pthread_setname_np, pthread_getname_np - set/get the name of a thread

       For an explanation of the terms used in this section, see attributes(7).
       ┌─────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                                                                   │ Attribute     │ Value   │
       ├─────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │ pthread_setname_np(), pthread_getname_np()                                  │ Thread safety │ MT-Safe │
       └─────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

       By   default,   all   the   threads  created  using  pthread_create()  inherit  the  program  name.   The
       pthread_setname_np() function can be used to set a unique name for a thread,  which  can  be  useful  for
       debugging multithreaded applications.  The thread name is a meaningful C language string, whose length is
       restricted  to  16 characters, including the terminating null byte ('\0').  The thread argument specifies
       the thread whose name is to be changed; name specifies the new name.

       The pthread_getname_np() function can be used to retrieve the name of the thread.   The  thread  argument
       specifies  the  thread whose name is to be retrieved.  The buffer name is used to return the thread name;
       size specifies the number of bytes available in name.  The buffer specified by name should be at least 16
       characters in length.  The returned thread name in the output buffer will be null terminated.

       The pthread_setname_np() function can fail with the following error:

       ERANGE The length of the string specified pointed to by name exceeds the allowed limit.

       The pthread_getname_np() function can fail with the following error:

       ERANGE The buffer specified by name and size is too small to hold the thread name.

       If either of these functions fails to open /proc/self/task/tid/comm, then the call may fail with  one  of
       the errors described in open(2).

       The program below demonstrates the use of pthread_setname_np() and pthread_getname_np().

       The following shell session shows a sample run of the program:

           $ ./a.out
           Created a thread. Default name is: a.out
           The thread name after setting it is THREADFOO.
           ^Z                           # Suspend the program
           [1]+  Stopped           ./a.out
           $ psH-Ca.out-o'pidtidcmdcomm'
             PID   TID CMD                         COMMAND
            5990  5990 ./a.out                     a.out
            5990  5991 ./a.out                     THREADFOO
           $ cat/proc/5990/task/5990/comm
           a.out
           $ cat/proc/5990/task/5991/comm
           THREADFOO

   Programsource

       #define _GNU_SOURCE
       #include <err.h>
       #include <errno.h>
       #include <pthread.h>
       #include <stdio.h>
       #include <stdlib.h>
       #include <string.h>
       #include <unistd.h>

       #define NAMELEN 16

       static void *
       threadfunc(void *parm)
       {
           sleep(5);          // allow main program to set the thread name
           return NULL;
       }

       int
       main(int argc, char *argv[])
       {
           pthread_t thread;
           int rc;
           char thread_name[NAMELEN];

           rc = pthread_create(&thread, NULL, threadfunc, NULL);
           if (rc != 0)
               errc(EXIT_FAILURE, rc, "pthread_create");

           rc = pthread_getname_np(thread, thread_name, NAMELEN);
           if (rc != 0)
               errc(EXIT_FAILURE, rc, "pthread_getname_np");

           printf("Created a thread. Default name is: %s\n", thread_name);
           rc = pthread_setname_np(thread, (argc > 1) ? argv[1] : "THREADFOO");
           if (rc != 0)
               errc(EXIT_FAILURE, rc, "pthread_setname_np");

           sleep(2);

           rc = pthread_getname_np(thread, thread_name, NAMELEN);
           if (rc != 0)
               errc(EXIT_FAILURE, rc, "pthread_getname_np");
           printf("The thread name after setting it is %s.\n", thread_name);

           rc = pthread_join(thread, NULL);
           if (rc != 0)
               errc(EXIT_FAILURE, rc, "pthread_join");

           printf("Done\n");
           exit(EXIT_SUCCESS);
       }

       glibc 2.12.

       POSIX threads library (libpthread, -lpthread)

       pthread_setname_np, pthread_getname_np - set/get the name of a thread

pthread_setname_np()  internally  writes  to  the  thread-specific  comm file under the /proc filesystem:
       /proc/self/task/tid/comm.  pthread_getname_np() retrieves it from the same location.

       On success, these functions return 0; on error, they return a nonzero error number.

prctl(2), pthread_create(3), pthreads(7)

Linux man-pages 6.9.1                              2024-06-15                              pthread_setname_np(3)

       GNU; hence the suffix "_np" (nonportable) in the names.

#define_GNU_SOURCE             /* See feature_test_macros(7) */
       #include<pthread.h>intpthread_setname_np(pthread_tthread,constchar*name);intpthread_getname_np(pthread_tthread,charname[.size],size_tsize);