mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-10-15 06:15:43 +00:00
49 lines
1.0 KiB
C
49 lines
1.0 KiB
C
/*-
|
|
* See the file LICENSE for redistribution information.
|
|
*
|
|
* Copyright (c) 1997, 1998
|
|
* Sleepycat Software. All rights reserved.
|
|
*/
|
|
|
|
#include "config.h"
|
|
|
|
#ifndef lint
|
|
static const char sccsid[] = "@(#)os_spin.c 10.6 (Sleepycat) 6/2/98";
|
|
#endif /* not lint */
|
|
|
|
#include "db_int.h"
|
|
|
|
/*
|
|
* __os_spin --
|
|
* Return the number of default spins before blocking.
|
|
*
|
|
* PUBLIC: int __os_spin __P((void));
|
|
*/
|
|
int
|
|
__os_spin()
|
|
{
|
|
static long sys_val;
|
|
SYSTEM_INFO SystemInfo;
|
|
|
|
/* If the application specified the spins, use its value. */
|
|
if (DB_GLOBAL(db_tsl_spins) != 0)
|
|
return (DB_GLOBAL(db_tsl_spins));
|
|
|
|
/* If we've already figured this out, return the value. */
|
|
if (sys_val != 0)
|
|
return (sys_val);
|
|
|
|
/* Get the number of processors */
|
|
GetSystemInfo(&SystemInfo);
|
|
|
|
/*
|
|
* Spin 50 times per processor -- we have anecdotal evidence that this
|
|
* is a reasonable value.
|
|
*/
|
|
if (SystemInfo.dwNumberOfProcessors > 1)
|
|
sys_val = 50 * SystemInfo.dwNumberOfProcessors;
|
|
else
|
|
sys_val = 1;
|
|
return (sys_val);
|
|
}
|