texmem.c

Mesa is an open-source implementation of the OpenGL specification - a system for rendering interacti

       */

      if ( (i * sz) > heap->size ) {
	 nr = heap->nrRegions;
	 break;
      }

      if (list[i].age > heap->local_age) 
	  driTexturesGone( heap, i * sz, sz, list[i].in_use); 
   }

   /* Loop or uninitialized heap detected.  Reset.
    */

   if (nr == heap->nrRegions) {
      driTexturesGone( heap, 0, heap->size, 0);
      resetGlobalLRU( heap );
   }

   if ( 0 ) {
      printGlobalLRU( heap, __FUNCTION__ );
      printLocalLRU( heap, __FUNCTION__ );
   }

   heap->local_age = heap->global_age[0];
}




#define INDEX_ARRAY_SIZE 6 /* I'm not aware of driver with more than 2 heaps */

/**
 * Allocate memory from a texture heap to hold a texture object.  This
 * routine will attempt to allocate memory for the texture from the heaps
 * specified by \c heap_array in order.  That is, first it will try to
 * allocate from \c heap_array[0], then \c heap_array[1], and so on.
 *
 * \param heap_array Array of pointers to texture heaps to use
 * \param nr_heaps Number of heap pointer in \a heap_array
 * \param t Texture object for which space is needed
 * \return The ID of the heap from which memory was allocated, or -1 if
 *         memory could not be allocated.
 *
 * \bug The replacement policy implemented by this function is horrible.
 */


int
driAllocateTexture( driTexHeap * const * heap_array, unsigned nr_heaps,
		    driTextureObject * t )
{
   driTexHeap       * heap;
   driTextureObject * temp;
   driTextureObject * cursor;
   unsigned           id;


   /* In case it already has texture space, initialize heap.  This also
    * prevents GCC from issuing a warning that heap might be used
    * uninitialized.
    */

   heap = t->heap;


   /* Run through each of the existing heaps and try to allocate a buffer
    * to hold the texture.
    */

   for ( id = 0 ; (t->memBlock == NULL) && (id < nr_heaps) ; id++ ) {
      heap = heap_array[ id ];
      if ( heap != NULL ) {
	 t->memBlock = mmAllocMem( heap->memory_heap, t->totalSize, 
				   heap->alignmentShift, 0 );
      }
   }


   /* Kick textures out until the requested texture fits.
    */

   if ( t->memBlock == NULL ) {
      unsigned index[INDEX_ARRAY_SIZE];
      unsigned nrGoodHeaps = 0;

      /* Trying to avoid dynamic memory allocation. If you have more
       * heaps, increase INDEX_ARRAY_SIZE. I'm not aware of any
       * drivers with more than 2 tex heaps. */
      assert( nr_heaps < INDEX_ARRAY_SIZE );

      /* Sort large enough heaps by duty. Insertion sort should be
       * fast enough for such a short array. */
      for ( id = 0 ; id < nr_heaps ; id++ ) {
	 heap = heap_array[ id ];

	 if ( heap != NULL && t->totalSize <= heap->size ) {
	    unsigned j;

	    for ( j = 0 ; j < nrGoodHeaps; j++ ) {
	       if ( heap->duty > heap_array[ index[ j ] ]->duty )
		  break;
	    }

	    if ( j < nrGoodHeaps ) {
	       memmove( &index[ j+1 ], &index[ j ],
			sizeof(index[ 0 ]) * (nrGoodHeaps - j) );
	    }

	    index[ j ] = id;

	    nrGoodHeaps++;
	 }
      }

      for ( id = 0 ; (t->memBlock == NULL) && (id < nrGoodHeaps) ; id++ ) {
	 heap = heap_array[ index[ id ] ];

	 for ( cursor = heap->texture_objects.prev, temp = cursor->prev;
	       cursor != &heap->texture_objects ; 
	       cursor = temp, temp = cursor->prev ) {
	       
	    /* The the LRU element.  If the texture is bound to one of
	     * the texture units, then we cannot kick it out.
	     */
	    if ( cursor->bound || cursor->reserved ) {
	       continue;
	    }

	    if ( cursor->memBlock )
	       heap->duty -= cursor->memBlock->size;

