vg_mem.h

   1 #ifndef VG_MEM_H
   2 #define VG_MEM_H
   3
   4 #include "vg.h"
   5 #include "vg_stdint.h"
   6 #include "vg_platform.h"
   7
   8 #include <stdlib.h>
   9 #include <malloc.h>
  10
  11 #define VG_MAX_ALLOCATIONS 64
  12 #define VG_FUZZ_ALLOCATIONS
  13
  14 typedef struct vg_linear_allocator vg_linear_allocator;
  15 typedef struct vg_allocation_meta vg_allocation_meta;
  16
  17 struct
  18 {
  19    void *rtmemory,
  20         *scratch;
  21
  22    int   use_libc_malloc;
  23    u32   quota;
  24 }
  25 static vg_mem;
  26
  27 struct vg_allocation_meta
  28 {
  29    void *data;
  30    enum allocation_type
  31    {
  32       k_allocation_type_block = 0,
  33       k_allocation_type_linear = 1
  34    }
  35    type;
  36 };
  37
  38 #define VG_MEMORY_SYSTEM    0x1  /* systems memory, slow and low counts */
  39 #define VG_MEMORY_REALTIME  0x2  /* per-frame. no max allocs, only size. fast */
  40
  41 /* systems memory cannot be declared inside realtime memory regions */
  42
  43 /*
  44  * Stored just behind the array. 32 bytes.
  45  */
  46 #pragma pack(push,1)
  47 struct vg_linear_allocator
  48 {
  49    u32 size;
  50    /*     */
  51    /*     */
  52    /*     */
  53    u32 cur;
  54    /*    */
  55    /*    */
  56    /*    */
  57    u16 allocation_count;
  58    /*                 */
  59    u16 flags;
  60    /*      */
  61    u32 last_alloc_size;
  62    /*                */
  63    /*                */
  64    /*                */
  65    void *last_alloc;
  66    /*             */
  67    /*             */
  68    /*             */
  69    /*             */
  70    /*             */
  71    /*             */
  72    /*             */
  73    vg_allocation_meta *alloc_table;
  74    /*                            */
  75    /*                            */
  76    /*                            */
  77    /*                            */
  78    /*                            */
  79    /*                            */
  80    /*                            */
  81
  82 #ifdef _WIN32
  83    /* 32 bit pointers! */
  84    u8 padding[ 8 ];
  85 #endif
  86 };
  87 #pragma pack(pop)
  88
  89 VG_STATIC void vg_fatal_exit_loop( const char *error );
  90 VG_STATIC void vg_error(const char *fmt, ...);
  91 VG_STATIC void vg_info(const char *fmt, ...);
  92
  93 /* Returns allocator structure from data pointer */
  94 static vg_linear_allocator *vg_linear_header( void *data )
  95 {
  96    vg_linear_allocator *ptr = data;
  97    ptr --;
  98
  99    return ptr;
 100 }
 101
 102 /* allocate something from a linear allocator */
 103 __attribute__((warn_unused_result))
 104 VG_STATIC void *vg_linear_alloc( void *buffer, u32 size )
 105 {
 106    vg_linear_allocator *alloc = vg_linear_header( buffer );
 107
 108    if( (alloc->cur + size) > alloc->size )
 109    {
 110       vg_error( "%u + %u > %u\n", alloc->cur, size, alloc->size );
 111       vg_fatal_exit_loop( "linear allocator overflow" );
 112    }
 113
 114    if( alloc->flags & VG_MEMORY_SYSTEM )
 115       if( (alloc->allocation_count + 1) > VG_MAX_ALLOCATIONS )
 116          vg_fatal_exit_loop( "Max linear allocations reached" );
 117
 118    void *data;
 119
 120    if( vg_mem.use_libc_malloc && (alloc->flags & VG_MEMORY_SYSTEM) )
 121    {
 122       data = malloc( size );
 123
 124       vg_allocation_meta *meta = &alloc->alloc_table[ alloc->allocation_count ];
 125       meta->type = k_allocation_type_block;
 126       meta->data = data;
 127    }
 128    else
 129    {
 130       data = buffer + alloc->cur;
 131    }
 132
 133    alloc->allocation_count ++;
