From 7b25bd8ba247ba7f0c1b3542b89aac220f0564ed Mon Sep 17 00:00:00 2001
From: akr <akr@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Thu, 2 Oct 2014 03:23:26 +0000
Subject: [PATCH] * ext/etc/etc.c (etc_nprocessors): New method.   Accepted by
 matz at RubyKaigi 2014.   [ruby-core:65142] [Feature #10267]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47761 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog            |  6 ++++++
 ext/etc/etc.c        | 33 +++++++++++++++++++++++++++++++++
 test/etc/test_etc.rb |  5 +++++
 3 files changed, 44 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index b59a09eb77..9dd8fac86b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Thu Oct  2 12:21:52 2014  Tanaka Akira  <akr@fsij.org>
+
+	* ext/etc/etc.c (etc_nprocessors): New method.
+	  Accepted by matz at RubyKaigi 2014.
+	  [ruby-core:65142] [Feature #10267]
+
 Thu Oct  2 07:56:49 2014  Eric Wong  <e@80x24.org>
 
 	* iseq.c (rb_iseq_line_trace_each): explicit cast
diff --git a/ext/etc/etc.c b/ext/etc/etc.c
index 6168ed1510..2546560713 100644
--- a/ext/etc/etc.c
+++ b/ext/etc/etc.c
@@ -891,6 +891,38 @@ io_pathconf(VALUE io, VALUE arg)
 #define io_pathconf rb_f_notimplement
 #endif
 
+#if defined(HAVE_SYSCONF) && defined(_SC_NPROCESSORS_ONLN)
+/*
+ * Returns the number of online processors.
+ *
+ * The result is intended as the number of processes to
+ * use all available processors.
+ *
+ * This method is implemented as:
+ * - sysconf(_SC_NPROCESSORS_ONLN): GNU/Linux, NetBSD, FreeBSD, OpenBSD, DragonFly BSD, OpenIndiana, Mac OS X, AIX
+ *
+ * Example:
+ *
+ *   require 'etc'
+ *   p Etc.nprocessors #=> 4
+ *
+ */
+static VALUE
+etc_nprocessors(VALUE obj)
+{
+    long ret;
+
+    errno = 0;
+    ret = sysconf(_SC_NPROCESSORS_ONLN);
+    if (ret == -1) {
+        rb_sys_fail("sysconf(_SC_NPROCESSORS_ONLN)");
+    }
+    return LONG2NUM(ret);
+}
+#else
+#define etc_nprocessors rb_f_notimplement
+#endif
+
 /*
  * The Etc module provides access to information typically stored in
  * files in the /etc directory on Unix systems.
@@ -946,6 +978,7 @@ Init_etc(void)
     rb_define_module_function(mEtc, "sysconf", etc_sysconf, 1);
     rb_define_module_function(mEtc, "confstr", etc_confstr, 1);
     rb_define_method(rb_cIO, "pathconf", io_pathconf, 1);
+    rb_define_module_function(mEtc, "nprocessors", etc_nprocessors, 0);
 
     sPasswd =  rb_struct_define_under(mEtc, "Passwd",
 				      "name",
diff --git a/test/etc/test_etc.rb b/test/etc/test_etc.rb
index 4a099e7df5..2f61ac7919 100644
--- a/test/etc/test_etc.rb
+++ b/test/etc/test_etc.rb
@@ -159,4 +159,9 @@ class TestEtc < Test::Unit::TestCase
     }
   end if defined?(Etc::PC_PIPE_BUF)
 
+  def test_nprocessors
+    n = Etc.nprocessors
+    assert_operator(1, :<=, n)
+  end
+
 end