ctest: Optionally avoid starting tests that may exceed a given CPU load

Add a TestLoad setting to CTest that can be set via a new --test-load
command-line option, CTEST_TEST_LOAD variable, or TEST_LOAD option to
the ctest_test command.  Teach cmCTestMultiProcessHandler to measure
the CPU load and avoid starting tests that may take more than the
spare load currently available.  The expression

 <current_load> + <test_processors> <= <max-load>

must be true to start a new test.

Co-Author: Zack Galbreath <zack.galbreath@kitware.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/Source/CTest/cmCTestMultiProcessHandler.h b/Source/CTest/cmCTestMultiProcessHandler.h
index 243318f..ed3e155 100644
--- a/Source/CTest/cmCTestMultiProcessHandler.h
+++ b/Source/CTest/cmCTestMultiProcessHandler.h
@@ -37,6 +37,7 @@ public:
   void SetTests(TestMap& tests, PropertiesMap& properties);
   // Set the max number of tests that can be run at the same time.
   void SetParallelLevel(size_t);
+  void SetTestLoad(unsigned long load);
   virtual void RunTests();
   void PrintTestList();
   void PrintLabels();
@@ -93,6 +94,7 @@ protected:
   bool CheckCycles();
   int FindMaxIndex();
   inline size_t GetProcessorsUsed(int index);
+  std::string GetName(int index);
 
   void LockResources(int index);
   void UnlockResources(int index);
@@ -116,6 +118,7 @@ protected:
   std::set<std::string> LockedResources;
   std::vector<cmCTestTestHandler::cmCTestTestResult>* TestResults;
   size_t ParallelLevel; // max number of process that can be run at once
+  unsigned long TestLoad;
   std::set<cmCTestRunTest*> RunningTests;  // current running tests
   cmCTestTestHandler * TestHandler;
   cmCTest* CTest;