along with this program; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
-/* Written by Glen Lenker. */
+/* Written by Glen Lenker and Bruno Haible. */
#include <config.h>
#include "nproc.h"
+#include <stdlib.h>
#include <unistd.h>
+#if HAVE_PTHREAD_AFFINITY_NP && 0
+# include <pthread.h>
+# include <sched.h>
+#endif
+#if HAVE_SCHED_GETAFFINITY_LIKE_GLIBC || HAVE_SCHED_GETAFFINITY_NP
+# include <sched.h>
+#endif
+
#include <sys/types.h>
#if HAVE_SYS_PSTAT_H
# include <windows.h>
#endif
+#include "c-ctype.h"
+
#define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
-/* Return the total number of processors. The result is guaranteed to
- be at least 1. */
unsigned long int
-num_processors (void)
+num_processors (enum nproc_query query)
{
+ if (query == NPROC_CURRENT_OVERRIDABLE)
+ {
+ /* Test the environment variable OMP_NUM_THREADS, recognized also by all
+ programs that are based on OpenMP. The OpenMP spec says that the
+ value assigned to the environment variable "may have leading and
+ trailing white space". */
+ const char *envvalue = getenv ("OMP_NUM_THREADS");
+
+ if (envvalue != NULL)
+ {
+ while (*envvalue != '\0' && c_isspace (*envvalue))
+ envvalue++;
+ /* Convert it from decimal to 'unsigned long'. */
+ if (c_isdigit (*envvalue))
+ {
+ char *endptr = NULL;
+ unsigned long int value = strtoul (envvalue, &endptr, 10);
+
+ if (endptr != NULL)
+ {
+ while (*endptr != '\0' && c_isspace (*endptr))
+ endptr++;
+ if (*endptr == '\0')
+ return (value > 0 ? value : 1);
+ }
+ }
+ }
+
+ query = NPROC_CURRENT;
+ }
+ /* Here query is one of NPROC_ALL, NPROC_CURRENT. */
+
+ if (query == NPROC_CURRENT)
+ {
+ /* glibc >= 2.3.3 with NPTL and NetBSD 5 have pthread_getaffinity_np,
+ but with different APIs. Also it requires linking with -lpthread.
+ Therefore this code is not enabled.
+ glibc >= 2.3.4 has sched_getaffinity whereas NetBSD 5 has
+ sched_getaffinity_np. */
+#if HAVE_PTHREAD_AFFINITY_NP && defined __GLIBC__ && 0
+ {
+ cpu_set_t set;
+
+ if (pthread_getaffinity_np (pthread_self (), sizeof (set), &set) == 0)
+ {
+ unsigned long count;
+
+# ifdef CPU_COUNT
+ /* glibc >= 2.6 has the CPU_COUNT macro. */
+ count = CPU_COUNT (&set);
+# else
+ size_t i;
+
+ count = 0;
+ for (i = 0; i < CPU_SETSIZE; i++)
+ if (CPU_ISSET (i, &set))
+ count++;
+# endif
+ if (count > 0)
+ return count;
+ }
+ }
+#elif HAVE_PTHREAD_AFFINITY_NP && defined __NetBSD__ && 0
+ {
+ cpuset_t *set;
+
+ set = cpuset_create ();
+ if (set != NULL)
+ {
+ unsigned long count = 0;
+
+ if (pthread_getaffinity_np (pthread_self (), cpuset_size (set), set)
+ == 0)
+ {
+ cpuid_t i;
+
+ for (i = 0;; i++)
+ {
+ int ret = cpuset_isset (i, set);
+ if (ret < 0)
+ break;
+ if (ret > 0)
+ count++;
+ }
+ }
+ cpuset_destroy (set);
+ if (count > 0)
