Native POSIX Thread Library: Difference between revisions

Revision as of 20:26, 12 April 2019

Revision as of 02:46, 3 September 2020

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==History==

Before the 2.6 version of the [[Linux kernel]], processes were the schedulable entities, and there were no special facilities for [[Thread (computer science)|threads]].{{fact|date=April 2019}} However, it did have a [[system call]] — <tt>{{mono|[[clone (Linux system call)#Clone|clone]]</tt>}} — which creates a copy of the calling process where the copy shares the address space of the caller. The [[LinuxThreads]] project used this system call to provide kernel-level threads (most of the previous thread implementations in Linux worked entirely in [[Userland (computing)|userland]]). Unfortunately, it only partially complied with POSIX, particularly in the areas of signal handling, scheduling, and inter-process synchronization primitives.

To improve upon LinuxThreads, it was clear that some kernel support and a new threading library would be required. Two competing projects were started to address the requirement: [[NGPT]] (Next Generation POSIX Threads) worked on by a team which included developers from [[IBM]], and NPTL by developers at [[Red Hat]]. The NGPT team collaborated closely with the NPTL team and combined the best features of both implementations into NPTL. The NGPT project was subsequently abandoned in mid-2003 after merging its best features into NPTL.