Re: finishing the if.h/if_var.h split

From: Doug Rabson (dfr_at_nlsystems.com)
Date: 09/30/03

  • Next message: Brooks Davis: "Re: adding if_dev member to struct ifnet" 
    To: Bruce Evans <bde@zeta.org.au>
Date: 30 Sep 2003 18:25:38 +0100

    On Tue, 2003-09-30 at 09:22, Bruce Evans wrote:

    > That's one alternative. (Far too) many places already use the simple
    > alternative of just using "struct device *". Grep shows 68 lines
    > containing "struct device" in *.h and 32 in *.c. For "device_t", the
    > numbers are 2140 in *.h and 5089 in *.c. This is in a sys tree with
    > about 1000 matches of "device_t" in generated files. There are non-bogus
    > uses of "struct device" to avoid namespace pollution in <sys/rman.h>.
    > Most other uses are just bogus (modulo the existence of device_t being
    > non-bogus -- its opaqueness is negative since anything that wants to
    > use it must include <sys/bus.h> and thus can see its internals. style(9)
    > says to not use negatively opaque typedefs).

    The internals of struct device are not contained in <sys/bus.h> - it is
    completely opaque to users outside subr_bus.c. The main 'bug' here is
    the idea that its a good thing to export kernel data structures (struct
    ifnet) to userland. The layout of struct ifnet is an implementation
    detail - it shouldn't form part of the userland api.

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  • Next message: Brooks Davis: "Re: adding if_dev member to struct ifnet"

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