add heap walk test

include/mimalloc.h

@@ -256,6 +256,7 @@ typedef struct mi_heap_area_s {
   size_t committed;   // current available bytes for this area
   size_t used;        // number of allocated blocks
   size_t block_size;  // size in bytes of each block
+  size_t full_block_size; // size in bytes of a full block including padding and metadata.
 } mi_heap_area_t;
 
 typedef bool (mi_cdecl mi_block_visit_fun)(const mi_heap_t* heap, const mi_heap_area_t* area, void* block, size_t block_size, void* arg);

src/heap.c

@@ -470,13 +470,14 @@ static bool mi_heap_area_visit_blocks(const mi_heap_area_ex_t* xarea, mi_block_v
   if (page->used == 0) return true;
 
   const size_t bsize = mi_page_block_size(page);
+  const size_t ubsize = mi_page_usable_block_size(page); // without padding
   size_t   psize;
   uint8_t* pstart = _mi_page_start(_mi_page_segment(page), page, &psize);
 
   if (page->capacity == 1) {
     // optimize page with one block
     mi_assert_internal(page->used == 1 && page->free == NULL);
-    return visitor(mi_page_heap(page), area, pstart, bsize, arg);
+    return visitor(mi_page_heap(page), area, pstart, ubsize, arg);
   }
 
   // create a bitmap of free blocks.
@@ -510,7 +511,7 @@ static bool mi_heap_area_visit_blocks(const mi_heap_area_ex_t* xarea, mi_block_v
     else if ((m & ((uintptr_t)1 << bit)) == 0) {
       used_count++;
       uint8_t* block = pstart + (i * bsize);
-      if (!visitor(mi_page_heap(page), area, block, bsize, arg)) return false;
+      if (!visitor(mi_page_heap(page), area, block, ubsize, arg)) return false;
     }
   }
   mi_assert_internal(page->used == used_count);
@@ -526,12 +527,14 @@ static bool mi_heap_visit_areas_page(mi_heap_t* heap, mi_page_queue_t* pq, mi_pa
   mi_heap_area_visit_fun* fun = (mi_heap_area_visit_fun*)vfun;
   mi_heap_area_ex_t xarea;
   const size_t bsize = mi_page_block_size(page);
+  const size_t ubsize = mi_page_usable_block_size(page);
   xarea.page = page;
   xarea.area.reserved = page->reserved * bsize;
   xarea.area.committed = page->capacity * bsize;
   xarea.area.blocks = _mi_page_start(_mi_page_segment(page), page, NULL);
   xarea.area.used = page->used * bsize;
-  xarea.area.block_size = bsize;
+  xarea.area.block_size = ubsize;
+  xarea.area.full_block_size = bsize;
   return fun(heap, &xarea, arg);
 }
 

test/main-override-static.c

@@ -16,6 +16,9 @@ static void test_aslr(void);
 static void test_process_info(void);
 static void test_reserved(void);
 static void negative_stat(void);
+static void alloc_huge(void);
+static void test_heap_walk(void);
+
 
 int main() {
   mi_version();
@@ -29,6 +32,8 @@ int main() {
   // invalid_free();
   // test_reserved();
   // negative_stat();
+  test_heap_walk();
+  // alloc_huge();
   