	    /* If this is a placeholder, there's no need to keep it */
	    if (cursor->tObj)
	       driSwapOutTextureObject( cursor );
	    else
	       driDestroyTextureObject( cursor );

	    t->memBlock = mmAllocMem( heap->memory_heap, t->totalSize, 
				      heap->alignmentShift, 0 );

	    if (t->memBlock)
	       break;
	 }
      }

      /* Rebalance duties. If a heap kicked more data than its duty,
       * then all other heaps get that amount multiplied with their
       * relative weight added to their duty. The negative duty is
       * reset to 0. In the end all heaps have a duty >= 0.
       *
       * CAUTION: we must not change the heap pointer here, because it
       * is used below to update the texture object.
       */
      for ( id = 0 ; id < nr_heaps ; id++ )
	 if ( heap_array[ id ] != NULL && heap_array[ id ]->duty < 0) {
	    int duty = -heap_array[ id ]->duty;
	    double weight = heap_array[ id ]->weight;
	    unsigned j;

	    for ( j = 0 ; j < nr_heaps ; j++ )
	       if ( j != id && heap_array[ j ] != NULL ) {
		  heap_array[ j ]->duty += (double) duty *
		     heap_array[ j ]->weight / weight;
	       }

	    heap_array[ id ]->duty = 0;
	 }
   }


   if ( t->memBlock != NULL ) {
      /* id and heap->heapId may or may not be the same value here.
       */

      assert( heap != NULL );
      assert( (t->heap == NULL) || (t->heap == heap) );

      t->heap = heap;
      return heap->heapId;
   }
   else {
      assert( t->heap == NULL );

      fprintf( stderr, "[%s:%d] unable to allocate texture\n",
	       __FUNCTION__, __LINE__ );
      return -1;
   }
}






/**
 * Set the location where the texture-swap counter is stored.
 */

void
driSetTextureSwapCounterLocation( driTexHeap * heap, unsigned * counter )
{
   heap->texture_swaps = (counter == NULL) ? & dummy_swap_counter : counter;
}




/**
 * Create a new heap for texture data.
 * 
 * \param heap_id             Device-dependent heap identifier.  This value
 *                            will returned by driAllocateTexture when memory
 *                            is allocated from this heap.
 * \param context             Device-dependent driver context.  This is
 *                            supplied as the first parameter to the
 *                            \c destroy_tex_obj function.
 * \param size                Size, in bytes, of the texture region
 * \param alignmentShift      Alignment requirement for textures.  If textures 
 *                            must be allocated on a 4096 byte boundry, this
 *                            would be 12.
 * \param nr_regions          Number of regions into which this texture space
 *                            should be partitioned
 * \param global_regions      Array of \c drmTextureRegion structures in the SAREA
 * \param global_age          Pointer to the global texture age in the SAREA
 * \param swapped_objects     Pointer to the list of texture objects that are
 *                            not in texture memory (i.e., have been swapped
 *                            out).
 * \param texture_object_size Size, in bytes, of a device-dependent texture
 *                            object
 * \param destroy_tex_obj     Function used to destroy a device-dependent
 *                            texture object
 *
 * \sa driDestroyTextureHeap
 */

driTexHeap *
driCreateTextureHeap( unsigned heap_id, void * context, unsigned size,
		      unsigned alignmentShift, unsigned nr_regions,
		      drmTextureRegionPtr global_regions, unsigned * global_age,
		      driTextureObject * swapped_objects, 
		      unsigned texture_object_size,
		      destroy_texture_object_t * destroy_tex_obj
		    )
{
   driTexHeap * heap;
   unsigned     l;
    
    
   if ( 0 )
       fprintf( stderr, "%s( %u, %p, %u, %u, %u )\n",
		__FUNCTION__,
		heap_id, (void *)context, size, alignmentShift, nr_regions );

   heap = (driTexHeap *) CALLOC( sizeof( driTexHeap ) );
   if ( heap != NULL ) {
      l = driLog2( (size - 1) / nr_regions );
      if ( l < alignmentShift )
      {
	 l = alignmentShift;
      }

      heap->logGranularity = l;
      heap->size = size & ~((1L << l) - 1);

      heap->memory_heap = mmInit( 0, heap->size );
      if ( heap->memory_heap != NULL ) {
	 heap->heapId = heap_id;
	 heap->driverContext = context;

	 heap->alignmentShift = alignmentShift;
	 heap->nrRegions = nr_regions;
	 heap->global_regions = global_regions;
	 heap->global_age = global_age;
	 heap->swapped_objects = swapped_objects;
	 heap->texture_object_size = texture_object_size;
	 heap->destroy_texture_object = destroy_tex_obj;

