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Date: Thu, 09 Oct 2008 09:25:56 +0800
From: David Xu <davidxu@freebsd.org>
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To: John Hein <jhein@timing.com>
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Cc: threads@freebsd.org
Subject: Re: pthread_cleanup_push & pthread_cleanup_pop usage
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John Hein wrote:
> In June pthread_cleanup_push & pthread_cleanup_pop were changed to macros
> that look like so...
> 
> +#define        pthread_cleanup_push(cleanup_routine, cleanup_arg)              \
> +               {                                                               \
> +                       struct _pthread_cleanup_info __cleanup_info__;          \
> +                       __pthread_cleanup_push_imp(cleanup_routine, cleanup_arg,\
> +                               &__cleanup_info__);                             \
> +                       {
> +
> +#define        pthread_cleanup_pop(execute)                                    \
> +                       }                                                       \
> +                       __pthread_cleanup_pop_imp(execute);                     \
> +               }
> +
> 
> 
> This breaks code where the pop is done in an inner block level.
> 
> simplified example:
> 
>     pthread_cleanup_push(docleanup, &foo);
>     try
>     {   
>         dostuff();
>     }
>     catch (...)
>     {   
>         pthread_cleanup_pop(1);
>         throw;
>     }
>     pthread_cleanup_pop(1);
> 
> Does anyone have a recommended fix?


Your problem can be fixed as deischen@ said. but I think it can be
resolved by stack unwinding code I am working in progress, when a
C++ exception is thrown, onstack C++ objects along with pthread
cleanup handlers will be invoked automatically.

Regards,
David Xu