1 files changed, 60 insertions, 0 deletions
diff --git a/spec/ruby/core/process/setpriority_spec.rb b/spec/ruby/core/process/setpriority_spec.rb
new file mode 100644
index 0000000000..4d60973429
--- /dev/null
+++ b/spec/ruby/core/process/setpriority_spec.rb
@@ -0,0 +1,60 @@
+require_relative '../../spec_helper'
+
+describe "Process.setpriority" do
+  platform_is_not :windows do
+    it "sets the scheduling priority for a specified process" do
+      priority = Process.getpriority(Process::PRIO_PROCESS, 0)
+
+      out = ruby_exe(fixture(__FILE__, "setpriority.rb"), args: "process")
+      out = out.lines.map { |l| Integer(l) }
+      pr = out[0]
+      out.should == [pr, 0, pr+1]
+
+      Process.getpriority(Process::PRIO_PROCESS, 0).should == priority
+    end
+
+    # Darwin and FreeBSD don't seem to handle these at all, getting all out of
+    # whack with either permission errors or just the wrong value
+    platform_is_not :darwin, :freebsd do
+      it "sets the scheduling priority for a specified process group" do
+        priority = Process.getpriority(Process::PRIO_PGRP, 0)
+
+        out = ruby_exe(fixture(__FILE__, "setpriority.rb"), args: "group")
+        out = out.lines.map { |l| Integer(l) }
+        pr = out[0]
+        out.should == [pr, 0, pr+1]
+
+        Process.getpriority(Process::PRIO_PGRP, 0).should == priority
+      end
+    end
+
+    as_superuser do
+      guard -> {
+        prio = Process.getpriority(Process::PRIO_USER, 0)
+        # The nice value is a value in the range -20 to 19.
+        # This test tries to change the nice value to +-1, so it cannot run if prio == -20 || prio == 19.
+        if -20 < prio && prio < 19
+          begin
+            # Check if we can lower the nice value or not.
+            #
+            # We are not always able to do it even as a root.
+            # Docker container is not always able to do it depending upon the configuration,
+            # which cannot know from the container itself.
+            Process.setpriority(Process::PRIO_USER, 0, prio - 1)
+            Process.setpriority(Process::PRIO_USER, 0, prio)
+            true
+          rescue Errno::EACCES
+            false
+          end
+        end
+      } do
+        it "sets the scheduling priority for a specified user" do
+          prio = Process.getpriority(Process::PRIO_USER, 0)
+          Process.setpriority(Process::PRIO_USER, 0, prio + 1).should == 0
+          Process.getpriority(Process::PRIO_USER, 0).should == (prio + 1)
+          Process.setpriority(Process::PRIO_USER, 0, prio).should == 0
+        end
+      end
+    end
+  end
+end