Subversion Repositories Kolibri OS

Rev

Go to most recent revision | Blame | Last modification | View Log | Download | RSS feed

  1. /* TLS emulation.
  2.    Copyright (C) 2006, 2008, 2009 Free Software Foundation, Inc.
  3.    Contributed by Jakub Jelinek <jakub@redhat.com>.
  4.  
  5. This file is part of GCC.
  6.  
  7. GCC is free software; you can redistribute it and/or modify it under
  8. the terms of the GNU General Public License as published by the Free
  9. Software Foundation; either version 3, or (at your option) any later
  10. version.
  11.  
  12. GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13. WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14. FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15. for more details.
  16.  
  17. Under Section 7 of GPL version 3, you are granted additional
  18. permissions described in the GCC Runtime Library Exception, version
  19. 3.1, as published by the Free Software Foundation.
  20.  
  21. You should have received a copy of the GNU General Public License and
  22. a copy of the GCC Runtime Library Exception along with this program;
  23. see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24. <http://www.gnu.org/licenses/>.  */
  25.  
  26.  
  27. #include <stdlib.h>
  28. #include <memory.h>
  29. #include <malloc.h>
  30. #include <errno.h>
  31. #include <gthr.h>
  32.  
  33. void *tls_alloc(void);
  34. void __mutex_lock(volatile int *val);
  35.  
  36.  
  37. static inline void yield(void)
  38. {
  39.     __asm__ __volatile__(
  40.     "int $0x40"
  41.     ::"a"(68), "b"(1));
  42. };
  43.  
  44. int __gthread_once (__gthread_once_t *once, void (*func) (void))
  45. {
  46.     if (once == NULL || func == NULL)
  47.         return EINVAL;
  48.  
  49.     if (! once->done)
  50.     {
  51.         if(++once->started == 0)
  52.         {
  53.             (*func) ();
  54.             once->done = 1;
  55.         }
  56.         else
  57.         {
  58.       /* Another thread is currently executing the code, so wait for it
  59.          to finish; yield the CPU in the meantime.  If performance
  60.          does become an issue, the solution is to use an Event that
  61.          we wait on here (and set above), but that implies a place to
  62.          create the event before this routine is called.  */
  63.             while (! once->done)
  64.                 yield();
  65.         }
  66.     }
  67.     return 0;
  68. }
  69.  
  70.  
  71. #define __GTHREAD_ONCE_INIT {0, -1}
  72.  
  73. typedef unsigned int word __attribute__((mode(word)));
  74. typedef unsigned int pointer __attribute__((mode(pointer)));
  75.  
  76. struct __emutls_object
  77. {
  78.   word size;
  79.   word align;
  80.   union {
  81.     pointer offset;
  82.     void *ptr;
  83.   } loc;
  84.   void *templ;
  85. };
  86.  
  87. struct __emutls_array
  88. {
  89.   pointer size;
  90.   void **data[];
  91. };
  92.  
  93. void *__emutls_get_address (struct __emutls_object *);
  94. void __emutls_register_common (struct __emutls_object *, word, word, void *);
  95.  
  96. static __gthread_mutex_t emutls_mutex;
  97. static __gthread_key_t   emutls_key;
  98. static pointer           emutls_size;
  99.  
  100. static void emutls_destroy (void *ptr)
  101. {
  102.     struct __emutls_array *arr = ptr;
  103.     pointer size = arr->size;
  104.     pointer i;
  105.  
  106.     for (i = 0; i < size; ++i)
  107.     {
  108.         if (arr->data[i])
  109.             free (arr->data[i][-1]);
  110.     }
  111.     free (ptr);
  112. };
  113.  
  114. static void emutls_init (void)
  115. {
  116.     if (__gthread_key_create (&emutls_key, emutls_destroy) != 0)
  117.         abort ();
  118. }
  119.  
  120. static void *emutls_alloc (struct __emutls_object *obj)
  121. {
  122.     void *ptr;
  123.     void *ret;
  124.  
  125.   /* We could use here posix_memalign if available and adjust
  126.      emutls_destroy accordingly.  */
  127.     if (obj->align <= sizeof (void *))
  128.     {
  129.         ptr = malloc (obj->size + sizeof (void *));
  130.         if (ptr == NULL)
  131.             abort ();
  132.         ((void **) ptr)[0] = ptr;
  133.         ret = ptr + sizeof (void *);
  134.     }
  135.     else
  136.     {
  137.         ptr = malloc (obj->size + sizeof (void *) + obj->align - 1);
  138.         if (ptr == NULL)
  139.             abort ();
  140.         ret = (void *) (((pointer) (ptr + sizeof (void *) + obj->align - 1))
  141.               & ~(pointer)(obj->align - 1));
  142.         ((void **) ret)[-1] = ptr;
  143.     }
  144.  
  145.     if (obj->templ)
  146.         memcpy (ret, obj->templ, obj->size);
  147.     else
  148.         memset (ret, 0, obj->size);
  149.  
  150.     return ret;
  151. }
  152.  
  153. void * __emutls_get_address (struct __emutls_object *obj)
  154. {
  155.     pointer offset = obj->loc.offset;
  156.  
  157.     if (__builtin_expect (offset == 0, 0))
  158.     {
  159.         static __gthread_once_t once = __GTHREAD_ONCE_INIT;
  160.         __gthread_once (&once, emutls_init);
  161.         __gthread_mutex_lock (&emutls_mutex);
  162.         offset = obj->loc.offset;
  163.         if (offset == 0)
  164.         {
  165.             offset = ++emutls_size;
  166.             obj->loc.offset = offset;
  167.         }
  168.         __gthread_mutex_unlock (&emutls_mutex);
  169.     }
  170.  
  171.     struct __emutls_array *arr = __gthread_getspecific (emutls_key);
  172.     if (__builtin_expect (arr == NULL, 0))
  173.     {
  174.         pointer size = offset + 32;
  175.         arr = calloc (size + 1, sizeof (void *));
  176.         if (arr == NULL)
  177.             abort ();
  178.         arr->size = size;
  179.         __gthread_setspecific (emutls_key, (void *) arr);
  180.     }
  181.     else if (__builtin_expect (offset > arr->size, 0))
  182.     {
  183.         pointer orig_size = arr->size;
  184.         pointer size = orig_size * 2;
  185.         if (offset > size)
  186.             size = offset + 32;
  187.         arr = realloc (arr, (size + 1) * sizeof (void *));
  188.         if (arr == NULL)
  189.             abort ();
  190.         arr->size = size;
  191.         memset (arr->data + orig_size, 0,
  192.                (size - orig_size) * sizeof (void *));
  193.         __gthread_setspecific (emutls_key, (void *) arr);
  194.     }
  195.  
  196.     void *ret = arr->data[offset - 1];
  197.     if (__builtin_expect (ret == NULL, 0))
  198.     {
  199.         ret = emutls_alloc (obj);
  200.         arr->data[offset - 1] = ret;
  201.     }
  202.   return ret;
  203. }
  204.  
  205.  
  206. void __emutls_register_common (struct __emutls_object *obj,
  207.               word size, word align, void *templ)
  208. {
  209.     if (obj->size < size)
  210.     {
  211.         obj->size = size;
  212.         obj->templ = NULL;
  213.     }
  214.     if (obj->align < align)
  215.         obj->align = align;
  216.     if (templ && size == obj->size)
  217.         obj->templ = templ;
  218. }
  219.