BufferPool.c

 
#include <winpr/config.h>
 
#include <winpr/crt.h>
 
#include <winpr/collections.h>
 
#ifndef MAX
#define MAX(a, b) ((a) > (b)) ? (a) : (b)
#endif
 
typedef struct
{
  SSIZE_T size;
  void* buffer;
} wBufferPoolItem;
 
struct s_wBufferPool
{
  SSIZE_T fixedSize;
  DWORD alignment;
  BOOL synchronized;
  CRITICAL_SECTION lock;
 
  SSIZE_T size;
  SSIZE_T capacity;
  void** array;
 
  SSIZE_T aSize;
  SSIZE_T aCapacity;
  wBufferPoolItem* aArray;
 
  SSIZE_T uSize;
  SSIZE_T uCapacity;
  wBufferPoolItem* uArray;
};
 
static BOOL BufferPool_Lock(wBufferPool* pool)
{
  if (!pool)
    return FALSE;
 
  if (pool->synchronized)
    EnterCriticalSection(&pool->lock);
  return TRUE;
}
 
static BOOL BufferPool_Unlock(wBufferPool* pool)
{
  if (!pool)
    return FALSE;
 
  if (pool->synchronized)
    LeaveCriticalSection(&pool->lock);
  return TRUE;
}
 
static BOOL BufferPool_ShiftAvailable(wBufferPool* pool, size_t index, int count)
{
  if (count > 0)
  {
    if (pool->aSize + count > pool->aCapacity)
    {
      wBufferPoolItem* newArray = nullptr;
      SSIZE_T newCapacity = pool->aSize + count;
      newCapacity += (newCapacity + 2) / 2;
 
      newArray = (wBufferPoolItem*)winpr_aligned_recalloc(
          pool->aArray, sizeof(wBufferPoolItem),
          WINPR_ASSERTING_INT_CAST(size_t, newCapacity), pool->alignment);
      if (!newArray)
        return FALSE;
      pool->aArray = newArray;
      pool->aCapacity = newCapacity;
    }
 
    MoveMemory(
        &pool->aArray[index + WINPR_ASSERTING_INT_CAST(size_t, count)], &pool->aArray[index],
        (WINPR_ASSERTING_INT_CAST(size_t, pool->aSize) - index) * sizeof(wBufferPoolItem));
    pool->aSize += count;
  }
  else if (count < 0)
  {
    MoveMemory(
        &pool->aArray[index], &pool->aArray[index + WINPR_ASSERTING_INT_CAST(size_t, -count)],
        (WINPR_ASSERTING_INT_CAST(size_t, pool->aSize) - index) * sizeof(wBufferPoolItem));
    pool->aSize += count;
  }
  return TRUE;
}
 
static BOOL BufferPool_ShiftUsed(wBufferPool* pool, SSIZE_T index, SSIZE_T count)
{
  if (count > 0)
  {
    const SSIZE_T required = pool->uSize + count;
    // check for overflow
    if ((required < count) || (required < pool->uSize))
      return FALSE;
 
    if (required > pool->uCapacity)
    {
      SSIZE_T newUCapacity = pool->uCapacity;
      do
      {
        if (newUCapacity > SSIZE_MAX - 128ll)
          return FALSE;
        newUCapacity += 128ll;
      } while (newUCapacity <= required);
      wBufferPoolItem* newUArray = nullptr;
      newUArray = (wBufferPoolItem*)winpr_aligned_realloc(
          pool->uArray,
          sizeof(wBufferPoolItem) * WINPR_ASSERTING_INT_CAST(size_t, newUCapacity),
          pool->alignment);
 
      if (!newUArray)
        return FALSE;
      pool->uCapacity = newUCapacity;
      pool->uArray = newUArray;
    }
 
    MoveMemory(&pool->uArray[index + count], &pool->uArray[index],
               WINPR_ASSERTING_INT_CAST(size_t, pool->uSize - index) * sizeof(wBufferPoolItem));
    pool->uSize += count;
  }
  else if (count < 0)
  {
    MoveMemory(&pool->uArray[index], &pool->uArray[index - count],
               WINPR_ASSERTING_INT_CAST(size_t, pool->uSize - index) * sizeof(wBufferPoolItem));
    pool->uSize += count;
  }
  return TRUE;
}
 
SSIZE_T BufferPool_GetPoolSize(wBufferPool* pool)
{
  SSIZE_T size = 0;
 
  BufferPool_Lock(pool);
 
  if (pool->fixedSize)
  {
    /* fixed size buffers */
    size = pool->size;
  }
  else
  {
    /* variable size buffers */
    size = pool->uSize;
  }
 
  BufferPool_Unlock(pool);
 
  return size;
}
 
SSIZE_T BufferPool_GetBufferSize(wBufferPool* pool, const void* buffer)
{
  SSIZE_T size = 0;
  BOOL found = FALSE;
 
  BufferPool_Lock(pool);
 
  if (pool->fixedSize)
  {
    /* fixed size buffers */
    size = pool->fixedSize;
    found = TRUE;
  }
  else
  {
    /* variable size buffers */
 
    for (SSIZE_T index = 0; index < pool->uSize; index++)
    {
      if (pool->uArray[index].buffer == buffer)
      {
        size = pool->uArray[index].size;
        found = TRUE;
        break;
      }
    }
  }
 
  BufferPool_Unlock(pool);
 
  return (found) ? size : -1;
}
 
void* BufferPool_Take(wBufferPool* pool, SSIZE_T size)
{
  SSIZE_T maxSize = 0;
  SSIZE_T maxIndex = 0;
  SSIZE_T foundIndex = -1;
  BOOL found = FALSE;
  void* buffer = nullptr;
 
  BufferPool_Lock(pool);
 
  if (pool->fixedSize)
  {
    /* fixed size buffers */
 
    if (pool->size > 0)
      buffer = pool->array[--(pool->size)];
 
    if (!buffer)
    {
      buffer = winpr_aligned_calloc(WINPR_ASSERTING_INT_CAST(size_t, pool->fixedSize), 1,
                                    pool->alignment);
    }
 
    if (!buffer)
      goto out_error;
  }
  else
  {
    /* variable size buffers */
 
    maxSize = 0;
    maxIndex = 0;
 
    if (size < 1)
      size = pool->fixedSize;
 
    for (SSIZE_T index = 0; index < pool->aSize; index++)
    {
      if (pool->aArray[index].size > maxSize)
      {
        maxIndex = index;
        maxSize = pool->aArray[index].size;
      }
 
      if (pool->aArray[index].size >= size)
      {
        foundIndex = index;
        found = TRUE;
        break;
      }
    }
 
    if (!found && maxSize)
    {
      foundIndex = maxIndex;
      found = TRUE;
    }
 
    if (!found)
    {
      if (!size)
        buffer = nullptr;
      else
      {
        buffer = winpr_aligned_calloc(WINPR_ASSERTING_INT_CAST(size_t, size), 1,
                                      pool->alignment);
 
        if (!buffer)
          goto out_error;
      }
    }
    else
    {
      buffer = pool->aArray[foundIndex].buffer;
 
      if (maxSize < size)
      {
        void* newBuffer = nullptr;
        newBuffer = winpr_aligned_realloc(buffer, WINPR_ASSERTING_INT_CAST(size_t, size),
                                          pool->alignment);
 
        if (!newBuffer)
          goto out_error_no_free;
 
        buffer = newBuffer;
      }
 
      if (!BufferPool_ShiftAvailable(pool, WINPR_ASSERTING_INT_CAST(size_t, foundIndex), -1))
        goto out_error;
    }
 
    if (!buffer)
      goto out_error;
 
    if (pool->uSize + 1 > pool->uCapacity)
    {
      size_t newUCapacity = WINPR_ASSERTING_INT_CAST(size_t, pool->uCapacity);
      newUCapacity += (newUCapacity + 2) / 2;
      if (newUCapacity > SSIZE_MAX)
        goto out_error;
      wBufferPoolItem* newUArray =
          (wBufferPoolItem*)realloc(pool->uArray, sizeof(wBufferPoolItem) * newUCapacity);
      if (!newUArray)
        goto out_error;
 
      pool->uCapacity = (SSIZE_T)newUCapacity;
      pool->uArray = newUArray;
    }
 
    pool->uArray[pool->uSize].buffer = buffer;
    pool->uArray[pool->uSize].size = size;
    (pool->uSize)++;
  }
 
  BufferPool_Unlock(pool);
 
  return buffer;
 
out_error:
  winpr_aligned_free(buffer);
out_error_no_free:
  BufferPool_Unlock(pool);
  return nullptr;
}
 
BOOL BufferPool_Return(wBufferPool* pool, void* buffer)
{
  BOOL rc = FALSE;
  SSIZE_T size = 0;
  BOOL found = FALSE;
 
  BufferPool_Lock(pool);
 
  if (pool->fixedSize)
  {
    /* fixed size buffers */
 
    if ((pool->size + 1) >= pool->capacity)
    {
      SSIZE_T newCapacity = MAX(2, pool->size + (pool->size + 2) / 2 + 1);
      void** newArray = (void**)realloc(
          (void*)pool->array, sizeof(void*) * WINPR_ASSERTING_INT_CAST(size_t, newCapacity));
      if (!newArray)
        goto out_error;
 
      pool->capacity = newCapacity;
      pool->array = newArray;
    }
 
    pool->array[(pool->size)++] = buffer;
  }
  else
  {
    /* variable size buffers */
 
