From 8db90ca2f6889b1a34f5deffcc28137abbbcd62d Mon Sep 17 00:00:00 2001
From: Chris Sweeney <kip622@gmail.com>
Date: Sun, 15 Mar 2015 19:01:46 +0100
Subject: [PATCH] Less strict check for multithreading.

Removes the CHECK-fail for num_threads > 1 when
OpenMP is not detected

Change-Id: I5c1d48aad66c8b7a1f73c93dae572b73953859a0
---
 internal/ceres/program_evaluator.h | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/internal/ceres/program_evaluator.h b/internal/ceres/program_evaluator.h
index 00724fe38..82bb67a08 100644
--- a/internal/ceres/program_evaluator.h
+++ b/internal/ceres/program_evaluator.h
@@ -116,9 +116,13 @@ class ProgramEvaluator : public Evaluator {
         evaluate_preparers_(
             jacobian_writer_.CreateEvaluatePreparers(options.num_threads)) {
 #ifndef CERES_USE_OPENMP
-    CHECK_EQ(1, options_.num_threads)
-        << "OpenMP support is not compiled into this binary; "
-        << "only options.num_threads=1 is supported.";
+    if (options_.num_threads > 1) {
+      LOG(WARNING)
+          << "OpenMP support is not compiled into this binary; "
+          << "only options.num_threads = 1 is supported. Switching "
+          << "to single threaded mode.";
+      options_.num_threads = 1;
+    }
 #endif
 
     BuildResidualLayout(*program, &residual_layout_);