/* A thread pool (C++ version). */
-/* Copyright (c) 2004-2018 The SimGrid Team. All rights reserved. */
+/* Copyright (c) 2004-2019 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. */
#include "xbt/xbt_os_thread.h"
#include <boost/optional.hpp>
+#include <condition_variable>
+#include <mutex>
+#include <thread>
#if HAVE_FUTEX_H
#include <linux/futex.h>
#include <sys/syscall.h>
#endif
+#if HAVE_PTHREAD_NP_H
+#include <pthread_np.h>
+#endif
+
XBT_LOG_EXTERNAL_CATEGORY(xbt_parmap);
namespace simgrid {
namespace xbt {
-/** \addtogroup XBT_parmap
- * \ingroup XBT_misc
- * \brief Parallel map class
- * \{
- */
+/** @addtogroup XBT_parmap
+ * @ingroup XBT_misc
+ * @brief Parallel map class
+ * @{
+ */
template <typename T> class Parmap {
public:
Parmap(unsigned num_workers, e_xbt_parmap_mode_t mode);
enum Flag { PARMAP_WORK, PARMAP_DESTROY };
/**
- * \brief Thread data transmission structure
+ * @brief Thread data transmission structure
*/
class ThreadData {
public:
};
/**
- * \brief Synchronization object (different specializations).
+ * @brief Synchronization object (different specializations).
*/
class Synchro {
public:
explicit Synchro(Parmap<T>& parmap) : parmap(parmap) {}
virtual ~Synchro() = default;
/**
- * \brief Wakes all workers and waits for them to finish the tasks.
+ * @brief Wakes all workers and waits for them to finish the tasks.
*
* This function is called by the controller thread.
*/
virtual void master_signal() = 0;
/**
- * \brief Starts the parmap: waits for all workers to be ready and returns.
+ * @brief Starts the parmap: waits for all workers to be ready and returns.
*
* This function is called by the controller thread.
*/
virtual void master_wait() = 0;
/**
- * \brief Ends the parmap: wakes the controller thread when all workers terminate.
+ * @brief Ends the parmap: wakes the controller thread when all workers terminate.
*
* This function is called by all worker threads when they end (not including the controller).
*/
virtual void worker_signal() = 0;
/**
- * \brief Waits for some work to process.
+ * @brief Waits for some work to process.
*
* 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 round the expected round number
*/
virtual void worker_wait(unsigned) = 0;
void worker_wait(unsigned round);
private:
- xbt_os_cond_t ready_cond;
- xbt_os_mutex_t ready_mutex;
- xbt_os_cond_t done_cond;
- xbt_os_mutex_t done_mutex;
+ std::condition_variable ready_cond;
+ std::mutex ready_mutex;
+ std::condition_variable done_cond;
+ std::mutex done_mutex;
};
#if HAVE_FUTEX_H
Flag status; /**< is the parmap active or being destroyed? */
unsigned work_round; /**< index of the current round */
- xbt_os_thread_t* workers; /**< worker thread handlers */
+ std::vector<std::thread*> workers; /**< worker thread handlers */
unsigned num_workers; /**< total number of worker threads including the controller */
Synchro* synchro; /**< synchronization object */
};
/**
- * \brief Creates a parallel map object
- * \param num_workers number of worker threads to create
- * \param mode how to synchronize the worker threads
+ * @brief Creates a parallel map object
+ * @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)
{
/* Initialize the thread pool data structure */
this->status = PARMAP_WORK;
this->work_round = 0;
- this->workers = new xbt_os_thread_t[num_workers];
+ this->workers.resize(num_workers);
this->num_workers = num_workers;
this->synchro = new_synchro(mode);
- /* Create the pool of worker threads */
+ /* Create the pool of worker threads (the caller of apply() will be worker[0]) */
this->workers[0] = nullptr;
-#if HAVE_PTHREAD_SETAFFINITY
- int core_bind = 0;
-#endif
+ XBT_ATTRIB_UNUSED unsigned int core_bind = 0;
+
for (unsigned i = 1; i < num_workers; i++) {
- ThreadData* data = new ThreadData(*this, i);
- this->workers[i] = xbt_os_thread_create(nullptr, worker_main, data, nullptr);
+ this->workers[i] = new std::thread(worker_main, new ThreadData(*this, i));
+
+ /* Bind the worker to a core if possible */
#if HAVE_PTHREAD_SETAFFINITY
- xbt_os_thread_bind(this->workers[i], core_bind);
- if (core_bind != xbt_os_get_numcores() - 1)
+#if HAVE_PTHREAD_NP_H /* FreeBSD ? */
+ cpuset_t cpuset;
+ size_t size = sizeof(cpuset_t);
+#else /* Linux ? */
+ cpu_set_t cpuset;
+ size_t size = sizeof(cpu_set_t);
+#endif
+ pthread_t pthread = this->workers[i]->native_handle();
+ 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;
}
/**
- * \brief Destroys a parmap
+ * @brief Destroys a parmap
*/
template <typename T> Parmap<T>::~Parmap()
{
synchro->master_signal();
for (unsigned i = 1; i < num_workers; i++)
- xbt_os_thread_join(workers[i], nullptr);
+ workers[i]->join();
- delete[] workers;
delete synchro;
}
/**
- * \brief Applies a list of tasks in parallel.
