Mercurial > sdl-ios-xcode
view src/joystick/SDL_sysjoystick.h @ 3162:dc1eb82ffdaa
Von: Thomas Zimmermann
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
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Wed, 03 Jun 2009 04:37:27 +0000 |
parents | 99210400e8b9 |
children | f7b03b6838cb |
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/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2009 Sam Lantinga This library is SDL_free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA Sam Lantinga slouken@libsdl.org */ #include "SDL_config.h" /* This is the system specific header for the SDL joystick API */ #include "SDL_joystick.h" /* The SDL joystick structure */ struct _SDL_Joystick { Uint8 index; /* Device index */ const char *name; /* Joystick name - system dependent */ int naxes; /* Number of axis controls on the joystick */ Sint16 *axes; /* Current axis states */ int nhats; /* Number of hats on the joystick */ Uint8 *hats; /* Current hat states */ int nballs; /* Number of trackballs on the joystick */ struct balldelta { int dx; int dy; } *balls; /* Current ball motion deltas */ int nbuttons; /* Number of buttons on the joystick */ Uint8 *buttons; /* Current button states */ struct joystick_hwdata *hwdata; /* Driver dependent information */ int ref_count; /* Reference count for multiple opens */ }; /* Function to scan the system for joysticks. * Joystick 0 should be the system default joystick. * This function should return the number of available joysticks, or -1 * on an unrecoverable fatal error. */ extern int SDL_SYS_JoystickInit(void); /* Function to get the device-dependent name of a joystick */ extern const char *SDL_SYS_JoystickName(int index); /* Function to open a joystick for use. The joystick to open is specified by the index field of the joystick. This should fill the nbuttons and naxes fields of the joystick structure. It returns 0, or -1 if there is an error. */ extern int SDL_SYS_JoystickOpen(SDL_Joystick * joystick); /* Function to update the state of a joystick - called as a device poll. * This function shouldn't update the joystick structure directly, * but instead should call SDL_PrivateJoystick*() to deliver events * and update joystick device state. */ extern void SDL_SYS_JoystickUpdate(SDL_Joystick * joystick); /* Function to close a joystick after use */ extern void SDL_SYS_JoystickClose(SDL_Joystick * joystick); /* Function to perform any system-specific joystick related cleanup */ extern void SDL_SYS_JoystickQuit(void); /* vi: set ts=4 sw=4 expandtab: */