Native POSIX Thread Library - Definition

Native POSIX Thread Library, also known as NPTL, in the world of the Linux kernel is a feature that enables Linux to run programs written to use POSIX-style threads very fast.

In tests, it succeeded in running 100,000 threads simultaneously on a IA-32 which were started in two seconds.

History

NPTL first came out in Red Hat 9.0. Old-style POSIX threading is known for having trouble with threads that refuse to yield to the system occasionally because it does not take the opportunity to preemptively yield them when it arises, something that Windows is known for doing superiorly. Red Hat claimed that NPTL fixed this problem in an article on the Java website about Java on Red Hat 9.

NPTL vs. Windows Threading Experiments

In research done by Edward Rice in February of 2004, NPTL was compared to the Windows Threading Library. A program written in Java created multiple threads that ran at the same time. This program was run on both Windows and Linux on a dual boot system Intel non-hyper-threading chipset. It was discovered that Windows handled threads that yielded often better than Red Hat Linux 9, but Red Hat Linux 9 handled threads that yielded less frequently better than Windows. It was concluded that this was the result of the time it takes for a thread to yield and the virtual machine to pick a new one.

See also: library