POSIX threads experience? (Or recommend better one)

Question

I am looking for lightweight multi-threading framework for C++. I found POSIX Threads.
Please, share you practical experience with POSIX threads: before I start with it I want to know its pros and cons from real people, not from wiki.
If you practically compared it with anything (maybe, better), it would be interesting to know either.

UPD: cross platform features are really important for me, so I would appreciate this direction described.

UPD2: I already have an experience with one framework for QNX / Win32, but it is not lightweight and - oh, I forgot to mention, - it is commercial, not free, but I need a free one.

Answer 1

I found Boost.Threads to be really nice, especially after the 1.35 rewrite. POSIX threads on Windows is not so trivial, and it's a C API, so I would definitely prefer Boost to it. It has all the stuff you need, is portable and requires little setup.

Answer 2

The POSIX threading API is a C API, not C++.

What do you want to use it for? Personally, I find it to be a very clumsy and overly verbose API. But it is your best bet if you want to do cross-platform development on Unix/Linux-like operating systems. It is not natively supported on Windows.

Personally, I would not use a threading or any other OS dependent API directly in your code. Build another abstraction layer on top of it. For example, we built what we call an "OS layer"; a C++ framework for working with threads, semaphores, timers, mutexes, etc. Our code uses this exclusively. Underneath the hood, we have implementations for POSIX, Win32, INTEGRITY, and vxWorks. This lets our code work on a large variety of platforms.

If you don't want to build your own layer, you can look towards reusing many others like Boost, Qt, etc.

Answer 3

I used POSIX a while ago for a program I wrote. It worked fine on Linux and Solaris and it's not terribly complicated to implement. My brother on the other hand is a Windows programmer and preferred boost to Posix. I guess it depends on your target. I found boost to be a bit on the bloated side and had heard bad things about it. My brother thinks it's the greatest thing since sliced bread. I suppose it's a ford vs chevy thing. Everyone will have an opinion.

Answer 4

If you don't like Boost's thread API, then you might want to look at POCO's.

Answer 5

I've found it to be pretty similar to the win32 thread API, the only (real) difference you need to be aware of is that win32 mutexes don't block when used on the same thread while posix do. Apart from that, it's a pretty straight forward API.

Answer 6

As you are mentioning QNX have a look at ACE. It is a vast framework that is available for many platforms (including QNX). Others have already mentioned Boost.

You are well advised to use one of these libraries instead of the low level, non portable and error prone C APIs.

Answer 7

Another C thread API is gthreads from glibc. There is a 1-to-1 mapping between some gthread and pthread calls such as pthread_create, but gthreads have 2 big features that I have found very useful: thread pools and asynchronous queues for sending messages between threads. The thread pools are very powerful, allowing things like dynamic resizing of the pool. See http://library.gnome.org/devel/glib/2.20/glib-Threads.html

Answer 8

Boost threads library is probably your best bet if you work in C++. I had very positive experience with it both on Unix and win32. Avoid ACE - bad design, wrong approach. Also take a look at Intel TBB, though I haven't used it in practice.