Expose RabitAllGatherRing and RabitGetRingPrevRank (#113)

* add unittests

* Expose RabitAllGatherRing and RabitGetRingPrevRank

* Enabled TCP_NODELAY to decrease latency

test/cpp/allreduce_base_test.cpp

@@ -0,0 +1,66 @@
+#define RABIT_CXXTESTDEFS_H
+#include <gtest/gtest.h>
+
+#include <string>
+#include <iostream>
+#include "../../src/allreduce_base.h"
+
+TEST(allreduce_base, init_task)
+{
+  rabit::engine::AllreduceBase base;
+
+  std::string rabit_task_id = "rabit_task_id=1";
+  char cmd[rabit_task_id.size()+1];
+  std::copy(rabit_task_id.begin(), rabit_task_id.end(), cmd);
+  cmd[rabit_task_id.size()] = '\0';
+
+  char* argv[] = {cmd};
+  base.Init(1, argv);
+  EXPECT_EQ(base.task_id, "1");
+}
+
+TEST(allreduce_base, init_with_cache_on)
+{
+  rabit::engine::AllreduceBase base;
+
+  std::string rabit_task_id = "rabit_task_id=1";
+  char cmd[rabit_task_id.size()+1];
+  std::copy(rabit_task_id.begin(), rabit_task_id.end(), cmd);
+  cmd[rabit_task_id.size()] = '\0';
+
+  std::string rabit_bootstrap_cache = "rabit_bootstrap_cache=1";
+  char cmd2[rabit_bootstrap_cache.size()+1];
+  std::copy(rabit_bootstrap_cache.begin(), rabit_bootstrap_cache.end(), cmd2);
+  cmd2[rabit_bootstrap_cache.size()] = '\0';
+
+  std::string rabit_debug = "rabit_debug=1";
+  char cmd3[rabit_debug.size()+1];
+  std::copy(rabit_debug.begin(), rabit_debug.end(), cmd3);
+  cmd3[rabit_debug.size()] = '\0';
+
+  char* argv[] = {cmd, cmd2, cmd3};
+  base.Init(3, argv);
+  EXPECT_EQ(base.task_id, "1");
+  EXPECT_EQ(base.rabit_bootstrap_cache, 1);
+  EXPECT_EQ(base.rabit_debug, 1);
+}
+
+TEST(allreduce_base, init_with_ring_reduce)
+{
+  rabit::engine::AllreduceBase base;
+
+  std::string rabit_task_id = "rabit_task_id=1";
+  char cmd[rabit_task_id.size()+1];
+  std::copy(rabit_task_id.begin(), rabit_task_id.end(), cmd);
+  cmd[rabit_task_id.size()] = '\0';
+
+  std::string rabit_reduce_ring_mincount = "rabit_reduce_ring_mincount=1";
+  char cmd2[rabit_reduce_ring_mincount.size()+1];
+  std::copy(rabit_reduce_ring_mincount.begin(), rabit_reduce_ring_mincount.end(), cmd2);
+  cmd2[rabit_reduce_ring_mincount.size()] = '\0';
+
+  char* argv[] = {cmd, cmd2};
+  base.Init(2, argv);
+  EXPECT_EQ(base.task_id, "1");
+  EXPECT_EQ(base.reduce_ring_mincount, 1);
+}

test/cpp/allreduce_mock_test.cpp

@@ -0,0 +1,51 @@
+#define RABIT_CXXTESTDEFS_H
+#include <gtest/gtest.h>
+
+#include <string>
+#include <iostream>
+#include "../../src/allreduce_mock.h"
+
+TEST(allreduce_mock, mock_allreduce)
+{
+  rabit::engine::AllreduceMock m;
+
+  std::string mock_str = "mock=0,0,0,0";
+  char cmd[mock_str.size()+1];
+  std::copy(mock_str.begin(), mock_str.end(), cmd);
+  cmd[mock_str.size()] = '\0';
+
+  char* argv[] = {cmd};
+  m.Init(1, argv);
+  m.rank = 0;
+  EXPECT_EXIT(m.Allreduce(nullptr,0,0,nullptr,nullptr,nullptr), ::testing::ExitedWithCode(255), "");
+}
+
+TEST(allreduce_mock, mock_broadcast)
+{
+  rabit::engine::AllreduceMock m;
+  std::string mock_str = "mock=0,1,2,0";
+  char cmd[mock_str.size()+1];
+  std::copy(mock_str.begin(), mock_str.end(), cmd);
+  cmd[mock_str.size()] = '\0';
+  char* argv[] = {cmd};
+  m.Init(1, argv);
+  m.rank = 0;
+  m.version_number=1;
+  m.seq_counter=2;
+  EXPECT_EXIT(m.Broadcast(nullptr,0,0), ::testing::ExitedWithCode(255), "");
+}
+
+TEST(allreduce_mock, mock_gather)
+{
+  rabit::engine::AllreduceMock m;
+  std::string mock_str = "mock=3,13,22,0";
+  char cmd[mock_str.size()+1];
+  std::copy(mock_str.begin(), mock_str.end(), cmd);
+  cmd[mock_str.size()] = '\0';
+  char* argv[] = {cmd};
+  m.Init(1, argv);
+  m.rank = 3;
+  m.version_number=13;
+  m.seq_counter=22;
+  EXPECT_EXIT(m.Allgather(nullptr,0,0,0,0), ::testing::ExitedWithCode(255), "");
+}