	 /* Force global heap init */
	 if (heap->global_age[0] == 0)
	     heap->local_age = ~0;
	 else
	     heap->local_age = 0;

	 make_empty_list( & heap->texture_objects );
	 driSetTextureSwapCounterLocation( heap, NULL );

	 heap->weight = heap->size;
	 heap->duty = 0;
      }
      else {
	 FREE( heap );
	 heap = NULL;
      }
   }


   if ( 0 )
       fprintf( stderr, "%s returning %p\n", __FUNCTION__, (void *)heap );

   return heap;
}




/** Destroys a texture heap
 * 
 * \param heap Texture heap to be destroyed
 */

void
driDestroyTextureHeap( driTexHeap * heap )
{
   driTextureObject * t;
   driTextureObject * temp;


   if ( heap != NULL ) {
      foreach_s( t, temp, & heap->texture_objects ) {
	 driDestroyTextureObject( t );
      }
      foreach_s( t, temp, heap->swapped_objects ) {
	 driDestroyTextureObject( t );
      }

      mmDestroy( heap->memory_heap );
      FREE( heap );
   }
}




/****************************************************************************/
/**
 * Determine how many texels (including all mipmap levels) would be required
 * for a texture map of size \f$2^^\c base_size_log2\f$ would require.
 *
 * \param base_size_log2 \f$log_2\f$ of the size of a side of the texture
 * \param dimensions Number of dimensions of the texture.  Either 2 or 3.
 * \param faces Number of faces of the texture.  Either 1 or 6 (for cube maps).
 * \return Number of texels
 */

static unsigned
texels_this_map_size( int base_size_log2, unsigned dimensions, unsigned faces )
{
   unsigned  texels;


   assert( (faces == 1) || (faces == 6) );
   assert( (dimensions == 2) || (dimensions == 3) );

   texels = 0;
   if ( base_size_log2 >= 0 ) {
      texels = (1U << (dimensions * base_size_log2));

      /* See http://www.mail-archive.com/[e-mail]/msg03636.html
       * for the complete explaination of why this formulation is used.
       * Basically, the smaller mipmap levels sum to 0.333 the size of the
       * level 0 map.  The total size is therefore the size of the map
       * multipled by 1.333.  The +2 is there to round up.
       */

      texels = (texels * 4 * faces + 2) / 3;
   }

   return texels;
}




struct maps_per_heap {
   unsigned  c[32];
};

static void
fill_in_maximums( driTexHeap * const * heaps, unsigned nr_heaps,
		  unsigned max_bytes_per_texel, unsigned max_size,
		  unsigned mipmaps_at_once, unsigned dimensions,
		  unsigned faces, struct maps_per_heap * max_textures )
{
   unsigned   heap;
   unsigned   log2_size;
   unsigned   mask;


   /* Determine how many textures of each size can be stored in each
    * texture heap.
    */

   for ( heap = 0 ; heap < nr_heaps ; heap++ ) {
      if ( heaps[ heap ] == NULL ) {
	 (void) memset( max_textures[ heap ].c, 0, 
			sizeof( max_textures[ heap ].c ) );
	 continue;
      }

      mask = (1U << heaps[ heap ]->logGranularity) - 1;

      if ( 0 ) {
	 fprintf( stderr, "[%s:%d] heap[%u] = %u bytes, mask = 0x%08x\n",
		  __FILE__, __LINE__,
		  heap, heaps[ heap ]->size, mask );
      }

      for ( log2_size = max_size ; log2_size > 0 ; log2_size-- ) {
	 unsigned   total;


	 /* Determine the total number of bytes required by a texture of
	  * size log2_size.
	  */

	 total = texels_this_map_size( log2_size, dimensions, faces )
	     - texels_this_map_size( log2_size - mipmaps_at_once,
				     dimensions, faces );
	 total *= max_bytes_per_texel;
	 total = (total + mask) & ~mask;

	 /* The number of textures of a given size that will fit in a heap
	  * is equal to the size of the heap divided by the size of the
	  * texture.
	  */

	 max_textures[ heap ].c[ log2_size ] = heaps[ heap ]->size / total;

	 if ( 0 ) {
	    fprintf( stderr, "[%s:%d] max_textures[%u].c[%02u] "
		     "= 0x%08x / 0x%08x "
		     "= %u (%u)\n",
		     __FILE__, __LINE__,
		     heap, log2_size,
		     heaps[ heap ]->size, total,
		     heaps[ heap ]->size / total,
		     max_textures[ heap ].c[ log2_size ] );
	 }
      }
   }
}


static unsigned
get_max_size( unsigned nr_heaps,
	      unsigned texture_units,
	      unsigned max_size,
	      int all_textures_one_heap,
	      struct maps_per_heap * max_textures )