Re: threading question
"scott mcfadden" <nospam.smcfadden@criticaltech.com> wrote in message
news:ucq6lXW6GHA.4404@TK2MSFTNGP04.phx.gbl...
C# has a easy way of waking another thread (Thread.Interupt). Does C++
/MFC have a nice way of checking the status of another thread and if it is
sleeping, to wake it?
The languages involved are not relevant here - this is a .NET framework
versus Win32 question. So, does Win32 provide anything like .NET's
Thread.Interrupt function?
In simple terms: no.
In general, there's no way under Win32 to wake a thread that's waiting
unless you can signal one of the objects the thread is waiting on. There
are some special cases (e.g. "alertable wait states"), but those really are
special cases and don't apply in this case.
What's really going on here is that when a .NET thread blocks, it always
blocks on multiple objects - the .NET framework adds an additional wait to
whatever the programmer wanted to wait for. Thread.Interrupt simply signals
that additional wait object, which is most likely an auto-reset event
allocated when the thread was created.
You can, of course, implement this same sort of arrangement in your own
code - for threads that you control, but there's no general solution to wake
an arbitrary thread in Win32.
-cd