src/thread/windows/SDL_systls.c
author Sam Lantinga <slouken@libsdl.org>
Wed, 10 Jul 2013 18:31:17 -0700
changeset 7393 358696c354a8
parent 7391 a29895dc5e9a
child 7828 1451063c8ecd
permissions -rw-r--r--
Added release/acquire memory barriers to the atomic API
* Added a destructor to clean up TLS memory at thread shutdown
* Refactored the TLS code to have platform independent code and a small platform dependent core with a fallback to generic code if platform dependent functions fail.
* Fixed recursion issues with SDL_GetErrBuf()
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2013 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 
    22 #include "SDL_config.h"
    23 #include "SDL_thread.h"
    24 #include "../SDL_thread_c.h"
    25 
    26 #if SDL_THREAD_WINDOWS
    27 
    28 #include "../../core/windows/SDL_windows.h"
    29 
    30 
    31 static DWORD thread_local_storage = TLS_OUT_OF_INDEXES;
    32 static SDL_bool generic_local_storage = SDL_FALSE;
    33 
    34 SDL_TLSData *
    35 SDL_SYS_GetTLSData()
    36 {
    37     if (thread_local_storage == TLS_OUT_OF_INDEXES && !generic_local_storage) {
    38         static SDL_SpinLock lock;
    39         SDL_AtomicLock(&lock);
    40         if (thread_local_storage == TLS_OUT_OF_INDEXES && !generic_local_storage) {
    41             DWORD storage = TlsAlloc();
    42             if (storage != TLS_OUT_OF_INDEXES) {
    43                 SDL_MemoryBarrierRelease();
    44                 thread_local_storage = storage;
    45             } else {
    46                 generic_local_storage = SDL_TRUE;
    47             }
    48         }
    49         SDL_AtomicUnlock(&lock);
    50     }
    51     if (generic_local_storage) {
    52         return SDL_Generic_GetTLSData();
    53     }
    54     SDL_MemoryBarrierAcquire();
    55     return (SDL_TLSData *)TlsGetValue(thread_local_storage);
    56 }
    57 
    58 int
    59 SDL_SYS_SetTLSData(SDL_TLSData *data)
    60 {
    61     if (generic_local_storage) {
    62         return SDL_Generic_SetTLSData(data);
    63     }
    64     if (!TlsSetValue(thread_local_storage, data)) {
    65         return SDL_SetError("TlsSetValue() failed");
    66     }
    67     return 0;
    68 }
    69 
    70 #endif /* SDL_THREAD_WINDOWS */
    71 
    72 /* vi: set ts=4 sw=4 expandtab: */