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Diffstat (limited to 'src/cgame/cg_mem.c')
| -rw-r--r-- | src/cgame/cg_mem.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/src/cgame/cg_mem.c b/src/cgame/cg_mem.c new file mode 100644 index 0000000..6cf5ddd --- /dev/null +++ b/src/cgame/cg_mem.c @@ -0,0 +1,202 @@ +/* +=========================================================================== +Copyright (C) 1999-2005 Id Software, Inc. +Copyright (C) 2000-2006 Tim Angus + +This file is part of Tremulous. + +Tremulous is free software; you can redistribute it +and/or modify it under the terms of the GNU General Public License as +published by the Free Software Foundation; either version 2 of the License, +or (at your option) any later version. + +Tremulous is distributed in the hope that it will be +useful, but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with Tremulous; if not, write to the Free Software +Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +=========================================================================== +*/ + +#include "cg_local.h" + +#define POOLSIZE (256 * 1024) +#define FREEMEMCOOKIE ((int)0xDEADBE3F) // Any unlikely to be used value +#define ROUNDBITS 31 // Round to 32 bytes + +struct freememnode +{ + // Size of ROUNDBITS + int cookie, size; // Size includes node (obviously) + struct freememnode *prev, *next; +}; + +static char memoryPool[ POOLSIZE ]; +static struct freememnode *freehead; +static int freemem; + +void *CG_Alloc( int size ) +{ + // Find a free block and allocate. + // Does two passes, attempts to fill same-sized free slot first. + + struct freememnode *fmn, *prev, *next, *smallest; + int allocsize, smallestsize; + char *endptr; + int *ptr; + + allocsize = ( size + sizeof(int) + ROUNDBITS ) & ~ROUNDBITS; // Round to 32-byte boundary + ptr = NULL; + + smallest = NULL; + smallestsize = POOLSIZE + 1; // Guaranteed not to miss any slots :) + for( fmn = freehead; fmn; fmn = fmn->next ) + { + if( fmn->cookie != FREEMEMCOOKIE ) + CG_Error( "CG_Alloc: Memory corruption detected!\n" ); + + if( fmn->size >= allocsize ) + { + // We've got a block + if( fmn->size == allocsize ) + { + // Same size, just remove + + prev = fmn->prev; + next = fmn->next; + if( prev ) + prev->next = next; // Point previous node to next + if( next ) + next->prev = prev; // Point next node to previous + if( fmn == freehead ) + freehead = next; // Set head pointer to next + ptr = (int *) fmn; + break; // Stop the loop, this is fine + } + else + { + // Keep track of the smallest free slot + if( fmn->size < smallestsize ) + { + smallest = fmn; + smallestsize = fmn->size; + } + } + } + } + + if( !ptr && smallest ) + { + // We found a slot big enough + smallest->size -= allocsize; + endptr = (char *) smallest + smallest->size; + ptr = (int *) endptr; + } + + if( ptr ) + { + freemem -= allocsize; + if( cg_debugAlloc.integer ) + CG_Printf( "CG_Alloc of %i bytes (%i left)\n", allocsize, freemem ); + memset( ptr, 0, allocsize ); + *ptr++ = allocsize; // Store a copy of size for deallocation + return( (void *) ptr ); + } + + CG_Error( "CG_Alloc: failed on allocation of %i bytes\n", size ); + return( NULL ); +} + +void CG_Free( void *ptr ) +{ + // Release allocated memory, add it to the free list. + + struct freememnode *fmn; + char *freeend; + int *freeptr; + + freeptr = ptr; + freeptr--; + + freemem += *freeptr; + if( cg_debugAlloc.integer ) + CG_Printf( "CG_Free of %i bytes (%i left)\n", *freeptr, freemem ); + + for( fmn = freehead; fmn; fmn = fmn->next ) + { + freeend = ((char *) fmn) + fmn->size; + if( freeend == (char *) freeptr ) + { + // Released block can be merged to an existing node + + fmn->size += *freeptr; // Add size of node. + return; + } + } + // No merging, add to head of list + + fmn = (struct freememnode *) freeptr; + fmn->size = *freeptr; // Set this first to avoid corrupting *freeptr + fmn->cookie = FREEMEMCOOKIE; + fmn->prev = NULL; + fmn->next = freehead; + freehead->prev = fmn; + freehead = fmn; +} + +void CG_InitMemory( void ) +{ + // Set up the initial node + + freehead = (struct freememnode *) memoryPool; + freehead->cookie = FREEMEMCOOKIE; + freehead->size = POOLSIZE; + freehead->next = NULL; + freehead->prev = NULL; + freemem = sizeof(memoryPool); +} + +void CG_DefragmentMemory( void ) +{ + // If there's a frenzy of deallocation and we want to + // allocate something big, this is useful. Otherwise... + // not much use. + + struct freememnode *startfmn, *endfmn, *fmn; + + for( startfmn = freehead; startfmn; ) + { + endfmn = (struct freememnode *)(((char *) startfmn) + startfmn->size); + for( fmn = freehead; fmn; ) + { + if( fmn->cookie != FREEMEMCOOKIE ) + CG_Error( "CG_DefragmentMemory: Memory corruption detected!\n" ); + + if( fmn == endfmn ) + { + // We can add fmn onto startfmn. + + if( fmn->prev ) + fmn->prev->next = fmn->next; + if( fmn->next ) + { + if( !(fmn->next->prev = fmn->prev) ) + freehead = fmn->next; // We're removing the head node + } + startfmn->size += fmn->size; + memset( fmn, 0, sizeof(struct freememnode) ); // A redundant call, really. + + startfmn = freehead; + endfmn = fmn = NULL; // Break out of current loop + } + else + fmn = fmn->next; + } + + if( endfmn ) + startfmn = startfmn->next; // endfmn acts as a 'restart' flag here + } +} |