X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/f5792a3bf76ce15a573ae5e9c63097595ae5f2bd..420e66292bea56f21c29d230aa63c6bf6095db31:/src/include/xbt/parmap.hpp

diff --git a/src/include/xbt/parmap.hpp b/src/include/xbt/parmap.hpp
index 24affcc830..51f481805b 100644
--- a/src/include/xbt/parmap.hpp
+++ b/src/include/xbt/parmap.hpp
@@ -1,7 +1,6 @@
 /* A thread pool (C++ version).                                             */
 
-/* Copyright (c) 2004-2017 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. */
@@ -11,43 +10,45 @@
 
 #include "src/internal_config.h" // HAVE_FUTEX_H
 #include "src/kernel/context/Context.hpp"
-#include <atomic>
+#include "src/simix/smx_private.hpp" /* simix_global */
+
 #include <boost/optional.hpp>
-#include <simgrid/simix.h>
-#include <vector>
-#include <xbt/log.h>
-#include <xbt/parmap.h>
-#include <xbt/xbt_os_thread.h>
+#include <condition_variable>
+#include <functional>
+#include <mutex>
+#include <thread>
 
 #if HAVE_FUTEX_H
-#include <limits>
 #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);
   Parmap(const Parmap&) = delete;
+  Parmap& operator=(const Parmap&) = delete;
   ~Parmap();
-  void apply(void (*fun)(T), const std::vector<T>& data);
+  void apply(std::function<void(T)>&& fun, const std::vector<T>& data);
   boost::optional<T> next();
 
 private:
-  enum Flag { PARMAP_WORK, PARMAP_DESTROY };
-
   /**
-   * \brief Thread data transmission structure
+   * @brief Thread data transmission structure
    */
   class ThreadData {
   public:
@@ -57,40 +58,39 @@ private:
   };
 
   /**
-   * \brief Synchronization object (different specializations).
+   * @brief Synchronization object (different specializations).
    */
   class Synchro {
   public:
     explicit Synchro(Parmap<T>& parmap) : parmap(parmap) {}
-    virtual ~Synchro() {}
+    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;
+    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;
+    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;
+    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;
 
-  protected:
     Parmap<T>& parmap;
   };
 
@@ -98,134 +98,139 @@ private:
   public:
     explicit PosixSynchro(Parmap<T>& parmap);
     ~PosixSynchro();
-    void master_signal();
-    void master_wait();
-    void worker_signal();
-    void worker_wait(unsigned round);
+    void master_signal() override;
+    void master_wait() override;
+    void worker_signal() override;
+    void worker_wait(unsigned round) override;
 
   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
   class FutexSynchro : public Synchro {
   public:
     explicit FutexSynchro(Parmap<T>& parmap) : Synchro(parmap) {}
-    void master_signal();
-    void master_wait();
-    void worker_signal();
-    void worker_wait(unsigned);
+    void master_signal() override;
+    void master_wait() override;
+    void worker_signal() override;
+    void worker_wait(unsigned) override;
 
   private:
-    static void futex_wait(unsigned* uaddr, unsigned val);
-    static void futex_wake(unsigned* uaddr, unsigned val);
+    static void futex_wait(std::atomic_uint* uaddr, unsigned val);
+    static void futex_wake(std::atomic_uint* uaddr, unsigned val);
   };
 #endif
 
   class BusyWaitSynchro : public Synchro {
   public:
     explicit BusyWaitSynchro(Parmap<T>& parmap) : Synchro(parmap) {}
-    void master_signal();
-    void master_wait();
-    void worker_signal();
-    void worker_wait(unsigned);
+    void master_signal() override;
+    void master_wait() override;
+    void worker_signal() override;
+    void worker_wait(unsigned) override;
   };
 
-  static void* worker_main(void* arg);
+  static void worker_main(ThreadData* data);
   Synchro* new_synchro(e_xbt_parmap_mode_t mode);
   void work();
 
-  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 */
+  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 */
 
