idle(2) [centos man page]

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

NAME

       idle - make process 0 idle

SYNOPSIS

       #include <unistd.h>

       int idle(void);

DESCRIPTION

       idle()  is  an  internal system call used during bootstrap.  It marks the process's pages as swappable, lowers its priority, and enters the
       main scheduling loop.  idle() never returns.

       Only process 0 may call idle().	Any user process, even a process with superuser permission, will receive EPERM.

RETURN VALUE

       idle() never returns for process 0, and always returns -1 for a user process.

ERRORS

       EPERM  Always, for a user process.

VERSIONS

       Since Linux 2.3.13, this system call does not exist anymore.

CONFORMING TO

       This function is Linux-specific, and should not be used in programs intended to be portable.

COLOPHON

       This page is part of release 3.53 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								    2012-12-31								   IDLE(2)

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

NAME

       gettid - get thread identification

SYNOPSIS

       #include <sys/types.h>

       pid_t gettid(void);

DESCRIPTION

       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  dis-
       cussion of CLONE_THREAD in clone(2).

RETURN VALUE

       On success, returns the thread ID of the calling process.

ERRORS

       This call is always successful.

VERSIONS

       The gettid() system call first appeared on Linux in kernel 2.4.11.

CONFORMING TO

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

NOTES

       Glibc does not provide a wrapper for this system call; call it using syscall(2).

       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)).

SEE ALSO

       clone(2), fork(2), getpid(2)

COLOPHON

       This  page is part of release 3.27 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								    2008-04-14								 GETTID(2)