971016: EH frame_init trouble on Sparc

971016: EH frame_init trouble on Sparc

[Teemu Torma]

I attempted to throw exceptions in a large C++ application
using snapshot 971016, and ran into trouble.

The problem is that find_fde calls frame_init if pc_begin is zero.
However, frame_init finds the lowest pc_begin as zero, causing
the application to hang and eventually crash.  I think it is doing
initializations over and over again, and frame_init keeps allocating
more and more memory.

The quick fix to make it work at all is to set pc_begin to 1 in
frame_init if it would be zero, but I think the problem lies
somewhere else.  There seems to be a lot of fdes with pc_begin
is zero.

This always happens with the first object in find_fde where ob->count
is over 10000.  The application itself uses ~15 biggish shared C++
libraries and ~20 shared C libraries (Motif etc).

Any pointers where to start looking?

I also noticed that it takes considerable amount of time
to throw the first exception, due to initializations done
at that point.

Teemu

Re: 971016: EH frame_init trouble on Sparc

[H.J. Lu]

> 
> I attempted to throw exceptions in a large C++ application
> using snapshot 971016, and ran into trouble.
> 
> The problem is that find_fde calls frame_init if pc_begin is zero.
> However, frame_init finds the lowest pc_begin as zero, causing
> the application to hang and eventually crash.  I think it is doing
> initializations over and over again, and frame_init keeps allocating
> more and more memory.
> 

Please check my email "A frame.c patch". I ran into the same
problem.


H.J.

971016: EH frame_init trouble on Sparc

[Teemu Torma]

    From:  hjl@lucon.org (H.J. Lu)
    Date:  Wed, 22 Oct 1997 08:50:25 -0700 (PDT)

    Please check my email "A frame.c patch". I ran into the same
    problem.
    
Thanks, I must have skipped that one.

Teemu

Re: 971016: EH frame_init trouble on Sparc

[Jeffrey A Law]

  In message <199710221010.MAA21092@baht.labs.trema.com>you write:
  > I attempted to throw exceptions in a large C++ application
  > using snapshot 971016, and ran into trouble.
  > 
  > The problem is that find_fde calls frame_init if pc_begin is zero.
  > However, frame_init finds the lowest pc_begin as zero, causing
  > the application to hang and eventually crash.  I think it is doing
  > initializations over and over again, and frame_init keeps allocating
  > more and more memory.
I believe this was fixed in the 10/31 snapshot.

jeff