIC__) -#define inline inline __attribute__((always_inline)) -#endif - -static struct { - volatile uint64_t binmap; - struct bin bins[64]; - volatile int free_lock[2]; -} mal; - -int __malloc_replaced; - -/* Synchronization tools */ - -static inline void lock(volatile int *lk) -{ - if (libc.threads_minus_1) - while(a_swap(lk, 1)) __wait(lk, lk+1, 1, 1); -} - -static inline void unlock(volatile int *lk) -{ - if (lk[0]) { - a_store(lk, 0); - if (lk[1]) __wake(lk, 1, 1); - } -} - -static inline void lock_bin(int i) -{ - lock(mal.bins[i].lock); - if (!mal.bins[i].head) - mal.bins[i].head = mal.bins[i].tail = BIN_TO_CHUNK(i); -} - -static inline void unlock_bin(int i) -{ - unlock(mal.bins[i].lock); -} - -static int first_set(uint64_t x) -{ -#if 1 - return a_ctz_64(x); -#else - static const char debruijn64[64] = { - 0, 1, 2, 53, 3, 7, 54, 27, 4, 38, 41, 8, 34, 55, 48, 28, - 62, 5, 39, 46, 44, 42, 22, 9, 24, 35, 59, 56, 49, 18, 29, 11, - 63, 52, 6, 26, 37, 40, 33, 47, 61, 45, 43, 21, 23, 58, 17, 10, - 51, 25, 36, 32, 60, 20, 57, 16, 50, 31, 19, 15, 30, 14, 13, 12 - }; - static const char debruijn32[32] = { - 0, 1, 23, 2, 29, 24, 19, 3, 30, 27, 25, 11, 20, 8, 4, 13, - 31, 22, 28, 18, 26, 10, 7, 12, 21, 17, 9, 6, 16, 5, 15, 14 - }; - if (sizeof(long) < 8) { - uint32_t y = x; - if (!y) { - y = x>>32; - return 32 + debruijn32[(y&-y)*0x076be629 >> 27]; - } - return debruijn32[(y&-y)*0x076be629 >> 27]; - } - return debruijn64[(x&-x)*0x022fdd63cc95386dull >> 58]; -#endif -} - -static const unsigned char bin_tab[60] = { - 32,33,34,35,36,36,37,37,38,38,39,39, - 40,40,40,40,41,41,41,41,42,42,42,42,43,43,43,43, - 44,44,44,44,44,44,44,44,45,45,45,45,45,45,45,45, - 46,46,46,46,46,46,46,46,47,47,47,47,47,47,47,47, -}; - -static int bin_index(size_t x) -{ - x = x / SIZE_ALIGN - 1; - if (x <= 32) return x; - if (x < 512) return bin_tab[x/8-4]; - if (x > 0x1c00) return 63; - return bin_tab[x/128-4] + 16; -} - -static int bin_index_up(size_t x) -{ - x = x / SIZE_ALIGN - 1; - if (x <= 32) return x; - x--; - if (x < 512) return bin_tab[x/8-4] + 1; - return bin_tab[x/128-4] + 17; -} - -#if 0 -void __dump_heap(int x) -{ - struct chunk *c; - int i; - for (c = (void *)mal.heap; CHUNK_SIZE(c); c = NEXT_CHUNK(c)) - fprintf(stderr, "base %p size %zu (%d) flags %d/%d\n", - c, CHUNK_SIZE(c), bin_index(CHUNK_SIZE(c)), - c->csize & 15, - NEXT_CHUNK(c)->psize & 15); - for (i=0; i<64; i++) { - if (mal.bins[i].head != BIN_TO_CHUNK(i) && mal.bins[i].head) { - fprintf(stderr, "bin %d: %p\n", i, mal.bins[i].head); - if (!(mal.binmap & 1ULL<<i)) - fprintf(stderr, "missing from binmap!\n"); - } else if (mal.binmap & 1ULL<<i) - fprintf(stderr, "binmap wrongly contains %d!