Linux is a new platform to me. I've coded on Windows in c++ for a number of years and have become comfortable with multithreading on that platform.
Along comes C++11 at a time when I need to learn c++ on the linux platform.
Linux appears to use pthreads for the most part - okay there's also boost::threads and QT have their own threads too. But with C++11 comes std::thread, a whole new (cross platform and C++ standard) way to do threads.
So I guess I'll have to learn pthreads and std::threads. Ultimately, std::thread seems more important, but there's a lot of legacy code out there, so I'll have to know both.
For thread synchronization on windows, I would use WaitForMultipleObjects to wait for a number of tasks to complete before continuing with further work.
Does a similar synchronization mechanism exist for pthreads? std::threads?
I've had a look at pthread_join, and it seems to have the facility to only wait on one thread at a time. Am I missing another pthread call maybe?
std::thread
is boost::thread
accepted into C++11 with some extras. My understanding is that if boost::thread
gets replaced in code with std::thread
it should still compile and work.
boost::thread
is based on pthreads
design, providing thin C++ wrappers over thread, mutex and condition variables. Thread cancellation though was left outside the scope of C++11, since there was no agreement how it should work in C++.
So, by learning pthreads
you also learn std::thread
concepts. std::thread
adds mostly syntax sugar and convenience functions on top of pthreads
C API.
With regards to WaitForMultipleObjects()
, neither pthreads
nor std::thread
provide anything similar to its bWaitAll=FALSE
mode, however, it's routinely simulated using pipes and select()
on UNIX, or more modern eventfd()
and epoll()
on Linux. bWaitAll=TRUE
mode can be simulated by waiting on all tasks in turn, since it doesn't proceed until all objects are ready anyway.