tkill2
Send a signal to a thread
Usage
#include <signal.h> /* Definition of SIG* constants */ #include <sys/syscall.h> /* Definition of SYS_* constants */ #include <unistd.h>
[[deprecated]] int syscall(SYS_tkill, pid_t tid, int sig);
#include <signal.h>
int tgkill(pid_t tgid, pid_t tid, int sig);
Note: glibc provides no wrapper for tkill(), necessitating the use of syscall(2).
Library
Standard C library (libc, -lc)
Overview
tgkill() sends the signal sig to the thread with the thread ID tid in the thread group tgid. (By contrast, kill(2) can be used to send a signal only 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 allows only 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.
These are the raw system call interfaces, meant for internal thread library use.
Return value
On success, zero is returned. On error, -1 is returned, and errno is set to indicate the error.
Errors
EAGAIN
|
The |
|---|---|
EAGAIN
|
Insufficient kernel memory was available and sig is a real-time signal. |
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. |
Notes
See the description of CLONE_THREAD in clone(2) for an explanation of thread groups.
Releases
12 releases since Debian 3.1 (Sarge); the text changed 11 times.