    SSIZE_T index = 0;
    for (; index < pool->uSize; index++)
    {
      if (pool->uArray[index].buffer == buffer)
      {
        found = TRUE;
        break;
      }
    }
 
    if (found)
    {
      size = pool->uArray[index].size;
      if (!BufferPool_ShiftUsed(pool, index, -1))
        goto out_error;
    }
 
    if (size)
    {
      if ((pool->aSize + 1) >= pool->aCapacity)
      {
        SSIZE_T newCapacity = MAX(2, pool->aSize + (pool->aSize + 2) / 2 + 1);
        wBufferPoolItem* newArray = (wBufferPoolItem*)realloc(
            pool->aArray,
            sizeof(wBufferPoolItem) * WINPR_ASSERTING_INT_CAST(size_t, newCapacity));
        if (!newArray)
          goto out_error;
 
        pool->aCapacity = newCapacity;
        pool->aArray = newArray;
      }
 
      pool->aArray[pool->aSize].buffer = buffer;
      pool->aArray[pool->aSize].size = size;
      (pool->aSize)++;
    }
  }
 
  rc = TRUE;
out_error:
  BufferPool_Unlock(pool);
  return rc;
}
 
void BufferPool_Clear(wBufferPool* pool)
{
  BufferPool_Lock(pool);
 
  if (pool->fixedSize)
  {
    /* fixed size buffers */
 
    while (pool->size > 0)
    {
      (pool->size)--;
 
      winpr_aligned_free(pool->array[pool->size]);
    }
  }
  else
  {
    /* variable size buffers */
 
    while (pool->aSize > 0)
    {
      (pool->aSize)--;
 
      winpr_aligned_free(pool->aArray[pool->aSize].buffer);
    }
 
    while (pool->uSize > 0)
    {
      (pool->uSize)--;
 
      winpr_aligned_free(pool->uArray[pool->uSize].buffer);
    }
  }
 
  BufferPool_Unlock(pool);
}
 
wBufferPool* BufferPool_New(BOOL synchronized, SSIZE_T fixedSize, DWORD alignment)
{
  wBufferPool* pool = nullptr;
 
  pool = (wBufferPool*)calloc(1, sizeof(wBufferPool));
 
  if (pool)
  {
    pool->fixedSize = fixedSize;
 
    if (pool->fixedSize < 0)
      pool->fixedSize = 0;
 
    pool->alignment = alignment;
    pool->synchronized = synchronized;
 
    if (pool->synchronized)
    {
      if (!InitializeCriticalSectionAndSpinCount(&pool->lock, 4000))
        goto out_error;
    }
 
    if (pool->fixedSize)
    {
      /* fixed size buffers */
 
      pool->size = 0;
      pool->capacity = 32;
      pool->array =
          (void**)calloc(WINPR_ASSERTING_INT_CAST(size_t, pool->capacity), sizeof(void*));
      if (!pool->array)
        goto out_error;
    }
    else
    {
      /* variable size buffers */
 
      pool->aSize = 0;
      pool->aCapacity = 32;
      pool->aArray = (wBufferPoolItem*)calloc(
          WINPR_ASSERTING_INT_CAST(size_t, pool->aCapacity), sizeof(wBufferPoolItem));
      if (!pool->aArray)
        goto out_error;
 
      pool->uSize = 0;
      pool->uCapacity = 32;
      pool->uArray = (wBufferPoolItem*)calloc(
          WINPR_ASSERTING_INT_CAST(size_t, pool->uCapacity), sizeof(wBufferPoolItem));
      if (!pool->uArray)
        goto out_error;
    }
  }
 
  return pool;
 
out_error:
  WINPR_PRAGMA_DIAG_PUSH
  WINPR_PRAGMA_DIAG_IGNORED_MISMATCHED_DEALLOC
  BufferPool_Free(pool);
  WINPR_PRAGMA_DIAG_POP
  return nullptr;
}
 
void BufferPool_Free(wBufferPool* pool)
{
  if (pool)
  {
    BufferPool_Clear(pool);
 
    if (pool->synchronized)
      DeleteCriticalSection(&pool->lock);
 
    if (pool->fixedSize)
    {
      /* fixed size buffers */
 
      free((void*)pool->array);
    }
    else
    {
      /* variable size buffers */
 
      free(pool->aArray);
      free(pool->uArray);
    }
 
    free(pool);
  }
}