su_alloc.c

Sofia SIP is an open-source SIP User-Agent library, compliant with the IETF RFC3261 specification.

  if (home->suh_blocks == NULL) 
    su_home_init(home);

  sub = MEMLOCK(home);
  if (!sub->sub_preload) {
    size_t size;
    void *preload;

    size = n * ALIGN(isize);
    if (size > 65535)		/* We have 16 bits... */
      size = 65535 & (ALIGNMENT - 1);

    preload = malloc(size);

    home->suh_blocks->sub_preload = preload;
    home->suh_blocks->sub_prsize = (unsigned)size;
  }
  UNLOCK(home);
}

/** Preload a memory home from stack.
 *
 * Initializes a memory home using an area allocated from stack. Poor man's
 * alloca().
 */
su_home_t *su_home_auto(void *area, isize_t size)
{
  su_home_t *home;
  su_block_t *sub;
  size_t homesize = ALIGN(sizeof *home);
  size_t subsize = ALIGN(offsetof(su_block_t, sub_nodes[SUB_N_AUTO]));
  size_t prepsize;

  char *p = area;

  prepsize = homesize + subsize + (ALIGN((intptr_t)p) - (intptr_t)p);

  if (area == NULL || size < prepsize)
    return NULL;

  if (size > INT_MAX)
    size = INT_MAX;

  home = memset(p, 0, homesize);
  home->suh_size = (int)size;

  sub = memset(p + homesize, 0, subsize);
  home->suh_blocks = sub;

  if (size > prepsize + 65535)
    size = prepsize + 65535;

  sub->sub_n = SUB_N_AUTO;
  sub->sub_ref = 1;
  sub->sub_preload = p + prepsize;
  sub->sub_prsize = (unsigned)(size - prepsize);
  sub->sub_hauto = 1;
  sub->sub_auto = 1;
  sub->sub_preauto = 1;
  sub->sub_auto_all = 1;

  return home;
}


/** Reallocate a memory block.
 *
 *   Allocates a memory block of @a size bytes.
 *   It copies the old block contents to the new block and frees the old
 *   block.
 *
 *   If @a home is NULL, this function behaves exactly like realloc().
 *
 *   @param home  pointer to memory pool object
 *   @param data  pointer to old memory block
 *   @param size  size of the memory block to be allocated
 *   
 * @return
 *   A pointer to the allocated memory block or
 *   NULL if an error occurred.
 */
void *su_realloc(su_home_t *home, void *data, isize_t size)
{
  void *ndata;
  su_alloc_t *sua;
  su_block_t *sub;
  size_t p;
  size_t term = 0 - size;

  if (!home) 
    return realloc(data, size);

  if (size == 0) {
    if (data)
      su_free(home, data);
    return NULL;
  }

  sub = MEMLOCK(home);
  if (!data) {
    data = sub_alloc(home, sub, size, 0);
    UNLOCK(home);
    return data;
  }

  sua = su_block_find(sub, data);

  if (!su_alloc_check(sub, sua))
    return UNLOCK(home);
  
  assert(!sua->sua_home);
  if (sua->sua_home)
    return UNLOCK(home);
  
  if (!su_is_preloaded(sub, data)) {
    ndata = realloc(data, size + MEMCHECK_EXTRA);
    if (ndata) {
      if (sub->sub_stats) {
	su_home_stats_free(sub, data, 0, sua->sua_size);
	su_home_stats_alloc(sub, data, 0, size, 1);
      }

#if MEMCHECK_EXTRA
      memcpy((char *)ndata + size, &term, sizeof (term));
#else
      (void)term;
#endif
      memset(sua, 0, sizeof *sua);
      sub->sub_used--;
      su_block_add(sub, ndata)->sua_size = (unsigned)size;
    }
    UNLOCK(home);

    return ndata;
  }

  p = (char *)data - home->suh_blocks->sub_preload;
  p += sua->sua_size + MEMCHECK_EXTRA;
  p = ALIGN(p);

  if (p == sub->sub_prused) {
    size_t p2 = (char *)data - sub->sub_preload + size + MEMCHECK_EXTRA;
    p2 = ALIGN(p2);
    if (p2 <= sub->sub_prsize) {
      /* Extend/reduce existing preload */
      if (sub->sub_stats) {
	su_home_stats_free(sub, data, data, sua->sua_size);
	su_home_stats_alloc(sub, data, data, size, 0);
      }

      sub->sub_prused = (unsigned)p2;
      sua->sua_size = (unsigned)size;

