Boost Equivalent for Windows Events

Question

In windows c++ I can create a handle to event

Handle h = CreateEvent(...)

I can then set and reset that event

SetEvent(...) and ResetEvent(...)

Finally, I can OpenEvents using the command OpenEvent(...)

Is there a boost equivelent for events?

Do you require the multi-process IPC aspect of `OpenEvent`, or are you only needing within-process communication? — Thanatos, Apr 08 '11 at 17:53
Even though not strictly a duplicate, this http://stackoverflow.com/questions/1677070/cross-platform-equivalent-to-windows-events question provides the proper answer to your question. — Cray, Nov 25 '12 at 22:15

score 6 · Accepted Answer · 2011-04-08T19:08:12.403

I think you need to use boost::mutex, boost::unique_lock, boost::condition_variable and possibly bool in order to imitate Events.

You actually might need sort of WaitForSingleObject in order to wait for an event. Might be like this:

void wait_for_user_input()
{
    boost::unique_lock<boost::mutex> lock(mut);
    while(!data_ready)
    {
        cond.wait(lock);
    }
    process_user_input(); // it might be not necessary to hold mutex locked here!!!
                          // if so just add curly braces like this:
                          // void wait_for_user_input()
                          // {
                          //    { 
                          //      boost::unique_lock<boost::mutex> lock(mut);
                          //      while(!data_ready) { cond.wait(lock); }
                          //    }
                          //    process_user_input();
                          // }



}

score 4 · Answer 2 · edited Feb 21 '14 at 11:33

4

The threadsafe Boost Signals2 library might be of use to you. The original Signals library was not thread-safe, but implemented a signals/slots framework which isn't too many miles away from the ideas of events. Since Signals2 is threadsafe, you should be able to utilize it for passing events between threads.

edited Feb 21 '14 at 11:33

gbjbaanb

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answered Apr 08 '11 at 18:27

csj

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zdan · Answer 3 · 2011-04-08T18:26:58.817

0

What you want is named_condition variable from the boost interprocess library. The main difference from windows events is that you must use them in conjunction with a named_mutex.

Note, you can use these boost interprocess primitives within a single process. I assume you need these because you are using OpenEvent (which implies sharing of the object by use of a name). If you can avoid using a name, then you can use the non-named variants from the boost thread library.

edited Apr 08 '11 at 18:26

answered Apr 08 '11 at 18:21

zdan

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IPC is not required according to the author. Besides `name mutexes` if an application crashes are not removed automaticly. And as a result after one adds named mutexes he or she also has to handle somehow this sitution. IMHO it just create unneccessary complexity. – Apr 08 '11 at 18:25
It's not required according to the author, but that part of the question is buried in a comment below the question. This is the right answer without that comment. – aggieNick02 Oct 19 '18 at 18:35

score -1 · Answer 4 · answered Apr 08 '11 at 17:54

-1

A boost lock (mutex) would do pretty much the same thing. You can wait on those.

answered Apr 08 '11 at 17:54

T.E.D.

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Not necessarily. I would like to run a while loop in thread A continuously until thread B triggers an event. – rossb83 Apr 08 '11 at 17:56
so use "timed_lock(mutex, timeout)" inside of your loop – J T Apr 08 '11 at 18:03
I don't want any timings coming into play. I simply want an event trigger. When user clicks a button that causes an event. – rossb83 Apr 08 '11 at 18:10

Boost Equivalent for Windows Events

4 Answers4