added openmp set num threads in CParallel

CMakeLists.txt

@@ -528,6 +528,7 @@ ENDIF()
 
 FIND_PACKAGE(OpenMP)
 if (OPENMP_FOUND)
+	SET(HAVE_OPENMP 1)
 	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OpenMP_C_FLAGS}")
 	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
 	set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${OpenMP_EXE_LINKER_FLAGS}")
@@ -1158,7 +1159,7 @@ IF(ENABLE_TESTING)
 		IF (NOT TRAVIS_DISABLE_UNIT_TESTS AND EXISTS ${CMAKE_SOURCE_DIR}/tests/unit)
 			add_subdirectory(${CMAKE_SOURCE_DIR}/tests/unit)
 		ENDIF()
-		
+
 		IF(BUILD_META_EXAMPLES)
 		    IF(NOT TRAVIS_DISABLE_META_INTEGRATION_TESTS AND EXISTS ${CMAKE_SOURCE_DIR}/tests/meta)
                 add_subdirectory(${CMAKE_SOURCE_DIR}/tests/meta)

src/shogun/base/Parallel.cpp

@@ -20,19 +20,30 @@
 #include <sys/sysctl.h>
 #endif
 
+#ifdef HAVE_OPENMP
+#include <omp.h>
+#endif
 
 using namespace shogun;
 
 Parallel::Parallel()
 {
 	num_threads=get_num_cpus();
 	m_refcount = new RefCount();
+#ifdef HAVE_OPENMP
+	omp_set_dynamic(0);
+	omp_set_num_threads(num_threads);
+#endif
 }
 
 Parallel::Parallel(const Parallel& orig)
 {
 	num_threads=orig.get_num_threads();
 	m_refcount = new RefCount();
+#ifdef HAVE_OPENMP
+	omp_set_dynamic(0);
+	omp_set_num_threads(num_threads);
+#endif
 }
 
 Parallel::~Parallel()
@@ -43,14 +54,14 @@ Parallel::~Parallel()
 int32_t Parallel::get_num_cpus() const
 {
 #if defined(LINUX) && defined(_SC_NPROCESSORS_ONLN)
-		return sysconf( _SC_NPROCESSORS_ONLN );
+	return sysconf( _SC_NPROCESSORS_ONLN );
 #elif defined(DARWIN)
-		int num; /* for calling external lib */
-		size_t size=sizeof(num);
-		if (!sysctlbyname("hw.ncpu", &num, &size, NULL, 0))
-			return num;
+	int num; /* for calling external lib */
+	size_t size=sizeof(num);
+	if (!sysctlbyname("hw.ncpu", &num, &size, NULL, 0))
+		return num;
 #endif
-		return 1;
+	return 1;
 }
 
 void Parallel::set_num_threads(int32_t n)
@@ -59,6 +70,9 @@ void Parallel::set_num_threads(int32_t n)
 	ASSERT(n==1)
 #endif
 	num_threads=n;
+#ifdef HAVE_OPENMP
+	omp_set_num_threads(num_threads);
+#endif
 }
 
 int32_t Parallel::get_num_threads() const

src/shogun/lib/config.h.in

@@ -29,6 +29,7 @@
 #cmakedefine HAVE_NLOPT 1
 #cmakedefine USE_LPSOLVE 1
 #cmakedefine HAVE_PTHREAD 1
+#cmakedefine HAVE_OPENMP 1
 #cmakedefine USE_CPLEX 1
 #cmakedefine HAVE_COLPACK 1
 #cmakedefine HAVE_ARPREC 1

tests/unit/base/Parallel_unittest.cc

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) The Shogun Machine Learning Toolbox
+ * Written (w) 2016 Soumyajit De
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * The views and conclusions contained in the software and documentation are those
+ * of the authors and should not be interpreted as representing official policies,
+ * either expressed or implied, of the Shogun Development Team.
+ */
+
+#include <shogun/lib/config.h>
+#ifdef HAVE_OPENMP
+#include <shogun/base/init.h>
+#include <shogun/base/Parallel.h>
+#include <gtest/gtest.h>
+#include <omp.h>
+
+using namespace shogun;
+
+TEST(Parallel, openmp_get_num_threads)
+{
+	int32_t omp_num_threads=omp_get_num_threads();
+	ASSERT_EQ(1, omp_num_threads);
+
+	int32_t sg_num_threads=get_global_parallel()->get_num_threads();
+#pragma omp parallel
+	{
+		#pragma omp master
+			omp_num_threads=omp_get_num_threads();
+	}
+
+	ASSERT_EQ(sg_num_threads, omp_num_threads);
+}
+
+TEST(Parallel, openmp_set_num_threads)
+{
+	int32_t orig_num_threads=get_global_parallel()->get_num_threads();
+	int32_t omp_num_threads=omp_get_num_threads();
+
+	int32_t desired_num_threads=10;
+	get_global_parallel()->set_num_threads(desired_num_threads);
+
+#pragma omp parallel
+	{
+		#pragma omp master
+			omp_num_threads=omp_get_num_threads();
+	}
+
+	ASSERT_EQ(desired_num_threads, omp_num_threads);
+
+	get_global_parallel()->set_num_threads(orig_num_threads);
+}
+#endif // HAVE_OPENMP