+ return count;
+ }
+ }
+#elif HAVE_SCHED_GETAFFINITY_LIKE_GLIBC /* glibc >= 2.3.4 */
+ {
+ cpu_set_t set;
+
+ if (sched_getaffinity (0, sizeof (set), &set) == 0)
+ {
+ unsigned long count;
+
+# ifdef CPU_COUNT
+ /* glibc >= 2.6 has the CPU_COUNT macro. */
+ count = CPU_COUNT (&set);
+# else
+ size_t i;
+
+ count = 0;
+ for (i = 0; i < CPU_SETSIZE; i++)
+ if (CPU_ISSET (i, &set))
+ count++;
+# endif
+ if (count > 0)
+ return count;
+ }
+ }
+#elif HAVE_SCHED_GETAFFINITY_NP /* NetBSD >= 5 */
+ {
+ cpuset_t *set;
+
+ set = cpuset_create ();
+ if (set != NULL)
+ {
+ unsigned long count = 0;
+
+ if (sched_getaffinity_np (getpid (), cpuset_size (set), set) == 0)
+ {
+ cpuid_t i;
+
+ for (i = 0;; i++)
+ {
+ int ret = cpuset_isset (i, set);
+ if (ret < 0)
+ break;
+ if (ret > 0)
+ count++;
+ }
+ }
+ cpuset_destroy (set);
+ if (count > 0)
+ return count;
+ }
+ }
+#endif
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+ { /* This works on native Windows platforms. */
+ DWORD_PTR process_mask;
+ DWORD_PTR system_mask;
+
+ if (GetProcessAffinityMask (GetCurrentProcess (),
+ &process_mask, &system_mask))
+ {
+ DWORD_PTR mask = process_mask;
+ unsigned long count = 0;
+
+ for (; mask != 0; mask = mask >> 1)
+ if (mask & 1)
+ count++;
+ if (count > 0)
+ return count;
+ }
+ }
+#endif
+
#if defined _SC_NPROCESSORS_ONLN
- { /* This works on glibc, MacOS X 10.5, FreeBSD, AIX, OSF/1, Solaris, Cygwin,
- Haiku. */
- long int nprocs = sysconf (_SC_NPROCESSORS_ONLN);
- if (0 < nprocs)
- return nprocs;
- }
+ { /* This works on glibc, MacOS X 10.5, FreeBSD, AIX, OSF/1, Solaris,
+ Cygwin, Haiku. */
+ long int nprocs = sysconf (_SC_NPROCESSORS_ONLN);
+ if (nprocs > 0)
+ return nprocs;
+ }
+#endif
+ }
+ else /* query == NPROC_ALL */
+ {
+#if defined _SC_NPROCESSORS_CONF
+ { /* This works on glibc, MacOS X 10.5, FreeBSD, AIX, OSF/1, Solaris,
+ Cygwin, Haiku. */
+ long int nprocs = sysconf (_SC_NPROCESSORS_CONF);
+ if (nprocs > 0)
+ return nprocs;
+ }
#endif
+ }
#if HAVE_PSTAT_GETDYNAMIC
{ /* This works on HP-UX. */
struct pst_dynamic psd;
- if (0 <= pstat_getdynamic (&psd, sizeof psd, 1, 0)
- && 0 < psd.psd_proc_cnt)
- return psd.psd_proc_cnt;
+ if (pstat_getdynamic (&psd, sizeof psd, 1, 0) >= 0)
+ {
+ /* The field psd_proc_cnt contains the number of active processors.
+ In newer releases of HP-UX 11, the field psd_max_proc_cnt includes
+ deactivated processors. */
+ if (query == NPROC_CURRENT)
+ {
+ if (psd.psd_proc_cnt > 0)
+ return psd.psd_proc_cnt;
+ }
+ else
+ {
+ if (psd.psd_max_proc_cnt > 0)
+ return psd.psd_max_proc_cnt;
+ }
+ }
}
#endif
-#if HAVE_SYSMP && defined MP_NAPROCS
+#if HAVE_SYSMP && defined MP_NAPROCS && defined MP_NPROCS
{ /* This works on IRIX. */
/* MP_NPROCS yields the number of installed processors.