#if MEMCHECK_EXTRA
      memcpy((char *)data + size, &term, sizeof (term));
#endif
      UNLOCK(home);
      return data;
    }
  }
  else if (size < (size_t)sua->sua_size) {
    /* Reduce existing preload */
    if (sub->sub_stats) {
      su_home_stats_free(sub, data, data, sua->sua_size);
      su_home_stats_alloc(sub, data, data, size, 0);
    }
#if MEMCHECK_EXTRA
    memcpy((char *)data + size, &term, sizeof (term));
#endif
    sua->sua_size = (unsigned)size;
    UNLOCK(home);
    return data;
  }

  ndata = malloc(size + MEMCHECK_EXTRA);

  if (ndata) {
    if (p == sub->sub_prused) {
      /* Free preload */
      sub->sub_prused = (char *)data - home->suh_blocks->sub_preload;
      if (sub->sub_stats)
	su_home_stats_free(sub, data, data, sua->sua_size);
    }
    
    memcpy(ndata, data,
	   (size_t)sua->sua_size < size
	   ? (size_t)sua->sua_size
	   : size);
#if MEMCHECK_EXTRA
    memcpy((char *)ndata + size, &term, sizeof (term));
#endif

    if (sub->sub_stats)
      su_home_stats_alloc(sub, data, 0, size, 1);

    memset(sua, 0, sizeof *sua); sub->sub_used--;

    su_block_add(sub, ndata)->sua_size = (unsigned)size;
  }

  UNLOCK(home);

  return ndata;
}


/**Check if a memory block has been allocated from the @a home.
 *
 * Check if the given memory block has been allocated from the home.
 *
 * @param home pointer to memory pool object
 * @param memory ponter to memory block
 *
 * @retval 1 if @a memory has been allocated from @a home.
 * @retval 0 otherwise
 *
 * @since New in @VERSION_1_12_4.
 */
int su_in_home(su_home_t *home, void const *memory)
{
  su_alloc_t *sua;
  su_block_t *sub;
  int retval = 0;

  if (!home || !memory)
    return 0;

  sub = MEMLOCK(home);

  if (sub) {
    sua = su_block_find(sub, memory);

    retval = su_alloc_check(sub, sua);

    UNLOCK(home);
  }
  
  return retval;
}


/**Allocate and zero a memory block.
 *
 * Allocates a memory block with a given size from
 * given memory home @a home and zeroes the allocated block.
 *
 *  @param home  pointer to memory pool object
 *  @param size  size of the memory block
 *
 * @note The memory home pointer @a home may be @c NULL. In that case, the
 * allocated memory block is not associated with any memory home, and it
 * must be freed by calling su_free() or free().
 *
 * @return
 * The function su_zalloc() returns a pointer to the allocated memory block,
 * or NULL upon an error.
 */
void *su_zalloc(su_home_t *home, isize_t size)
{
  void *data;

  assert (size >= 0);

  if (home) {
    data = sub_alloc(home, MEMLOCK(home), size, 1);
    UNLOCK(home);
  }
  else
    data = calloc(1, size);

  return data;
}

/** Allocate a structure
 *
 * Allocates a structure with a given size, zeros
 * it, and initializes the size field to the given size.  The size field
 * is an int at the beginning of the structure. Note that it has type of int. 
 *
 * @param home  pointer to memory pool object
 * @param size  size of the structure
 *
 * @par Example
 * The structure is defined and allocated as follows:
 * @code
 *   struct test {
 *     int   tst_size;
 *     char *tst_name;
 *     void *tst_ptr[3];
 *   };
 * 
 *   struct test *t;
 *   ...
 *   t = su_salloc(home, sizeof (*t)); 
 *   assert(t && t->t_size == sizeof (*t));
 *   
 * @endcode
 * After calling su_salloc() we get a pointer t to a struct test,
 * initialized to zero except the tst_size field, which is initialized to
 * sizeof (*t).
 *
 * @return A pointer to the allocated structure, or NULL upon an error.
 */
void *su_salloc(su_home_t *home, isize_t size)
{
  struct { int size; } *retval;

