/* A thread pool (C++ version). */
-/* Copyright (c) 2004-2019 The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2004-2022 The SimGrid Team. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
#define XBT_PARMAP_HPP
#include "src/internal_config.h" // HAVE_FUTEX_H
+#include "src/kernel/EngineImpl.hpp"
#include "src/kernel/context/Context.hpp"
-#include "src/simix/smx_private.hpp" /* simix_global */
#include <boost/optional.hpp>
#include <condition_variable>
*
* This function is called by each worker thread (not including the controller) when it has no more work to do.
*
- * @param round the expected round number
+ * @param expected_round the expected round number
*/
virtual void worker_wait(unsigned) = 0;
class PosixSynchro : public Synchro {
public:
- explicit PosixSynchro(Parmap<T>& parmap);
- ~PosixSynchro();
+ explicit PosixSynchro(Parmap<T>& parmap) : Synchro(parmap) {}
void master_signal() override;
void master_wait() override;
void worker_signal() override;
- void worker_wait(unsigned round) override;
+ void worker_wait(unsigned expected_round) override;
private:
std::condition_variable ready_cond;
Synchro* new_synchro(e_xbt_parmap_mode_t mode);
void work();
- bool destroying; /**< is the parmap being destroyed? */
- std::atomic_uint work_round; /**< index of the current round */
+ bool destroying = false; /**< is the parmap being destroyed? */
+ std::atomic_uint work_round{0}; /**< index of the current round */
std::vector<std::thread*> workers; /**< worker thread handlers */
unsigned num_workers; /**< total number of worker threads including the controller */
Synchro* synchro; /**< synchronization object */
std::atomic_uint thread_counter{0}; /**< number of workers that have done the work */
- std::function<void(T)> fun; /**< function to run in parallel on each element of data */
- const std::vector<T>* data = nullptr; /**< parameters to pass to fun in parallel */
- std::atomic_uint index; /**< index of the next element of data to pick */
+ std::function<void(T)> worker_fun; /**< function to run in parallel on each element of data */
+ const std::vector<T>* common_data = nullptr; /**< parameters to pass to fun in parallel */
+ std::atomic_uint common_index{0}; /**< index of the next element of data to pick */
};
/**
* @param num_workers number of worker threads to create
* @param mode how to synchronize the worker threads
*/
-template <typename T> Parmap<T>::Parmap(unsigned num_workers, e_xbt_parmap_mode_t mode)
+template <typename T>
+Parmap<T>::Parmap(unsigned num_workers, e_xbt_parmap_mode_t mode)
+ : workers(num_workers), num_workers(num_workers), synchro(new_synchro(mode))
{
XBT_CDEBUG(xbt_parmap, "Create new parmap (%u workers)", num_workers);
- /* Initialize the thread pool data structure */
- this->destroying = false;
- this->work_round = 0;
- this->workers.resize(num_workers);
- this->num_workers = num_workers;
- this->synchro = new_synchro(mode);
-
/* Create the pool of worker threads (the caller of apply() will be worker[0]) */
- this->workers[0] = nullptr;
- XBT_ATTRIB_UNUSED unsigned int core_bind = 0;
+ workers[0] = nullptr;
for (unsigned i = 1; i < num_workers; i++) {
- this->workers[i] = new std::thread(worker_main, new ThreadData(*this, i));
+ auto* data = new ThreadData(*this, i);
+ workers[i] = new std::thread(worker_main, data);
/* Bind the worker to a core if possible */
#if HAVE_PTHREAD_SETAFFINITY
cpu_set_t cpuset;
size_t size = sizeof(cpu_set_t);
#endif
- pthread_t pthread = this->workers[i]->native_handle();
+ pthread_t pthread = workers[i]->native_handle();
+ int core_bind = (i - 1) % std::thread::hardware_concurrency();
CPU_ZERO(&cpuset);
CPU_SET(core_bind, &cpuset);
pthread_setaffinity_np(pthread, size, &cpuset);
- if (core_bind != std::thread::hardware_concurrency() - 1)
- core_bind++;
- else
- core_bind = 0;
#endif
}
}
template <typename T> void Parmap<T>::apply(std::function<void(T)>&& fun, const std::vector<T>& data)
{
/* Assign resources to worker threads (we are maestro here)*/
- this->fun = std::move(fun);
- this->data = &data;