\n", i); - } -} -#endif - -static struct chunk *expand_heap(size_t n) -{ - static int heap_lock[2]; - static void *end; - void *p; - struct chunk *w; - - /* The argument n already accounts for the caller's chunk - * overhead needs, but if the heap can't be extended in-place, - * we need room for an extra zero-sized sentinel chunk. */ - n += SIZE_ALIGN; - - lock(heap_lock); - - p = __expand_heap(&n); - if (!p) { - unlock(heap_lock); - return 0; - } - - /* If not just expanding existing space, we need to make a - * new sentinel chunk below the allocated space. */ - if (p != end) { - /* Valid/safe because of the prologue increment. */ - n -= SIZE_ALIGN; - p = (char *)p + SIZE_ALIGN; - w = MEM_TO_CHUNK(p); - w->psize = 0 | C_INUSE; - } - - /* Record new heap end and fill in footer. */ - end = (char *)p + n; - w = MEM_TO_CHUNK(end); - w->psize = n | C_INUSE; - w->csize = 0 | C_INUSE; - - /* Fill in header, which may be new or may be replacing a - * zero-size sentinel header at the old end-of-heap. */ - w = MEM_TO_CHUNK(p); - w->csize = n | C_INUSE; - - unlock(heap_lock); - - return w; -} - -static int adjust_size(size_t *n) -{ - /* Result of pointer difference must fit in ptrdiff_t. */ - if (*n-1 > PTRDIFF_MAX - SIZE_ALIGN - PAGE_SIZE) { - if (*n) { - errno = ENOMEM; - return -1; - } else { - *n = SIZE_ALIGN; - return 0; - } - } - *n = (*n + OVERHEAD + SIZE_ALIGN - 1) & SIZE_MASK; - return 0; -} - -static void unbin(struct chunk *c, int i) -{ - if (c->prev == c->next) - a_and_64(&mal.binmap, ~(1ULL<<i)); - c->prev->next = c->next; - c->next->prev = c->prev; - c->csize |= C_INUSE; - NEXT_CHUNK(c)->psize |= C_INUSE; -} - -static int alloc_fwd(struct chunk *c) -{ - int i; - size_t k; - while (!((k=c->csize) & C_INUSE)) { - i = bin_index(k); - lock_bin(i); - if (c->csize == k) { - unbin(c, i); - unlock_bin(i); - return 1; - } - unlock_bin(i); - } - return 0; -} - -static int alloc_rev(struct chunk *c) -{ - int i; - size_t k; - while (!((k=c->psize) & C_INUSE)) { - i = bin_index(k); - lock_bin(i); - if (c->psize == k) { - unbin(PREV_CHUNK(c), i); - unlock_bin(i); - return 1; - } - unlock_bin(i); - } - return 0; -} - - -/* pretrim - trims a chunk _prior_ to removing it from its bin. - * Must be called with i as the ideal bin for size n, j the bin - * for the _free_ chunk self, and bin j locked. */ -static int pretrim(struct chunk *self, size_t n, int i, int j) -{ - size_t n1; - struct chunk *next, *split; - - /* We cannot pretrim if it would require re-binning. */ - if (j < 40) return 0; - if (j < i+3) { - if (j != 63) return 0; - n1 = CHUNK_SIZE(self); - if (n1-n <= MMAP_THRESHOLD) return 0; - } else { - n1 = CHUNK_SIZE(self); - } - if (bin_index(n1-n) != j) return 0; - - next = NEXT_CHUNK(self); - split = (void *)((char *)self + n); - - split->prev = self->prev; - split->next = self->next; - split->prev->next = split; - split->next->prev = split; - split->psize = n | C_INUSE; - split->csize = n1-n; - next->psize = n1-n; - self->csize = n | C_INUSE; - return 1; -} - -static void trim(struct chunk *self, size_t n) -{ - size_t n1 = CHUNK_SIZE(self); - struct chunk *next, *split; - - if (n >= n1 - DONTCARE) return; - - next = NEXT_CHUNK(self); - split = (void *)((char *)self + n); - - split->psize = n | C_INUSE; - split->csize = n1-n | C_INUSE; - next->psize = n1-n | C_INUSE; - self->csize = n | C_INUSE; - - __bin_chunk(split); -} - -void *malloc(size_t n) -{ - struct chunk *c; - int i, j; - - if (adjust_size(&n) < 0) return 0; - - if (n > MMAP_THRESHOLD) { - size_t len = n + OVERHEAD + PAGE_SIZE - 1 & -PAGE_SIZE; - char *base = __mmap(0, len, PROT_READ|PROT_WRITE, - MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); - if (base == (void *)-1) return 0; - c = (void *)(base + SIZE_ALIGN - OVERHEAD); - c->csize = len - (SIZE_ALIGN - OVERHEAD); - c->psize = SIZE_ALIGN - OVERHEAD; - return CHUNK_TO_MEM(c); - } - - i = bin_index_up(n); - for (;;) { - uint64_t mask = mal.binmap & -(1ULL<<i); - if (!mask) { - c = expand_heap(n); - if (!c) return 0; - if (alloc_rev(c)) { - struct chunk *x = c; - c = PREV_CHUNK(c); - NEXT_CHUNK(x)->psize = c->csize = - x->csize + CHUNK_SIZE(c); - } - break; - } - j = first_set(mask); - lock_bin(j); - c = mal.bins[j].head; - if (c != BIN_TO_CHUNK(j)) { - if (!pretrim(c, n, i, j)) unbin(c, j); - unlock_bin(j); - break; - } - unlock_bin(j); - } - - /* Now patch up in case we over-allocated */ - trim(c, n); - - return CHUNK_TO_MEM(c); -} - -static size_t mal0_clear(char *p, size_t pagesz, size_t n) -{ -#ifdef __GNUC__ - typedef uint64_t __attribute__((__may_alias__)) T; -#else - typedef unsigned char T; -#endif - char *pp = p + n; - size_t i = (uintptr_t)pp & (pagesz - 1); - for (;;) { - pp = memset(pp - i, 0, i); - if (pp - p < pagesz) return pp - p; - for (i = pagesz; i; i -= 2*sizeof(T), pp -= 2*sizeof(T)) - if (((T *)pp)[-1] | ((T *)pp)[-2]) - break; - } -} - -void *calloc(size_t m, size_t n) -{ - if (n && m > (size_t)-1/n) { - errno = ENOMEM; - return 0; - } - n *= m; - void *p = malloc(n); - if (!p) return p; - if (!__malloc_replaced) { - if (IS_MMAPPED(MEM_TO_CHUNK(p))) - return p; - if (n >= PAGE_SIZE) - n = mal0_clear(p, PAGE_SIZE, n); - } - return memset(p, 0, n); -} - -void *realloc(void *p, size_t n) -{ - struct chunk *self, *next; - size_t n0, n1; - void *new; - - if (!p) return malloc(n); - - if (adjust_size(&n) < 0) return 0; - - self = MEM_TO_CHUNK(p); - n1 = n0 = CHUNK_SIZE(self); - - if (IS_MMAPPED(self)) { - size_t extra = self->psize; - char *base = (char *)self - extra; - size_t oldlen = n0 + extra; - size_t newlen = n + extra; - /* Crash on realloc of freed chunk */ - if (extra & 1) a_crash(); - if (newlen < PAGE_SIZE && (new = malloc(n-OVERHEAD))) { - n0 = n; - goto copy_free_ret; - } - newlen = (newlen + PAGE_SIZE-1) & -PAGE_SIZE; - if (oldlen == newlen) return p; - base = __mremap(base, oldlen, newlen, MREMAP_MAYMOVE); - if (base == (void *)-1) - goto copy_realloc; - self = (void *)(base + extra); - self->csize = newlen - extra; - return CHUNK_TO_MEM(self); - } - - next = NEXT_CHUNK(self); - - /* Crash on corrupted footer (likely from buffer overflow) */ - if (next->psize != self->csize) a_crash(); - - /* Merge adjacent chunks if we need more space. This is not - * a waste of time even if we fail to get enough space, because our - * subsequent call to free would otherwise have to do the merge. */ - if (n > n1 && alloc_fwd(next)) { - n1 += CHUNK_SIZE(next); - next = NEXT_CHUNK(next); - } - /* FIXME: find what's wrong here and reenable it..? */ - if (0 && n > n1 && alloc_rev(self)) { - self = PREV_CHUNK(self); - n1 += CHUNK_SIZE(self); - } - self->csize = n1 | C_INUSE; - next->psize = n1 | C_INUSE; - - /* If we got enough