Teuchos Package Browser (Single Doxygen Collection) Version of the Day
Loading...
Searching...
No Matches
scatter.cpp
Go to the documentation of this file.
1// @HEADER
2// ***********************************************************************
3//
4// Teuchos: Common Tools Package
5// Copyright (2004) Sandia Corporation
6//
7// Under terms of Contract DE-AC04-94AL85000, there is a non-exclusive
8// license for use of this work by or on behalf of the U.S. Government.
9//
10// Redistribution and use in source and binary forms, with or without
11// modification, are permitted provided that the following conditions are
12// met:
13//
14// 1. Redistributions of source code must retain the above copyright
15// notice, this list of conditions and the following disclaimer.
16//
17// 2. Redistributions in binary form must reproduce the above copyright
18// notice, this list of conditions and the following disclaimer in the
19// documentation and/or other materials provided with the distribution.
20//
21// 3. Neither the name of the Corporation nor the names of the
22// contributors may be used to endorse or promote products derived from
23// this software without specific prior written permission.
24//
25// THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
26// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
29// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
30// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
31// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
32// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
33// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
34// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
35// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36//
37// Questions? Contact Michael A. Heroux (maherou@sandia.gov)
38//
39// ***********************************************************************
40// @HEADER
41
45#ifdef HAVE_TEUCHOS_MPI
47#endif // HAVE_TEUCHOS_MPI
49
50
51template<class PacketType>
52bool
53testScatter (bool& success, std::ostream& out,
54 const int root, const Teuchos::Comm<int>& comm)
55{
56 using Teuchos::scatter;
58 using std::endl;
59 typedef PacketType packet_type;
60
61 // Teuchos constructs the output stream such that it only prints on
62 // Process 0 anyway.
63 Teuchos::OSTab tab0 (out);
64 out << "Testing Teuchos::scatter<int, "
65 << TypeNameTraits<packet_type>::name ()
66 << "> with root = " << root << endl;
67 Teuchos::OSTab tab1 (out);
68
69 int lclSuccess = 1;
70 int gblSuccess = lclSuccess;
71
72#ifdef HAVE_TEUCHOS_MPI
73 using Teuchos::MpiComm;
74 int errCode = MPI_SUCCESS;
75
76 const MpiComm<int>* mpiComm = dynamic_cast<const MpiComm<int>* > (&comm);
78 (mpiComm == NULL, std::logic_error, "Building with MPI, but default "
79 "communicator is not a Teuchos::MpiComm!");
80 MPI_Comm rawMpiComm = * (mpiComm->getRawMpiComm ());
81#endif // HAVE_TEUCHOS_MPI
82
83 const packet_type ZERO = Teuchos::ScalarTraits<packet_type>::zero ();
84 const packet_type ONE = Teuchos::ScalarTraits<packet_type>::one ();
85 const int myRank = comm.getRank ();
86 const int numProcs = comm.getSize ();
87 const int sendCount = 10;
88 const int recvCount = 10;
89
90 out << "Initializing receive buffer (on all processes)" << endl;
91
92 // Set up the receive buffer on each process.
93 Teuchos::Array<packet_type> recvBuf (recvCount);
94 for (int i = 0; i < recvCount; ++i) {
95 recvBuf[i] = ZERO;
96 }
97
98 out << "Filling send buffer (on root process only)" << endl;
99
100 // The send buffer is only needed on the root process. It exists
101 // elsewhere for syntax's sake, but is only allocated with nonzero
102 // size on the root process.
104 if (myRank == root) {
105 sendBuf.resize (sendCount * numProcs);
106 try {
107 // Fill the send buffer. The root process will send (p+1)*1, (p+1)*2,
108 // ..., (p+1)*sendCount to Process p. This helps us test whether the
109 // scatter worked correctly.
110 for (int p = 0; p < numProcs; ++p) {
111 for (int k = 0; k < sendCount; ++k) {
112 const packet_type val = static_cast<packet_type> (p+1) *
113 (ONE + static_cast<packet_type> (k));
114 sendBuf[p*sendCount + k] = val;
115 }
116 }
117 } catch (std::exception& e) {
118 std::cerr << "Root process " << root << " threw an exception: "
119 << e.what () << endl;
120 lclSuccess = 0;
121 }
122 }
123
124#ifdef HAVE_TEUCHOS_MPI
125 // Make sure that the root process didn't throw an exception when
126 // filling the send buffer, by broadcasting from it to all the other
127 // processes.
128 gblSuccess = lclSuccess;
129 errCode = MPI_Bcast (&gblSuccess, 1, MPI_INT, root, rawMpiComm);
131 (errCode != MPI_SUCCESS, std::logic_error, "MPI_Bcast failed!");
133 (gblSuccess != 1, std::logic_error, "Filling the send buffer failed on "
134 "the root (" << root << ") process! This probably indicates a bug in "
135 "the test.");
136#endif // HAVE_TEUCHOS_MPI
137
138 // Invoke the function to test.
