texmem.c

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

/*
 * Copyright 2000-2001 VA Linux Systems, Inc.
 * (C) Copyright IBM Corporation 2002, 2003
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * on the rights to use, copy, modify, merge, publish, distribute, sub
 * license, and/or sell copies of the Software, and to permit persons to whom
 * the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEM, IBM AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * Authors:
 *    Ian Romanick <[e-mail]>
 *    Keith Whitwell <[e-mail]>
 *    Kevin E. Martin <[e-mail]>
 *    Gareth Hughes <[e-mail]>
 */
/* $XFree86:$ */

/** \file texmem.c
 * Implements all of the device-independent texture memory management.
 * 
 * Currently, only a simple LRU texture memory management policy is
 * implemented.  In the (hopefully very near) future, better policies will be
 * implemented.  The idea is that the DRI should be able to run in one of two
 * modes.  In the default mode the DRI will dynamically attempt to discover
 * the best texture management policy for the running application.  In the
 * other mode, the user (via some sort of as yet TBD mechanism) will select
 * a texture management policy that is known to work well with the
 * application.
 */

#include "texmem.h"
#include "simple_list.h"
#include "imports.h"
#include "macros.h"
#include "texformat.h"

#include <assert.h>



static unsigned dummy_swap_counter;


/**
 * Calculate \f$\log_2\f$ of a value.  This is a particularly poor
 * implementation of this function.  However, since system performance is in
 * no way dependent on this function, the slowness of the implementation is
 * irrelevent.
 * 
 * \param n Value whose \f$\log_2\f$ is to be calculated
 */

static GLuint
driLog2( GLuint n )
{
   GLuint log2;

   for ( log2 = 1 ; n > 1 ; log2++ ) {
      n >>= 1;
   }

   return log2;
}




/**
 * Determine if a texture is resident in textureable memory.  Depending on
 * the driver, this may or may not be on-card memory.  It could be AGP memory
 * or anyother type of memory from which the hardware can directly read
 * texels.
 * 
 * This function is intended to be used as the \c IsTextureResident function
 * in the device's \c dd_function_table.
 * 
 * \param ctx GL context pointer (currently unused)
 * \param texObj Texture object to be tested
 */

GLboolean
driIsTextureResident( GLcontext * ctx, 
		      struct gl_texture_object * texObj )
{
   driTextureObject * t;


   t = (driTextureObject *) texObj->DriverData;
   return( (t != NULL) && (t->memBlock != NULL) );
}




/**
 * (Re)initialize the global circular LRU list.  The last element
 * in the array (\a heap->nrRegions) is the sentinal.  Keeping it
 * at the end of the array allows the other elements of the array
 * to be addressed rationally when looking up objects at a particular
 * location in texture memory.
 * 
 * \param heap Texture heap to be reset
 */

static void resetGlobalLRU( driTexHeap * heap )
{
   drmTextureRegionPtr list = heap->global_regions;
   unsigned       sz = 1U << heap->logGranularity;
   unsigned       i;

   for (i = 0 ; (i+1) * sz <= heap->size ; i++) {
      list[i].prev = i-1;
      list[i].next = i+1;
      list[i].age = 0;
   }

   i--;
   list[0].prev = heap->nrRegions;
   list[i].prev = i-1;
   list[i].next = heap->nrRegions;
   list[heap->nrRegions].prev = i;
   list[heap->nrRegions].next = 0;
   heap->global_age[0] = 0;
}

/**
 * Print out debugging information about the local texture LRU.
 *
 * \param heap Texture heap to be printed
 * \param callername Name of calling function
 */
static void printLocalLRU( driTexHeap * heap, const char *callername  )
{
   driTextureObject *t;
   unsigned sz = 1U << heap->logGranularity;

   fprintf( stderr, "%s in %s:\nLocal LRU, heap %d:\n", 
	    __FUNCTION__, callername, heap->heapId );

