[SPAM] Re: Self-contained one purpose objects

[Chris Johns]

Spam detection software, running on the system "corb.contemporary.net.au",
has identified this incoming email as possible spam.  The original
message has been attached to this so you can view it or label
similar future email.  If you have any questions, see
The administrator of that system for details.

Content preview:  On 23/07/2015 7:16 pm, Sebastian Huber wrote: > The Classic
   RTEMS and POSIX APIs have at least three weaknesses. > > * Dynamic memory
   (the workspace) is used to allocate object pools. This > requires a complex
   configuration with heavy use of the C pre-processor. > > * Objects are created
   via function calls which return an object identifier. > The object operations
   use this identifier and internally map it to an > internal object representation.
   > > * The object operations use a rich set of options and attributes. Each
   time > these parameters must be evaluated and validated to figure out what
   to > do. > > For applications that use fine grained locking the overhead
  to map the > identifier to the object representation and the parameter evaluation
   is a > significant overhead the may degrade the performance dramatically.
   An > example > is the FreeBSD network stack which hundreds of locks in a
  basic setup. > Here > the performance can be easily measured in terms of throughput
   and processor > utilization. The port of the FreeBSD network stack uses now
   its own > priority > inheritance mutex implementation which is not based
  on the classic RTEMS > objects. The blocking part however uses the standard
   thread queues. The > overall implementation is quite simple. > > Another
  example which benefits from self-contained objects is OpenMP. For > OpenMP
   the performance of the POSIX configuration of libgomp and an > optimized
  > implementation using self-contained objects available via Newlib > <sys/lock.h>
   > is significantly different, see https://devel.rtems.org/ticket/2274. >
  Some test > cases are more than a hundred times slower in the POSIX configuration
   of > libgomp. > > Since the Newlib should use locks to protect some global
   data structures > (https://devel.rtems.org/ticket/1247) and the GCC uses
  locks for the C++ > and > OpenMP support the application must take this into
   account. It is > difficult to > figure out how many and which objects will
   be used by Newlib and GCC for a > particular application. It would be much
   [...] 

Content analysis details:   (3.7 points, 2.7 required)

 pts rule name              description
---- ---------------------- --------------------------------------------------
 3.3 RCVD_IN_PBL            RBL: Received via a relay in Spamhaus PBL
                            [144.132.189.169 listed in zen.spamhaus.org]
 1.3 RCVD_IN_RP_RNBL        RBL: Relay in RNBL,
                            https://senderscore.org/blacklistlookup/
                          [144.132.189.169 listed in bl.score.senderscore.com]
 0.0 URIBL_BLOCKED          ADMINISTRATOR NOTICE: The query to URIBL was blocked.
                            See
                            http://wiki.apache.org/spamassassin/DnsBlocklists#dnsbl-block
                             for more information.
                            [URIs: rtems.org]
-1.9 BAYES_00               BODY: Bayes spam probability is 0 to 1%
                            [score: 0.0000]
 1.0 RDNS_DYNAMIC           Delivered to internal network by host with
                            dynamic-looking rDNS


-------------- next part --------------
An embedded message was scrubbed...
From: Chris Johns <chrisj at rtems.org>
Subject: Re: Self-contained one purpose objects
Date: Thu, 23 Jul 2015 20:29:26 +1000
Size: 6596
URL: <http://lists.rtems.org/pipermail/devel/attachments/20150723/59797adf/attachment-0002.mht>