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Re: GDB: Does "catch vfork" work?
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Re: GDB: Does "catch vfork" work?


  • Subject: Re: GDB: Does "catch vfork" work?
  • From: "Justin C. Walker" <email@hidden>
  • Date: Sun, 9 Oct 2005 09:23:58 -0700


On Oct 9, 2005, at 08:20 , Daniel Jalkut wrote:

On Oct 9, 2005, at 11:07 AM, Justin C. Walker wrote:
This was a "hack" made at a time when copy-on-write had either not been invented, or was not possible on much of the hardware (i.e., pdp-11's) in use. The intent was to speed up the typical fork()/ exec() sequence by avoiding the copy of the process space.
Maybe you can explain the reasoning behind what SystemUIServer seems to be doing when a screen capture occurs. It vforks, then from the parent (I'm in gdb observing that vfork has returned 0), it immediately forks. It's like a double-fork-wammy. Any idea what the purpose of that might be?

Having the benefit of no source or other knowledge of the architecture, I'm happy to reply :-}


However, those same benefits leave me short of a good explanation.

Does the code appear to be:
   if (vfork() == 0) fork();

or is there something going on between the two?

Sorry I can't be more helpful.

Regards,

Justin

--
Justin C. Walker, Curmudgeon at Large
Institute for General Semantics
-----------
My wife 'n kids 'n dogs are gone,
I can't get Jesus on the phone,
But Ol' Milwaukee's Best is my best friend.
-----------



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  • Follow-Ups:
    • Re: GDB: Does "catch vfork" work?
      • From: Marc Manthey <email@hidden>
    • Re: GDB: Does "catch vfork" work?
      • From: Daniel Jalkut <email@hidden>
References: 
 >GDB: Does "catch vfork" work? (From: Daniel Jalkut <email@hidden>)
 >Re: GDB: Does "catch vfork" work? (From: Damien Bobillot <email@hidden>)
 >Re: GDB: Does "catch vfork" work? (From: Daniel Jalkut <email@hidden>)
 >Re: GDB: Does "catch vfork" work? (From: Damien Bobillot <email@hidden>)
 >Re: GDB: Does "catch vfork" work? (From: Jim Correia <email@hidden>)
 >Re: GDB: Does "catch vfork" work? (From: "Justin C. Walker" <email@hidden>)
 >Re: GDB: Does "catch vfork" work? (From: Daniel Jalkut <email@hidden>)

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