space, split off the excess and return */ - if (n <= n1) { - //memmove(CHUNK_TO_MEM(self), p, n0-OVERHEAD); - trim(self, n); - return CHUNK_TO_MEM(self); - } - -copy_realloc: - /* As a last resort, allocate a new chunk and copy to it. */ - new = malloc(n-OVERHEAD); - if (!new) return 0; -copy_free_ret: - memcpy(new, p, n0-OVERHEAD); - free(CHUNK_TO_MEM(self)); - return new; -} - -void __bin_chunk(struct chunk *self) -{ - struct chunk *next = NEXT_CHUNK(self); - size_t final_size, new_size, size; - int reclaim=0; - int i; - - final_size = new_size = CHUNK_SIZE(self); - - /* Crash on corrupted footer (likely from buffer overflow) */ - if (next->psize != self->csize) a_crash(); - - for (;;) { - if (self->psize & next->csize & C_INUSE) { - self->csize = final_size | C_INUSE; - next->psize = final_size | C_INUSE; - i = bin_index(final_size); - lock_bin(i); - lock(mal.free_lock); - if (self->psize & next->csize & C_INUSE) - break; - unlock(mal.free_lock); - unlock_bin(i); - } - - if (alloc_rev(self)) { - self = PREV_CHUNK(self); - size = CHUNK_SIZE(self); - final_size += size; - if (new_size+size > RECLAIM && (new_size+size^size) > size) - reclaim = 1; - } - - if (alloc_fwd(next)) { - size = CHUNK_SIZE(next); - final_size += size; - if (new_size+size > RECLAIM && (new_size+size^size) > size) - reclaim = 1; - next = NEXT_CHUNK(next); - } - } - - if (!(mal.binmap & 1ULL<<i)) - a_or_64(&mal.binmap, 1ULL<<i); - - self->csize = final_size; - next->psize = final_size; - unlock(mal.free_lock); - - self->next = BIN_TO_CHUNK(i); - self->prev = mal.bins[i].tail; - self->next->prev = self; - self->prev->next = self; - - /* Replace middle of large chunks with fresh zero pages */ - if (reclaim) { - uintptr_t a = (uintptr_t)self + SIZE_ALIGN+PAGE_SIZE-1 & -PAGE_SIZE; - uintptr_t b = (uintptr_t)next - SIZE_ALIGN & -PAGE_SIZE; -#if 1 - __madvise((void *)a, b-a, MADV_DONTNEED); -#else - __mmap((void *)a, b-a, PROT_READ|PROT_WRITE, - MAP_PRIVATE|MAP_ANONYMOUS|MAP_FIXED, -1, 0); -#endif - } - - unlock_bin(i); -} - -static void unmap_chunk(struct chunk *self) -{ - size_t extra = self->psize; - char *base = (char *)self - extra; - size_t len = CHUNK_SIZE(self) + extra; - /* Crash on double free */ - if (extra & 1) a_crash(); - __munmap(base, len); -} - -void free(void *p) -{ - if (!p) return; - - struct chunk *self = MEM_TO_CHUNK(p); - - if (IS_MMAPPED(self)) - unmap_chunk(self); - else - __bin_chunk(self); -} - -void __malloc_donate(char *start, char *end) -{ - size_t align_start_up = (SIZE_ALIGN-1) & (-(uintptr_t)start - OVERHEAD); - size_t align_end_down = (SIZE_ALIGN-1) & (uintptr_t)end; - - /* Getting past this condition ensures that the padding for alignment - * and header overhead will not overflow and will leave a nonzero - * multiple of SIZE_ALIGN bytes between start and end. */ - if (end - start <= OVERHEAD + align_start_up + align_end_down) - return; - start += align_start_up + OVERHEAD; - end -= align_end_down; - - struct chunk *c = MEM_TO_CHUNK(start), *n = MEM_TO_CHUNK(end); - c->psize = n->csize = C_INUSE; - c->csize = n->psize = C_INUSE | (end-start); - __bin_chunk(c); -} |