e526b61873
Betreff: [SDL] [PATCH] Make static variables const
Datum: Tue, 19 May 2009 19:45:37 +0200
Hi,
this is a set of simple changes which make some of SDL's internal static
arrays constant. The purpose is to shrink the number of write-able
static bytes and thus increase the number of memory pages shared between
SDL applications.
The patch set is against trunk@4513. Each of the attached patch files is
specific to a sub-system. The set is completed by a second mail, because
of the list's 40 KiB limit.
The files readelf-r4513.txt and readelf-const-patch.txt where made by
calling 'readelf -S libSDL.so'. They show the difference in ELF sections
without and with the patch. Some numbers measured on my x86-64:
Before
[13] .rodata PROGBITS 00000000000eaaa0 000eaaa0
0000000000008170 0000000000000000 A 0 0 32
[19] .data.rel.ro PROGBITS 00000000003045e0 001045e0
00000000000023d0 0000000000000000 WA 0 0 32
[23] .data PROGBITS 00000000003076e0 001076e0
0000000000004988 0000000000000000 WA 0 0 32
After
[13] .rodata PROGBITS 00000000000eaaa0 000eaaa0
0000000000009a50 0000000000000000 A 0 0 32
[19] .data.rel.ro PROGBITS 0000000000306040 00106040
0000000000002608 0000000000000000 WA 0 0 32
[23] .data PROGBITS 0000000000309360 00109360
0000000000002e88 0000000000000000 WA 0 0 32
The size of the write-able data section decreased considerably. Some
entries became const-after-relocation, while most of its content went
straight into the read-only data section.
Best regards, Thomas
--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%403618
140 lines
3.3 KiB
C
140 lines
3.3 KiB
C
/*
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SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2009 Sam Lantinga
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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This library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with this library; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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Sam Lantinga
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slouken@libsdl.org
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*/
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#include "SDL_config.h"
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/* General fatal signal handling code for SDL */
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#ifdef HAVE_SIGNAL_H
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#include <signal.h>
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#include "SDL_stdinc.h"
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#include "SDL_fatal.h"
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/* This installs some signal handlers for the more common fatal signals,
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so that if the programmer is lazy, the app doesn't die so horribly if
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the program crashes.
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*/
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static void
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SDL_Parachute(int sig)
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{
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signal(sig, SIG_DFL);
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SDL_Quit();
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raise(sig);
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}
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static const int SDL_fatal_signals[] = {
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SIGSEGV,
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#ifdef SIGBUS
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SIGBUS,
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#endif
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#ifdef SIGFPE
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SIGFPE,
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#endif
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#ifdef SIGQUIT
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SIGQUIT,
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#endif
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0
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};
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void
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SDL_InstallParachute(void)
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{
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/* Set a handler for any fatal signal not already handled */
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int i;
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#ifdef HAVE_SIGACTION
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struct sigaction action;
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for (i = 0; SDL_fatal_signals[i]; ++i) {
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sigaction(SDL_fatal_signals[i], NULL, &action);
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if (action.sa_handler == SIG_DFL) {
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action.sa_handler = SDL_Parachute;
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sigaction(SDL_fatal_signals[i], &action, NULL);
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}
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}
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#ifdef SIGALRM
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/* Set SIGALRM to be ignored -- necessary on Solaris */
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sigaction(SIGALRM, NULL, &action);
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if (action.sa_handler == SIG_DFL) {
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action.sa_handler = SIG_IGN;
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sigaction(SIGALRM, &action, NULL);
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}
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#endif
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#else
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void (*ohandler) (int);
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for (i = 0; SDL_fatal_signals[i]; ++i) {
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ohandler = signal(SDL_fatal_signals[i], SDL_Parachute);
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if (ohandler != SIG_DFL) {
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signal(SDL_fatal_signals[i], ohandler);
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}
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}
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#endif /* HAVE_SIGACTION */
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return;
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}
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void
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SDL_UninstallParachute(void)
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{
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/* Remove a handler for any fatal signal handled */
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int i;
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#ifdef HAVE_SIGACTION
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struct sigaction action;
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for (i = 0; SDL_fatal_signals[i]; ++i) {
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sigaction(SDL_fatal_signals[i], NULL, &action);
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if (action.sa_handler == SDL_Parachute) {
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action.sa_handler = SIG_DFL;
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sigaction(SDL_fatal_signals[i], &action, NULL);
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}
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}
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#else
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void (*ohandler) (int);
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for (i = 0; SDL_fatal_signals[i]; ++i) {
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ohandler = signal(SDL_fatal_signals[i], SIG_DFL);
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if (ohandler != SDL_Parachute) {
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signal(SDL_fatal_signals[i], ohandler);
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}
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}
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#endif /* HAVE_SIGACTION */
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}
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#else
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/* No signals on this platform, nothing to do.. */
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void
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SDL_InstallParachute(void)
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{
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return;
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}
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void
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SDL_UninstallParachute(void)
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{
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return;
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}
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#endif /* HAVE_SIGNAL_H */
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/* vi: set ts=4 sw=4 expandtab: */
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