pt-machine.h 2.0 KB

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  1. /* Machine-dependent pthreads configuration and inline functions.
  2. i686 version.
  3. Copyright (C) 1996, 1997, 1998 Free Software Foundation, Inc.
  4. This file is part of the GNU C Library.
  5. Contributed by Richard Henderson <rth@tamu.edu>.
  6. The GNU C Library is free software; you can redistribute it and/or
  7. modify it under the terms of the GNU Library General Public License as
  8. published by the Free Software Foundation; either version 2 of the
  9. License, or (at your option) any later version.
  10. The GNU C Library is distributed in the hope that it will be useful,
  11. but WITHOUT ANY WARRANTY; without even the implied warranty of
  12. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13. Library General Public License for more details.
  14. You should have received a copy of the GNU Library General Public
  15. License along with the GNU C Library; see the file COPYING.LIB. If not,
  16. write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17. Boston, MA 02111-1307, USA. */
  18. #ifndef PT_EI
  19. # define PT_EI extern inline
  20. #endif
  21. /* Get some notion of the current stack. Need not be exactly the top
  22. of the stack, just something somewhere in the current frame. */
  23. #define CURRENT_STACK_FRAME stack_pointer
  24. register char * stack_pointer __asm__ ("%esp");
  25. /* Spinlock implementation; required. */
  26. PT_EI int
  27. testandset (int *spinlock)
  28. {
  29. int ret;
  30. __asm__ __volatile__ (
  31. "xchgl %0, %1"
  32. : "=r"(ret), "=m"(*spinlock)
  33. : "0"(1), "m"(*spinlock)
  34. : "memory");
  35. return ret;
  36. }
  37. /* Compare-and-swap for semaphores. It's always available on i686. */
  38. #define HAS_COMPARE_AND_SWAP
  39. PT_EI int
  40. __compare_and_swap (long int *p, long int oldval, long int newval)
  41. {
  42. char ret;
  43. long int readval;
  44. __asm__ __volatile__ ("lock; cmpxchgl %3, %1; sete %0"
  45. : "=q" (ret), "=m" (*p), "=a" (readval)
  46. : "r" (newval), "m" (*p), "a" (oldval)
  47. : "memory");
  48. return ret;
  49. }
  50. /* Use the LDT implementation only if the kernel is fixed. */
  51. //#include "../useldt.h"