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, 2 insertions, 0 deletions

diff --git a/Source/CTest/cmCTestGenericHandler.cxx b/Source/CTest/cmCTestGenericHandler.cxx
index 81eb0a8..ad79ba2 100644
--- a/Source/CTest/cmCTestGenericHandler.cxx
+++ b/Source/CTest/cmCTestGenericHandler.cxx
@@ -23,6 +23,7 @@ cmCTestGenericHandler::cmCTestGenericHandler()
   this->SubmitIndex = 0;
   this->AppendXML = false;
   this->Quiet = false;
+  this->TestLoad = 0;
 }
 
 //----------------------------------------------------------------------
@@ -70,6 +71,7 @@ void cmCTestGenericHandler::SetPersistentOption(const std::string& op,
 void cmCTestGenericHandler::Initialize()
 {
   this->AppendXML = false;
+  this->TestLoad = 0;
   this->Options.clear();
   t_StringToString::iterator it;
   for ( it = this->PersistentOptions.begin();