我们可以在 C++ 中使用 Google Test/Gmock 模拟调用 std::thread 函数的函数吗？

Question

Can I mock the function that calls std::thread function.

eg Creating thread:

std::thread thread_id

void myfun()
{
thread_id = std::thread(&threadfunction, this);
logger_.Info(LOG001, "Myfun() is called");
}

Joining a thread in another function

void final()
{
    if (thread_id.joinable())
      thread_id.join();
}

in test part:

TEST_F(mytest, myfun)
{
EXPECT_CALL(logger_mock_, Info(LOG001, ::testing::_)); //logging expect call
my_class_.myfun();  //my_class_ is instance object.
}

I want to test this function but I am getting errors "terminate called without an active exception." That means the thread is created and became out of scope and testing is terminated. :(

Is it possible to use std::thread in gmock?

I also read that pthread is used in multi-threading Google test from documentation at:

https://chromium.googlesource.com/external/github.com/google/googletest/+/refs/tags/release-1.8.0/googletest#multi-threaded-tests

Please help with this.

Answer 1

There's no problem with setting expect calls on a mock that is used in a separate thread. Your problem with terminate called without an active exception. is that you've created a thread that is never joined. Try:

void myfun()
{
    auto t = std::thread(&threadfunction, this);
    logger_.Info(LOG001, "Myfun() is called");
    t.join();
}

But be aware that logger_.Info(LOG001, "Myfun() is called"); will be executed in the same thread in which myfun is called (ie in the main thread of the test app in your example). In order to logger_.Info to be called in thread t , it must be moved to threadfunction .