1 /*

     2  * Copyright (C) 2003 Apple Computer, Inc.

     3  *

     4  * Portions are Copyright (C) 1998 Netscape Communications Corporation.

     5  *

     6  * This library is free software; you can redistribute it and/or

     7  * modify it under the terms of the GNU Lesser General Public

     8  * License as published by the Free Software Foundation; either

     9  * version 2.1 of the License, or (at your option) any later version.

    10  *

    11  * This library is distributed in the hope that it will be useful,

    12  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    14  * Lesser General Public License for more details.

    15  *

    16  * You should have received a copy of the GNU Lesser General Public

    17  * License along with this library; if not, write to the Free Software

    18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

    19  *

    20  * Alternatively, the contents of this file may be used under the terms

    21  * of either the Mozilla Public License Version 1.1, found at

    22  * http://www.mozilla.org/MPL/ (the "MPL") or the GNU General Public

    23  * License Version 2.0, found at http://www.fsf.org/copyleft/gpl.html

    24  * (the "GPL"), in which case the provisions of the MPL or the GPL are

    25  * applicable instead of those above.  If you wish to allow use of your

    26  * version of this file only under the terms of one of those two

    27  * licenses (the MPL or the GPL) and not to allow others to use your

    28  * version of this file under the LGPL, indicate your decision by

    29  * deletingthe provisions above and replace them with the notice and

    30  * other provisions required by the MPL or the GPL, as the case may be.

    31  * If you do not delete the provisions above, a recipient may use your

    32  * version of this file under any of the LGPL, the MPL or the GPL.

    33  */

    34 

    35 #include "config.h"

    36 #include "RenderArena.h"

    37 

    38 #include <stdlib.h>

    39 #include <string.h>

    40 #include <wtf/Assertions.h>

    41 

    42 #define ROUNDUP(x,y) ((((x)+((y)-1))/(y))*(y))

    43 

    44 namespace WebCore {

    45 

    46 #ifndef NDEBUG

    47 

    48 const int signature = 0xDBA00AEA;

    49 const int signatureDead = 0xDBA00AED;

    50 

    51 typedef struct {

    52     RenderArena* arena;

    53     size_t size;

    54     int signature;

    55 } RenderArenaDebugHeader;

    56 

    57 #endif

    58 

    59 RenderArena::RenderArena(unsigned arenaSize)

    60 {

    61     // Initialize the arena pool

    62     INIT_ARENA_POOL(&m_pool, "RenderArena", arenaSize);

    63 

    64     // Zero out the recyclers array

    65     memset(m_recyclers, 0, sizeof(m_recyclers));

    66 }

    67 

    68 RenderArena::~RenderArena()

    69 {

    70     FinishArenaPool(&m_pool);

    71 }

    72 

    73 void* RenderArena::allocate(size_t size)

    74 {

    75 #ifndef NDEBUG

    76     // Use standard malloc so that memory debugging tools work.

    77     ASSERT(this);

    78     void* block = ::malloc(sizeof(RenderArenaDebugHeader) + size);

    79     RenderArenaDebugHeader* header = (RenderArenaDebugHeader*)block;

    80     header->arena = this;

    81     header->size = size;

    82     header->signature = signature;

    83     return header + 1;

    84 #else

    85     void* result = 0;

    86 

    87     // Ensure we have correct alignment for pointers.  Important for Tru64

    88     size = ROUNDUP(size, sizeof(void*));

    89 

    90     // Check recyclers first

    91     if (size < gMaxRecycledSize) {

    92         const int index = size >> 2;

    93 

    94         result = m_recyclers[index];

    95         if (result) {

    96             // Need to move to the next object

    97             void* next = *((void**)result);

    98             m_recyclers[index] = next;

    99         }

   100     }

   101 

   102     if (!result) {

   103         // Allocate a new chunk from the arena

   104         ARENA_ALLOCATE(result, &m_pool, size);

   105     }

   106 

   107     return result;

   108 #endif

   109 }

   110 

   111 void RenderArena::free(size_t size, void* ptr)

   112 {

   113 #ifndef NDEBUG

   114     // Use standard free so that memory debugging tools work.

   115     RenderArenaDebugHeader* header = (RenderArenaDebugHeader*)ptr - 1;

   116     ASSERT(header->signature == signature);

   117     ASSERT(header->size == size);

   118     ASSERT(header->arena == this);

   119     header->signature = signatureDead;

   120     ::free(header);

   121 #else

   122     // Ensure we have correct alignment for pointers.  Important for Tru64

   123     size = ROUNDUP(size, sizeof(void*));

   124 

   125     // See if it's a size that we recycle

   126     if (size < gMaxRecycledSize) {

   127         const int index = size >> 2;

   128         void* currentTop = m_recyclers[index];

   129         m_recyclers[index] = ptr;

   130         *((void**)ptr) = currentTop;

   131     }

   132 #endif

   133 }

   134 

   135 } // namespace WebCore