[fusl] clang-format fusl

fusl/src/malloc/malloc.c

 #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"
 
 #if defined(__GNUC__) && defined(__PIC__)
 #define inline inline __attribute__((always_inline))
 #endif
 
-void *__mmap(void *, size_t, int, int, int, off_t);
-int __munmap(void *, size_t);
-void *__mremap(void *, size_t, size_t, int, ...);
-int __madvise(void *, size_t, int);
+void* __mmap(void*, size_t, int, int, int, off_t);
+int __munmap(void*, size_t);
+void* __mremap(void*, size_t, size_t, int, ...);
+int __madvise(void*, size_t, int);
 
 struct chunk {
-        size_t psize, csize;
-        struct chunk *next, *prev;
+  size_t psize, csize;
+  struct chunk *next, *prev;
 };
 
 struct bin {
-        volatile int lock[2];
-        struct chunk *head;
-        struct chunk *tail;
+  volatile int lock[2];
+  struct chunk* head;
+  struct chunk* tail;
 };
 
 static struct {
-        volatile uint64_t binmap;
-        struct bin bins[64];
-        volatile int free_lock[2];
+  volatile uint64_t binmap;
+  struct bin bins[64];
+  volatile int free_lock[2];
 } mal;
 
-
-#define SIZE_ALIGN (4*sizeof(size_t))
+#define SIZE_ALIGN (4 * sizeof(size_t))
 #define SIZE_MASK (-SIZE_ALIGN)
-#define OVERHEAD (2*sizeof(size_t))
-#define MMAP_THRESHOLD (0x1c00*SIZE_ALIGN)
+#define OVERHEAD (2 * sizeof(size_t))
+#define MMAP_THRESHOLD (0x1c00 * SIZE_ALIGN)
 #define DONTCARE 16
 #define RECLAIM 163840
 
 #define CHUNK_SIZE(c) ((c)->csize & -2)
 #define CHUNK_PSIZE(c) ((c)->psize & -2)
-#define PREV_CHUNK(c) ((struct chunk *)((char *)(c) - CHUNK_PSIZE(c)))
-#define NEXT_CHUNK(c) ((struct chunk *)((char *)(c) + CHUNK_SIZE(c)))
-#define MEM_TO_CHUNK(p) (struct chunk *)((char *)(p) - OVERHEAD)
-#define CHUNK_TO_MEM(c) (void *)((char *)(c) + OVERHEAD)
+#define PREV_CHUNK(c) ((struct chunk*)((char*)(c)-CHUNK_PSIZE(c)))
+#define NEXT_CHUNK(c) ((struct chunk*)((char*)(c) + CHUNK_SIZE(c)))
+#define MEM_TO_CHUNK(p) (struct chunk*)((char*)(p)-OVERHEAD)
+#define CHUNK_TO_MEM(c) (void*)((char*)(c) + OVERHEAD)
 #define BIN_TO_CHUNK(i) (MEM_TO_CHUNK(&mal.bins[i].head))
 
-#define C_INUSE  ((size_t)1)
+#define C_INUSE ((size_t)1)
 
 #define IS_MMAPPED(c) !((c)->csize & (C_INUSE))
 
-
 /* 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 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 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 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 inline void unlock_bin(int i) {
+  unlock(mal.bins[i].lock);
 }
 
-static int first_set(uint64_t x)
-{
+static int first_set(uint64_t x) {
 #if 1
-        return a_ctz_64(x);
+  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];
+  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 int bin_index(size_t x)
-{
-        x = x / SIZE_ALIGN - 1;
-        if (x <= 32) return x;
-        if (x > 0x1c00) return 63;
-        return ((union { float v; uint32_t r; }){(int)x}.r>>21) - 496;
+static int bin_index(size_t x) {
+  x = x / SIZE_ALIGN - 1;
+  if (x <= 32)
+    return x;
+  if (x > 0x1c00)
+    return 63;
+  return ((union {
+            float v;
+            uint32_t r;
+          }){(int)x}
+              .r >>
+          21) -
+         496;
 }
 
