Re: Draft: musl promo materials

[Isaac Dunham <idunham@lavabit.com>]

On Fri, 13 Jul 2012 19:30:52 -0400
Rich Felker <dalias@aerifal.cx> wrote:

> Updated version based on some comments.. I think the list is getting
> long enough that it would possibly make sense to reorder/trim it for
> the intended target audience in some usages, and only include the full
> thing on the website.
> 
> Rich
> 
> 
> ----------------------------------------------------------------------
> 
> Consistent quality and implementation behavior from tiny embedded
> systems to full servers.
> 
> Minimal machine-specific code, meaning less chance of breakage on
> minority architectures and better success with "write once run
> everywhere" development.

One criticism I've heard (not saying I agree!) is that you lose
performance with musl thanks to most functions being in C...

> Extremely efficient static and dynamic linking support, yielding small
> binaries and minimal startup overhead.
> 
> Realtime-quality robustness. No unnecessary dynamic allocation. No
> unrecoverable late failures. No lazy binding or lazy allocation.
> 
This reminded me about _XOPEN_REALTIME:
"This Option Group consists of the set of the following options from
within POSIX.1-2008 (see Options ):

    _POSIX_FSYNC
    _POSIX_MEMLOCK
    _POSIX_MEMLOCK_RANGE
    _POSIX_MESSAGE_PASSING
    _POSIX_PRIORITIZED_IO
    _POSIX_PRIORITY_SCHEDULING
    _POSIX_SHARED_MEMORY_OBJECTS
    _POSIX_SYNCHRONIZED_IO
"
Of these, the MEMLOCK ones are the only ones defined yet.
It seems _POSIX_FSYNC is supported, but not advertised.
The other 4 are not defined yet; what's musl's  support for them?
I'm curious how far from  complete _XOPEN_REALTIME support musl is.

X/Open also defines the Advanced Realtime, Realtime Threads, and
Advanced Realtime Threads options.

> MIT license.
> 
> Full math library with a focus on correctness. Exact and
> correctly rounded conversion between binary floating point and decimal
> strings.
> 
> Reentrancy, thread-safety, and async-signal safety well beyond the
> requirements of POSIX. Even snprintf and dprintf are fully reentrant
> and async-signal-safe.
> 
> Highly resource-efficient POSIX threads implementation, making
> multi-threaded application design viable even for memory-constrained
> systems.
> 
> Simple source code and source tree layout, so it's easy to customize
> or track down the cause of unexpected behavior or bugs, or simply
> learn how the library works.

Other than the mention of realtime when no proper realtime support is
advertised in the headers, seems pretty good.