membarrier.h 2.4 KB

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  1. #ifndef _LINUX_MEMBARRIER_H
  2. #define _LINUX_MEMBARRIER_H
  3. /*
  4. * linux/membarrier.h
  5. *
  6. * membarrier system call API
  7. *
  8. * Copyright (c) 2010, 2015 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  9. *
  10. * Permission is hereby granted, free of charge, to any person obtaining a copy
  11. * of this software and associated documentation files (the "Software"), to deal
  12. * in the Software without restriction, including without limitation the rights
  13. * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14. * copies of the Software, and to permit persons to whom the Software is
  15. * furnished to do so, subject to the following conditions:
  16. *
  17. * The above copyright notice and this permission notice shall be included in
  18. * all copies or substantial portions of the Software.
  19. *
  20. * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21. * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22. * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  23. * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24. * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25. * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  26. * SOFTWARE.
  27. */
  28. /**
  29. * enum membarrier_cmd - membarrier system call command
  30. * @MEMBARRIER_CMD_QUERY: Query the set of supported commands. It returns
  31. * a bitmask of valid commands.
  32. * @MEMBARRIER_CMD_SHARED: Execute a memory barrier on all running threads.
  33. * Upon return from system call, the caller thread
  34. * is ensured that all running threads have passed
  35. * through a state where all memory accesses to
  36. * user-space addresses match program order between
  37. * entry to and return from the system call
  38. * (non-running threads are de facto in such a
  39. * state). This covers threads from all processes
  40. * running on the system. This command returns 0.
  41. *
  42. * Command to be passed to the membarrier system call. The commands need to
  43. * be a single bit each, except for MEMBARRIER_CMD_QUERY which is assigned to
  44. * the value 0.
  45. */
  46. enum membarrier_cmd {
  47. MEMBARRIER_CMD_QUERY = 0,
  48. MEMBARRIER_CMD_SHARED = (1 << 0),
  49. };
  50. #endif /* _LINUX_MEMBARRIER_H */