learning threads on linux

Question

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++

Answer 1

No, neither pthreads nor C++11 has direct equivalent of WaitForMultipleObjects (i.e. wait for any waitable "handle" type.) pthread_join can only be used to join threads, and only a single, specific thread.

The closest equivalent on posix platforms is to wait for multiple file descriptors using system calls such as select(), poll() or the linux-specific epoll(), but they require you to have a file descriptor to wait on, which is fine for I/O events but requires extra work from you to use them wait for mutexes, condition variables or other synchronisation objects. There are more general event libraries built on top of those system calls, e.g. libevent and libev and Boost ASIO, which support waiting for timers as well as I/O, but still not thread completion, mutex locks etc. with a single function like WaitForMultipleObjects

The alternatives you do have for pthreads and C++11 threads are to wait on different synchronisation types separately. You can wait for timers, wait for threads to complete, wait for mutexes, wait on condition variables, wait for asynchronous results to be ready (std::async in C++11, no direct equivalent in pthreads) ... but there's no call that will allow you to wait a heterogeneous set of those types all at once.