Grace delay feature added

`proxy -g8000,3,10`

First parameter is average read size we want to keep, second parameter is
minimal number of packets in the same direction to apply algorythm,
last value is delay added after polling and prior to reading data.
An example above adds 10 millisecond delay before reading data if average
polling size is below 8000 bytes and 3 read operations are made in the same
direction. It's specially usefule with splice. `logdump 1 1` is useful
to see how grace delays work, choose delay value to avoid filling the read
pipe/buffer (typically 64K) but keep the request sizes close to chosen average
on large file upload/download.

doc/html/highload.html

@@ -285,3 +285,16 @@ requirements.
 system bus are bottlenecks.
 <p>TCP_NODELAY and splice are not contrary to each over and should be combined on
 high-speed connections.
+
+<h4>Add grace delay to reduce system calls<h4>
+
+<pre>proxy -g8000,3,10</pre>
+First parameter is average read size we want to keep, second parameter is
+minimal number of packets in the same direction to apply algorythm,
+last value is delay added after polling and prior to reading data.
+An example above adds 10 millisecond delay before reading data if average
+polling size is below 8000 bytes and 3 read operations are made in the same
+direction. It's specially usefule with splice. <pre>logdump 1 1</pre> is useful
+to see how grace delays work, choose delay value to avoid filling the read
+pipe/buffer (typically 64K) but keep the request sizes close to chosen average
+on large file upload/download.

man/3proxy.cfg.3

@@ -110,6 +110,8 @@ disable NTLM authentication (required if passwords are stored in Unix crypt form
 .B -n1
 enable NTLMv1 authentication.
 .br
+.B -g(GRACE_TRAFF,GRACE_NUM,GRACE_DELAY)
+delay GRACE_DELAY  milliseconds before polling if average polling size below  GRACE_TRAFF bytes and GRACE_NUM read operations in single directions are detected within 1 second. Useful to minimize polling
 .B -s
  (for admin) secure, allow only secure operations, currently only traffic counters
 view without ability to reset.

src/common.c

@@ -103,6 +103,7 @@ struct extparam conf = {
 	0,
 	0, -1, 0, 0, 0, 0, 
 	0, 500, 0, 0, 0, 0, 0, 2,
+	0, 0, 0,
 	6, 600,
 	1048576,
 	NULL, NULL,

src/proxy.c

@@ -131,7 +131,7 @@ char * proxy_stringtable[] = {
 	NULL
 };
 
-#define LINESIZE 4096
+#define LINESIZE 32768
 #define BUFSIZE (LINESIZE*2)
 #define FTPBUFSIZE 1536
 

src/proxy.h

@@ -30,7 +30,7 @@
 #define MAXNSERVERS 5
 
 #define UDPBUFSIZE 16384
-#define TCPBUFSIZE  8192
+#define TCPBUFSIZE 65536
 #define SRVBUFSIZE (param->srv->bufsize?param->srv->bufsize:((param->service == S_UDPPM)?UDPBUFSIZE:TCPBUFSIZE))
 
 

src/proxymain.c

@@ -223,6 +223,7 @@ int MODULEMAINFUNC (int argc, char** argv){
 #ifdef WITHSLICE
 	" -s Use slice() - faster proxing, but no filtering for data\n"
 #endif
+	"-g(GRACE_TRAFF,GRACE_NUM,GRACE_DELAY) - delay GRACE_DELAY milliseconds before polling if average polling size below  GRACE_TRAFF bytes and GRACE_NUM read operations in single directions are detected within 1 second to minimize polling\n"
 	" -fFORMAT logging format (see documentation)\n"
 	" -l log to stderr\n"
 	" -lFILENAME log to FILENAME\n"
@@ -428,6 +429,9 @@ int MODULEMAINFUNC (int argc, char** argv){
 		case 'a':
 			srv.anonymous = 1 + atoi(argv[i]+2);
 			break;
+		case 'g':
+			sscanf(argv[i]+2, "%d,%d,%d", &srv.gracetraf, &srv.gracenum, &srv.gracedelay);
+			break;
 		case 's':
 #ifdef WITHSPLICE
 			if(isudp || srv.service == S_ADMIN)

src/sockmap.c

@@ -60,6 +60,7 @@ int sockmap(struct clientparam * param, int timeo, int usesplice){
  int res;
  SASIZETYPE sasize;
  int needaction = 0;
+ int graceclinum=0, gracesrvnum=0, graceclitraf=0, gracesrvtraf=0, gracetime=0;
 
