src/timer/dummy/SDL_systimer.c
author Ryan C. Gordon
Sun, 03 Jan 2016 06:50:50 -0500
changeset 10003 d91a2c45825e
parent 9998 f67cf37e9cd4
child 10737 3406a0f8b041
permissions -rw-r--r--
Remove almost all instances of "volatile" keyword.

As Tiffany pointed out in Bugzilla, volatile is not useful for thread safety:

https://software.intel.com/en-us/blogs/2007/11/30/volatile-almost-useless-for-multi-threaded-programming/

Some of these volatiles didn't need to be, some were otherwise protected by
spinlocks or mutexes, and some got moved over to SDL_atomic_t data, etc.

Fixes Bugzilla #3220.
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 #include "../../SDL_internal.h"
    22 
    23 #if defined(SDL_TIMER_DUMMY) || defined(SDL_TIMERS_DISABLED)
    24 
    25 #include "SDL_timer.h"
    26 
    27 static SDL_bool ticks_started = SDL_FALSE;
    28 
    29 void
    30 SDL_TicksInit(void)
    31 {
    32     if (ticks_started) {
    33         return;
    34     }
    35     ticks_started = SDL_TRUE;
    36 }
    37 
    38 void
    39 SDL_TicksQuit(void)
    40 {
    41     ticks_started = SDL_FALSE;
    42 }
    43 
    44 Uint32
    45 SDL_GetTicks(void)
    46 {
    47     if (!ticks_started) {
    48         SDL_TicksInit();
    49     }
    50 
    51     SDL_Unsupported();
    52     return 0;
    53 }
    54 
    55 Uint64
    56 SDL_GetPerformanceCounter(void)
    57 {
    58     return SDL_GetTicks();
    59 }
    60 
    61 Uint64
    62 SDL_GetPerformanceFrequency(void)
    63 {
    64     return 1000;
    65 }
    66 
    67 void
    68 SDL_Delay(Uint32 ms)
    69 {
    70     SDL_Unsupported();
    71 }
    72 
    73 #endif /* SDL_TIMER_DUMMY || SDL_TIMERS_DISABLED */
    74 
    75 /* vi: set ts=4 sw=4 expandtab: */