pike.git / src / block_allocator.c

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pike.git/src/block_allocator.c:1: + #include "global.h" + #include "pike_error.h" + #include "pike_memory.h"    -  + #include "block_allocator.h" + #include "bitvector.h" +  + #include <stdlib.h> +  + #define BA_BLOCKN(l, p, n) ((struct ba_block_header *)((char*)(p) + (l).doffset + (n)*((l).block_size))) + #define BA_LASTBLOCK(l, p) ((struct ba_block_header*)((char*)(p) + (l).doffset + (l).offset)) + #define BA_CHECK_PTR(l, p, ptr) ((size_t)((char*)(ptr) - (char*)(p)) <= (l).offset + (l).doffset) +  + #define BA_ONE ((struct ba_block_header *)1) + static void print_allocator(const struct block_allocator * a); +  + static INLINE void ba_dec_layout(struct ba_layout * l, int i) { +  l->blocks >>= i; +  l->offset += l->block_size; +  l->offset >>= i; +  l->offset -= l->block_size; + } +  + static INLINE void ba_inc_layout(struct ba_layout * l, int i) { +  l->blocks <<= i; +  l->offset += l->block_size; +  l->offset <<= i; +  l->offset -= l->block_size; + } +  + static INLINE void ba_double_layout(struct ba_layout * l) { +  ba_inc_layout(l, 1); + } +  + static INLINE void ba_half_layout(struct ba_layout * l) { +  ba_dec_layout(l, 1); + } +  + static INLINE struct ba_layout ba_get_layout(const struct block_allocator * a, int i) { +  struct ba_layout l = a->l; +  ba_inc_layout(&l, i); +  return l; + } +  + struct ba_block_header { +  struct ba_block_header * next; + }; +  + static struct ba_page * ba_alloc_page(struct block_allocator * a, int i) { +  struct ba_layout l = ba_get_layout(a, i); +  size_t n = l.offset + l.block_size + l.doffset; +  struct ba_page * p; +  if (l.alignment) { +  p = (struct ba_page*)aligned_alloc(n, l.alignment); +  } else { + #ifdef DEBUG_MALLOC +  /* In debug malloc mode, calling xalloc from the block alloc may result +  * in a deadlock, since xalloc will call ba_alloc, which in turn may call xalloc. +  */ +  p = (struct ba_page*)system_malloc(n); +  if (!p) { +  fprintf(stderr, "Fatal: Out of memory.\n"); +  exit(17); +  } + #else +  p = (struct ba_page*)xalloc(n); + #endif +  } +  p->h.first = BA_BLOCKN(a->l, p, 0); +  p->h.first->next = BA_ONE; +  p->h.used = 0; +  PIKE_MEM_NA_RANGE((char*)p + l.doffset, n - l.doffset); +  return p; + } +  +  + PMOD_EXPORT void ba_init_aligned(struct block_allocator * a, unsigned INT32 block_size, +  unsigned INT32 blocks, unsigned INT32 alignment) { +  block_size = MAXIMUM(block_size, sizeof(struct ba_block_header)); +  if (alignment) { +  if (alignment & (alignment - 1)) +  Pike_fatal("Block allocator alignment is not a power of 2.\n"); +  if (block_size & (alignment-1)) +  Pike_fatal("Block allocator block size is not aligned.\n"); +  a->l.doffset = PIKE_ALIGNTO(sizeof(struct ba_page), alignment); +  } else { +  a->l.doffset = sizeof(struct ba_page); +  } +  +  blocks = round_up32(blocks); +  a->alloc = a->last_free = 0; +  a->size = 1; +  a->l.block_size = block_size; +  a->l.blocks = blocks; +  a->l.offset = block_size * (blocks-1); +  a->l.alignment = alignment; +  memset(a->pages, 0, sizeof(a->pages)); +  a->pages[0] = ba_alloc_page(a, 0); +  PIKE_MEMPOOL_CREATE(a); + } +  + PMOD_EXPORT void ba_destroy(struct block_allocator * a) { +  int i; +  for (i = 0; i < a->size; i++) { +  if (a->pages[i]) { + #ifdef DEBUG_MALLOC +  system_free(a->pages[i]); + #else +  free(a->pages[i]); + #endif +  a->pages[i] = NULL; +  } +  } +  a->size = 0; +  a->alloc = 0; +  a->last_free = 0; + } +  + PMOD_EXPORT size_t ba_count(const struct block_allocator * a) { +  size_t c = 0; +  unsigned int i; +  for (i = 0; i < a->size; i++) { +  c += a->pages[i]->h.used; +  } +  +  return c; + } +  + PMOD_EXPORT void ba_count_all(const struct block_allocator * a, size_t * num, size_t * size) { +  if (a->size) { +  size_t n = (a->l.blocks << (a->size-1)) - a->l.blocks; +  *num = n; +  *size = a->l.block_size * n; +  } else { +  *num = *size = 0; +  } + } +  + static void ba_low_alloc(struct block_allocator * a) { +  if (a->l.offset) { +  unsigned int i; +  +  for (i = 1; i <= a->size; i++) { +  struct ba_page * p = a->pages[a->size - i]; +  +  if (p->h.first) { +  a->alloc = a->size - i; +  return; +  } +  } +  if (a->size == (sizeof(a->pages)/sizeof(a->pages[0]))) { +  Pike_error("Out of memory."); +  } +  a->pages[a->size] = ba_alloc_page(a, a->size); +  a->alloc = a->size; +  a->size++; +  } else { +  ba_init_aligned(a, a->l.block_size, a->l.blocks, a->l.alignment); +  } + } +  + ATTRIBUTE((malloc)) + PMOD_EXPORT void * ba_alloc(struct block_allocator * a) { +  struct ba_page * p = a->pages[a->alloc]; +  struct ba_block_header * ptr; +  +  if (!p || !p->h.first) { +  ba_low_alloc(a); +  p = a->pages[a->alloc]; +  } +  +  ptr = p->h.first; +  PIKE_MEMPOOL_ALLOC(a, ptr, a->l.block_size); +  PIKE_MEM_RW_RANGE(ptr, sizeof(struct ba_block_header)); +  +  p->h.used++; +  + #ifdef PIKE_DEBUG +  { +  struct ba_layout l = ba_get_layout(a, a->alloc); +  if (!BA_CHECK_PTR(l, p, ptr)) { +  print_allocator(a); +  Pike_fatal("about to return pointer from hell: %p\n", ptr); +  } +  } + #endif +  +  if (ptr->next == BA_ONE) { +  struct ba_layout l = ba_get_layout(a, a->alloc); +  p->h.first = (struct ba_block_header*)((char*)ptr + a->l.block_size); +  PIKE_MEMPOOL_ALLOC(a, p->h.first, a->l.block_size); +  p->h.first->next = (struct ba_block_header*)(ptrdiff_t)!(p->h.first == BA_LASTBLOCK(l, p)); +  PIKE_MEMPOOL_FREE(a, p->h.first, a->l.block_size); +  } else { +  p->h.first = ptr->next; +  } +  PIKE_MEM_WO_RANGE(ptr, sizeof(struct ba_block_header)); +  + #if PIKE_DEBUG +  if (a->l.alignment && (size_t)ptr & (a->l.alignment - 1)) { +  print_allocator(a); +  Pike_fatal("Returning unaligned pointer.\n"); +  } + #endif +  +  return ptr; + } +  + PMOD_EXPORT void ba_free(struct block_allocator * a, void * ptr) { +  int i = a->last_free; +  struct ba_page * p = a->pages[i]; +  struct ba_layout l = ba_get_layout(a, i); +  + #if PIKE_DEBUG +  if (a->l.alignment && (size_t)ptr & (a->l.alignment - 1)) { +  print_allocator(a); +  Pike_fatal("Returning unaligned pointer.\n"); +  } + #endif +  +  if (BA_CHECK_PTR(l, p, ptr)) goto found; +  + #ifdef PIKE_DEBUG +  p = NULL; + #endif +  +  for (i = a->size-1, l = ba_get_layout(a, i); i >= 0; i--, ba_half_layout(&l)) { +  if (BA_CHECK_PTR(l, a->pages[i], ptr)) { +  a->last_free = i; +  p = a->pages[i]; +  break; +  } +  } + found: +  + #ifdef PIKE_DEBUG +  if (p) { + #endif +  { +  struct ba_block_header * b = (struct ba_block_header*)ptr; +  b->next = p->h.first; +  p->h.first = b; + #ifdef PIKE_DEBUG +  if (!p->h.used) { +  print_allocator(a); +  Pike_fatal("freeing from empty page %p\n", p); +  } + #endif +  if (!(--p->h.used) && i+1 == a->size) { +  while (i >= 0 && !(p->h.used)) { + #ifdef DEBUG_MALLOC +  system_free(p); + #else +  free(p); + #endif +  a->pages[i] = NULL; +  +  p = a->pages[--i]; +  } +  a->size = i+1; +  a->alloc = a->last_free = MAXIMUM(0, i); +  } +  } + #ifdef PIKE_DEBUG +  } else { +  print_allocator(a); +  Pike_fatal("ptr %p not in any page.\n", ptr); +  } + #endif +  PIKE_MEMPOOL_FREE(a, ptr, a->l.block_size); + } +  + static void print_allocator(const struct block_allocator * a) { +  int i; +  struct ba_layout l; +  +  for (i = a->size-1, l = ba_get_layout(a, i); i >= 0; ba_half_layout(&l), i--) { +  struct ba_page * p = a->pages[i]; +  fprintf(stderr, "page: %p used: %u/%u last: %p p+offset: %p\n", a->pages[i], +  p->h.used, l.blocks, +  BA_BLOCKN(l, p, l.blocks-1), BA_LASTBLOCK(l, p)); +  } + }   Newline at end of file added.