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   pthread_getcpuclockid    ( 3 )

получить идентификатор времени процессора потока (retrieve ID of a thread's CPU time clock)

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)