sal/rtl/strimp.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19 #include <sal/config.h>
  20
  21 #include <assert.h>
  22 #include <rtl/alloc.h>
  23 #include <rtl/ustring.h>
  24 #include <rtllifecycle.h>
  25
  26 #include "strimp.hxx"
  27 #include "alloc_impl.hxx"
  28 #include "alloc_arena.hxx"
  29
  30 /*
  31  * TODO: add a slower, more awful, but more space efficient
  32  * custom allocator for the pre-init phase. Existing slab
  33  * allocator's minimum alloc size is 24bytes, and by default
  34  * is 32 bytes.
  35  */
  36 static rtl_arena_type *pre_arena = nullptr;
  37
  38 rtl_allocateStringFn rtl_allocateString = malloc;
  39 rtl_freeStringFn rtl_freeString = free;
  40
  41 extern "C" {
  42 static void *pre_allocateStringFn(size_t n)
  43 {
  44     sal_Size size = RTL_MEMORY_ALIGN(n + 4, 4);
  45     char *addr = static_cast<char*>(rtl_arena_alloc(pre_arena, &size));
  46     assert(size>= 12);
  47     reinterpret_cast<sal_uInt32*>(addr)[0] = size - 12;
  48     return addr + 4;
  49 }
  50
  51 static void pre_freeStringFn(void *data)
  52 {
  53     char    *addr = static_cast<char*>(data) - 4;
  54     sal_uInt32 size = reinterpret_cast<sal_uInt32*>(addr)[0] + 12;
  55
  56     rtl_arena_free(pre_arena, addr, size);
  57 }
  58 } // extern "C"
  59
  60 static void mark_static(void *addr, sal_Size /* size */)
  61 {
  62     char *inner = static_cast<char*>(addr) + 4;
  63     rtl_uString *str = reinterpret_cast<rtl_uString *>(inner);
  64     str->refCount |= SAL_STRING_STATIC_FLAG;
  65 }
  66
  67 void SAL_CALL rtl_alloc_preInit (sal_Bool start) SAL_THROW_EXTERN_C()
  68 {
  69     if (start)
  70     {
  71         rtl_allocateString = pre_allocateStringFn;
  72         rtl_freeString = pre_freeStringFn;
  73         pre_arena = rtl_arena_create("pre-init strings", 4, 0,
  74                                      nullptr, rtl_arena_alloc,
  75                                      rtl_arena_free, 0);
  76
  77         // To be consistent (and to ensure the rtl_cache threads are started).
  78         ensureCacheSingleton();
  79     }
  80     else
  81     {
  82         rtl_arena_foreach(pre_arena, mark_static);
  83         rtl_allocateString = malloc;
  84         rtl_freeString = free;
  85
  86         // TODO: also re-initialize main allocator as well.
  87     }
  88 }
  89
  90 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */