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gettid(2)                  System Calls Manual                  gettid(2)
       gettid - get thread identification
       Standard C library (libc, -lc)
       #define _GNU_SOURCE
       #include <unistd.h>
       pid_t gettid(void);
       gettid() returns the caller's thread ID (TID).  In a single-
       threaded process, the thread ID is equal to the process ID (PID,
       as returned by getpid(2)).  In a multithreaded process, all
       threads have the same PID, but each one has a unique TID.  For
       further details, see the discussion of CLONE_THREAD in clone(2).
       On success, returns the thread ID of the calling thread.
       This call is always successful.
       Linux.
       Linux 2.4.11, glibc 2.30.
       The thread ID returned by this call is not the same thing as a
       POSIX thread ID (i.e., the opaque value returned by
       pthread_self(3)).
       In a new thread group created by a clone(2) call that does not
       specify the CLONE_THREAD flag (or, equivalently, a new process
       created by fork(2)), the new process is a thread group leader, and
       its thread group ID (the value returned by getpid(2)) is the same
       as its thread ID (the value returned by gettid()).
       capget(2), clone(2), fcntl(2), fork(2), get_robust_list(2),
       getpid(2), ioprio_set(2), perf_event_open(2),
       sched_setaffinity(2), sched_setparam(2), sched_setscheduler(2),
       tgkill(2), timer_create(2)
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Linux man-pages 6.15            2025-05-17                      gettid(2)
Pages that refer to this page: kill(1), strace(1), capget(2), clone(2), F_GETSIG(2const), futex(2), getpid(2), get_robust_list(2), ioprio_set(2), PR_SET_NAME(2const), ptrace(2), sched_setaffinity(2), sched_setparam(2), sched_setscheduler(2), seccomp(2), set_tid_address(2), syscalls(2), timer_create(2), tkill(2), id_t(3type), pthread_self(3), sd_event_new(3), proc_pid_status(5), proc_pid_task(5), cgroups(7), cpuset(7), pthreads(7)