faux-folly/folly/futures/test/ThreadWheelTimekeeperTest.cpp

#include <gtest/gtest.h>
#include <folly/futures/detail/ThreadWheelTimekeeper.h>
#include <chrono>

#include <unistd.h>

using folly::detail::ThreadWheelTimekeeper;
using std::chrono::milliseconds;

/* If a callback tries to add a timer, it should not deadlock */
TEST(ThreadWheelTimekeeper, callbackAddsTimer)
{
    ThreadWheelTimekeeper tk;
    milliseconds now(0);
    unsigned a = 0;
    unsigned b = 0;

    /* If this doesn't complete in 5 seconds... crash */
    alarm(5);

    tk.after(now)
        .then([&] {
                a = 1;
                return tk.after(now)
                    .then([&] {
                            b = 1;
                        });
            })
        .get();

    /* cancel timeout */
    alarm(0);

    EXPECT_EQ(1, a);
    EXPECT_EQ(1, b);
}