Re: [boost] Re: Boost Jam question: how to set "features"?

From: Peter Dimov (pdimov_at_[hidden])
Date: 2001-11-13 09:29:05

From: <williamkempf_at_[hidden]>
> If by "per-thread state" you mean TLS slots, yes it does.  A TLS slot
> is allocated for cleanup handlers in tss.cpp on Win32.  Again,
> though, I see nothing documented that says calls to TlsAlloc/TlsFree
> have problems crossing DLL boundaries, and these methods are part of
> the Win32 API not the RTL so should be totally unaffected by the
> linkage option chosen for the RTL.  Or am I missing something
> important?

Yes, TlsAlloc/TlsFree are not affected by the RTL.

The problem that I'm speculating about is that the EXE and the DLL will have
their own separate TLS slot. This is not a problem with tss.cpp AFAICS
because Boost.Threads doesn't assume anywhere that this particular TLS slot
is unique.

If, on the other hand, you decide to keep a per-thread flag ("bool
canceled", say), in a situation where the EXE sets this flag to true, the
DLL will not see the change.

Again, this is not related to how the RTL is linked, but rather to the fact
that the EXE and the DLL may have their own copy of Boost.Threads (with its
own statics.)

As I said this is not currently a problem.

--
Peter Dimov
Multi Media Ltd.