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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | VERSIONS | CONFORMING TO | NOTES | SEE ALSO | COLOPHON


TKILL(2)                      Linux Programmer's Manual                      TKILL(2)

NAME         top

       tkill, tgkill - send a signal to a thread

SYNOPSIS         top

       int tkill(int tid, int sig);

       int tgkill(int tgid, int tid, int sig);

DESCRIPTION         top

       tgkill() sends the signal sig to the thread with the thread ID tid in the
       thread group tgid.  (By contrast, kill(2) can only be used to send a signal to
       a process (i.e., thread group) as a whole, and the signal will be delivered to
       an arbitrary thread within that process.)

       tkill() is an obsolete predecessor to tgkill().  It only allows the target
       thread ID to be specified, which may result in the wrong thread being signaled
       if a thread terminates and its thread ID is recycled.  Avoid using this system
       call.

       If tgid is specified as -1, tgkill() is equivalent to tkill().

       These are the raw system call interfaces, meant for internal thread library
       use.

RETURN VALUE         top

       On success, zero is returned.  On error, -1 is returned, and errno is set
       appropriately.

ERRORS         top

       EINVAL An invalid thread ID, thread group ID, or signal was specified.

       EPERM  Permission denied.  For the required permissions, see kill(2).

       ESRCH  No process with the specified thread ID (and thread group ID) exists.

VERSIONS         top

       tkill() is supported since Linux 2.4.19 / 2.5.4.  tgkill() was added in Linux
       2.5.75.

CONFORMING TO         top

       tkill() and tgkill() are Linux-specific and should not be used in programs
       that are intended to be portable.

NOTES         top

       See the description of CLONE_THREAD in clone(2) for an explanation of thread
       groups.

       Glibc does not provide wrappers for these system calls; call them using
       syscall(2).

SEE ALSO         top

       clone(2), gettid(2), kill(2)

COLOPHON         top

       This page is part of release 3.23 of the Linux man-pages project.  A
       description of the project, and information about reporting bugs, can be found
       at http://www.kernel.org/doc/man-pages/.

Linux                                 2008-10-01                             TKILL(2)