-  unsigned thread_counter    = 0;       /**< number of workers that have done the work */
-  void (*fun)(const T)       = nullptr; /**< function to run in parallel on each element of data */
+  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<unsigned> index;          /**< index of the next element of data to pick */
+  std::atomic_uint index{0};            /**< index of the next element of data to pick */
 };
 
 /**
- * \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)
 {
   XBT_CDEBUG(xbt_parmap, "Create new parmap (%u workers)", num_workers);
 
   /* 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
+
   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, data);
+
+    /* 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)
-      core_bind++;
-    else
-      core_bind = 0;
+#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();
+    int core_bind     = (i - 1) % std::thread::hardware_concurrency();
+    CPU_ZERO(&cpuset);
+    CPU_SET(core_bind, &cpuset);
+    pthread_setaffinity_np(pthread, size, &cpuset);
 #endif
   }
 }
 
 /**
- * \brief Destroys a parmap
+ * @brief Destroys a parmap
  */
 template <typename T> Parmap<T>::~Parmap()
 {
-  status = PARMAP_DESTROY;
+  destroying = true;
   synchro->master_signal();
 
-  for (unsigned i = 1; i < num_workers; i++)
-    xbt_os_thread_join(workers[i], nullptr);
-
-  delete[] workers;
+  for (unsigned i = 1; i < num_workers; i++) {
+    workers[i]->join();
+    delete workers[i];
+  }
   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)
+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   = fun;
+  this->fun   = std::move(fun);
   this->data  = &data;
   this->index = 0;
-  this->synchro->master_signal(); // maestro runs futex_wait to wake all the minions (the working threads)
+  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
   XBT_CDEBUG(xbt_parmap, "Job done"); //   ... and proceeds
 }
 
 /**
- * \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()
 {
-  unsigned index = this->index++;
+  unsigned index = this->index.fetch_add(1, std::memory_order_relaxed);
   if (index < this->data->size())
     return (*this->data)[index];
   else
@@ -233,21 +238,21 @@ 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()
 {
-  unsigned index = this->index++;
   unsigned length = this->data->size();
+  unsigned index  = this->index.fetch_add(1, std::memory_order_relaxed);
   while (index < length) {
     this->fun((*this->data)[index]);
-    index = this->index++;
+    index = this->index.fetch_add(1, std::memory_order_relaxed);
   }
 }
 
 /**
  * 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)
 {
@@ -267,7 +272,7 @@ template <typename T> typename Parmap<T>::Synchro* Parmap<T>::new_synchro(e_xbt_
 #if HAVE_FUTEX_H
       res = new FutexSynchro(*this);
 #else
-      xbt_die("Fute is not available on this OS.");
+      xbt_die("Futex is not available on this OS.");
 #endif
       break;
     case XBT_PARMAP_BUSY_WAIT:
@@ -279,24 +284,21 @@ template <typename T> typename Parmap<T>::Synchro* Parmap<T>::new_synchro(e_xbt_
   return res;
 }
 
-/**
- * \brief Main function of a worker thread.
- */
-template <typename T> void* Parmap<T>::worker_main(void* arg)
+/** @brief Main function of a worker thread */
+template <typename T> void Parmap<T>::worker_main(ThreadData* data)
 {
-  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* context = simix_global->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) {
-    round++;
+    round++; // New scheduling round
     parmap.synchro->worker_wait(round);
-    if (parmap.status == PARMAP_DESTROY)
+    if (parmap.destroying)
       break;
 
     XBT_CDEBUG(xbt_parmap, "Worker %d got a job", data->worker_id);
@@ -307,74 +309,61 @@ template <typename T> void* Parmap<T>::worker_main(void* arg)
   /* We are destroying the parmap */
   delete context;
   delete data;
-  return nullptr;
 }
 
 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);
-  if (this->parmap.thread_counter < this->parmap.num_workers) {
+  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 */
-  if (this->parmap.work_round != round) {
-    xbt_os_cond_wait(ready_cond, ready_mutex);
+  while (this->parmap.work_round != round) {
+    ready_cond.wait(lk);
   }
-  xbt_os_mutex_release(ready_mutex);
 }
 
