mirror of
https://github.com/boostorg/atomic.git
synced 2026-01-19 16:12:09 +00:00
80cfbfd0de
The inter-process atomics have ipc_ prefixes: ipc_atomic, ipc_atomic_ref and ipc_atomic_flag. These types are similar to their unprefixed counterparts with the following distinctions: - The operations are provided with an added precondition that is_lock_free() returns true. - All operations, including waiting/notifying operations, are address-free, so the types are suitable for inter-process communication. - The new has_native_wait_notify() operation and always_has_native_wait_notify static constant allow to test if the target platform has native support for address-free waiting/notifying operations. If it does not, a generic implementation is used based on a busy wait. - The new set of capability macros added. The macros are named BOOST_ATOMIC_HAS_NATIVE_<T>_IPC_WAIT_NOTIFY and indicate whether address-free waiting/notifying operations are supported natively for a given type. Additionally, to unify interface and implementation of different components, the has_native_wait_notify() operation and always_has_native_wait_notify static constant were added to non-IPC atomic types as well. Added BOOST_ATOMIC_HAS_NATIVE_<T>_WAIT_NOTIFY capability macros to indicate native support for inter-thread waiting/notifying operations. Also, added is_lock_free() and is_always_lock_free to atomic_flag. This commit adds implementation, docs and tests.
79 lines
2.3 KiB
C++
79 lines
2.3 KiB
C++
// Copyright (c) 2020 Andrey Semashev
|
|
//
|
|
// Distributed under the Boost Software License, Version 1.0.
|
|
// See accompanying file LICENSE_1_0.txt or copy at
|
|
// http://www.boost.org/LICENSE_1_0.txt)
|
|
|
|
// This is a fuzzing test for waiting and notifying operations.
|
|
// The test creates a number of threads exceeding the number of hardware threads, each of which
|
|
// blocks on the atomic object. The main thread then notifies one or all threads repeatedly,
|
|
// while incrementing the atomic object. The test ends when the atomic counter reaches the predefined limit.
|
|
// The goal of the test is to verify that (a) it doesn't crash and (b) all threads get unblocked in the end.
|
|
|
|
#include <boost/memory_order.hpp>
|
|
#include <boost/atomic/atomic.hpp>
|
|
|
|
#include <iostream>
|
|
#include <boost/config.hpp>
|
|
#include <boost/bind/bind.hpp>
|
|
#include <boost/chrono/chrono.hpp>
|
|
#include <boost/thread/thread.hpp>
|
|
#include <boost/thread/barrier.hpp>
|
|
#include <boost/smart_ptr/scoped_array.hpp>
|
|
|
|
namespace chrono = boost::chrono;
|
|
|
|
boost::atomic< unsigned int > g_atomic(0u);
|
|
|
|
BOOST_CONSTEXPR_OR_CONST unsigned int loop_count = 4096u;
|
|
|
|
void thread_func(boost::barrier* barrier)
|
|
{
|
|
barrier->wait();
|
|
|
|
unsigned int old_count = 0u;
|
|
while (true)
|
|
{
|
|
unsigned int new_count = g_atomic.wait(old_count, boost::memory_order_relaxed);
|
|
if (new_count >= loop_count)
|
|
break;
|
|
|
|
old_count = new_count;
|
|
}
|
|
}
|
|
|
|
int main()
|
|
{
|
|
const unsigned int thread_count = boost::thread::hardware_concurrency() + 4u;
|
|
boost::barrier barrier(thread_count + 1u);
|
|
boost::scoped_array< boost::thread > threads(new boost::thread[thread_count]);
|
|
|
|
for (unsigned int i = 0u; i < thread_count; ++i)
|
|
boost::thread(boost::bind(&thread_func, &barrier)).swap(threads[i]);
|
|
|
|
barrier.wait();
|
|
|
|
// Let the threads block on the atomic counter
|
|
boost::this_thread::sleep_for(chrono::milliseconds(100));
|
|
|
|
while (true)
|
|
{
|
|
for (unsigned int i = 0u; i < thread_count; ++i)
|
|
{
|
|
g_atomic.opaque_add(1u, boost::memory_order_relaxed);
|
|
g_atomic.notify_one();
|
|
}
|
|
|
|
unsigned int old_count = g_atomic.fetch_add(1u, boost::memory_order_relaxed);
|
|
g_atomic.notify_all();
|
|
|
|
if ((old_count + 1u) >= loop_count)
|
|
break;
|
|
}
|
|
|
|
for (unsigned int i = 0u; i < thread_count; ++i)
|
|
threads[i].join();
|
|
|
|
return 0u;
|
|
}
|