Nice automatic updates up to a point, then renice if necessary.

utils_unittest.cc

 // Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <errno.h>
 #include <string>
 #include <vector>
 #include <gtest/gtest.h>
@@ skipping 139 matching lines @@
 TEST(UtilsTest, IsRemovableDeviceTest) {
   EXPECT_FALSE(utils::IsRemovableDevice(""));
   EXPECT_FALSE(utils::IsRemovableDevice("/dev/non-existent-device"));
 }
 
 TEST(UtilsTest, PartitionNumberTest) {
   EXPECT_EQ("3", utils::PartitionNumber("/dev/sda3"));
   EXPECT_EQ("3", utils::PartitionNumber("/dev/mmc0p3"));
 }
 
+TEST(UtilsTest, ComparePriorities) {
+  EXPECT_LT(utils::ComparePriorities(utils::kProcessPriorityLow,
+                                     utils::kProcessPriorityNormal), 0);
+  EXPECT_GT(utils::ComparePriorities(utils::kProcessPriorityNormal,
+                                     utils::kProcessPriorityLow), 0);
+  EXPECT_EQ(utils::ComparePriorities(utils::kProcessPriorityNormal,
+                                     utils::kProcessPriorityNormal), 0);
+  EXPECT_GT(utils::ComparePriorities(utils::kProcessPriorityHigh,
+                                     utils::kProcessPriorityNormal), 0);
+}
+
 }  // namespace chromeos_update_engine