mirror of
https://github.com/WinampDesktop/winamp.git
synced 2024-09-24 15:54:12 +00:00
43 lines
No EOL
1.2 KiB
C
43 lines
No EOL
1.2 KiB
C
#include "nxonce.h"
|
|
#include "foundation/error.h"
|
|
#if 0 && _WIN32_WINNT >= 0x600
|
|
|
|
void NXOnce(nx_once_t once, int (NX_ONCE_API *init_fn)(nx_once_t, void *, void **), void *param)
|
|
{
|
|
InitOnceExecuteOnce(once, (PINIT_ONCE_FN)init_fn, param, 0);
|
|
}
|
|
|
|
void NXOnceInit(nx_once_t once)
|
|
{
|
|
InitOnceInitialize(once);
|
|
}
|
|
#else
|
|
/* this ONLY works because of the strict(ish) memory ordering of the AMD64/x86 processors.
|
|
Don't use this implementation for a processor that has loose memory ordering restriction (e.g. ARM, PowerPC)
|
|
see http://www.aristeia.com/Papers/DDJ_Jul_Aug_2004_revised.pdf
|
|
*/
|
|
void NXOnce(nx_once_t once, int (NX_ONCE_API *init_fn)(nx_once_t, void *, void **), void *param)
|
|
{
|
|
if (once->status)
|
|
return;
|
|
|
|
EnterCriticalSection(&once->critical_section);
|
|
if (once->status)
|
|
{
|
|
LeaveCriticalSection(&once->critical_section);
|
|
return;
|
|
}
|
|
|
|
init_fn(once, param, 0);
|
|
// benski> not important for the x86, but on processors with weak memory-order on stores, once->status might set to 1 BEFORE all stores from init_fn complete!
|
|
once->status = 1;
|
|
LeaveCriticalSection(&once->critical_section);
|
|
}
|
|
|
|
void NXOnceInit(nx_once_t once)
|
|
{
|
|
once->status=0;
|
|
InitializeCriticalSection(&once->critical_section);
|
|
}
|
|
|
|
#endif |