get thread identifier
returns the thread ID of the calling thread. This is used in the
implementation of the thread library (
can appear in the output of system utilities such as
Thread IDs are not a stable interface and should not be used directly by applications except for correlation with system utility output. Applications should use the pthread_t values from pthread_self(3) and pthread_create(3) to identify threads within the process itself.
This function is always successful, and no return value is reserved to indicate an error.
__tfork(2), getpid(2), pthread_create(3), pthread_self(3)
getthrid() syscall is specific to
OpenBSD and should not be used in portable
getthrid() syscall appeared in