root/src/dps8/dps8_memalign.h

/* */

INCLUDED FROM

DEFINITIONS

1. ALLOC_SIZE
2. ALLOC_SIZE

   1 /*
   2  * vim: filetype=c:tabstop=4:ai:expandtab
   3  * SPDX-License-Identifier: ICU
   4  * scspell-id: f720964c-f3ed-11ef-b468-922037bebb33
   5  *
   6  * ---------------------------------------------------------------------------
   7  *
   8  * Copyright (c) 2025 The DPS8M Development Team
   9  *
  10  * This software is made available under the terms of the ICU License.
  11  * See the LICENSE.md file at the top-level directory of this distribution.
  12  *
  13  * ---------------------------------------------------------------------------
  14  */
  15 
  16 #if !defined(_DPS8_MEMALIGN_H)
  17 # define _DPS8_MEMALIGN_H
  18 
  19 # include <stdlib.h>
  20 # include <stdatomic.h>
  21 # include "dps8_sir.h"
  22 
  23 # undef ALLOC_SIZE
  24 # if HAS_ATTRIBUTE(alloc_size)
  25 #  define ALLOC_SIZE(size) __attribute__((alloc_size(size)))
  26 # endif
  27 # if !defined(ALLOC_SIZE)
  28 #  define ALLOC_SIZE(size)
  29 # endif
  30 
  31 # undef ATTR_MALLOC
  32 # if HAS_ATTRIBUTE(malloc)
  33 #  define ATTR_MALLOC __attribute__((malloc))
  34 # endif
  35 # if !defined(ATTR_MALLOC)
  36 #  define ATTR_MALLOC
  37 # endif
  38 
  39 # if (!defined(_WIN32) && !defined(__CYGWIN__)) && !defined(__MINGW64__) && !defined(__MINGW32__) && \
  40      !defined(CROSS_MINGW64) && !defined(CROSS_MINGW32) && !defined(DUMA)
  41 #  include <unistd.h>
  42 
  43 #  if defined(_SC_PAGESIZE)
  44 #   define DPS8_MEMALIGN_PAGESIZE _SC_PAGESIZE
  45 #  elif defined(_SC_PAGE_SIZE)
  46 #   define DPS8_MEMALIGN_PAGESIZE _SC_PAGE_SIZE
  47 #  else
  48 #   error No _SC_PAGESIZE or _SC_PAGE_SIZE defined
  49 #  endif
  50 
  51 ATTR_MALLOC ALLOC_SIZE(1)
     /*  */
  52 static inline void *
  53 aligned_malloc(size_t size)
  54 {
  55     static atomic_size_t page_size = 0;
  56     size_t current_page_size = atomic_load(&page_size);
  57 
  58     if (current_page_size == 0) {
  59         long sys_page_size = sysconf(DPS8_MEMALIGN_PAGESIZE);
  60         size_t temp_ps;
  61         size_t expected = 0;
  62 
  63         if (sys_page_size < 1) {
  64             temp_ps = 4096UL;
  65         } else {
  66             temp_ps = (size_t)sys_page_size;
  67         }
  68 
  69         if (atomic_compare_exchange_strong(&page_size, &expected, temp_ps)) {
  70             current_page_size = temp_ps;
  71         } else {
  72             current_page_size = atomic_load(&page_size);
  73         }
  74     }
  75 
  76     void *ptr = NULL;
  77     if (posix_memalign(&ptr, current_page_size, size) != 0)
  78         return NULL;
  79 
  80     return ptr;
  81 }
  82 
  83 # else
  84 
  85 ATTR_MALLOC ALLOC_SIZE(1)
     /*  */
  86 static inline void *
  87 aligned_malloc(size_t size)
  88 {
  89     return malloc(size);
  90 }
  91 
  92 # endif
  93 #endif

/* */