Adds a ParallelFor wrapper for no threads and OpenMP.
With the addition of C++11 support we can simplify the parallel for code by
removing the ifdef branching. Converts coordinate_descent_minimizer.cc to use
the thread_id ParallelFor API.
Tested by building with OpenMP, C++11 threads, TBB, and no threads. All tests
pass.
Also compared timing via the bundle adjuster.
./bin/bundle_adjuster --input=../problem-744-543562-pre.txt
With OpenMP num_threads=8
Head:
Time (in seconds):
Residual only evaluation 0.807753 (5)
Jacobian & residual evaluation 4.489404 (6)
Linear solver 41.826481 (5)
Minimizer 50.745857
Total 73.294424
CL:
Time (in seconds):
Residual only evaluation 0.970483 (5)
Jacobian & residual evaluation 4.647438 (6)
Linear solver 41.781892 (5)
Minimizer 50.848904
Total 73.089983
With OpenMP num_threads=1
HEAD:
Time (in seconds):
Residual only evaluation 2.990246 (5)
Jacobian & residual evaluation 14.132090 (6)
Linear solver 79.631951 (5)
Minimizer 100.281847
Total 122.946267
CL:
Time (in seconds):
Residual only evaluation 3.075178 (5)
Jacobian & residual evaluation 13.966451 (6)
Linear solver 77.005441 (5)
Minimizer 97.568712
Total 120.410454
Change-Id: I1857d7943073be7465b6c6476bf46ab11c5475a3
diff --git a/internal/ceres/parallel_for_test.cc b/internal/ceres/parallel_for_test.cc
index 2de4865..04e5783 100644
--- a/internal/ceres/parallel_for_test.cc
+++ b/internal/ceres/parallel_for_test.cc
@@ -31,8 +31,6 @@
// This include must come before any #ifndef check on Ceres compile options.
#include "ceres/internal/port.h"
-#if defined(CERES_USE_TBB) || defined(CERES_USE_CXX11_THREADS)
-
#include "ceres/parallel_for.h"
#include <cmath>
@@ -129,6 +127,8 @@
}
}
+// This test is only valid when multithreading support is enabled.
+#ifndef CERES_NO_THREADS
TEST(ParallelForWithThreadId, UniqueThreadIds) {
// Ensure the hardware supports more than 1 thread to ensure the test will
// pass.
@@ -157,8 +157,7 @@
EXPECT_THAT(x, UnorderedElementsAreArray({0,1}));
}
+#endif // CERES_NO_THREADS
} // namespace internal
} // namespace ceres
-
-#endif // defined(CERES_USE_TBB) || defined(CERES_USE_CXX11_THREADS)