 134    alloc->last_alloc = data;
 135    alloc->last_alloc_size = size;
 136    alloc->cur += size;
 137
 138    return data;
 139 }
 140
 141
 142 /* resize latest block of memory from linear */
 143 __attribute__((warn_unused_result))
 144 VG_STATIC void *vg_linear_resize( void *buffer, void *data, u32 newsize )
 145 {
 146    vg_linear_allocator *alloc = vg_linear_header( buffer );
 147
 148    if( alloc->last_alloc != data )
 149       vg_fatal_exit_loop( "This block has been fixed!" );
 150
 151    if( (alloc->cur - alloc->last_alloc_size + newsize) > alloc->size )
 152       vg_fatal_exit_loop( "Cannot resize, overflow" );
 153
 154    alloc->cur -= alloc->last_alloc_size;
 155    alloc->cur += newsize;
 156    alloc->last_alloc_size = newsize;
 157
 158    if( vg_mem.use_libc_malloc && (alloc->flags & VG_MEMORY_SYSTEM) )
 159    {
 160       data = realloc( data, newsize );
 161       if( !data )
 162          vg_fatal_exit_loop( "realloc failed" );
 163
 164       alloc->alloc_table[ alloc->allocation_count-1 ].data = data;
 165       alloc->last_alloc = data;
 166       return data;
 167    }
 168    else
 169    {
 170       return data;
 171    }
 172 }
 173
 174 /* its possible to delete just the last item */
 175 VG_STATIC void vg_linear_del( void *buffer, void *data )
 176 {
 177    vg_linear_allocator *alloc = vg_linear_header( buffer );
 178
 179    if( alloc->last_alloc != data )
 180       vg_fatal_exit_loop( "This block has been fixed!" );
 181
 182    if( vg_mem.use_libc_malloc && (alloc->flags & VG_MEMORY_SYSTEM) )
 183    {
 184       vg_allocation_meta *meta = &alloc->alloc_table[alloc->allocation_count-1];
 185       if( meta->type == k_allocation_type_linear )
 186          vg_fatal_exit_loop( "Cannot free a linear allocator in this conext" );
 187
 188       free( data );
 189    }
 190
 191    alloc->allocation_count --;
 192    alloc->cur -= alloc->last_alloc_size;
 193    alloc->last_alloc = NULL;
 194    alloc->last_alloc_size = 0;
 195 }
 196
 197 /* extend latest block of memory from linear */
 198 __attribute__((warn_unused_result))
 199 VG_STATIC void *vg_linear_extend( void *buffer, void *data, u32 extra )
 200 {
 201    vg_linear_allocator *alloc = vg_linear_header( buffer );
 202
 203    if( alloc->last_alloc != data )
 204       vg_fatal_exit_loop( "This block has been fixed!" );
 205
 206    u32 new_size = alloc->last_alloc_size + extra;
 207    return vg_linear_resize( buffer, data, new_size );
 208 }
 209
 210 /* get the current usage of allocator */
 211 VG_STATIC u32 vg_linear_get_cur( void *buffer )
 212 {
 213    vg_linear_allocator *alloc = vg_linear_header( buffer );
 214    return alloc->cur;
 215 }
 216
 217 /* get the capacity of allocator. */
 218 VG_STATIC u32 vg_linear_get_capacity( void *buffer )
 219 {
 220    vg_linear_allocator *alloc = vg_linear_header( buffer );
 221    return alloc->size;
 222 }
 223
 224 /* get the remaining size of the allocator */
 225 VG_STATIC u32 vg_linear_remaining( void *buffer )
 226 {
 227    vg_linear_allocator *alloc = vg_linear_header( buffer );
 228    return alloc->size - alloc->cur;
 229 }
 230
 231 /* yeet all memory from linear allocator */
 232 VG_STATIC void vg_linear_clear( void *buffer )
 233 {
 234    vg_linear_allocator *alloc = vg_linear_header( buffer );
 235
 236    /* libc mode we recursively free any allocations made */
 237    if( vg_mem.use_libc_malloc && (alloc->flags & VG_MEMORY_SYSTEM) )
 238    {
 239       for( u32 i=0; i<alloc->allocation_count; i++ )
 240       {
 241          vg_allocation_meta *meta = &alloc->alloc_table[i];
 242
 243          if( meta->type == k_allocation_type_block )
