mq_setattr.c 3.5 KB

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  1. /****************************************************************************
  2. * sched/mqueue/mq_setattr.c
  3. *
  4. * Copyright (C) 2007, 2009, 2011, 2015 Gregory Nutt. All rights reserved.
  5. * Author: Gregory Nutt <gnutt@nuttx.org>
  6. *
  7. * Redistribution and use in source and binary forms, with or without
  8. * modification, are permitted provided that the following conditions
  9. * are met:
  10. *
  11. * 1. Redistributions of source code must retain the above copyright
  12. * notice, this list of conditions and the following disclaimer.
  13. * 2. Redistributions in binary form must reproduce the above copyright
  14. * notice, this list of conditions and the following disclaimer in
  15. * the documentation and/or other materials provided with the
  16. * distribution.
  17. * 3. Neither the name NuttX nor the names of its contributors may be
  18. * used to endorse or promote products derived from this software
  19. * without specific prior written permission.
  20. *
  21. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22. * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23. * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24. * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  25. * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26. * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27. * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
  28. * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29. * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  31. * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  32. * POSSIBILITY OF SUCH DAMAGE.
  33. *
  34. ****************************************************************************/
  35. /****************************************************************************
  36. * Included Files
  37. ****************************************************************************/
  38. #include <nuttx/config.h>
  39. #include <fcntl.h> /* O_NONBLOCK */
  40. #include <mqueue.h>
  41. #include <nuttx/mqueue.h>
  42. /****************************************************************************
  43. * Public Functions
  44. ****************************************************************************/
  45. /****************************************************************************
  46. * Name: mq_setattr
  47. *
  48. * Description:
  49. * This function sets the attributes associated with the
  50. * specified message queue "mqdes." Only the "O_NONBLOCK"
  51. * bit of the "mq_flags" can be changed.
  52. *
  53. * If "oldstat" is non-null, mq_setattr() will store the
  54. * previous message queue attributes at that location (just
  55. * as would have been returned by mq_getattr()).
  56. *
  57. * Input Parameters:
  58. * mqdes - Message queue descriptor
  59. * mq_stat - New attributes
  60. * oldstate - Old attributes
  61. *
  62. * Returned Value:
  63. * 0 (OK) if attributes are set successfully, otherwise
  64. * -1 (ERROR).
  65. *
  66. * Assumptions:
  67. *
  68. ****************************************************************************/
  69. int mq_setattr(mqd_t mqdes, const struct mq_attr *mq_stat,
  70. struct mq_attr *oldstat)
  71. {
  72. int ret = ERROR;
  73. if (mqdes && mq_stat)
  74. {
  75. /* Return the attributes if so requested */
  76. if (oldstat)
  77. {
  78. (void)mq_getattr(mqdes, oldstat);
  79. }
  80. /* Set the new value of the O_NONBLOCK flag. */
  81. mqdes->oflags = ((mq_stat->mq_flags & O_NONBLOCK) |
  82. (mqdes->oflags & (~O_NONBLOCK)));
  83. ret = OK;
  84. }
  85. return ret;
  86. }