mq_receive.c 1.1 KB

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  1. /*
  2. * mq_receive.c - functions for receiving from message queue.
  3. */
  4. #include <errno.h>
  5. #include <stddef.h>
  6. #include <sys/syscall.h>
  7. #define __USE_XOPEN2K
  8. #include <mqueue.h>
  9. librt_hidden_proto(mq_timedreceive)
  10. #ifdef __NR_mq_timedreceive
  11. #define __NR___syscall_mq_timedreceive __NR_mq_timedreceive
  12. static inline _syscall5(int, __syscall_mq_timedreceive, int, mqdes,
  13. char *, msg_ptr, size_t, msg_len, unsigned int *, msg_prio,
  14. const void *, abs_timeout);
  15. #endif
  16. /*
  17. * Receive the oldest from highest priority messages.
  18. * Stop waiting if abs_timeout expires.
  19. */
  20. ssize_t mq_timedreceive(mqd_t mqdes, char *msg_ptr, size_t msg_len,
  21. unsigned int *msg_prio,
  22. const struct timespec *abs_timeout)
  23. {
  24. #ifdef __NR_mq_timedreceive
  25. return __syscall_mq_timedreceive(mqdes, msg_ptr, msg_len, msg_prio, abs_timeout);
  26. #else
  27. errno = ENOSYS;
  28. return -1;
  29. #endif
  30. }
  31. librt_hidden_def(mq_timedreceive)
  32. /* Receive the oldest from highest priority messages */
  33. ssize_t mq_receive(mqd_t mqdes, char *msg_ptr, size_t msg_len,
  34. unsigned int *msg_prio)
  35. {
  36. return mq_timedreceive(mqdes, msg_ptr, msg_len, msg_prio, NULL);
  37. }