Added task_region - a fork/join task implementation

tests/unit_tests/CMakeLists.txt

@@ -50,6 +50,7 @@ set(unit_tests_sources
   test_format_utils.cpp
   test_peerlist.cpp
   test_protocol_pack.cpp
+  thread_group.cpp
   hardfork.cpp
   unbound.cpp
   varint.cpp

tests/unit_tests/thread_group.cpp

@@ -0,0 +1,177 @@
+// Copyright (c) 2014-2016, The Monero Project
+//
+// 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.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// 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 HOLDER 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.
+
+#include "gtest/gtest.h"
+
+#include <atomic>
+#include "common/task_region.h"
+#include "common/thread_group.h"
+
+TEST(ThreadGroup, NoThreads)
+{
+  tools::task_region(tools::thread_group(0), [] (tools::task_region_handle& region) {
+    std::atomic<bool> completed{false};
+    region.run([&] { completed = true; });
+    EXPECT_TRUE(completed);
+  });
+  {
+    tools::thread_group group(0);
+    std::atomic<bool> completed{false};
+    group.dispatch([&] { completed = true; });
+    EXPECT_TRUE(completed);
+  }
+}
+
+TEST(ThreadGroup, OneThread)
+{
+  tools::thread_group group(1);
+
+  for (unsigned i = 0; i < 3; ++i) {
+    std::atomic<bool> completed{false};
+    tools::task_region(group, [&] (tools::task_region_handle& region) {
+      region.run([&] { completed = true; });
+    });
+    EXPECT_TRUE(completed);
+  }
+}
+
+
+TEST(ThreadGroup, UseActiveThreadOnSync)
+{
+  tools::thread_group group(1);
+
+  for (unsigned i = 0; i < 3; ++i) {
+    std::atomic<bool> completed{false};
+    tools::task_region(group, [&] (tools::task_region_handle& region) {
+      region.run([&] { while (!completed); });
+      region.run([&] { completed = true; });
+    });
+    EXPECT_TRUE(completed);
+  }
+}
+
+TEST(ThreadGroup, InOrder)
+{
+  tools::thread_group group(1);
+
+  for (unsigned i = 0; i < 3; ++i) {
+    std::atomic<unsigned> count{0};
+    std::atomic<bool> completed{false};
+    tools::task_region(group, [&] (tools::task_region_handle& region) {
+      region.run([&] { while (!completed); });
+      region.run([&] { if (count == 0) completed = true; });
+      region.run([&] { ++count; });
+    });
+    EXPECT_TRUE(completed);
+    EXPECT_EQ(1u, count);
+  }
+}
+
+TEST(ThreadGroup, TwoThreads)
+{
+  tools::thread_group group(2);
+
+  for (unsigned i = 0; i < 3; ++i) {
+    std::atomic<bool> completed{false};
+    tools::task_region(group, [&] (tools::task_region_handle& region) {
+      region.run([&] { while (!completed); });
+      region.run([&] { while (!completed); });
+      region.run([&] { completed = true; });
+    });
+    EXPECT_TRUE(completed);
+  }
+}
+
+TEST(ThreadGroup, Nested) {
+  struct fib {
+    unsigned operator()(tools::thread_group& group, unsigned value) const {
+      if (value == 0 || value == 1) {
+        return value;
+      }
+      unsigned left = 0;
+      unsigned right = 0;
+      tools::task_region(group, [&, value] (tools::task_region_handle& region) {
+        region.run([&, value] { left = fib{}(group, value - 1); });
+        region.run([&, value] { right = fib{}(group, value - 2); } );
+      });
+      return left + right;
+    }
+
+    unsigned operator()(tools::thread_group&& group, unsigned value) const {
+      return (*this)(group, value);
+    }
+  };
+  // be careful of depth on asynchronous version
+  EXPECT_EQ(6765, fib{}(tools::thread_group(0), 20));
+  EXPECT_EQ(377, fib{}(tools::thread_group(1), 14));
+}
+
+TEST(ThreadGroup, Many)
+{
+  tools::thread_group group(1);
+
+  for (unsigned i = 0; i < 3; ++i) {
+    std::atomic<unsigned> count{0};
+    tools::task_region(group, [&] (tools::task_region_handle& region) {
+      for (unsigned tasks = 0; tasks < 1000; ++tasks) {
+        region.run([&] { ++count; });
+      }
+    });
+    EXPECT_EQ(1000u, count);
+  }
+}
+
+TEST(ThreadGroup, ThrowInTaskRegion)
+{
+  class test_exception final : std::exception {
+  public:
+    explicit test_exception() : std::exception() {}
+
+    virtual const char* what() const noexcept override {
+      return "test_exception";
+    }
+  };
+
+  tools::thread_group group(1);
+
+  for (unsigned i = 0; i < 3; ++i) {
+    std::atomic<unsigned> count{0};
+    EXPECT_THROW(
+      [&] {
+        tools::task_region(group, [&] (tools::task_region_handle& region) {
+          for (unsigned tasks = 0; tasks < 1000; ++tasks) {
+            region.run([&] { ++count; });
+          }
+          throw test_exception();
+        });
+      }(),
+      test_exception
+    );
+    EXPECT_GE(1000u, count);
+  }
+}