 #if HAVE_FUTEX_H
-template <typename T> inline void Parmap<T>::FutexSynchro::futex_wait(unsigned* uaddr, unsigned val)
+template <typename T> inline void Parmap<T>::FutexSynchro::futex_wait(std::atomic_uint* uaddr, unsigned val)
 {
   XBT_CVERB(xbt_parmap, "Waiting on futex %p", uaddr);
   syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, nullptr, nullptr, 0);
 }
 
-template <typename T> inline void Parmap<T>::FutexSynchro::futex_wake(unsigned* uaddr, unsigned val)
+template <typename T> inline void Parmap<T>::FutexSynchro::futex_wake(std::atomic_uint* uaddr, unsigned val)
 {
   XBT_CVERB(xbt_parmap, "Waking futex %p", uaddr);
   syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, nullptr, nullptr, 0);
@@ -382,25 +371,25 @@ template <typename T> inline void Parmap<T>::FutexSynchro::futex_wake(unsigned*
 
 template <typename T> void Parmap<T>::FutexSynchro::master_signal()
 {
-  this->parmap.thread_counter = 1;
-  __sync_add_and_fetch(&this->parmap.work_round, 1);
+  this->parmap.thread_counter.store(1);
+  this->parmap.work_round.fetch_add(1);
   /* wake all workers */
   futex_wake(&this->parmap.work_round, std::numeric_limits<int>::max());
 }
 
 template <typename T> void Parmap<T>::FutexSynchro::master_wait()
 {
-  unsigned count = this->parmap.thread_counter;
+  unsigned count = this->parmap.thread_counter.load();
   while (count < this->parmap.num_workers) {
     /* wait for all workers to be ready */
     futex_wait(&this->parmap.thread_counter, count);
-    count = this->parmap.thread_counter;
+    count = this->parmap.thread_counter.load();
   }
 }
 
 template <typename T> void Parmap<T>::FutexSynchro::worker_signal()
 {
-  unsigned count = __sync_add_and_fetch(&this->parmap.thread_counter, 1);
+  unsigned count = this->parmap.thread_counter.fetch_add(1) + 1;
   if (count == this->parmap.num_workers) {
     /* all workers have finished, wake the controller */
     futex_wake(&this->parmap.thread_counter, std::numeric_limits<int>::max());
@@ -409,42 +398,42 @@ template <typename T> void Parmap<T>::FutexSynchro::worker_signal()
 
 template <typename T> void Parmap<T>::FutexSynchro::worker_wait(unsigned round)
 {
-  unsigned work_round = this->parmap.work_round;
+  unsigned work_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;
+    work_round = this->parmap.work_round.load();
   }
 }
 #endif
 
 template <typename T> void Parmap<T>::BusyWaitSynchro::master_signal()
 {
-  this->parmap.thread_counter = 1;
-  __sync_add_and_fetch(&this->parmap.work_round, 1);
+  this->parmap.thread_counter.store(1);
+  this->parmap.work_round.fetch_add(1);
 }
 
 template <typename T> void Parmap<T>::BusyWaitSynchro::master_wait()
 {
-  while (this->parmap.thread_counter < this->parmap.num_workers) {
-    xbt_os_thread_yield();
+  while (this->parmap.thread_counter.load() < this->parmap.num_workers) {
+    std::this_thread::yield();
   }
 }
 
 template <typename T> void Parmap<T>::BusyWaitSynchro::worker_signal()
 {
-  __sync_add_and_fetch(&this->parmap.thread_counter, 1);
+  this->parmap.thread_counter.fetch_add(1);
 }
 
 template <typename T> void Parmap<T>::BusyWaitSynchro::worker_wait(unsigned round)
 {
   /* wait for more work */
-  while (this->parmap.work_round != round) {
-    xbt_os_thread_yield();
+  while (this->parmap.work_round.load() != round) {
+    std::this_thread::yield();
   }
 }
 
-/** \} */
+/** @} */
 }
 }