Expose schedulers_online and otp_release information

Author: José Valim

lib/elixir/lib/system.ex

@@ -34,7 +34,6 @@ defmodule System do
       next = System.monotonic_time()
       diff = next - prev
 
-
   Generally speaking, the VM provides three time measurements:
 
     * `os_time/0` - the time reported by the OS. This time may be
@@ -157,8 +156,7 @@ defmodule System do
     %{build:    build,
       date:     get_date,
       revision: revision,
-      version:  version,
-      }
+      version:  version}
   end
 
   # Returns a string of the build info
@@ -730,6 +728,30 @@ defmodule System do
     :os.system_time(normalize_time_unit(unit))
   end
 
+  @doc """
+  Returns the OTP release number.
+  """
+  @spec otp_release :: String.t
+  def otp_release do
+    :erlang.list_to_binary :erlang.system_info(:otp_release)
+  end
+
+  @doc """
+  Returns the number of schedulers in the VM.
+  """
+  @spec schedulers :: pos_integer
+  def schedulers do
+    :erlang.system_info(:schedulers)
+  end
+
+  @doc """
+  Returns the number of schedulers online in the VM.
+  """
+  @spec schedulers_online :: pos_integer
+  def schedulers_online do
+    :erlang.system_info(:schedulers_online)
+  end
+
   @doc """
   Generates and returns an integer that is unique in the current runtime
   instance.

lib/elixir/test/elixir/system_test.exs

@@ -187,4 +187,16 @@ defmodule SystemTest do
     time = System.monotonic_time(:nanoseconds)
     assert abs(System.convert_time_unit(time, :nanoseconds, :microseconds)) < abs(time)
   end
+
+  test "schedulers/0" do
+    assert System.schedulers >= 1
+  end
+
+  test "schedulers_online/0" do
+    assert System.schedulers_online >= 1
+  end
+
+  test "otp_release/0" do
+    assert is_binary System.otp_release
+  end
 end