nptl/nptl-stack.h

   1 /* Stack cache management for NPTL.
   2    Copyright (C) 2002-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef _NPTL_STACK_H
  20 #define _NPTL_STACK_H
  21
  22 #include <nptl/descr.h>
  23 #include <ldsodefs.h>
  24 #include <list.h>
  25 #include <stdbool.h>
  26
  27 /* Maximum size of the cache, in bytes.  40 MiB by default.  */
  28 extern size_t __nptl_stack_cache_maxsize attribute_hidden;
  29
  30 /* Should allow stacks to use hugetlb. (1) is default.  */
  31 extern int32_t __nptl_stack_hugetlb;
  32
  33 /* Check whether the stack is still used or not.  */
  34 static inline bool
  35 __nptl_stack_in_use (struct pthread *pd)
  36 {
  37   return pd->tid <= 0;
  38 }
  39
  40 /* Remove the stack ELEM from its list.  */
  41 void __nptl_stack_list_del (list_t *elem);
  42 libc_hidden_proto (__nptl_stack_list_del)
  43
  44 /* Add ELEM to a stack list.  LIST can be either &GL (dl_stack_used)
  45    or &GL (dl_stack_cache).  */
  46 void __nptl_stack_list_add (list_t *elem, list_t *list);
  47 libc_hidden_proto (__nptl_stack_list_add)
  48
  49 /* Free allocated stack.  */
  50 extern void __nptl_deallocate_stack (struct pthread *pd);
  51 libc_hidden_proto (__nptl_deallocate_stack)
  52
  53 /* Free stacks until cache size is lower than LIMIT.  */
  54 void __nptl_free_stacks (size_t limit) attribute_hidden;
  55
  56 /* Compute the size of the static TLS area based on data from the
  57    dynamic loader.  */
  58 static inline size_t
  59 __nptl_tls_static_size_for_stack (void)
  60 {
  61   return roundup (GLRO (dl_tls_static_size), GLRO (dl_tls_static_align));
  62 }
  63
  64 #endif /* _NPTL_STACK_H */