condvar-implementation

From	Bonita Montero <Bonita.Montero@gmail.com>
Newsgroups	comp.lang.c++
Subject	condvar-implementation
Date	2021-09-20 20:44 +0200
Organization	A noiseless patient Spider
Message-ID	<siakpt$oha$1@dont-email.me> (permalink)

Show all headers | View raw

A long time ago I found a page describing different approaches to imple-
ment a condvar under Windows, but this would apply to any operating-sys-
tem having parallelism through supplying semaphores and being designed
for CPUs with atomic operations.
I just wrote a special Java-like monitor-object for Win32 and __unix__.
One speciality with my implementation is, that there's a method to
signal the monitor (for a single or multiple threads) and relinquish
ownership in one step. On Windows this only summarizes two atomic ope-
rations in one, but on __unix__ I increase efficiency by using a SysV
semaphore set and with semop I can raise two semaphores at once so
that I save one kernel-call.
A monitor object has the disadvantage that you can't signal multiple
states to different threads with it - it's functionally like a single
mutex bound to a single condvar. So I wrote a dual_monitor class which
allows bidirectional communications of two threads bound to the same
mutual exclusion. You cann call notify(_all)( bool b ) on it where b
is a bool that says which state has to be signalled. Theres no prority
on either direction and the threads are awakened in an arbitrary order.
There's also a notify_(all_)and_unlock( bool b ) method that does the
same signalling and unlocking in one step as for the first monitor.

But I'm still interested in the paper which describes the different
approaches in implementing a condvar for Win32. Maybe I can implement
some improvemehts here also.
Chris, I _only_ want this paper and no chaotic descriptions, salves
of chaotic postings, or chaotic sourcecode. Your replies are usually
no help at all.

Back to comp.lang.c++ | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

condvar-implementation Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-20 20:44 +0200
  Re: condvar-implementation scott@slp53.sl.home (Scott Lurndal) - 2021-09-20 19:54 +0000
  Re: condvar-implementation "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-09-20 15:52 -0700
    Re: condvar-implementation Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-21 13:24 +0200
      Re: condvar-implementation "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-09-21 16:08 -0700
        Re: condvar-implementation "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-09-22 12:37 -0700
          Re: condvar-implementation Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-23 06:18 +0200
            Re: condvar-implementation "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-09-22 22:23 -0700
              Re: condvar-implementation Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-23 09:09 +0000
                Re: condvar-implementation "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-09-23 10:28 -0700
              Re: condvar-implementation Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-23 19:06 +0200
            Re: condvar-implementation Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-23 09:07 +0000
              Re: condvar-implementation Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-23 19:07 +0200
      Re: condvar-implementation "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-09-21 16:33 -0700

csiph-web