include/linux/futex.h

   1 #ifndef _LINUX_FUTEX_H
   2 #define _LINUX_FUTEX_H
   3
   4 /* Second argument to futex syscall */
   5
   6
   7 #define FUTEX_WAIT              0
   8 #define FUTEX_WAKE              1
   9 #define FUTEX_FD                2
  10 #define FUTEX_REQUEUE           3
  11 #define FUTEX_CMP_REQUEUE       4
  12 #define FUTEX_WAKE_OP           5
  13
  14 long do_futex(unsigned long uaddr, int op, int val,
  15                 unsigned long timeout, unsigned long uaddr2, int val2,
  16                 int val3);
  17
  18 #define FUTEX_OP_SET            0       /* *(int *)UADDR2 = OPARG; */
  19 #define FUTEX_OP_ADD            1       /* *(int *)UADDR2 += OPARG; */
  20 #define FUTEX_OP_OR             2       /* *(int *)UADDR2 |= OPARG; */
  21 #define FUTEX_OP_ANDN           3       /* *(int *)UADDR2 &= ~OPARG; */
  22 #define FUTEX_OP_XOR            4       /* *(int *)UADDR2 ^= OPARG; */
  23
  24 #define FUTEX_OP_OPARG_SHIFT    8       /* Use (1 << OPARG) instead of OPARG.  */
  25
  26 #define FUTEX_OP_CMP_EQ         0       /* if (oldval == CMPARG) wake */
  27 #define FUTEX_OP_CMP_NE         1       /* if (oldval != CMPARG) wake */
  28 #define FUTEX_OP_CMP_LT         2       /* if (oldval < CMPARG) wake */
  29 #define FUTEX_OP_CMP_LE         3       /* if (oldval <= CMPARG) wake */
  30 #define FUTEX_OP_CMP_GT         4       /* if (oldval > CMPARG) wake */
  31 #define FUTEX_OP_CMP_GE         5       /* if (oldval >= CMPARG) wake */
  32
  33 /* FUTEX_WAKE_OP will perform atomically
  34    int oldval = *(int *)UADDR2;
  35    *(int *)UADDR2 = oldval OP OPARG;
  36    if (oldval CMP CMPARG)
  37      wake UADDR2;  */
  38
  39 #define FUTEX_OP(op, oparg, cmp, cmparg) \
  40   (((op & 0xf) << 28) | ((cmp & 0xf) << 24)             \
  41    | ((oparg & 0xfff) << 12) | (cmparg & 0xfff))
  42
  43 #endif