Line data    Source code

       1             : /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
       2             : 
       3             : /***
       4             :   This file is part of systemd.
       5             : 
       6             :   Copyright 2010-2014 Lennart Poettering
       7             :   Copyright 2014 Michal Schmidt
       8             : 
       9             :   systemd is free software; you can redistribute it and/or modify it
      10             :   under the terms of the GNU Lesser General Public License as published by
      11             :   the Free Software Foundation; either version 2.1 of the License, or
      12             :   (at your option) any later version.
      13             : 
      14             :   systemd is distributed in the hope that it will be useful, but
      15             :   WITHOUT ANY WARRANTY; without even the implied warranty of
      16             :   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
      17             :   Lesser General Public License for more details.
      18             : 
      19             :   You should have received a copy of the GNU Lesser General Public License
      20             :   along with systemd; If not, see <http://www.gnu.org/licenses/>.
      21             : ***/
      22             : 
      23             : #include "mempool.h"
      24             : #include "macro.h"
      25             : #include "util.h"
      26             : 
      27             : struct pool {
      28             :         struct pool *next;
      29             :         unsigned n_tiles;
      30             :         unsigned n_used;
      31             : };
      32             : 
      33        7316 : void* mempool_alloc_tile(struct mempool *mp) {
      34             :         unsigned i;
      35             : 
      36             :         /* When a tile is released we add it to the list and simply
      37             :          * place the next pointer at its offset 0. */
      38             : 
      39        7316 :         assert(mp->tile_size >= sizeof(void*));
      40        7316 :         assert(mp->at_least > 0);
      41             : 
      42        7316 :         if (mp->freelist) {
      43             :                 void *r;
      44             : 
      45        6165 :                 r = mp->freelist;
      46        6165 :                 mp->freelist = * (void**) mp->freelist;
      47        6165 :                 return r;
      48             :         }
      49             : 
      50        2233 :         if (_unlikely_(!mp->first_pool) ||
      51        1082 :             _unlikely_(mp->first_pool->n_used >= mp->first_pool->n_tiles)) {
      52             :                 unsigned n;
      53             :                 size_t size;
      54             :                 struct pool *p;
      55             : 
      56          73 :                 n = mp->first_pool ? mp->first_pool->n_tiles : 0;
      57          73 :                 n = MAX(mp->at_least, n * 2);
      58          73 :                 size = PAGE_ALIGN(ALIGN(sizeof(struct pool)) + n*mp->tile_size);
      59          73 :                 n = (size - ALIGN(sizeof(struct pool))) / mp->tile_size;
      60             : 
      61          73 :                 p = malloc(size);
      62          73 :                 if (!p)
      63           0 :                         return NULL;
      64             : 
      65          73 :                 p->next = mp->first_pool;
      66          73 :                 p->n_tiles = n;
      67          73 :                 p->n_used = 0;
      68             : 
      69          73 :                 mp->first_pool = p;
      70             :         }
      71             : 
      72        1151 :         i = mp->first_pool->n_used++;
      73             : 
      74        1151 :         return ((uint8_t*) mp->first_pool) + ALIGN(sizeof(struct pool)) + i*mp->tile_size;
      75             : }
      76             : 
      77        7316 : void* mempool_alloc0_tile(struct mempool *mp) {
      78             :         void *p;
      79             : 
      80        7316 :         p = mempool_alloc_tile(mp);
      81        7316 :         if (p)
      82        7316 :                 memzero(p, mp->tile_size);
      83        7316 :         return p;
      84             : }
      85             : 
      86        7314 : void mempool_free_tile(struct mempool *mp, void *p) {
      87        7314 :         * (void**) p = mp->freelist;
      88        7314 :         mp->freelist = p;
      89        7314 : }
      90             : 
      91             : #ifdef VALGRIND
      92             : 
      93             : void mempool_drop(struct mempool *mp) {
      94             :         struct pool *p = mp->first_pool;
      95             :         while (p) {
      96             :                 struct pool *n;
      97             :                 n = p->next;
      98             :                 free(p);
      99             :                 p = n;
     100             :         }
     101             : }
     102             : 
     103             : #endif