src/memory.c

   1 /* Copyright (C) 1996-1997 Aleksey Volynskov
   2  * Copyright (C) 2011 Rambo
   3  * Copyright (C) 2020 SovietPony
   4  *
   5  * This program is free software: you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation, version 3 of the License ONLY.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "glob.h"
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <assert.h>
  23 #include "error.h"
  24 #include "files.h"
  25 #include "memory.h"
  26
  27 #include "common/wadres.h"
  28 #include "common/streams.h"
  29
  30 typedef struct Block {
  31   int id;
  32   int ref;
  33   char data[];
  34 } Block;
  35
  36 static Block *blocks[MAX_RESOURCES];
  37
  38 void M_startup (void) {
  39   memset(blocks, 0, sizeof(blocks));
  40 }
  41
  42 void M_shutdown (void) {
  43   // stub
  44 }
  45
  46 void *M_lock (int id) {
  47   assert(id >= -1 && id < MAX_RESOURCES);
  48   if (id >= 0) {
  49     Block *x = blocks[id];
  50     if (x) {
  51       x->ref += 1;
  52       return x->data;
  53     } else {
  54       x = malloc(sizeof(Block) + WADRES_getsize(id));
  55       if (x) {
  56         x->id = id;
  57         x->ref = 1;
  58         WADRES_getdata(id, x->data);
  59         blocks[id] = x;
  60         return x->data;
  61       }
  62     }
  63   }
  64   return NULL;
  65 }
  66
  67 void M_unlock (void *p) {
  68   if (p) {
  69     Block *x = p - sizeof(Block);
  70     int id = x->id;
  71     assert(id >= 0 && id < MAX_RESOURCES);
  72     x->ref -= 1;
  73     assert(x->ref >= 0);
  74 #if 0
  75     if (x->ref == 0) {
  76       blocks[id] = NULL;
  77       free(x);
  78     }
  79 #endif
  80   }
  81 }
  82
  83 int M_locked (int id) {
  84   assert(id >= -1 && id < MAX_RESOURCES);
  85   return (id >= 0) && (blocks[id] != NULL) && (blocks[id]->ref >= 1);
  86 }
  87
  88 int M_was_locked (int id) {
  89   assert(id >= -1 && id < MAX_RESOURCES);
  90   return (id >= 0) && (blocks[id] != NULL) && (blocks[id]->ref >= 0);
  91 }