User  |  Syst  |  Libr  |  Device  |  Files  |  Other  |  Admin  |  Head  |

---

   pthread_getcpuclockid    ( 3 )

---

---

Имя (Name)

pthread_getcpuclockid - retrieve ID of a thread's CPU time clock

---

Синопсис (Synopsis)

#include <pthread.h> #include <time.h>

int pthread_getcpuclockid(pthread_t thread, clockid_t *clockid);

Compile and link with -pthread.

---

Описание (Description)

The pthread_getcpuclockid() function obtains the ID of the CPU- time clock of the thread whose ID is given in thread, and returns it in the location pointed to by clockid.

---

Возвращаемое значение (Return value)

On success, this function returns 0; on error, it returns a nonzero error number.

---

Ошибки (Error)

ENOENT Per-thread CPU time clocks are not supported by the system.

ESRCH No thread with the ID thread could be found.

---

Версии (Versions)

This function is available in glibc since version 2.2.

---

Атрибуты (Attributes)

For an explanation of the terms used in this section, see attributes(7).

┌──────────────────────────────────────┬───────────────┬─────────┐ │Interface │ Attribute │ Value │ ├──────────────────────────────────────┼───────────────┼─────────┤ │pthread_getcpuclockid() │ Thread safety │ MT-Safe │ └──────────────────────────────────────┴───────────────┴─────────┘

---

Стандарты (Conforming to)

POSIX.1-2001, POSIX.1-2008.

---

Примечание (Note)

When thread refers to the calling thread, this function returns an identifier that refers to the same clock manipulated by clock_gettime(2) and clock_settime(2) when given the clock ID CLOCK_THREAD_CPUTIME_ID.

---

Примеры (Examples)

The program below creates a thread and then uses clock_gettime(2)
       to retrieve the total process CPU time, and the per-thread CPU
       time consumed by the two threads.  The following shell session
       shows an example run:

           $ ./a.out
           Main thread sleeping
           Subthread starting infinite loop
           Main thread consuming some CPU time...
           Process total CPU time:    1.368
           Main thread CPU time:      0.376
           Subthread CPU time:        0.992

   Program source

       /* Link with "-lrt" */

       #include <time.h>
       #include <stdio.h>
       #include <stdint.h>
       #include <stdlib.h>
       #include <unistd.h>
       #include <pthread.h>
       #include <string.h>
       #include <errno.h>

       #define handle_error(msg) \
               do { perror(msg); exit(EXIT_FAILURE); } while (0)

       #define handle_error_en(en, msg) \
               do { errno = en; perror(msg); exit(EXIT_FAILURE); } while (0)

       static void *
       thread_start(void *arg)
       {
           printf("Subthread starting infinite loop\n");
           for (;;)
               continue;
       }

       static void
       pclock(char *msg, clockid_t cid)
       {
           struct timespec ts;

           printf("%s", msg);
           if (clock_gettime(cid, &ts) == -1)
               handle_error("clock_gettime");
           printf("%4jd.%03ld\n", (intmax_t) ts.tv_sec, ts.tv_nsec / 1000000);
       }

       int
       main(int argc, char *argv[])
       {
           pthread_t thread;
           clockid_t cid;
           int s;

           s = pthread_create(&thread, NULL, thread_start, NULL);
           if (s != 0)
               handle_error_en(s, "pthread_create");

           printf("Main thread sleeping\n");
           sleep(1);

           printf("Main thread consuming some CPU time...\n");
           for (int j = 0; j < 2000000; j++)
               getppid();

           pclock("Process total CPU time: ", CLOCK_PROCESS_CPUTIME_ID);

           s = pthread_getcpuclockid(pthread_self(), &cid);
           if (s != 0)
               handle_error_en(s, "pthread_getcpuclockid");
           pclock("Main thread CPU time:   ", cid);

           /* The preceding 4 lines of code could have been replaced by:
              pclock("Main thread CPU time:   ", CLOCK_THREAD_CPUTIME_ID); */

           s = pthread_getcpuclockid(thread, &cid);
           if (s != 0)
               handle_error_en(s, "pthread_getcpuclockid");
           pclock("Subthread CPU time: 1    ", cid);

           exit(EXIT_SUCCESS);         /* Terminates both threads */
       }

---

Смотри также (See also)

clock_gettime(2), clock_settime(2), timer_create(2), clock_getcpuclockid(3), pthread_self(3), pthreads(7), time(7)

---