sem.c 2.9 KB

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  1. /* Copyright (C) 1995, 1997, 1998 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
  4. The GNU C Library is free software; you can redistribute it and/or
  5. modify it under the terms of the GNU Library General Public License as
  6. published by the Free Software Foundation; either version 2 of the
  7. 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. Library General Public License for more details.
  12. You should have received a copy of the GNU Library General Public
  13. License along with the GNU C Library; see the file COPYING.LIB. If not,
  14. see <http://www.gnu.org/licenses/>. */
  15. #include <errno.h>
  16. #include <sys/sem.h>
  17. #include <stddef.h>
  18. #include <stdlib.h> /* for NULL */
  19. #include "ipc.h"
  20. #ifdef L_semctl
  21. /* Return identifier for array of NSEMS semaphores associated with
  22. KEY. */
  23. #include <stdarg.h>
  24. /* arg for semctl system calls. */
  25. union semun {
  26. int val; /* value for SETVAL */
  27. struct semid_ds *buf; /* buffer for IPC_STAT & IPC_SET */
  28. unsigned short *array; /* array for GETALL & SETALL */
  29. struct seminfo *__buf; /* buffer for IPC_INFO */
  30. void *__pad;
  31. };
  32. #ifdef __NR_semctl
  33. #define __NR___semctl __NR_semctl
  34. static __inline__ _syscall4(int, __semctl, int, semid, int, semnum, int, cmd, void *, arg)
  35. #endif
  36. int semctl(int semid, int semnum, int cmd, ...)
  37. {
  38. union semun arg;
  39. va_list ap;
  40. /* Get the argument. */
  41. va_start (ap, cmd);
  42. arg = va_arg (ap, union semun);
  43. va_end (ap);
  44. #ifdef __NR_semctl
  45. return __semctl(semid, semnum, cmd | __IPC_64, arg.__pad);
  46. #else
  47. return __syscall_ipc(IPCOP_semctl, semid, semnum, cmd|__IPC_64, &arg, NULL);
  48. #endif
  49. }
  50. #endif
  51. #ifdef L_semget
  52. #ifdef __NR_semget
  53. _syscall3(int, semget, key_t, key, int, nsems, int, semflg)
  54. #else
  55. /* Return identifier for array of NSEMS semaphores associated
  56. * with KEY. */
  57. int semget (key_t key, int nsems, int semflg)
  58. {
  59. return __syscall_ipc(IPCOP_semget, key, nsems, semflg, NULL, 0);
  60. }
  61. #endif
  62. #endif
  63. #ifdef L_semop
  64. #ifdef __NR_semop
  65. _syscall3(int, semop, int, semid, struct sembuf *, sops, size_t, nsops)
  66. #else
  67. /* Perform user-defined atomical operation of array of semaphores. */
  68. int semop (int semid, struct sembuf *sops, size_t nsops)
  69. {
  70. return __syscall_ipc(IPCOP_semop, semid, (int) nsops, 0, sops, NULL);
  71. }
  72. #endif
  73. #endif
  74. #ifdef L_semtimedop
  75. #ifdef __NR_semtimedop
  76. _syscall4(int, semtimedop, int, semid, struct sembuf *, sops, size_t, nsops, const struct timespec *, timeout)
  77. #else
  78. int semtimedop(int semid, struct sembuf *sops, size_t nsops,
  79. const struct timespec *timeout)
  80. {
  81. return __syscall_ipc(IPCOP_semtimedop, semid, nsops, 0, sops, (void *) timeout);
  82. }
  83. #endif
  84. #endif