   void* p1 = malloc(78);
   void* p2 = malloc(24);
@@ -48,8 +53,10 @@ int main() {
   //free(p1);
   //p2 = malloc(32);
   //mi_free(p2);
-  mi_collect(true);
+  
-  mi_stats_print(NULL);
+  //mi_collect(true);
+  //mi_stats_print(NULL);
+  
   // test_process_info();
   return 0;
 }
@@ -179,4 +186,196 @@ static void negative_stat(void) {
   *p = 100;
   mi_free(p);
   mi_stats_print_out(NULL, NULL);  
-}
+}
+
+static void alloc_huge(void) {
+  void* p = mi_malloc(67108872);
+  mi_free(p);
+}
+
+static bool test_visit(const mi_heap_t* heap, const mi_heap_area_t* area, void* block, size_t block_size, void* arg) {
+  printf("I'm visiting a block of size %zu, allocated size %zu\n", block_size, mi_usable_size(block));
+  return true;
+}
+
+static void test_heap_walk(void) {
+  mi_heap_t* heap = mi_heap_new();
+  //mi_heap_malloc(heap, 2097152);
+  mi_heap_malloc(heap, 2067152);
+  mi_heap_malloc(heap, 2097160);
+  mi_heap_malloc(heap, 24576);
+  mi_heap_visit_blocks(heap, true, &test_visit, NULL);
+}
+
+// ----------------------------
+// bin size experiments
+// ------------------------------
+
+#if 0
+#include <stdint.h>
+#include <stdbool.h>
+
+#define MI_INTPTR_SIZE 8
+#define MI_LARGE_WSIZE_MAX (4*1024*1024 / MI_INTPTR_SIZE)
+
+#define MI_BIN_HUGE 100
+//#define MI_ALIGN2W
+
+// Bit scan reverse: return the index of the highest bit.
+static inline uint8_t mi_bsr32(uint32_t x);
+
+#if defined(_MSC_VER)
+#include <windows.h>
+#include <intrin.h>
+static inline uint8_t mi_bsr32(uint32_t x) {
+  uint32_t idx;
+  _BitScanReverse((DWORD*)&idx, x);
+  return idx;
+}
+#elif defined(__GNUC__) || defined(__clang__)
+static inline uint8_t mi_bsr32(uint32_t x) {
+  return (31 - __builtin_clz(x));
+}
+#else
+static inline uint8_t mi_bsr32(uint32_t x) {
+  // de Bruijn multiplication, see <http://supertech.csail.mit.edu/papers/debruijn.pdf>
+  static const uint8_t debruijn[32] = {
+     31,  0, 22,  1, 28, 23, 18,  2, 29, 26, 24, 10, 19,  7,  3, 12,
+     30, 21, 27, 17, 25,  9,  6, 11, 20, 16,  8,  5, 15,  4, 14, 13,
+  };
+  x |= x >> 1;
+  x |= x >> 2;
+  x |= x >> 4;
+  x |= x >> 8;
+  x |= x >> 16;
+  x++;
+  return debruijn[(x*0x076be629) >> 27];
+}
+#endif
+
+/*
+// Bit scan reverse: return the index of the highest bit.
+uint8_t _mi_bsr(uintptr_t x) {
+  if (x == 0) return 0;
+  #if MI_INTPTR_SIZE==8
+  uint32_t hi = (x >> 32);
+  return (hi == 0 ? mi_bsr32((uint32_t)x) : 32 + mi_bsr32(hi));
+  #elif MI_INTPTR_SIZE==4
+  return mi_bsr32(x);
+  #else
+  # error "define bsr for non-32 or 64-bit platforms"
+  #endif
+}
+*/
+
+
+static inline size_t _mi_wsize_from_size(size_t size) {
+  return (size + sizeof(uintptr_t) - 1) / sizeof(uintptr_t);
+}
+
+// Return the bin for a given field size.
+// Returns MI_BIN_HUGE if the size is too large.
+// We use `wsize` for the size in "machine word sizes",
+// i.e. byte size == `wsize*sizeof(void*)`.
+extern inline uint8_t _mi_bin8(size_t size) {
+  size_t wsize = _mi_wsize_from_size(size);
+  uint8_t bin;
+  if (wsize <= 1) {
+    bin = 1;
+  }
+#if defined(MI_ALIGN4W)
+  else if (wsize <= 4) {
+    bin = (uint8_t)((wsize+1)&~1); // round to double word sizes
+  }
+#elif defined(MI_ALIGN2W)
+  else if (wsize <= 8) {
+    bin = (uint8_t)((wsize+1)&~1); // round to double word sizes
+  }
+#else
+  else if (wsize <= 8) {
+    bin = (uint8_t)wsize;
+  }
+#endif
+  else if (wsize > MI_LARGE_WSIZE_MAX) {
+    bin = MI_BIN_HUGE;
+  }
+  else {
+#if defined(MI_ALIGN4W)
+    if (wsize <= 16) { wsize = (wsize+3)&~3; } // round to 4x word sizes
+#endif
+    wsize--;
+    // find the highest bit
+    uint8_t b = mi_bsr32((uint32_t)wsize);
+    // and use the top 3 bits to determine the bin (~12.5% worst internal fragmentation).
+    // - adjust with 3 because we use do not round the first 8 sizes
+    //   which each get an exact bin
+    bin = ((b << 2) + (uint8_t)((wsize >> (b - 2)) & 0x03)) - 3;
+  }
+  return bin;
+}
+
+static inline uint8_t _mi_bin4(size_t size) {
+  size_t wsize = _mi_wsize_from_size(size);
+  uint8_t bin;
+  if (wsize <= 1) {
+    bin = 1;
+  }
+#if defined(MI_ALIGN4W)
+  else if (wsize <= 4) {
+    bin = (uint8_t)((wsize+1)&~1); // round to double word sizes
+  }
+#elif defined(MI_ALIGN2W)
+  else if (wsize <= 8) {
+    bin = (uint8_t)((wsize+1)&~1); // round to double word sizes
+  }
+#else
+  else if (wsize <= 8) {
+    bin = (uint8_t)wsize;
+  }
+#endif
+  else if (wsize > MI_LARGE_WSIZE_MAX) {
+    bin = MI_BIN_HUGE;
+  }
+  else {
+    uint8_t b = mi_bsr32((uint32_t)wsize);
+    bin = ((b << 1) + (uint8_t)((wsize >> (b - 1)) & 0x01)) + 3;
+  }
+  return bin;
+}
+
+static size_t _mi_binx4(size_t bsize) {
+  if (bsize==0) return 0;
+  uint8_t b = mi_bsr32((uint32_t)bsize);
+  if (b <= 1) return bsize;
+  size_t bin = ((b << 1) | (bsize >> (b - 1))&0x01);
+  return bin;
+}
+
+static size_t _mi_binx8(size_t bsize) {
+  if (bsize<=1) return bsize;
+  uint8_t b = mi_bsr32((uint32_t)bsize);
+  if (b <= 2) return bsize;
+  size_t bin = ((b << 2) | (bsize >> (b - 2))&0x03) - 5;
+  return bin;
+}
+
+static void mi_bins(void) {
+  //printf("  QNULL(1), /* 0 */ \\\n  ");
+  size_t last_bin = 0;
+  size_t min_bsize = 0;
+  size_t last_bsize = 0;
+  for (size_t bsize = 1; bsize < 2*1024; bsize++) {
+    size_t size = bsize * 64 * 1024;
+    size_t bin = _mi_binx8(bsize);
+    if (bin != last_bin) {
+      printf("min bsize: %6zd, max bsize: %6zd, bin: %6zd\n", min_bsize, last_bsize, last_bin);
+      //printf("QNULL(%6zd), ", wsize);
+      //if (last_bin%8 == 0) printf("/* %i */ \\\n  ", last_bin);
+      last_bin = bin;
+      min_bsize = bsize;
+    }
+    last_bsize = bsize;
+  }
+}
+#endif
+