Hi Roland,
I may be worried over something inconsequential, but the condition class creates three kernel objects per instance.
There is quite a lot of archived discussion available about this topic. There is agreement, that on windows this is the only reliable way of doing it. Beneath the boost list you might also google for "condition win32". As far as I understood the main issue that it is not possible to implement a condition on win32 with a single event is that it is not possible to awake a single thread _and_ awake all threads. You can't achive both available semantics with an event alone.
I agree that if _all_ capabilities of a posix condition variable are required, my approach would not work. I used one event per waiting thread, the condition variable was permanently associated with the mutex (not just when waiting), and the caller to notify/notifyAll had to have the same mutex. Adding a lightweight_mutex to the condition variable would enable the missing features, but as I said, I saw no need. Sadly, I must confess that I don't understand your reference to the Monitor pattern (been too long since I read that book) and how it relates.
As opposed to conditions your construct also would create a condition with "state". This is not a condition anymore.
It has nearly all the benefits of a full condition variable, is more convenient (safer?) in cases where the mutex passed to wait() is always the same, and is implementable on both platforms with minimal overhead. Unless I am missing something quite fundamental (which is certainly possible<g>), the extra power of on-the-fly association and notify-w/o-holding-mutex don't justify the cost these features entail. I just wrote this off as a satisfactory, least-common-denominator to gain most of the benefit condvars offer. Thanks & Best regards! Don PS: I searched on "condition win32" on www.boost.org and got only 9 hits. A full google turned up an article by Douglas Schmidt that I had read some years back (the top hit). How should I search to find these old discussions? ===== __________________________________ Do you Yahoo!? Send holiday email and support a worthy cause. Do good. http://celebrity.mail.yahoo.com