[boost] Re: Boost.Threads static linking FYI

From: Michael Glassford (glassfordm_at_[hidden])
Date: 2004-07-16 22:52:13

Edward Diener wrote:

> Michael Glassford wrote:
> 
>>I've made some changes to the Boost.Threads static linking support on
>>Win32. Previously I had added back support for static linking, but
>>without thread-specific storage classes. Now I've added the
>>thread-specific storage classes back in, and exposed two functions
>>that
>>need to be called at the appropriate time:
>>
>>The function on_thread_exit() should be called when a thread exists,
>>*in
>>the context of the exiting thread*. The function on_process_exit()
>>should be called when the process exit. If these functions are not
>>called at the appropriate time, leaks may occur. If you know you don't
>>need tss cleanup, of course you can just omit to call these functions.
>>
>>In addition, Boost.Threads static library on Win32 requires the user
>>of
>>the library to define a function called tss_cleanup_implemented(); if
>>it
>>is not defined, a link error results. The only purpose of this
>>function
>>is as a "link-time assertion": the linker error stating that the
>>function is missing warns the the user of the necessity of calling the
>>cleanup functions. In addition, if Boost.Threads later implements tss
>>cleanup in the static library, the linker's duplicate symbol error
>>should warn the user that their custom implementation is no longer
>>needed.
>>
>>Comments?
> 
> 
> I like this very much as my reticence to use the thread library was
> completely based on the fact that it did not have a static lib version.
> 
> While your tss_cleanup_imnplemented() is clever, I wonder if it is really
> necessary. The spirit of C++ is usuually to allow the programmer to do the
> wrong thing at their peril. Enforcing tss_cleanup_implemented just to warn
> the programmer of something which the documentation should make clear is not
> something I would do.

Who reads documentation? :)

Since the function can be empty, it won't be too much of a burden, I 
hope. As I also hope to make the Boost.Threads library support tss 
cleanup itself in the static library in a future release, this 
requirement should go away, too.

> I assume you mean above that on_thread_exit should be called when a thread
> exits, in the context of the exiting thread.

Yes, that's what I meant. Sorry for the typo.

Mike