Tango / Phobos / future dilemma

Frits van Bommel fvbommel at REMwOVExCAPSs.nl
Tue May 27 07:49:26 PDT 2008

Sascha Katzner wrote:
> I see no reason why those two IO systems couldn't coexist on top of a 
> common low level cache.

(All of the statements below are AFAIK & IIRC from the newsgroup 
discussions on this subject)

I do:
Walter seems convinced that using the libc buffering is the Right Thing 
To Do(TM) because it allows intermixing of *printf(), putc*(), etc. with 
writefln & friends without explicitly syncing them.
The Tango devs have a good reason to use their own, separate, buffering 
solution: the tests showing better performance. (And many people 
consider it bad style to use C-style I/O in D programs anyway, so "it's 
just not worth it" becomes a good argument pretty quickly here)

This just doesn't allow a "common low level cache" since neither of 
their buffering solutions allows the use of a common buffer unless the 
other one switches (Phobos can't change libc while much of the Tango IO 
functionality depends on using the custom buffer and its good 
performance depends on interfacing directly to the OS[1])...

In other words, it's a fundamental disagreement about how to best do I/O.

[1] Also, changing the Tango I/O code to use libc instead of direct OS 
calls isn't very helpful since it still won't be synced to C-style I/O 
(there'll still be an extra buffer in front of the Tango stuff that 
would only send stuff to libc when full or explicitly flushed).

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