  if (size < sizeof (*retval))
    size = sizeof (*retval);

  if (size > INT_MAX)
    return (void)(errno = ENOMEM), NULL;

  if (home) {
    retval = sub_alloc(home, MEMLOCK(home), size, 1);
    UNLOCK(home);
  }
  else
    retval = calloc(1, size);

  if (retval)
    retval->size = (int)size;

  return retval;
}

/** Check if a memory home is threadsafe */
int su_home_is_threadsafe(su_home_t const *home)
{
  return home && home->suh_lock;
}

/** Increase refcount and obtain exclusive lock on home. 
 *
 * @note The #su_home_t structure must be created with su_home_new() or
 * su_home_clone(), or initialized with su_home_init() before using this
 * function. 
 *
 * In order to enable actual locking, use su_home_threadsafe(), too. 
 * Otherwise the su_home_mutex_lock() will just increase the reference
 * count.
 */
int su_home_mutex_lock(su_home_t *home)
{
  int error;

  if (home == NULL)
    return su_seterrno(EFAULT);

  if (home->suh_blocks == NULL || !su_home_ref(home))
    return su_seterrno(EINVAL);  /* Uninitialized home */

  if (!home->suh_lock)
    return 0;			/* No-op */

  error = _su_home_mutex_locker(home->suh_lock);
  if (error)
    return su_seterrno(error);

  return 0;
}

/** Release exclusive lock on home and decrease refcount (if home is threadsafe).
 *
 * @sa su_home_unlock().
 */
int su_home_mutex_unlock(su_home_t *home)
{
  if (home == NULL)
    return su_seterrno(EFAULT);

  if (home->suh_lock) {
    int error = _su_home_mutex_unlocker(home->suh_lock);
    if (error)
      return su_seterrno(error);
  }

  if (home->suh_blocks == NULL)
    return su_seterrno(EINVAL), -1; /* Uninitialized home */

  su_home_unref(home);

  return 0;
}


/** Obtain exclusive lock on home without increasing refcount. 
 *
 * Unless su_home_threadsafe() has been used to intialize locking on home
 * object the function just returns -1.
 *
 * @return 0 if successful, -1 if not threadsafe, error code otherwise.
 *
 * @sa su_home_mutex_lock(), su_home_unlock(), su_home_trylock().
 *
 * @NEW_1_12_8
 */
int su_home_lock(su_home_t *home)
{
  if (home == NULL)
    return EFAULT;

  if (home->suh_lock == NULL)
    return -1;			/* No-op */

  return _su_home_mutex_locker(home->suh_lock);
}


/** Try to obtain exclusive lock on home without increasing refcount. 
 *
 * @return 0 if successful, -1 if not threadsafe, 
 * EBUSY if already locked, error code otherwise.
 *
 * @sa su_home_lock(), su_home_unlock().
 *
 * @NEW_1_12_8
 */
int su_home_trylock(su_home_t *home)
{
  if (home == NULL)
    return EFAULT;

  if (home->suh_lock == NULL)
    return -1;			/* No-op */

  return _su_home_mutex_trylocker(home->suh_lock);
}


/** Release exclusive lock on home.
 *
 * Release lock without decreasing refcount.
 *
 * @return 0 if successful, -1 if not threadsafe, error code otherwise.
 *
 * @sa su_home_lock(), su_home_trylock(), su_home_mutex_unlock().
 *
 * @NEW_1_12_8
 */
int su_home_unlock(su_home_t *home)
{
  if (home == NULL)
    return EFAULT;

  if (home->suh_lock == NULL)
    return -1;			/* No-op */

  return _su_home_mutex_unlocker(home->suh_lock);
}


/** Initialize statistics structure */
void su_home_init_stats(su_home_t *home)
{
  su_block_t *sub;
  size_t size;

  if (home == NULL)
    return;

  sub = home->suh_blocks;

  if (!sub)
    sub = home->suh_blocks = su_hash_alloc(SUB_N);
  if (!sub)
    return;

  if (!sub->sub_stats) {
    size = sizeof (*sub->sub_stats);
    sub->sub_stats = malloc(size);
    if (!sub->sub_stats)
      return;
  }
  else
    size = sub->sub_stats->hs_size;
  
  memset(sub->sub_stats, 0, size);
  sub->sub_stats->hs_size = (int)size;
  sub->sub_stats->hs_blocksize = sub->sub_n;
}

