sem_init.c 2.6 KB

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  1. /* Copyright (C) 2002-2019 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
  4. The GNU C Library is free software; you can redistribute it and/or
  5. modify it under the terms of the GNU Lesser General Public
  6. License as published by the Free Software Foundation; either
  7. version 2.1 of the License, or (at your option) any later version.
  8. The GNU C Library is distributed in the hope that it will be useful,
  9. but WITHOUT ANY WARRANTY; without even the implied warranty of
  10. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  11. Lesser General Public License for more details.
  12. You should have received a copy of the GNU Lesser General Public
  13. License along with the GNU C Library; if not, see
  14. <http://www.gnu.org/licenses/>. */
  15. #include <errno.h>
  16. #include <semaphore.h>
  17. #include <shlib-compat.h>
  18. #include "semaphoreP.h"
  19. #include <kernel-features.h>
  20. #include <futex-internal.h>
  21. int
  22. __new_sem_init (sem_t *sem, int pshared, unsigned int value)
  23. {
  24. ASSERT_PTHREAD_INTERNAL_SIZE (sem_t, struct new_sem);
  25. /* Parameter sanity check. */
  26. if (__glibc_unlikely (value > SEM_VALUE_MAX))
  27. {
  28. __set_errno (EINVAL);
  29. return -1;
  30. }
  31. pshared = pshared != 0 ? PTHREAD_PROCESS_SHARED : PTHREAD_PROCESS_PRIVATE;
  32. int err = futex_supports_pshared (pshared);
  33. if (err != 0)
  34. {
  35. __set_errno (err);
  36. return -1;
  37. }
  38. /* Map to the internal type. */
  39. struct new_sem *isem = (struct new_sem *) sem;
  40. /* Use the values the caller provided. */
  41. #if __HAVE_64B_ATOMICS
  42. isem->data = value;
  43. #else
  44. isem->value = value << SEM_VALUE_SHIFT;
  45. /* pad is used as a mutex on pre-v9 sparc and ignored otherwise. */
  46. isem->pad = 0;
  47. isem->nwaiters = 0;
  48. #endif
  49. isem->private = (pshared == PTHREAD_PROCESS_PRIVATE
  50. ? FUTEX_PRIVATE : FUTEX_SHARED);
  51. return 0;
  52. }
  53. versioned_symbol (libpthread, __new_sem_init, sem_init, GLIBC_2_1);
  54. #if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1)
  55. int
  56. attribute_compat_text_section
  57. __old_sem_init (sem_t *sem, int pshared, unsigned int value)
  58. {
  59. ASSERT_PTHREAD_INTERNAL_SIZE (sem_t, struct new_sem);
  60. /* Parameter sanity check. */
  61. if (__glibc_unlikely (value > SEM_VALUE_MAX))
  62. {
  63. __set_errno (EINVAL);
  64. return -1;
  65. }
  66. /* Map to the internal type. */
  67. struct old_sem *isem = (struct old_sem *) sem;
  68. /* Use the value the user provided. */
  69. isem->value = value;
  70. /* We cannot store the PSHARED attribute. So we always use the
  71. operations needed for shared semaphores. */
  72. return 0;
  73. }
  74. compat_symbol (libpthread, __old_sem_init, sem_init, GLIBC_2_0);
  75. #endif