   foreach ( t, &heap->texture_objects ) {
      if (!t->memBlock)
	 continue;
      if (!t->tObj) {
	 fprintf( stderr, "Placeholder (%p) %d at 0x%x sz 0x%x\n",
		  (void *)t,
		  t->memBlock->ofs / sz,
		  t->memBlock->ofs,
		  t->memBlock->size );
      } else {
	 fprintf( stderr, "Texture (%p) at 0x%x sz 0x%x\n",
		  (void *)t,
		  t->memBlock->ofs,
		  t->memBlock->size );
      }
   }
   foreach ( t, heap->swapped_objects ) {
      if (!t->tObj) {
	 fprintf( stderr, "Swapped Placeholder (%p)\n", (void *)t );
      } else {
	 fprintf( stderr, "Swapped Texture (%p)\n", (void *)t );
      }
   }

   fprintf( stderr, "\n" );
}

/**
 * Print out debugging information about the global texture LRU.
 *
 * \param heap Texture heap to be printed
 * \param callername Name of calling function
 */
static void printGlobalLRU( driTexHeap * heap, const char *callername )
{
   drmTextureRegionPtr list = heap->global_regions;
   unsigned int i, j;

   fprintf( stderr, "%s in %s:\nGlobal LRU, heap %d list %p:\n", 
	    __FUNCTION__, callername, heap->heapId, (void *)list );

   for ( i = 0, j = heap->nrRegions ; i < heap->nrRegions ; i++ ) {
      fprintf( stderr, "list[%d] age %d next %d prev %d in_use %d\n",
	       j, list[j].age, list[j].next, list[j].prev, list[j].in_use );
      j = list[j].next;
      if ( j == heap->nrRegions ) break;
   }

   if ( j != heap->nrRegions ) {
      fprintf( stderr, "Loop detected in global LRU\n" );
      for ( i = 0 ; i < heap->nrRegions ; i++ ) {
	 fprintf( stderr, "list[%d] age %d next %d prev %d in_use %d\n",
		  i, list[i].age, list[i].next, list[i].prev, list[i].in_use );
      }
   }

   fprintf( stderr, "\n" );
}


/**
 * Called by the client whenever it touches a local texture.
 * 
 * \param t Texture object that the client has accessed
 */

void driUpdateTextureLRU( driTextureObject * t )
{
   driTexHeap   * heap;
   drmTextureRegionPtr list;
   unsigned   shift;
   unsigned   start;
   unsigned   end;
   unsigned   i;


   heap = t->heap;
   if ( heap != NULL ) {
      shift = heap->logGranularity;
      start = t->memBlock->ofs >> shift;
      end = (t->memBlock->ofs + t->memBlock->size - 1) >> shift;


      heap->local_age = ++heap->global_age[0];
      list = heap->global_regions;


      /* Update the context's local LRU 
       */

      move_to_head( & heap->texture_objects, t );


      for (i = start ; i <= end ; i++) {
	 list[i].age = heap->local_age;

	 /* remove_from_list(i)
	  */
	 list[(unsigned)list[i].next].prev = list[i].prev;
	 list[(unsigned)list[i].prev].next = list[i].next;

	 /* insert_at_head(list, i)
	  */
	 list[i].prev = heap->nrRegions;
	 list[i].next = list[heap->nrRegions].next;
	 list[(unsigned)list[heap->nrRegions].next].prev = i;
	 list[heap->nrRegions].next = i;
      }

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




/**
 * Keep track of swapped out texture objects.
 * 
 * \param t Texture object to be "swapped" out of its texture heap
 */

void driSwapOutTextureObject( driTextureObject * t )
{
   unsigned   face;


   if ( t->memBlock != NULL ) {
      assert( t->heap != NULL );
      mmFreeMem( t->memBlock );
      t->memBlock = NULL;

      if (t->timestamp > t->heap->timestamp)
	 t->heap->timestamp = t->timestamp;

      t->heap->texture_swaps[0]++;
      move_to_tail( t->heap->swapped_objects, t );
      t->heap = NULL;
   }
   else {
      assert( t->heap == NULL );
   }


   for ( face = 0 ; face < 6 ; face++ ) {
      t->dirty_images[face] = ~0;
   }
}




/**
 * Destroy hardware state associated with texture \a t.  Calls the
 * \a destroy_texture_object method associated with the heap from which
 * \a t was allocated.
 * 
 * \param t Texture object to be destroyed
 */

void driDestroyTextureObject( driTextureObject * t )
{
   driTexHeap * heap;


   if ( 0 ) {
      fprintf( stderr, "[%s:%d] freeing %p (tObj = %p, DriverData = %p)\n",
	       __FILE__, __LINE__,
	       (void *)t,
	       (void *)((t != NULL) ? t->tObj : NULL),
	       (void *)((t != NULL && t->tObj != NULL) ? t->tObj->DriverData : NULL ));
   }

   if ( t != NULL ) {
      if ( t->memBlock ) {
	 heap = t->heap;
	 assert( heap != NULL );

	 heap->texture_swaps[0]++;

	 mmFreeMem( t->memBlock );
	 t->memBlock = NULL;

	 if (t->timestamp > t->heap->timestamp)
	    t->heap->timestamp = t->timestamp;

	 heap->destroy_texture_object( heap->driverContext, t );
	 t->heap = NULL;
      }

      if ( t->tObj != NULL ) {
	 assert( t->tObj->DriverData == t );
	 t->tObj->DriverData = NULL;
      }

      remove_from_list( t );
      FREE( t );
   }

   if ( 0 ) {
      fprintf( stderr, "[%s:%d] done freeing %p\n", __FILE__, __LINE__, (void *)t );
   }
}




/**
 * Update the local heap's representation of texture memory based on
 * data in the SAREA.  This is done each time it is detected that some other
 * direct rendering client has held the lock.  This pertains to both our local
 * textures and the textures belonging to other clients.  Keep track of other
 * client's textures by pushing a placeholder texture onto the LRU list --
 * these are denoted by \a tObj being \a NULL.
 * 
 * \param heap Heap whose state is to be updated
 * \param offset Byte offset in the heap that has been stolen
 * \param size Size, in bytes, of the stolen block
 * \param in_use Non-zero if the block is pinned/reserved by the kernel
 */

static void driTexturesGone( driTexHeap * heap, int offset, int size, 
			     int in_use )
{
   driTextureObject * t;
   driTextureObject * tmp;


   foreach_s ( t, tmp, & heap->texture_objects ) {
      if ( (t->memBlock->ofs < (offset + size))
	   && ((t->memBlock->ofs + t->memBlock->size) > offset) ) {
	 /* It overlaps - kick it out.  If the texture object is just a
	  * place holder, then destroy it all together.  Otherwise, mark
	  * it as being swapped out.
	  */

	 if ( t->tObj != NULL ) {
	    driSwapOutTextureObject( t );
	 }
	 else {
	    driDestroyTextureObject( t );
	 }
      }
   }


   {
      t = (driTextureObject *) CALLOC( heap->texture_object_size );
      if ( t == NULL ) return;

      t->memBlock = mmAllocMem( heap->memory_heap, size, 0, offset );
      if ( t->memBlock == NULL ) {
	 fprintf( stderr, "Couldn't alloc placeholder: heap %u sz %x ofs %x\n", heap->heapId,
		  (int)size, (int)offset );
	 mmDumpMemInfo( heap->memory_heap );
	 FREE(t);
	 return;
      }
      t->heap = heap;
      if (in_use) 
	 t->reserved = 1; 
      insert_at_head( & heap->texture_objects, t );
   }
}




/**
 * Called by the client on lock contention to determine whether textures have
 * been stolen.  If another client has modified a region in which we have
 * textures, then we need to figure out which of our textures have been
 * removed and update our global LRU.
 * 
 * \param heap Texture heap to be updated
 */

void driAgeTextures( driTexHeap * heap )
{
   drmTextureRegionPtr list = heap->global_regions;
   unsigned       sz = 1U << (heap->logGranularity);
   unsigned       i, nr = 0;


   /* Have to go right round from the back to ensure stuff ends up
    * LRU in the local list...  Fix with a cursor pointer.
    */

   for (i = list[heap->nrRegions].prev ; 
	i != heap->nrRegions && nr < heap->nrRegions ; 
	i = list[i].prev, nr++) {
      /* If switching texturing schemes, then the SAREA might not have been
       * properly cleared, so we need to reset the global texture LRU.