[Boost-users] Fwd: boost::thread and corresponding stack array

Subject: [Boost-users] Fwd: boost::thread and corresponding stack array
From: Aditya Arora (callmeadi_at_[hidden])
Date: 2010-06-05 04:04:28

I'd like to use boost threads, if possible, in an upcoming project, just for
the sake of portability.  The problem is that boost threads seem a bit
unwieldy when it comes to quickly creating multiple threads.  Since the
thread object constructor is what actually launches the thread, you can't
simply create an array of thread objects on the stack, since each thread is
only launched when the constructor is passed a functor.  Therefore, if you
want an array of threads, you need to allocate each thread object
individually on the heap, like:

boost::thread* thr[SIZE];
for (int i = 0; i < SIZE; ++i) thr[i] = new boost::thread(functor);

Then of course, you need to iterate through the array later and call delete
on each thread object.  It's much simpler to do this with plain old
pthreads, since pthreads need to be explicitly started by calling
pthread_create, so you can create an array of pthread structs on the stack,
and then call pthread_create on each one, without having to allocate/free
objects on the heap.

It would be really nice if boost threads simply had a start() member
function, or something, so that you could do something like:

boost::thread thr[SIZE];
for (int i =0 ; i < SIZE: ++i) thr[i].start(functor);

Does anyone know the design considerations that went into creating boost
threads, and why the designers chose to have the constructor the only way to
launch a new thread?

Aditya