util/unittest/event.cc

/*
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Copyright (c) 2022, Stable Cloud Computing, Inc.
 
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
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   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.
 
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   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
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DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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*/
#include <gtest/gtest.h>
#include <cstring>
#include <iostream>
#include <util/event.h>
#include <system_error>
#include <cerrno>
 
using std::cout;
using std::endl;
using scc::util::Event;
 
TEST(event_test, blocking)
{
    Event ev;
    ev.write(1);
    ev.write(2);
    ASSERT_EQ(ev.read(), 3);
}
 
TEST(event_test, nonblocking)
{
    Event ev(Event::nonblocking);
    ev.write(1);
    ev.write(2);
    ASSERT_EQ(ev.read(), 3);
    ASSERT_THROW(ev.read(), std::system_error);
    ASSERT_EQ(errno, EAGAIN); // most recent system error was EAGAIN "unavailable"
}
 
TEST(event_test, nonblocking_semaphore)
{
    Event ev(Event::nonblocking|Event::semaphore);
    ASSERT_THROW(ev.read(), std::system_error);
    ev.write(1);
    ev.write(2);
    ASSERT_EQ(ev.read(), 1);
    ASSERT_EQ(ev.read(), 1);
    ASSERT_EQ(ev.read(), 1);
}