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/*
* Copyright 2002, 2003 Red Hat Inc., Durham, North Carolina.
*
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation on the rights to use, copy, modify, merge,
* publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NON-INFRINGEMENT. IN NO EVENT SHALL RED HAT AND/OR THEIR SUPPLIERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
/*
* Authors:
* Rickard E. (Rik) Faith <faith@redhat.com>
*
*/
/** \file
*
* The DMX server code is written to call #dmxSync() whenever an XSync()
* might be necessary. However, since XSync() requires a two way
* communication with the other X server, eliminating unnecessary
* XSync() calls is a key performance optimization. Support for this
* optimization is provided in \a dmxsync.c. This file provides routines
* that evaluate this optimization by counting the number of XSync()
* calls and monitoring their latency. This functionality can be turned
* on using the -stat command-line parameter. */
#ifdef HAVE_DMX_CONFIG_H
#include <dmx-config.h>
#endif
#include "dmx.h"
#include "dmxstat.h"
#include "dmxlog.h"
#include <X11/Xos.h> /* For sys/time.h */
/** Used to compute a running average of value. */
typedef struct _DMXStatAvg {
int pos;
int count;
unsigned long value[DMX_STAT_LENGTH];
} DMXStatAvg;
/** Statistical information about XSync calls. */
struct _DMXStatInfo {
unsigned long syncCount;
unsigned long oldSyncCount;
DMXStatAvg usec;
DMXStatAvg pending;
unsigned long bins[DMX_STAT_BINS];
};
/* Interval in mS between statistic message log entries. */
int dmxStatInterval;
static int dmxStatDisplays;
static OsTimerPtr dmxStatTimer;
/** Return the number of microseconds as an unsigned long.
* Unfortunately, this is only useful for intervals < about 4 sec. */
static unsigned long usec(struct timeval *stop, struct timeval *start)
{
return (stop->tv_sec - start->tv_sec) * 1000000
+ stop->tv_usec - start->tv_usec;
}
static unsigned long avg(DMXStatAvg *data, unsigned long *max)
{
unsigned long sum;
int i;
*max = 0;
if (!data->count) return 0;
for (i = 0, sum = 0; i < data->count; i++) {
if (data->value[i] > *max) *max = data->value[i];
sum += data->value[i];
}
return sum / data->count;
}
/** Turn on XSync statistic gathering and printing. Print every \a
* interval seconds, with lines for the first \a displays. If \a
* interval is NULL, 1 will be used. If \a displays is NULL, 0 will be
* used (meaning a line for every display will be printed). Note that
* this function takes string arguments because it will usually be
* called from #ddxProcessArgument in \a dmxinit.c. */
void dmxStatActivate(const char *interval, const char *displays)
{
dmxStatInterval = (interval ? atoi(interval) : 1) * 1000;
dmxStatDisplays = (displays ? atoi(displays) : 0);
if (dmxStatInterval < 1000) dmxStatInterval = 1000;
if (dmxStatDisplays < 0) dmxStatDisplays = 0;
}
/** Allocate a \a DMXStatInfo structure. */
DMXStatInfo *dmxStatAlloc(void)
{
DMXStatInfo *pt = calloc(1, sizeof(*pt));
return pt;
}
/** Free the memory used by a \a DMXStatInfo structure. */
void dmxStatFree(DMXStatInfo *pt)
{
free(pt);
}
static void dmxStatValue(DMXStatAvg *data, unsigned long value)
{
if (data->count != DMX_STAT_LENGTH) ++data->count;
if (data->pos >= DMX_STAT_LENGTH-1) data->pos = 0;
data->value[data->pos++] = value;
}
/** Note that a XSync() was just done on \a dmxScreen with the \a start
* and \a stop times (from gettimeofday()) and the number of
* pending-but-not-yet-processed XSync requests. This routine is called
* from #dmxDoSync in \a dmxsync.c */
void dmxStatSync(DMXScreenInfo *dmxScreen,
struct timeval *stop, struct timeval *start,
unsigned long pending)
{
DMXStatInfo *s = dmxScreen->stat;
unsigned long elapsed = usec(stop, start);
unsigned long thresh;
int i;
++s->syncCount;
dmxStatValue(&s->usec, elapsed);
dmxStatValue(&s->pending, pending);
for (i = 0, thresh = DMX_STAT_BIN0; i < DMX_STAT_BINS-1; i++) {
if (elapsed < thresh) {
++s->bins[i];
break;
}
thresh *= DMX_STAT_BINMULT;
}
if (i == DMX_STAT_BINS-1) ++s->bins[i];
}
/* Actually do the work of printing out the human-readable message. */
static CARD32 dmxStatCallback(OsTimerPtr timer, CARD32 t, pointer arg)
{
int i, j;
static int header = 0;
int limit = dmxNumScreens;
if (!dmxNumScreens) {
header = 0;
return DMX_STAT_INTERVAL;
}
if (!header++ || !(header % 10)) {
dmxLog(dmxDebug,
" S SyncCount Sync/s avSync mxSync avPend mxPend | "
"<10ms <1s >1s\n");
}
if (dmxStatDisplays && dmxStatDisplays < limit) limit = dmxStatDisplays;
for (i = 0; i < limit; i++) {
DMXScreenInfo *dmxScreen = &dmxScreens[i];
DMXStatInfo *s = dmxScreen->stat;
unsigned long aSync, mSync;
unsigned long aPend, mPend;
if (!s) continue;
aSync = avg(&s->usec, &mSync);
aPend = avg(&s->pending, &mPend);
dmxLog(dmxDebug, "%2d %9lu %7lu %6lu %6lu %6lu %6lu |",
i, /* S */
s->syncCount, /* SyncCount */
(s->syncCount
- s->oldSyncCount) * 1000 / dmxStatInterval, /* Sync/s */
aSync, /* us/Sync */
mSync, /* max/Sync */
aPend, /* avgPend */
mPend); /* maxPend */
for (j = 0; j < DMX_STAT_BINS; j++)
dmxLogCont(dmxDebug, " %5lu", s->bins[j]);
dmxLogCont(dmxDebug, "\n");
/* Reset/clear */
s->oldSyncCount = s->syncCount;
for (j = 0; j < DMX_STAT_BINS; j++) s->bins[j] = 0;
}
return DMX_STAT_INTERVAL; /* Place on queue again */
}
/** Try to initialize the statistic gathering and printing routines.
* Initialization only takes place if #dmxStatActivate has already been
* called. We don't need the same generation protection that we used in
* dmxSyncInit because our timer is always on a queue -- hence, server
* generation will always free it. */
void dmxStatInit(void)
{
if (dmxStatInterval)
dmxStatTimer = TimerSet(NULL, 0,
dmxStatInterval, dmxStatCallback, NULL);
}
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