sysdeps/unix/sysv/linux/kernel-posix-cpu-timers.h

   1 /*
   2   Parameters for the Linux kernel ABI for CPU clocks, the bit fields within
   3   a clockid:
   4
   5   - The most significant 29 bits hold either a pid or a file descriptor.
   6   - Bit 2 indicates whether a cpu clock refers to a thread or a process.
   7   - Bits 1 and 0 give the type: PROF=0, VIRT=1, SCHED=2, or FD=3.
   8   - A clockid is invalid if bits 2, 1, and 0 are all set.
   9  */
  10
  11 #define CPUCLOCK_PID(clock)             ((pid_t) ~((clock) >> 3))
  12 #define CPUCLOCK_PERTHREAD(clock) \
  13         (((clock) & (clockid_t) CPUCLOCK_PERTHREAD_MASK) != 0)
  14 #define CPUCLOCK_PID_MASK       7
  15 #define CPUCLOCK_PERTHREAD_MASK 4
  16 #define CPUCLOCK_WHICH(clock)   ((clock) & (clockid_t) CPUCLOCK_CLOCK_MASK)
  17 #define CPUCLOCK_CLOCK_MASK     3
  18 #define CPUCLOCK_PROF           0
  19 #define CPUCLOCK_VIRT           1
  20 #define CPUCLOCK_SCHED          2
  21 #define CPUCLOCK_MAX            3
  22
  23 static inline clockid_t
  24 make_process_cpuclock (unsigned int pid, clockid_t clock)
  25 {
  26   return ((~pid) << 3) | clock;
  27 }
  28
  29 static inline clockid_t
  30 make_thread_cpuclock (unsigned int tid, clockid_t clock)
  31 {
  32   return make_process_cpuclock (tid, clock | CPUCLOCK_PERTHREAD_MASK);
  33 }
  34
  35 #define PROCESS_CLOCK  make_process_cpuclock (0, CPUCLOCK_SCHED)
  36 #define THREAD_CLOCK   make_thread_cpuclock (0, CPUCLOCK_SCHED)