- * \param fun the function to call in parallel
- * \param data each element of this vector will be passed as an argument to fun
+ * @brief Applies a list of tasks in parallel.
+ * @param fun the function to call in parallel
+ * @param data each element of this vector will be passed as an argument to fun
*/
template <typename T> void Parmap<T>::apply(void (*fun)(T), const std::vector<T>& data)
{
}
/**
- * \brief Returns a next task to process.
+ * @brief Returns a next task to process.
*
* Worker threads call this function to get more work.
*
- * \return the next task to process, or throws a std::out_of_range exception if there is no more work
+ * @return the next task to process, or throws a std::out_of_range exception if there is no more work
*/
template <typename T> boost::optional<T> Parmap<T>::next()
{
}
/**
- * \brief Main work loop: applies fun to elements in turn.
+ * @brief Main work loop: applies fun to elements in turn.
*/
template <typename T> void Parmap<T>::work()
{
/**
* Get a synchronization object for given mode.
- * \param mode the synchronization mode
+ * @param mode the synchronization mode
*/
template <typename T> typename Parmap<T>::Synchro* Parmap<T>::new_synchro(e_xbt_parmap_mode_t mode)
{
return res;
}
-/**
- * \brief Main function of a worker thread.
- */
+/** @brief Main function of a worker thread */
template <typename T> void* Parmap<T>::worker_main(void* arg)
{
ThreadData* data = static_cast<ThreadData*>(arg);
Parmap<T>& parmap = data->parmap;
unsigned round = 0;
smx_context_t context = SIMIX_context_new(std::function<void()>(), nullptr, nullptr);
- SIMIX_context_set_current(context);
+ kernel::context::Context::set_current(context);
XBT_CDEBUG(xbt_parmap, "New worker thread created");
/* Worker's main loop */
while (1) {
- round++;
+ round++; // New scheduling round
parmap.synchro->worker_wait(round);
if (parmap.status == PARMAP_DESTROY)
break;
template <typename T> Parmap<T>::PosixSynchro::PosixSynchro(Parmap<T>& parmap) : Synchro(parmap)
{
- ready_cond = xbt_os_cond_init();
- ready_mutex = xbt_os_mutex_init();
- done_cond = xbt_os_cond_init();
- done_mutex = xbt_os_mutex_init();
}
template <typename T> Parmap<T>::PosixSynchro::~PosixSynchro()
{
- xbt_os_cond_destroy(ready_cond);
- xbt_os_mutex_destroy(ready_mutex);
- xbt_os_cond_destroy(done_cond);
- xbt_os_mutex_destroy(done_mutex);
}
template <typename T> void Parmap<T>::PosixSynchro::master_signal()
{
- xbt_os_mutex_acquire(ready_mutex);
+ std::unique_lock<std::mutex> lk(ready_mutex);
this->parmap.thread_counter = 1;
this->parmap.work_round++;
/* wake all workers */
- xbt_os_cond_broadcast(ready_cond);
- xbt_os_mutex_release(ready_mutex);
+ ready_cond.notify_all();
}
template <typename T> void Parmap<T>::PosixSynchro::master_wait()
{
- xbt_os_mutex_acquire(done_mutex);
+ std::unique_lock<std::mutex> lk(done_mutex);
while (this->parmap.thread_counter < this->parmap.num_workers) {
/* wait for all workers to be ready */
- xbt_os_cond_wait(done_cond, done_mutex);
+ done_cond.wait(lk);
}
- xbt_os_mutex_release(done_mutex);
}
template <typename T> void Parmap<T>::PosixSynchro::worker_signal()
{
- xbt_os_mutex_acquire(done_mutex);
+ std::unique_lock<std::mutex> lk(done_mutex);
this->parmap.thread_counter++;
if (this->parmap.thread_counter == this->parmap.num_workers) {
/* all workers have finished, wake the controller */
- xbt_os_cond_signal(done_cond);
+ done_cond.notify_one();
}
- xbt_os_mutex_release(done_mutex);
}
template <typename T> void Parmap<T>::PosixSynchro::worker_wait(unsigned round)
{
- xbt_os_mutex_acquire(ready_mutex);
+ std::unique_lock<std::mutex> lk(ready_mutex);
/* wait for more work */
while (this->parmap.work_round != round) {
- xbt_os_cond_wait(ready_cond, ready_mutex);
+ ready_cond.wait(lk);
}
- xbt_os_mutex_release(ready_mutex);
}
#if HAVE_FUTEX_H
template <typename T> void Parmap<T>::BusyWaitSynchro::master_wait()
{
while (__atomic_load_n(&this->parmap.thread_counter, __ATOMIC_SEQ_CST) < this->parmap.num_workers) {
- xbt_os_thread_yield();
+ std::this_thread::yield();
}
}
{
/* wait for more work */
while (__atomic_load_n(&this->parmap.work_round, __ATOMIC_SEQ_CST) != round) {
- xbt_os_thread_yield();
+ std::this_thread::yield();
}
}
-/** \} */
+/** @} */
}
}
