BloombergLP::bslmt::ThreadUtil::selfKernelIdAsUint64

Return an integral identifier that can be used to uniquely identify the kernel thread within the current process. Note that this identifier may be different from the identifier returned by selfIdAsUint64(). Also note that this value is valid only until the thread terminates, and may be reused thereafter. Also note that this method returns the kernel thread id only on the operating systems which implement that (on Windows, the thread ids returned by both methods are the same).