Also use TBB to build Hasse_complex in parallel.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/branches/tbb@870 636b058d-ea47-450e-bf9e-a15bfbe3eedb

Former-commit-id: 6633f9b8261cfb2acfb62d1f4748df73375086bd

2 files changed, 75 insertions, 10 deletions

diff --git a/src/Hasse_complex/include/gudhi/Hasse_complex.h b/src/Hasse_complex/include/gudhi/Hasse_complex.h
index 67079687..af9ae5e9 100644
--- a/src/Hasse_complex/include/gudhi/Hasse_complex.h
+++ b/src/Hasse_complex/include/gudhi/Hasse_complex.h
@@ -29,6 +29,12 @@
 #include <utility>  // for pair
 #include <vector>
 
+#include <gudhi/allocator.h>
+
+#ifdef GUDHI_USE_TBB
+#include <tbb/parallel_for.h>
+#endif
+
 namespace Gudhi {
 
 template < class HasseCpx >
@@ -97,20 +103,24 @@ class Hasse_complex {
 
   template < class Complex_ds >
   Hasse_complex(Complex_ds & cpx)
-      : complex_()
+      : complex_(cpx.num_simplices())
       , vertices_()
       , threshold_(cpx.filtration())
       , num_vertices_()
       , dim_max_(cpx.dimension()) {
-    complex_.reserve(cpx.num_simplices());
-    int idx = 0;
-    for (auto cpx_sh : cpx.filtration_simplex_range()) {
-      complex_.push_back(Hasse_simp(cpx, cpx_sh));
-      if (dimension(idx) == 0) {
+    int size = complex_.size();
+#ifdef GUDHI_USE_TBB
+    tbb::parallel_for(0,size,[&](int idx){new (&complex_[idx]) Hasse_simp(cpx, cpx.simplex(idx));});
+    for (int idx=0; idx<size; ++idx)
+      if (complex_[idx].boundary_.empty())
+        vertices_.push_back(idx);
+#else
+    for (int idx=0; idx<size; ++idx) {
+      new (&complex_[idx]) Hasse_simp(cpx, cpx.simplex(idx));
+      if (complex_[idx].boundary_.empty())
         vertices_.push_back(idx);
-      }
-      ++idx;
     }
+#endif
   }
 
   Hasse_complex()
@@ -194,7 +204,7 @@ class Hasse_complex {
     }
   }
 
-  std::vector< Hasse_simp > complex_;
+  std::vector< Hasse_simp, Gudhi::no_init_allocator<Hasse_simp> > complex_;
   std::vector<Simplex_handle> vertices_;
   Filtration_value threshold_;
   size_t num_vertices_;
@@ -218,7 +228,7 @@ std::istream& operator>>(std::istream & is
   // read all simplices in the file as a list of vertices
   while (read_hasse_simplex(is, boundary, fil)) {
     // insert every simplex in the simplex tree
-    hcpx.complex_.push_back(Hasse_simplex< Hasse_complex<T1, T2, T3> >(key, fil, boundary));
+    hcpx.complex_.emplace_back(key, fil, boundary);
 
     if (max_dim < hcpx.dimension(key)) {
       max_dim = hcpx.dimension(key);
diff --git a/src/common/include/gudhi/allocator.h b/src/common/include/gudhi/allocator.h
new file mode 100644
index 00000000..b825173b
--- /dev/null
+++ b/src/common/include/gudhi/allocator.h
@@ -0,0 +1,55 @@
+/*    This file is part of the Gudhi Library. The Gudhi library
+ *    (Geometric Understanding in Higher Dimensions) is a generic C++
+ *    library for computational topology.
+ *
+ *    Author(s):       Marc Glisse
+ *
+ *    Copyright (C) 2015  INRIA Saclay - Ile de France
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU General Public License for more details.
+ *
+ *    You should have received a copy of the GNU General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GUDHI_ALLOCATOR_H_
+#define GUDHI_ALLOCATOR_H_
+
+#include <memory>
+#include <utility>
+
+namespace Gudhi {
+
+/** \private
+ * An allocator that can be used to build an uninitialized vector.
+ */
+template <class T, class Base = std::allocator<T>>
+struct no_init_allocator : Base {
+  typedef std::allocator_traits<Base> Base_traits;
+  template <class U> struct rebind {
+    typedef no_init_allocator<U, typename Base_traits::template rebind_alloc<U>> other;
+  };
+
+  // Inherit constructors.
+  using Base::Base;
+
+  // Do nothing: that's the whole point!
+  template<class P>
+  void construct(P*)noexcept{}
+
+  template<class P, class...U> void construct(P*p, U&&...u){
+    Base_traits::construct(*(Base*)this, p, std::forward<U>(u)...);
+  }
+};
+
+}  // namespace Gudhi
+
+#endif  // GUDHI_ALLOCATOR_H_