[Live-devel] Overuse of CPU in binaries of CYGWIN

[Martínez Contador, Daniel [ELIMCO] (CA)]

Re: Overuse of CPU in binaries of CYGWIN

>> Cygwin tries very hard to be as minimal a layer between
>> your program and the Windows kernel as it can be, but in
>> certain places, it has to be thicker than we'd like to
>> emulate the POSIX semantics programs built on Cygwin
>> expect, in terms of the Windows kernel API, which often
>> isn't implemented with POSIX-like semantics.  I/O is one
>> of these places, and Live555 is all about I/O.

This is an educated guess. In Cygwin the RTSPClientConnection
socket doesn't close explicitly after a TEAR. The read bitmask
in the call to select in BasicTaskScheduler remains active
and the call returns immediately by some reason which doesn't
apply to other posixes.

Modifying handleCmd_TEARDOWN so that the RTSPClientSession
deletes itself and its ourClientConnection closes sockets
seem to restore normal CPU usage after a TEAR with no
(evident) adverse effects.

> I must admit that I don't understand why so many people
> are trying to develop server applications (LIVE555-based
> or otherwise) on Windows.  The Windows OS is not
> well-suited for running servers.

I mostly agree. What I'm doing will be part of both a server
and a test/development tool. The server will run in Windows
among other servers already in Windows, all of them will be
eventually ported to Linux (hopefully). The test tool will
have to run in Windows too however.


Daniel Martínez Contador
ELIMCO- Soluciones Integrales S.A.
Navantia - Sistemas de Control
Ctra. Algameca, s/n
30205 Cartagena (Murcia)
Tlfo: 968 323 387
Email: elimco.dmartinez at navantia.es
www.elimco.com



NAVANTIA
______________________________
Este mensaje, y cualquier fichero anexo al mismo, contiene informacion de caracter confidencial dirigida exclusivamente a su(s) destinatario(s) y, en su caso, sometida a secreto profesional. Queda prohibida su difusion, copia o distribucion a terceros sin la previa autorizacion escrita. Si Vd. ha recibido este mensaje por error, se ruega lo comunique inmediatamente por esta misma via y proceda a su completa eliminacion.
The information in this e-mail, and in any attachments, is confidential and, if any, protected by a professional privilege, and intended solely for the attention and use of the named addressee(s). You are hereby notified that any dissemination, copy or distribution of this information is prohibited without the prior written consent. If you have received this communication in error, please notify the sender by reply e-mail and delete it.
______________________________