/** Retrieve statistics from memory home.
 */
void su_home_get_stats(su_home_t *home, int include_clones, 
		       su_home_stat_t *hs,
		       isize_t size)
{
  su_block_t *sub;

  if (hs == NULL || size < (sizeof hs->hs_size))
    return;

  memset((void *)hs, 0, size);

  sub = MEMLOCK(home);

  if (sub && sub->sub_stats) {
    int sub_size = sub->sub_stats->hs_size;
    if (sub_size > (int)size)
      sub_size = (int)size;
    sub->sub_stats->hs_preload.hsp_size = sub->sub_prsize;
    sub->sub_stats->hs_preload.hsp_used = sub->sub_prused;
    memcpy(hs, sub->sub_stats, sub_size);
    hs->hs_size = sub_size;
  }

  UNLOCK(home);
}

static 
void su_home_stats_alloc(su_block_t *sub, void *p, void *preload,
			 size_t size, int zero)
{
  su_home_stat_t *hs = sub->sub_stats;

  size_t rsize = ALIGN(size);

  hs->hs_rehash += (sub->sub_n != hs->hs_blocksize);
  hs->hs_blocksize = sub->sub_n;

  hs->hs_clones += zero > 1;

  if (preload) {
    hs->hs_allocs.hsa_preload++;
    return;
  }

  hs->hs_allocs.hsa_number++;
  hs->hs_allocs.hsa_bytes += size;
  hs->hs_allocs.hsa_rbytes += rsize;
  if (hs->hs_allocs.hsa_rbytes > hs->hs_allocs.hsa_maxrbytes)
    hs->hs_allocs.hsa_maxrbytes = hs->hs_allocs.hsa_rbytes;
  
  hs->hs_blocks.hsb_number++;
  hs->hs_blocks.hsb_bytes += size;
  hs->hs_blocks.hsb_rbytes += rsize;
}

static 
void su_home_stats_free(su_block_t *sub, void *p, void *preload,
			unsigned size)
{
  su_home_stat_t *hs = sub->sub_stats;

  size_t rsize = ALIGN(size);

  if (preload) {
    hs->hs_frees.hsf_preload++;
    return;
  }

  hs->hs_frees.hsf_number++;
  hs->hs_frees.hsf_bytes += size;
  hs->hs_frees.hsf_rbytes += rsize;

  hs->hs_blocks.hsb_number--;
  hs->hs_blocks.hsb_bytes -= size;
  hs->hs_blocks.hsb_rbytes -= rsize;
}

void su_home_stat_add(su_home_stat_t total[1], su_home_stat_t const hs[1])
{
  total->hs_clones               += hs->hs_clones;
  total->hs_rehash               += hs->hs_rehash;

  if (total->hs_blocksize < hs->hs_blocksize)
    total->hs_blocksize = hs->hs_blocksize;

  total->hs_allocs.hsa_number    += hs->hs_allocs.hsa_number;
  total->hs_allocs.hsa_bytes     += hs->hs_allocs.hsa_bytes;
  total->hs_allocs.hsa_rbytes    += hs->hs_allocs.hsa_rbytes;
  total->hs_allocs.hsa_maxrbytes += hs->hs_allocs.hsa_maxrbytes;

  total->hs_frees.hsf_number     += hs->hs_frees.hsf_number;
  total->hs_frees.hsf_bytes      += hs->hs_frees.hsf_bytes;
  total->hs_frees.hsf_rbytes     += hs->hs_frees.hsf_rbytes;

  total->hs_blocks.hsb_number    += hs->hs_blocks.hsb_number;
  total->hs_blocks.hsb_bytes     += hs->hs_blocks.hsb_bytes;
  total->hs_blocks.hsb_rbytes    += hs->hs_blocks.hsb_rbytes;
}