glibc/db2/os/os_spin.c

57 lines
1.0 KiB
C

/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1997
* Sleepycat Software. All rights reserved.
*/
#include "config.h"
#ifndef lint
static const char sccsid[] = "@(#)os_spin.c 10.3 (Sleepycat) 11/25/97";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <limits.h>
#include <unistd.h>
#endif
#include "db_int.h"
/*
* __os_spin --
* Return the number of default spins before blocking.
*
* PUBLIC: int __os_spin __P((void));
*/
int
__os_spin()
{
extern int __db_tsl_spins;
/* If the application specified the spins, use its value. */
if (__db_tsl_spins != 0)
return (__db_tsl_spins);
/*
* XXX
* Sysconf: Solaris uses _SC_NPROCESSORS_ONLN to return the number
* of online processors. I don't know if this call is portable or
* not.
*/
#if defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_ONLN)
{
long sys_val;
sys_val = sysconf(_SC_NPROCESSORS_ONLN);
if (sys_val > 0)
return (sys_val * 50);
}
#endif
/* Default to a single processor. */
return (1);
}