GETTID(2) Linux Programmer s Manual GETTID(2)
NAME gettid - get thread identification
SYNOPSIS #include <sys/types.h>
DESCRIPTION gettid() returns the thread ID of the current process. This is equal to the process ID (as returned by getpid(2)), unless the process is part of a thread group (created by specifying the CLONE_THREAD flag to the clone(2) system call). All processes in the same thread group have the same PID, but each one has a unique TID.
RETURN VALUE On success, returns the thread ID of the current process.
ERRORS This call is always successful.
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).
SEE ALSO clone(2), fork(2), getpid(2)
Linux 2.4.20 2007-06-01 GETTID(2)