unittest/gunit/thd_manager-t.cc

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   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

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   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

/**
  This is unit test for the Global_THD_manager class.
*/

#include "my_config.h"

#include <gtest/gtest.h>
#include <stddef.h>
#include <sys/types.h>

#include "my_inttypes.h"
#include "sql/mysqld.h"
#include "sql/mysqld_thd_manager.h"  // Global_THD_manager
#include "sql/sql_class.h"
#include "unittest/gunit/thread_utils.h"

using thread::Notification;
using thread::Thread;

namespace thd_manager_unittest {

class ThreadManagerTest : public ::testing::Test {
 protected:
  ThreadManagerTest() {}

  void SetUp() {
    Global_THD_manager::create_instance();
    thd_manager = Global_THD_manager::get_instance();
    thd_manager->set_unit_test();
  }

  void TearDown() {}

  Global_THD_manager *thd_manager;

 private:
  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadManagerTest);
};

enum TEST_TYPE { TEST_WAIT = 0, TEST_TIMED_WAIT = 1 };

/*
  Verify add_thd(), remove_thd() methods
*/
TEST_F(ThreadManagerTest, AddRemoveTHDWithGuard) {
  THD thd1(false), thd2(false);
  thd1.server_id = 1;
  thd1.set_new_thread_id();
  thd2.server_id = 2;
  thd2.set_new_thread_id();

  EXPECT_EQ(0U, thd_manager->get_thd_count());
  thd_manager->add_thd(&thd1);
  EXPECT_EQ(1U, thd_manager->get_thd_count());
  thd_manager->add_thd(&thd2);

  thd_manager->remove_thd(&thd1);
  EXPECT_EQ(1U, thd_manager->get_thd_count());
  thd_manager->remove_thd(&thd2);
  EXPECT_EQ(0U, thd_manager->get_thd_count());
}

TEST_F(ThreadManagerTest, IncDecThreadRunning) {
  EXPECT_EQ(0, thd_manager->get_num_thread_running());
  thd_manager->inc_thread_running();
  EXPECT_EQ(1, thd_manager->get_num_thread_running());
  thd_manager->dec_thread_running();
  EXPECT_EQ(0, thd_manager->get_num_thread_running());
}

TEST_F(ThreadManagerTest, IncThreadCreated) {
  EXPECT_EQ(0U, thd_manager->get_num_thread_created());
  thd_manager->inc_thread_created();
  EXPECT_EQ(1U, thd_manager->get_num_thread_created());
}

/*
  Test function to validate do_for_all_thd, do_for_all_thd_copy.
  It emulates counter function to count number of thds in thd list.
*/
class TestFunc1 : public Do_THD_Impl {
 private:
  int cnt;

 public:
  TestFunc1() : cnt(0) {}
  int get_count() { return cnt; }
  void reset_count() { cnt = 0; }
  void operator()(THD *) { cnt = cnt + 1; }
};

TEST_F(ThreadManagerTest, TestTHDCopyDoFunc) {
  THD thd1(false), thd2(false);
  thd1.server_id = 1;
  thd1.set_new_thread_id();
  thd2.server_id = 2;
  thd2.set_new_thread_id();
  // Add two THD into thd list.
  thd_manager->add_thd(&thd1);
  thd_manager->add_thd(&thd2);

  int cnt = 0;
  TestFunc1 testFunc1;
  thd_manager->do_for_all_thd_copy(&testFunc1);
  cnt = testFunc1.get_count();
  EXPECT_EQ(2, cnt);

  testFunc1.reset_count();
  thd_manager->do_for_all_thd(&testFunc1);
  cnt = testFunc1.get_count();
  EXPECT_EQ(2, cnt);

  // Cleanup - Remove added THD.
  thd_manager->remove_thd(&thd1);
  thd_manager->remove_thd(&thd2);
}

/*
  Test class to verify find_thd()
*/
class TestFunc2 : public Find_THD_Impl {
 public:
  TestFunc2() : search_value(0) {}
  bool operator()(THD *thd) {
    if (thd->server_id == search_value) {
      return true;
    }
    return false;
  }
  void set_search_value(uint val) { search_value = val; }

 private:
  uint search_value;
};

/*
  Test class to verify do_all_for_thd() function.
  Counts all thd whose server_id value is less than or equal to 2.
*/
class TestFunc3 : public Do_THD_Impl {
 public:
  TestFunc3() : count(0) {}
  void operator()(THD *thd) {
    if (thd->server_id <= 2) {
      count++;
    }
  }
  int get_count() { return count; }

 private:
  int count;
};