 244          {
 245             free( meta->data );
 246          }
 247          else
 248          {
 249             vg_linear_clear( meta->data );
 250             vg_linear_allocator *sub = vg_linear_header( meta->data );
 251
 252             free( sub->alloc_table );
 253             free( sub );
 254          }
 255       }
 256    }
 257
 258    alloc->last_alloc = NULL;
 259    alloc->last_alloc_size = 0;
 260    alloc->allocation_count = 0;
 261    alloc->cur = 0;
 262 }
 263
 264 /* allocate a FIXED SIZE linear allocator */
 265 VG_STATIC void *vg_create_linear_allocator( void *lin_alloc, u32 size,
 266                                             u16 flags )
 267 {
 268    assert( sizeof( vg_linear_allocator ) == 32 );
 269
 270    vg_linear_allocator *header;
 271    u32 block_size = size + sizeof(vg_linear_allocator);
 272
 273    /* Creating it inside an existing one */
 274    if( lin_alloc )
 275    {
 276       vg_linear_allocator *alloc = vg_linear_header( lin_alloc );
 277
 278       if( alloc->cur + block_size > alloc->size )
 279          vg_fatal_exit_loop( "Out of memory" );
 280
 281       if( alloc->allocation_count + 1 > VG_MAX_ALLOCATIONS )
 282          vg_fatal_exit_loop( "Max allocations in linear allocator" );
 283
 284       if( (flags && VG_MEMORY_SYSTEM) && (alloc->flags & VG_MEMORY_REALTIME) )
 285          vg_fatal_exit_loop( "Cannot declare realtime allocator inside systems"
 286                              " allocator" );
 287
 288       if( vg_mem.use_libc_malloc )
 289       {
 290          vg_allocation_meta *meta =
 291             &alloc->alloc_table[ alloc->allocation_count ];
 292
 293          if( flags & VG_MEMORY_REALTIME )
 294             header = malloc( block_size );
 295          else
 296             header = malloc( sizeof(vg_linear_allocator) );
 297
 298          meta->data = header+1;
 299          meta->type = k_allocation_type_linear;
 300       }
 301       else
 302       {
 303          header = lin_alloc + alloc->cur;
 304       }
 305
 306       alloc->cur += block_size;
 307       alloc->last_alloc = NULL; /* cant resize this block! */
 308       alloc->last_alloc_size = block_size;
 309
 310       alloc->allocation_count ++;
 311    }
 312    else
 313    {
 314       if( vg_mem.use_libc_malloc && (flags & VG_MEMORY_SYSTEM) )
 315          header = malloc( sizeof(vg_linear_allocator) );
 316       else
 317          header = malloc( block_size );
 318    }
 319
 320    header->allocation_count = 0;
 321    header->cur = 0;
 322    header->last_alloc = NULL;
 323    header->last_alloc_size = 0;
 324    header->size = size;
 325    header->flags = flags;
 326
 327    if( vg_mem.use_libc_malloc && (flags & VG_MEMORY_SYSTEM) )
 328    {
 329       u32 table_size = sizeof(vg_allocation_meta)*VG_MAX_ALLOCATIONS;
 330       header->alloc_table = malloc( table_size );
 331    }
 332    else
 333       header->alloc_table = NULL;
 334
 335    return header+1;
 336 }
 337
 338 /* request all the memory we need in advance */
 339 VG_STATIC void vg_set_mem_quota( u32 size )
 340 {
 341    vg_mem.quota = size;
 342 }
 343
 344 VG_STATIC void vg_alloc_quota(void)
 345 {
 346    u32 size_scratch = 10*1024*1024;
 347    u32 size = VG_MAX( vg_mem.quota, size_scratch );
 348
 349    vg_mem.rtmemory = vg_create_linear_allocator( NULL, size, VG_MEMORY_SYSTEM );
 350    vg_mem.scratch = vg_create_linear_allocator( vg_mem.rtmemory,
 351                                                 size_scratch,
 352                                                 VG_MEMORY_SYSTEM );
 353 }
 354
 355 #endif /* VG_MEM_H */