 #ifdef WITHSPLICE
  uint64_t inclientpipe = 0, inserverpipe = 0;
@@ -158,6 +159,18 @@ sprintf(logbuf, "int FROMCLIENT = %d, TOCLIENTBUF = %d, FROMCLIENTBUF = %d, TOSE
 log(logbuf);
 #endif
 
+	if(needaction && param->srv->gracedelay && !sleeptime){
+		if(gracetime != conf.time){
+		    gracetime = conf.time;
+		    graceclinum=gracesrvnum=graceclitraf=gracesrvtraf=0;
+		}
+		else {
+		    if( (graceclinum && graceclitraf && graceclinum>=param->srv->gracenum && (!param->srv->gracetraf || graceclitraf/graceclinum <= param->srv->gracetraf)) ||
+			(gracesrvnum && gracesrvtraf && gracesrvnum>=param->srv->gracenum && (!param->srv->gracetraf || gracesrvtraf/gracesrvnum <= param->srv->gracetraf))) {
+			    sleeptime = param->srv->gracedelay;
+			}
+		}
+	}
 	if(needaction > 2 && !sleeptime){
 		if(needaction > (MAXFAILATTEMPT+1)){RETURN (93);}
 		sleeptime = (1<<(needaction-2));
@@ -354,6 +367,9 @@ log(logbuf);
 #ifdef WITHLOG
 log("done read from client to pipe");
 #endif
+				graceclinum++;
+				graceclitraf += res;
+				gracesrvnum = gracesrvtraf = 0;
 				inclientpipe += res;
 				if(inclientpipe >= MAXSPLICE) TOCLIENTPIPE = 0;
 				needaction = 0;
@@ -388,6 +404,9 @@ log(logbuf);
 #ifdef WITHLOG
 log("done read from server to pipe\n");
 #endif
+				gracesrvnum++;
+				gracesrvtraf += res;
+				graceclinum = graceclitraf = 0;
 			    	param->nreads++;
 				param->statssrv64 += res;
 				inserverpipe += res;
@@ -426,6 +445,9 @@ log("read from client to buf");
 #ifdef WITHLOG
 log("done read from client to buf");
 #endif
+				graceclinum++;
+				graceclitraf += res;
+				gracesrvnum = gracesrvtraf = 0;
 				inclientbuf += res;
 				param->cliinbuf += res;
 				if(param->clibufsize == param->cliinbuf) TOCLIENTBUF = 0;
@@ -451,6 +473,9 @@ log("read from server to buf");
 #ifdef WITHLOG
 log("done read from server to buf");
 #endif
+				gracesrvnum++;
+				gracesrvtraf += res;
+				graceclinum = graceclitraf = 0;
 			    	param->nreads++;
 				param->statssrv64 += res;
 				inserverbuf += res;

src/structures.h

@@ -437,6 +437,7 @@ struct srvparam {
 	int noforce;
 	int anonymous;
 	int clisockopts, srvsockopts, lissockopts, cbcsockopts, cbssockopts;
+	int gracetraf, gracenum, gracedelay;
 #ifdef WITHSPLICE
 	int usesplice;
 #endif
@@ -576,6 +577,7 @@ struct extparam {
 		demon, maxchild, needreload, timetoexit, version, noforce, bandlimver, parentretries;
 	int authcachetype, authcachetime;
 	int filtermaxsize;
+	int gracetraf, gracenum, gracedelay;
 	unsigned char *logname, **archiver;
 	ROTATION logtype, countertype;
 	char * counterfile;