-static int bin_index_up(size_t x)
-{
-        x = x / SIZE_ALIGN - 1;
-        if (x <= 32) return x;
-        return (((union { float v; uint32_t r; }){(int)x}.r+0x1fffff)>>21) - 496;
+static int bin_index_up(size_t x) {
+  x = x / SIZE_ALIGN - 1;
+  if (x <= 32)
+    return x;
+  return (((union {
+             float v;
+             uint32_t r;
+           }){(int)x}
+               .r +
+           0x1fffff) >>
+          21) -
+         496;
 }
 
 #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
 
-void *__expand_heap(size_t *);
-
-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;
-}
-
+void* __expand_heap(size_t*);
+
+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;
-
-        free(CHUNK_TO_MEM(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);
-}
-
-void *__malloc0(size_t n)
-{
-        void *p = malloc(n);
-        if (p && !IS_MMAPPED(MEM_TO_CHUNK(p))) {
-                size_t *z;
-                n = (n + sizeof *z - 1)/sizeof *z;
-                for (z=p; n; n--, z++) if (*z) *z=0;
-        }
-        return p;
-}
-
-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))) {
-                        memcpy(new, p, n-OVERHEAD);
-                        free(p);
-                        return new;
-                }
-                newlen = (newlen + PAGE_SIZE-1) & -PAGE_SIZE;
-                if (oldlen == newlen) return p;
-                base = __mremap(base, oldlen, newlen, MREMAP_MAYMOVE);
-                if (base == (void *)-1)
-                        return newlen < oldlen ? p : 0;
-                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);
-        }
-
-        /* As a last resort, allocate a new chunk and copy to it. */
-        new = malloc(n-OVERHEAD);
-        if (!new) return 0;
-        memcpy(new, p, n0-OVERHEAD);
-        free(CHUNK_TO_MEM(self));
-        return new;
-}
-
-void free(void *p)
-{
-        struct chunk *self = MEM_TO_CHUNK(p);
-        struct chunk *next;
-        size_t final_size, new_size, size;
-        int reclaim=0;
-        int i;
-
-        if (!p) return;
-
-        if (IS_MMAPPED(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);
-                return;
-        }
-
-        final_size = new_size = CHUNK_SIZE(self);
-        next = NEXT_CHUNK(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;
+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;
+
+  free(CHUNK_TO_MEM(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);
+}
+
+void* __malloc0(size_t n) {
+  void* p = malloc(n);
+  if (p && !IS_MMAPPED(MEM_TO_CHUNK(p))) {
+    size_t* z;
+    n = (n + sizeof *z - 1) / sizeof *z;
+    for (z = p; n; n--, z++)
+      if (*z)
+        *z = 0;
+  }
+  return p;
+}
+
+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))) {
+      memcpy(new, p, n - OVERHEAD);
+      free(p);
+      return new;
+    }
+    newlen = (newlen + PAGE_SIZE - 1) & -PAGE_SIZE;
+    if (oldlen == newlen)
+      return p;
+    base = __mremap(base, oldlen, newlen, MREMAP_MAYMOVE);
+    if (base == (void*)-1)
+      return newlen < oldlen ? p : 0;
+    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);
+  }
+
+  /* As a last resort, allocate a new chunk and copy to it. */
+  new = malloc(n - OVERHEAD);
+  if (!new)
+    return 0;
+  memcpy(new, p, n0 - OVERHEAD);
+  free(CHUNK_TO_MEM(self));
+  return new;
+}
+
+void free(void* p) {
+  struct chunk* self = MEM_TO_CHUNK(p);
+  struct chunk* next;
+  size_t final_size, new_size, size;
+  int reclaim = 0;
+  int i;
+
+  if (!p)
+    return;
+
+  if (IS_MMAPPED(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);
+    return;
+  }
+
+  final_size = new_size = CHUNK_SIZE(self);
+  next = NEXT_CHUNK(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);
+    __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);
+    __mmap((void*)a, b - a, PROT_READ | PROT_WRITE,
+           MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
 #endif
-        }
-
-        unlock_bin(i);
-}
+  }
+
+  unlock_bin(i);
+}