139 out << "About to invoke scatter" << endl;
140 scatter<int, packet_type> (sendBuf.getRawPtr (), sendCount,
141 recvBuf.getRawPtr (), recvCount,
142 root, comm);
143 out << "Done with scatter" << endl;
144
145 // Test whether each process got the expected results.
146 for (int k = 0; k < recvCount; ++k) {
147 const packet_type expectedVal = static_cast<packet_type> (myRank+1) *
148 (ONE + static_cast<packet_type> (k));
149 TEST_EQUALITY( recvBuf[k], expectedVal );
150 }
151 lclSuccess = success ? 1 : 0;
152 gblSuccess = lclSuccess;
153
154 // Use an all-reduce to check whether all processes got what they
155 // should have gotten.
156 //
157 // Don't trust that any other Teuchos communicator wrapper functions
158 // work here. Instead, if building with MPI, use raw MPI. If not
159 // building with MPI, first test that comm has only one process,
160 // then assume this in the test.
161
162#ifdef HAVE_TEUCHOS_MPI
163 errCode = MPI_Allreduce (&lclSuccess, &gblSuccess, 1,
164 MPI_INT, MPI_MIN, rawMpiComm);
166 (errCode != MPI_SUCCESS, std::logic_error, "MPI_Allreduce failed!");
167#else // HAVE_TEUCHOS_MPI
169 (comm.getSize () != 1, std::logic_error, "Not building with MPI, but "
170 "communicator has size = " << comm.getSize () << " != 1. We don't know "
171 "how to test this case.");
173 (comm.getRank () != root, std::logic_error, "Not building with MPI, but "
174 "the one process of rank " << comm.getRank () << " is not the root "
175 "process of rank " << root << ". We don't know how to test this case.");
176#endif // HAVE_TEUCHOS_MPI
177
178 return gblSuccess == 1;
179}
180
181
182TEUCHOS_UNIT_TEST_TEMPLATE_1_DECL( Comm, Scatter, PacketType )
183{
184 using Teuchos::Comm;
185 using Teuchos::RCP;
186 using std::endl;
187 typedef PacketType packet_type;
188
189 Teuchos::OSTab tab0 (out);
190 out << "Testing Teuchos::scatter" << endl;
191 Teuchos::OSTab tab1 (out);
192
193 RCP<const Comm<int> > comm = Teuchos::DefaultComm<int>::getComm ();
194 const int numProcs = comm->getSize ();
195
196 // Make sure that it works for all possible root processes in the
197 // communicator, not just Process 0.
198 for (int root = 0; root < numProcs; ++root) {
199 out << "Test for root = " << root << endl;
200 const bool curSuccess = testScatter<packet_type> (success, out, root, *comm);
201 TEST_EQUALITY_CONST( curSuccess, true );
202 success = success && curSuccess;
203 }
204
205 comm->barrier (); // make sure that everybody finished
206 out << "Done with test!" << endl;
207}
208
209//
210// mfh 14 Jul 2015: We only need to test int for now. See Bug 6375.
211//
212TEUCHOS_UNIT_TEST_TEMPLATE_1_INSTANT( Comm, Scatter, int )
Teuchos header file which uses auto-configuration information to include necessary C++ headers.
Implementation of Teuchos wrappers for MPI.
#define TEST_EQUALITY_CONST(v1, v2)
Assert the equality of v1 and constant v2.
#define TEST_EQUALITY(v1, v2)
Assert the equality of v1 and v2.
Unit testing support.
#define TEUCHOS_UNIT_TEST_TEMPLATE_1_DECL(TEST_GROUP, TEST_NAME, TYPE)
Macro for defining a templated unit test with one template parameter.
#define TEUCHOS_UNIT_TEST_TEMPLATE_1_INSTANT(TEST_GROUP, TEST_NAME, TYPE)
Instantiate a templated unit test with one template parameter.
Replacement for std::vector that is compatible with the Teuchos Memory Management classes.
T * getRawPtr()
Return a raw pointer to beginning of array or NULL if unsized.
void resize(size_type new_size, const value_type &x=value_type())
Abstract interface for distributed-memory communication.
virtual int getSize() const =0
Returns the number of processes that make up this communicator.
virtual int getRank() const =0
Returns the rank of this process.
static Teuchos::RCP< const Comm< OrdinalType > > getComm()
Return the default global communicator.
Smart reference counting pointer class for automatic garbage collection.
Default traits class that just returns typeid(T).name().
Tabbing class for helping to create formated, indented output for a basic_FancyOStream object.
#define TEUCHOS_TEST_FOR_EXCEPTION(throw_exception_test, Exception, msg)
Macro for throwing an exception with breakpointing to ease debugging.
TEUCHOSCOMM_LIB_DLL_EXPORT void scatter(const int sendBuf[], const int sendCount, int recvBuf[], const int recvCount, const int root, const Comm< int > &comm)
bool testScatter(bool &success, std::ostream &out, const int root, const Teuchos::Comm< int > &comm)
Definition: scatter.cpp:53
static T one()
Returns representation of one for this scalar type.
static T zero()
Returns representation of zero for this scalar type.