- this->index = 0;
- this->synchro->master_signal(); // maestro runs futex_wake to wake all the minions (the working threads)
- this->work(); // maestro works with its minions
- this->synchro->master_wait(); // When there is no more work to do, then maestro waits for the last minion to stop
+ worker_fun = std::move(fun);
+ common_data = &data;
+ common_index = 0;
+ synchro->master_signal(); // maestro runs futex_wake to wake all the minions (the working threads)
+ work(); // maestro works with its minions
+ synchro->master_wait(); // When there is no more work to do, then maestro waits for the last minion to stop
XBT_CDEBUG(xbt_parmap, "Job done"); // ... and proceeds
}
*/
template <typename T> boost::optional<T> Parmap<T>::next()
{
- unsigned index = this->index.fetch_add(1, std::memory_order_relaxed);
- if (index < this->data->size())
- return (*this->data)[index];
+ unsigned index = common_index.fetch_add(1, std::memory_order_relaxed);
+ if (index < common_data->size())
+ return (*common_data)[index];
else
return boost::none;
}
*/
template <typename T> void Parmap<T>::work()
{
- unsigned length = this->data->size();
- unsigned index = this->index.fetch_add(1, std::memory_order_relaxed);
+ unsigned length = static_cast<unsigned>(common_data->size());
+ unsigned index = common_index.fetch_add(1, std::memory_order_relaxed);
while (index < length) {
- this->fun((*this->data)[index]);
- index = this->index.fetch_add(1, std::memory_order_relaxed);
+ worker_fun((*common_data)[index]);
+ index = common_index.fetch_add(1, std::memory_order_relaxed);
}
}
/** @brief Main function of a worker thread */
template <typename T> void Parmap<T>::worker_main(ThreadData* data)
{
+ auto engine = simgrid::kernel::EngineImpl::get_instance();
Parmap<T>& parmap = data->parmap;
unsigned round = 0;
- smx_context_t context = simix_global->context_factory->create_context(std::function<void()>(), nullptr);
+ kernel::context::Context* context = engine->get_context_factory()->create_context(std::function<void()>(), nullptr);
kernel::context::Context::set_current(context);
XBT_CDEBUG(xbt_parmap, "New worker thread created");
/* Worker's main loop */
- while (1) {
+ while (true) {
round++; // New scheduling round
parmap.synchro->worker_wait(round);
if (parmap.destroying)
delete data;
}
-template <typename T> Parmap<T>::PosixSynchro::PosixSynchro(Parmap<T>& parmap) : Synchro(parmap)
-{
-}
-
-template <typename T> Parmap<T>::PosixSynchro::~PosixSynchro()
-{
-}
-
template <typename T> void Parmap<T>::PosixSynchro::master_signal()
{
std::unique_lock<std::mutex> lk(ready_mutex);
template <typename T> void Parmap<T>::PosixSynchro::master_wait()
{
std::unique_lock<std::mutex> lk(done_mutex);
- while (this->parmap.thread_counter < this->parmap.num_workers) {
- /* wait for all workers to be ready */
- done_cond.wait(lk);
- }
+ /* wait for all workers to be ready */
+ done_cond.wait(lk, [this]() { return this->parmap.thread_counter >= this->parmap.num_workers; });
}
template <typename T> void Parmap<T>::PosixSynchro::worker_signal()
}
}
-template <typename T> void Parmap<T>::PosixSynchro::worker_wait(unsigned round)
+template <typename T> void Parmap<T>::PosixSynchro::worker_wait(unsigned expected_round)
{
std::unique_lock<std::mutex> lk(ready_mutex);
/* wait for more work */
- while (this->parmap.work_round != round) {
- ready_cond.wait(lk);
- }
+ ready_cond.wait(lk, [this, expected_round]() { return this->parmap.work_round == expected_round; });
}
#if HAVE_FUTEX_H
}
}
-template <typename T> void Parmap<T>::FutexSynchro::worker_wait(unsigned round)
+template <typename T> void Parmap<T>::FutexSynchro::worker_wait(unsigned expected_round)
{
- unsigned work_round = this->parmap.work_round.load();
+ unsigned round = this->parmap.work_round.load();
/* wait for more work */
- while (work_round != round) {
- futex_wait(&this->parmap.work_round, work_round);
- work_round = this->parmap.work_round.load();
+ while (round != expected_round) {
+ futex_wait(&this->parmap.work_round, round);
+ round = this->parmap.work_round.load();
}
}
#endif
