tcpperf.c

来自「用于嵌入式系统的TCP/IP协议栈及若干服务」· C语言 代码 · 共 96 行

/*
*            Copyright (c) 1998-2001 by NETsilicon Inc.
*
*  This software is copyrighted by and is the sole property of
*  NETsilicon.  All rights, title, ownership, or other interests
*  in the software remain the property of NETsilicon.  This
*  software may only be used in accordance with the corresponding
*  license agreement.  Any unauthorized use, duplication, transmission,
*  distribution, or disclosure of this software is expressly forbidden.
*
*  This Copyright notice may not be removed or modified without prior
*  written consent of NETsilicon.
*
*  NETsilicon, reserves the right to modify this software
*  without notice.
*
*  NETsilicon
*  411 Waverley Oaks Road                  USA 781.647.1234
*  Suite 227                               http://www.netsilicon.com
*  Waltham, MA 02452                       [e-mail]
*
*************************************************************************
*  $Name: Fusion 6.52 Fusion 6.51 $
*  $Date: 2001/09/20 10:21:44 $
*  $Source: M:/psisrc/stack/tcp/rcs/tcpperf.c $
*  $Revision: 1.12 $
**************************************************************************
*  File Description:  TCP - Transmission Control Protocol
*                     Performance monitoring and optimization routines
**************************************************************************/
#include "std.h"

#include "ip.h"
#include "m.h"
#include "tcp.h"
#include "timer.h"
#include "debug.h"
#include "fnsproto.h"

#define MIN_PERF_BYTES       8000    /* min # of bytes in a sample */
#define MAX_PERF_INTERVAL    2000L   /* max sampling interval */

#define RETRY_SAMPLES   16      /* # of stable samples before forced
				 * attempt to optimize again */


local   void    tcp_sqadjust(tcpsv_t * svp);
import  u32     tcp_sq_max;


/* periodic timer to sample performance and make improvements */
export  int     tcp_perftimer (void * uarg)
{
#define lsvp    ((tcpsv_t *)uarg)
	int     last_int;
	use_critical;

	critical;
	last_int = (int)(t_clicks - lsvp->sv_rsclicks);
	if ( lsvp->sv_sqcntdwn > 0 && (lsvp->sv_sqcntdwn -= last_int) <= 0 )
		tcp_sqadjust(lsvp);
	lsvp->sv_rsclicks = t_clicks;

	normal;
	return 0;
}


/* tcp_sqadjust is called periodically following an attack of Source Quench
 * on a socket.  The send queue max is gradually increased back to the
 * maximum allowed, as long as we don't get SQ'd again.  The only reason
 * this code is in this module is that it is sort of a performance issue,
 * and the performance timer is a convenient mechanism to time the sq max
 * regrowth.
 */
local   void    tcp_sqadjust (fast tcpsv_t * svp)
{
    int     new_sq_max;
    fast    so_t    * sop;

	sop = sv_valid_sop(svp, sop);
	if (!sop)
		return;
        
	new_sq_max = (&sop->so_sq)->gq_max << 1;
	if ( (new_sq_max = min(new_sq_max, (int)tcp_sq_max)) == (int)tcp_sq_max ) {
		/* Back to normal for now */
		svp->sv_sqcntdwn = 0;
	}
	else
		/* Schedule next increase in one minute */
		svp->sv_sqcntdwn = 60000 / MS_PER_TICK;
        
	gq_max_set(&sop->so_sq, new_sq_max);
}