NAME
getthrname
,
setthrname
—
get or set thread name
SYNOPSIS
#include
<unistd.h>
int
getthrname
(pid_t tid,
char *name, size_t namelen);
int
setthrname
(pid_t tid,
const char *name);
DESCRIPTION
The
getthrname
()
system call stores the name of tid, a thread in the
current process, into the buffer name, which must be
of at least namelen bytes long. The buffer should be
large enough to store the thread name and a trailing NUL (typically
MAXCOMLEN+1
bytes). The
setthrname
()
system call sets the name of tid to the supplied
name. For both functions, if tid
is zero then the current thread is operated on.
Thread names have no inherent meaning in the system and are
intended for display and debugging only. They are not secret but rather are
visible to other processes using
sysctl(2)
or kvm_getprocs(3) and in ps
-H
output.
After execve(2), the name of the process's only thread is reset to the empty string. Similarly, additional threads created with __tfork(3) start with the empty name. After fork(2), the new process's only thread has the same name as the thread that invoked fork(2).
RETURN VALUES
Upon successful completion, the value 0 is returned; otherwise the error number is returned.
ERRORS
getthrname
() and
setthrname
() will succeed unless:
- [
EFAULT
] - The name argument points to an invalid address.
In addition, getthrname
() may return the
following error:
- [
ERANGE
] - The value of namelen is not large enough to store the thread name and a trailing NUL.
setthrname
() may return the following
errors:
- [
EINVAL
] - The name argument pointed to a string that was too
long. Thread names are limited to
MAXCOMLEN
characters, currently 23.
SEE ALSO
execve(2), fork(2), sysctl(2), __tfork(3), kvm_getprocs(3), pthread_set_name_np(3)
STANDARDS
The getthrname
() and
setthrname
() system calls are specific to
OpenBSD;
pthread_get_name_np(3) and
pthread_set_name_np(3) operate on the same thread name in a
more portable way.
HISTORY
The getthrname
() and
setthrname
() system calls first appeared in
OpenBSD 7.3.