LUMIERA.clone/tests/library/sync-waiting-test.cpp
Ichthyostega 0b9e184fa3 Library: replace usages of rand() in the whole code base
* most usages are drop-in replacements
 * occasionally the other convenience functions can be used
 * verify call-paths from core code to identify usages
 * ensure reseeding for all tests involving some kind of randomness...

__Note__: some tests were not yet converted,
since their usage of randomness is actually not thread-safe.
This problem existed previously, since also `rand()` is not thread safe,
albeit in most cases it is possible to ignore this problem, as
''garbled internal state'' is also somehow „random“
2024-11-13 04:23:46 +01:00

127 lines
3.5 KiB
C++

/*
SyncWaiting(Test) - check the monitor object based wait/notification
Copyright (C) Lumiera.org
2008, Hermann Vosseler <Ichthyostega@web.de>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
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., 675 Mass Ave, Cambridge, MA 02139, USA.
* *****************************************************/
/** @file sync-waiting-test.cpp
** unit test \ref SyncWaiting_test
*/
#include "lib/test/run.hpp"
#include "lib/error.hpp"
#include "lib/thread.hpp"
#include "lib/sync.hpp"
#include <atomic>
using test::Test;
using std::atomic_uint;
using std::atomic_bool;
using std::this_thread::sleep_for;
using std::chrono_literals::operator ""ms;
namespace lib {
namespace test{
namespace { // test subject...
/** demonstrates how to wait on a simple boolean flag */
class SyncOnBool
: public Sync<NonrecursiveLock_Waitable>
{
atomic_uint sum_{0}, input_{0};
atomic_bool got_new_data_{false};
public:
void getIt()
{
Lock await{this, [&]{ return bool(got_new_data_); }};
sum_ += input_;
}
void provide (uint val)
{
Lock sync{this};
input_ = val;
got_new_data_ = true;
sync.notify_all();
}
/** harvesting the result...*/
uint result () { return sum_; }
};
}//(End) test subject.
/************************************************************************//**
* @test concurrent waiting and notification, implemented via object monitor.
* This test covers the second part of the monitor pattern, which builds upon
* the locking part, additionally using an embedded condition. Two interwoven
* threads are created, both blocked until a start value is given. Once awakened,
* each thread should add the start value to a common sum field.
* @see SyncLocking_test
* @see sync.hpp
*/
class SyncWaiting_test : public Test
{
virtual void
run (Arg)
{
seedRand();
SyncOnBool token;
ThreadJoinable ping ("SyncWaiting ping", [&]{ token.getIt(); });
ThreadJoinable pong ("SyncWaiting pong", [&]{ token.getIt(); });
CHECK (ping);
CHECK (pong);
CHECK (0 == token.result());
sleep_for (100ms); // if the threads don't block correctly, they've missed their chance by now...
// kick off the notification cascade...
uint val = rani(1000);
token.provide (val);
// wait for the two Threads to finish their handshake
pong.join();
ping.join();
CHECK (2*val == token.result());
}
};
/** Register this test class... */
LAUNCHER (SyncWaiting_test, "unit common");
}} // namespace lib::test