MP_NAPROCS yields the number of processors available to unprivileged
- processes. We need the latter. */
- int nprocs = sysmp (MP_NAPROCS);
- if (0 < nprocs)
+ processes. */
+ int nprocs =
+ sysmp (query == NPROC_CURRENT && getpid () != 0
+ ? MP_NAPROCS
+ : MP_NPROCS);
+ if (nprocs > 0)
return nprocs;
}
#endif
+ /* Finally, as fallback, use the APIs that don't distinguish between
+ NPROC_CURRENT and NPROC_ALL. */
+
#if HAVE_SYSCTL && defined HW_NCPU
{ /* This works on MacOS X, FreeBSD, NetBSD, OpenBSD. */
int nprocs;
along with this program; if not, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
-/* Written by Glen Lenker. */
+/* Written by Glen Lenker and Bruno Haible. */
/* Allow the use in C++ code. */
#ifdef __cplusplus
extern "C" {
#endif
-unsigned long int num_processors (void);
+/* A "processor" in this context means a thread execution unit, that is either
+ - an execution core in a (possibly multi-core) chip, in a (possibly multi-
+ chip) module, in a single computer, or
+ - a thread execution unit inside a core
+ (hyper-threading, see <http://en.wikipedia.org/wiki/Hyper-threading>).
+ Which of the two definitions is used, is unspecified. */
+
+enum nproc_query
+{
+ NPROC_ALL, /* total number of processors */
+ NPROC_CURRENT, /* processors available to the current process */
+ NPROC_CURRENT_OVERRIDABLE /* likewise, but overridable through the
+ OMP_NUM_THREADS environment variable */
+};
+
+/* Return the total number of processors. The result is guaranteed to
+ be at least 1. */
+extern unsigned long int num_processors (enum nproc_query query);
#ifdef __cplusplus
}
-# nproc.m4 serial 3
+# nproc.m4 serial 4
dnl Copyright (C) 2009 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
# Prerequisites of lib/nproc.c.
AC_DEFUN([gl_PREREQ_NPROC],
[
+ dnl Persuade glibc <sched.h> to declare CPU_SETSIZE, CPU_ISSET etc.
+ AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
AC_CHECK_HEADERS([sys/pstat.h sys/sysmp.h sys/param.h],,,
[AC_INCLUDES_DEFAULT])
dnl <sys/sysctl.h> requires <sys/param.h> on OpenBSD 4.0.
# include <sys/param.h>
#endif
])
- AC_CHECK_FUNCS([pstat_getdynamic sysmp sysctl])
+
+ AC_CHECK_FUNCS([sched_getaffinity sched_getaffinity_np \
+ pstat_getdynamic sysmp sysctl])
+
+ dnl Test whether sched_getaffinity has the expected declaration.
+ dnl glibc 2.3.[0-2]:
+ dnl int sched_getaffinity (pid_t, unsigned int, unsigned long int *);
+ dnl glibc 2.3.3:
+ dnl int sched_getaffinity (pid_t, cpu_set_t *);
+ dnl glibc >= 2.3.4:
+ dnl int sched_getaffinity (pid_t, size_t, cpu_set_t *);
+ if test $ac_cv_func_sched_getaffinity = yes; then
+ AC_CACHE_CHECK([for glibc compatible sched_getaffinity],
+ [gl_cv_func_sched_getaffinity3],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <sched.h>]],
+ [[sched_getaffinity (0, 0, (cpu_set_t *) 0);]])],
+ [gl_cv_func_sched_getaffinity3=yes],
+ [gl_cv_func_sched_getaffinity3=no])
+ ])
+ if test $gl_cv_func_sched_getaffinity3 = yes; then
+ AC_DEFINE([HAVE_SCHED_GETAFFINITY_LIKE_GLIBC], [1],
+ [Define to 1 if sched_getaffinity has a glibc compatible declaration.])
+ fi
+ fi
])
projects / gnulib.git / commitdiff