strtoimax: port to HP-UX 11.11

[gnulib.git] / lib / nproc.c

diff --git a/lib/nproc.c b/lib/nproc.c
index b72d721..1403f67 100644 (file)
--- a/lib/nproc.c
+++ b/lib/nproc.c
@@ -1,6 +1,6 @@
 /* Detect the number of processors.
 
-   Copyright (C) 2009-2010 Free Software Foundation, Inc.
+   Copyright (C) 2009-2013 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -13,8 +13,7 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software Foundation,
-   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
 
 /* Written by Glen Lenker and Bruno Haible.  */
 
@@ -24,7 +23,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 
-#if HAVE_PTHREAD_AFFINITY_NP && 0
+#if HAVE_PTHREAD_GETAFFINITY_NP && 0
 # include <pthread.h>
 # include <sched.h>
 #endif
@@ -71,7 +70,7 @@ num_processors_via_affinity_mask (void)
      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
+#if HAVE_PTHREAD_GETAFFINITY_NP && defined __GLIBC__ && 0
   {
     cpu_set_t set;
 
@@ -94,7 +93,7 @@ num_processors_via_affinity_mask (void)
           return count;
       }
   }
-#elif HAVE_PTHREAD_AFFINITY_NP && defined __NetBSD__ && 0
+#elif HAVE_PTHREAD_GETAFFINITY_NP && defined __NetBSD__ && 0
   {
     cpuset_t *set;
 
@@ -239,7 +238,12 @@ num_processors (enum nproc_query query)
      The first number is the number of CPUs configured in the system.
      The second number is the number of CPUs available to the scheduler.
      The third number is the number of CPUs available to the current process.
-   */
+
+     Note! On Linux systems with glibc, the first and second number come from
+     the /sys and /proc file systems (see
+     glibc/sysdeps/unix/sysv/linux/getsysstats.c).
+     In some situations these file systems are not mounted, and the sysconf
+     call returns 1, which does not reflect the reality.  */
 
   if (query == NPROC_CURRENT)
     {
@@ -252,7 +256,7 @@ num_processors (enum nproc_query query)
       }
 
 #if defined _SC_NPROCESSORS_ONLN
-      { /* This works on glibc, MacOS X 10.5, FreeBSD, AIX, OSF/1, Solaris,
+      { /* This works on glibc, Mac OS X 10.5, FreeBSD, AIX, OSF/1, Solaris,
            Cygwin, Haiku.  */
         long int nprocs = sysconf (_SC_NPROCESSORS_ONLN);
         if (nprocs > 0)
@@ -263,9 +267,25 @@ num_processors (enum nproc_query query)
   else /* query == NPROC_ALL */
     {
 #if defined _SC_NPROCESSORS_CONF
-      { /* This works on glibc, MacOS X 10.5, FreeBSD, AIX, OSF/1, Solaris,
+      { /* This works on glibc, Mac OS X 10.5, FreeBSD, AIX, OSF/1, Solaris,
            Cygwin, Haiku.  */
         long int nprocs = sysconf (_SC_NPROCESSORS_CONF);
+
+# if __GLIBC__ >= 2 && defined __linux__
+        /* On Linux systems with glibc, this information comes from the /sys and
+           /proc file systems (see glibc/sysdeps/unix/sysv/linux/getsysstats.c).
+           In some situations these file systems are not mounted, and the
+           sysconf call returns 1.  But we wish to guarantee that
+           num_processors (NPROC_ALL) >= num_processors (NPROC_CURRENT).  */
+        if (nprocs == 1)
+          {
+            unsigned long nprocs_current = num_processors_via_affinity_mask ();
+
+            if (nprocs_current > 0)
+              nprocs = nprocs_current;
+          }
+# endif
+
         if (nprocs > 0)
           return nprocs;
       }
@@ -312,7 +332,7 @@ num_processors (enum nproc_query query)
      NPROC_CURRENT and NPROC_ALL.  */
 
 #if HAVE_SYSCTL && defined HW_NCPU
-  { /* This works on MacOS X, FreeBSD, NetBSD, OpenBSD.  */
+  { /* This works on Mac OS X, FreeBSD, NetBSD, OpenBSD.  */
     int nprocs;
     size_t len = sizeof (nprocs);
     static int mib[2] = { CTL_HW, HW_NCPU };