1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
/*
* Copyright 2002-2004 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 here. Statistics about XSync() calls and
* latency are gathered in \a dmxstat.c.
*
* During the initial conversion from calling XSync() immediately to the
* XSync() batching method implemented in this file, it was noted that,
* out of more than 300 \a x11perf tests, 8 tests became more than 100
* times faster, with 68 more than 50X faster, 114 more than 10X faster,
* and 181 more than 2X faster. */
#ifdef HAVE_DMX_CONFIG_H
#include <dmx-config.h>
#endif
#include "dmx.h"
#include "dmxsync.h"
#include "dmxstat.h"
#include "dmxlog.h"
#include <sys/time.h>
static int dmxSyncInterval = 100; /* Default interval in milliseconds */
static OsTimerPtr dmxSyncTimer;
static int dmxSyncPending;
static void dmxDoSync(DMXScreenInfo *dmxScreen)
{
dmxScreen->needsSync = FALSE;
if (!dmxScreen->beDisplay)
return; /* FIXME: Is this correct behavior for sync stats? */
if (!dmxStatInterval) {
XSync(dmxScreen->beDisplay, False);
} else {
struct timeval start, stop;
gettimeofday(&start, 0);
XSync(dmxScreen->beDisplay, False);
gettimeofday(&stop, 0);
dmxStatSync(dmxScreen, &stop, &start, dmxSyncPending);
}
}
static CARD32 dmxSyncCallback(OsTimerPtr timer, CARD32 time, pointer arg)
{
int i;
if (dmxSyncPending) {
for (i = 0; i < dmxNumScreens; i++) {
DMXScreenInfo *dmxScreen = &dmxScreens[i];
if (dmxScreen->needsSync) dmxDoSync(dmxScreen);
}
}
dmxSyncPending = 0;
return 0; /* Do not place on queue again */
}
static void dmxSyncBlockHandler(pointer blockData, OSTimePtr pTimeout,
pointer pReadMask)
{
TimerForce(dmxSyncTimer);
}
static void dmxSyncWakeupHandler(pointer blockData, int result,
pointer pReadMask)
{
}
/** Request the XSync() batching optimization with the specified \a
* interval (in mS). If the \a interval is 0, 100mS is used. If the \a
* interval is less than 0, then the XSync() batching optimization is
* not requested (e.g., so the -syncbatch -1 command line option can
* turn off the default 100mS XSync() batching).
*
* Note that the parameter to this routine is a string, since it will
* usually be called from #ddxProcessArgument in \a dmxinit.c */
void dmxSyncActivate(const char *interval)
{
dmxSyncInterval = (interval ? atoi(interval) : 100);
if (dmxSyncInterval < 0) dmxSyncInterval = 0;
}
/** Initialize the XSync() batching optimization, but only if
* #dmxSyncActivate was last called with a non-negative value. */
void dmxSyncInit(void)
{
if (dmxSyncInterval) {
RegisterBlockAndWakeupHandlers(dmxSyncBlockHandler,
dmxSyncWakeupHandler,
NULL);
dmxLog(dmxInfo, "XSync batching with %d ms interval\n",
dmxSyncInterval);
} else {
dmxLog(dmxInfo, "XSync batching disabled\n");
}
}
/** Request an XSync() to the display used by \a dmxScreen. If \a now
* is TRUE, call XSync() immediately instead of waiting for the next
* XSync() batching point. Note that if XSync() batching was deselected
* with #dmxSyncActivate() before #dmxSyncInit() was called, then no
* XSync() batching is performed and this function always calles XSync()
* immediately.
*
* (Note that this function uses TimerSet but works correctly in the
* face of a server generation. See the source for details.)
*
* If \a dmxScreen is \a NULL, then all pending syncs will be flushed
* immediately.
*/
void dmxSync(DMXScreenInfo *dmxScreen, Bool now)
{
static unsigned long dmxGeneration = 0;
if (dmxSyncInterval) {
if (dmxGeneration != serverGeneration) {
/* Server generation does a TimerInit, which frees all
* timers. So, at this point dmxSyncTimer is either:
* 1) NULL, iff dmxGeneration == 0,
* 2) freed, if it was on a queue (dmxSyncPending != 0), or
* 3) allocated, if it wasn't on a queue (dmxSyncPending == 0)
*/
if (dmxSyncTimer && !dmxSyncPending) free(dmxSyncTimer);
dmxSyncTimer = NULL;
now = TRUE;
dmxGeneration = serverGeneration;
}
/* Queue sync */
if (dmxScreen) {
dmxScreen->needsSync = TRUE;
++dmxSyncPending;
}
/* Do sync or set time for later */
if (now || !dmxScreen) {
if (!TimerForce(dmxSyncTimer)) dmxSyncCallback(NULL, 0, NULL);
/* At this point, dmxSyncPending == 0 because
* dmxSyncCallback must have been called. */
if (dmxSyncPending)
dmxLog(dmxFatal, "dmxSync(%s,%d): dmxSyncPending = %d\n",
dmxScreen ? dmxScreen->name : "", now, dmxSyncPending);
} else {
dmxScreen->needsSync = TRUE;
if (dmxSyncPending == 1)
dmxSyncTimer = TimerSet(dmxSyncTimer, 0, dmxSyncInterval,
dmxSyncCallback, NULL);
}
} else {
/* If dmxSyncInterval is not being used,
* then all the backends are already
* up-to-date. */
if (dmxScreen) dmxDoSync(dmxScreen);
}
}
|
