X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/666a812d1b3ee4568f2beb317dfcd08d99055697..3d96858a5d972ece808c8bb79a8add51f6235603:/src/include/xbt/parmap.hpp

diff --git a/src/include/xbt/parmap.hpp b/src/include/xbt/parmap.hpp
index 1bde553e5c..f2360eb4d3 100644
--- a/src/include/xbt/parmap.hpp
+++ b/src/include/xbt/parmap.hpp
@@ -1,6 +1,6 @@
 /* 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. */
@@ -13,22 +13,29 @@
 #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);
@@ -42,7 +49,7 @@ private:
   enum Flag { PARMAP_WORK, PARMAP_DESTROY };
 
   /**
-   * \brief Thread data transmission structure
+   * @brief Thread data transmission structure
    */
   class ThreadData {
   public:
@@ -52,36 +59,36 @@ private:
   };
 
   /**
-   * \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;
 
@@ -98,10 +105,10 @@ private:
     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
@@ -134,7 +141,7 @@ private:
 
   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 */
 
@@ -145,9 +152,9 @@ private:
 };
 
 /**
- * \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)
 {
@@ -156,21 +163,25 @@ template <typename T> Parmap<T>::Parmap(unsigned num_workers, e_xbt_parmap_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.reserve(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)
+    pthread_t pthread = this->workers[i]->native_handle();
+    cpu_set_t cpuset;
+    CPU_ZERO(&cpuset);
+    CPU_SET(core_bind, &cpuset);
+    pthread_setaffinity_np(pthread, sizeof(cpu_set_t), &cpuset);
+    if (core_bind != std::thread::hardware_concurrency() - 1)
       core_bind++;
     else
       core_bind = 0;
@@ -179,7 +190,7 @@ template <typename T> Parmap<T>::Parmap(unsigned num_workers, e_xbt_parmap_mode_
 }
 
 /**
- * \brief Destroys a parmap
+ * @brief Destroys a parmap
  */
 template <typename T> Parmap<T>::~Parmap()
 {
@@ -187,16 +198,16 @@ 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;
+  workers.clear();
   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)
 {
@@ -211,11 +222,11 @@ template <typename T> void Parmap<T>::apply(void (*fun)(T), const std::vector<T>
 }
 
 /**
- * \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()
 {
@@ -227,7 +238,7 @@ 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()
 {
@@ -241,7 +252,7 @@ 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)
 {
@@ -273,22 +284,20 @@ template <typename T> typename Parmap<T>::Synchro* Parmap<T>::new_synchro(e_xbt_
   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;
@@ -306,59 +315,47 @@ template <typename T> void* Parmap<T>::worker_main(void* arg)
 
 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
@@ -421,7 +418,7 @@ template <typename T> void Parmap<T>::BusyWaitSynchro::master_signal()
 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();
   }
 }
 
@@ -434,11 +431,11 @@ template <typename T> void Parmap<T>::BusyWaitSynchro::worker_wait(unsigned roun
 {
   /* wait for more work */
   while (__atomic_load_n(&this->parmap.work_round, __ATOMIC_SEQ_CST) != round) {
-    xbt_os_thread_yield();
+    std::this_thread::yield();
   }
 }
 
-/** \} */
+/** @} */
 }
 }