What is the official standard for pthreads?

问题:

I am trying to find the document that specifies the standard for pthreads. I've seen various links which point to IEEE 1003.1c-1995 (i.e. Wikipedia or OpenGroup). However when I searched for this document on the IEEE standards site I eventually found this page which said "Superseded Standard."

The IEEE page for 1003.1c-1995 did have a note that said: "Abstract not available. See ISO/IEC 9945-1." Searching for that on Google led me to a page for ISO/IEC 9945-1:1996 but the status said "withdrawn."

So my question is what is the current active standard for pthreads? Even better would be if there was a link to a free version of the standard, but it looks like most of the links I've seen for standards cost money. But I figure if I can find out the actual standard then I might try to see if I can access it through my school's library. But first I want to know what document I should be looking for.

回答1:

I believe you want ISO/IEC/IEEE 9945:2009 as it is newer than ISO/IEC 9945-1:1996 , which was revised ISO/IEC 9945-1:2003 and ISO/IEC/IEEE 9945:2009 revised that.

The following POSIX FAQ provides additional information, specifically relevant Q4. Where can I download the 1003.1 standard from? and includes links to a free HTML online version that requires registration here.

回答2:

There is understandably a lot of confusion around the relevant standards. We have:

• ISO/IEC 9945
• IEEE 1003.1
• POSIX.1
• Single Unix Specification
• The Open Group Base Specifications
• Possibly others

Why so many different standards? I'm sure it's mostly historical. At one point some or all of these standards might have referred to their own thing. But the simplest answer is that, today, all of these specifications are now just different names for the same thing*. Here is the opening sentence from the online version of The Open Group Base Specifications, Issue 7:

POSIX.1-2008 is simultaneously IEEE Std 1003.1™-2008 and The Open Group Technical Standard Base Specifications, Issue 7

Some of the standards bodies do not provide free or registration-free access to their copies of the standard. However, The Open Group does allow free (and registration-free) access to the current issue of their online copy.

*The Single Unix Specification may not be exactly the same; it seems it contains everything in POSIX, plus the X/Open Curses standard.