TEST_F(ThreadManagerTest, TestTHDFindFunc) {
  THD thd1(false), thd2(false);
  thd1.server_id = 1;
  thd1.set_new_thread_id();
  thd2.server_id = 2;
  thd2.set_new_thread_id();
  thd_manager->add_thd(&thd1);
  thd_manager->add_thd(&thd2);
  TestFunc2 testFunc2;
  testFunc2.set_search_value(2);
  THD *thd = thd_manager->find_thd(&testFunc2);
  /* Returns the last thd which matches. */
  EXPECT_EQ(2U, thd->server_id);

  testFunc2.set_search_value(6);
  thd = thd_manager->find_thd(&testFunc2);
  /* Find non existing thd with server_id value 6. Expected to return NULL. */
  const THD *null_thd = nullptr;
  EXPECT_EQ(null_thd, thd);

  // Cleanup - Remove added THD.
  thd_manager->remove_thd(&thd1);
  thd_manager->remove_thd(&thd2);
}

TEST_F(ThreadManagerTest, TestTHDCountFunc) {
  THD thd1(false), thd2(false), thd3(false);
  thd1.server_id = 1;
  thd1.set_new_thread_id();
  thd2.server_id = 2;
  thd2.set_new_thread_id();
  thd3.server_id = 3;
  thd3.set_new_thread_id();
  thd_manager->add_thd(&thd1);
  thd_manager->add_thd(&thd2);
  thd_manager->add_thd(&thd3);

  TestFunc3 testFunc3;
  thd_manager->do_for_all_thd(&testFunc3);
  int ret = testFunc3.get_count();
  // testFunc3 counts for thd->server_id values, 1 and 2.
  EXPECT_EQ(2, ret);

  // Cleanup - Remove added THD.
  thd_manager->remove_thd(&thd1);
  thd_manager->remove_thd(&thd2);
  thd_manager->remove_thd(&thd3);
}

TEST_F(ThreadManagerTest, ThreadID) {
  // Code assumes that the size of my_thread_id is 32 bit.
  ASSERT_EQ(4U, sizeof(my_thread_id));

  // Reset the thread ID counter
  thd_manager->set_thread_id_counter(1);
  EXPECT_EQ(1U, thd_manager->get_thread_id());

  // The counter is incremented after ID is assigned.
  EXPECT_EQ(1U, thd_manager->get_new_thread_id());
  EXPECT_EQ(2U, thd_manager->get_thread_id());

  // Two increments in a row
  EXPECT_EQ(2U, thd_manager->get_new_thread_id());
  EXPECT_EQ(3U, thd_manager->get_new_thread_id());
  EXPECT_EQ(4U, thd_manager->get_thread_id());

  // Force wrap of the counter
  thd_manager->set_thread_id_counter(UINT_MAX32);
  EXPECT_EQ(UINT_MAX32, thd_manager->get_new_thread_id());

  // We should not use the value reserved for temporary THDs (0).
  // The next available value should be 4.
  EXPECT_EQ(4U, thd_manager->get_new_thread_id());
  EXPECT_EQ(5U, thd_manager->get_thread_id());

  // Release thread ID 3 and reset counter.
  thd_manager->release_thread_id(3);
  thd_manager->set_thread_id_counter(1U);
  EXPECT_EQ(3U, thd_manager->get_new_thread_id());

  // Releasing the reserved thread ID is allowed - multiple times.
  thd_manager->release_thread_id(Global_THD_manager::reserved_thread_id);
  thd_manager->release_thread_id(Global_THD_manager::reserved_thread_id);

  // Cleanup
  thd_manager->release_thread_id(1);
  thd_manager->release_thread_id(2);
  thd_manager->release_thread_id(3);
  thd_manager->release_thread_id(4);
  thd_manager->release_thread_id(UINT_MAX32);
}

#if !defined(DBUG_OFF)
TEST_F(ThreadManagerTest, ThreadIDDeathTest) {
  ::testing::FLAGS_gtest_death_test_style = "threadsafe";
  my_thread_id thread_id = thd_manager->get_new_thread_id();
  thd_manager->release_thread_id(thread_id);
  // Releasing the same ID twice should assert.
  EXPECT_DEATH_IF_SUPPORTED(thd_manager->release_thread_id(thread_id),
                            ".*Assertion .*1 == num_erased.*");
}
#endif

}  // namespace thd_manager_unittest