From owner-freebsd-hackers  Fri May 24 08:33:38 1996
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To: ormonde@trem.cnt.org.br (Rodrigo Ormonde)
cc: freebsd-hackers@freebsd.org
Subject: Re: splnet() and splx() 
In-reply-to: Your message of "Fri, 24 May 1996 10:17:33 -0300."
             <9605241317.AA09726@trem.cnt.org.br> 
From: David Greenman <davidg@Root.COM>
Reply-To: davidg@Root.COM
Date: Fri, 24 May 1996 08:32:30 -0700
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>  I'm working inside the FreeBSD kernel and sometimes I see the following 
>construction: (it is present in many modules)
> 
>	int s;	
>
>        s = splnet();
>
>	/* There is code here */ 
>
>	splx(s);
>
>  Does anybody know what are the functions splnet() and splx() ?

   spl*() and splx() block and restore, respectively, specific classes of
interrupts. splnet() blocks software network ASTs, for example, while splimp()
blocks network device interrupts. splx() restores the previously saved state.

-DG

David Greenman
Core-team/Principal Architect, The FreeBSD Project