X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/97251bcf38f652d22db8a323d026209b52348a76..d18416a04b075e719e3860a11292b6ac98546949:/src/include/xbt/parmap.hpp

diff --git a/src/include/xbt/parmap.hpp b/src/include/xbt/parmap.hpp
index dd5037f7aa..f37540bbcb 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) 2004-2018 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. */
@@ -11,16 +10,14 @@
 
 #include "src/internal_config.h" // HAVE_FUTEX_H
 #include "src/kernel/context/Context.hpp"
-#include <atomic>
+#include "xbt/xbt_os_thread.h"
+
 #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 <mutex>
+#include <thread>
 
 #if HAVE_FUTEX_H
-#include <limits>
 #include <linux/futex.h>
 #include <sys/syscall.h>
 #endif
@@ -30,15 +27,16 @@ 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);
   boost::optional<T> next();
@@ -47,7 +45,7 @@ private:
   enum Flag { PARMAP_WORK, PARMAP_DESTROY };
 
   /**
-   * \brief Thread data transmission structure
+   * @brief Thread data transmission structure
    */
   class ThreadData {
   public:
@@ -57,40 +55,39 @@ 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;
 
-  protected:
     Parmap<T>& parmap;
   };
 
@@ -104,10 +101,10 @@ 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
@@ -151,9 +148,9 @@ 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)
 {
@@ -168,24 +165,20 @@ template <typename T> Parmap<T>::Parmap(unsigned num_workers, e_xbt_parmap_mode_
 
   /* Create the pool of worker threads */
   this->workers[0] = nullptr;
-#if HAVE_PTHREAD_SETAFFINITY
-  int core_bind = 0;
-#endif
+  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);
-#if HAVE_PTHREAD_SETAFFINITY
     xbt_os_thread_bind(this->workers[i], core_bind);
-    if (core_bind != xbt_os_get_numcores() - 1)
+    if (core_bind != std::thread::hardware_concurrency() - 1)
       core_bind++;
     else
       core_bind = 0;
-#endif
   }
 }
 
 /**
- * \brief Destroys a parmap
+ * @brief Destroys a parmap
  */
 template <typename T> Parmap<T>::~Parmap()
 {
@@ -200,9 +193,9 @@ template <typename T> Parmap<T>::~Parmap()
 }
 
 /**
- * \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)
 {
@@ -210,22 +203,22 @@ template <typename T> void Parmap<T>::apply(void (*fun)(T), const std::vector<T>
   this->fun   = 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 +226,21 @@ 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 +260,7 @@ 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:
@@ -280,7 +273,7 @@ template <typename T> typename Parmap<T>::Synchro* Parmap<T>::new_synchro(e_xbt_
 }
 
 /**
- * \brief Main function of a worker thread.
+ * @brief Main function of a worker thread.
  */
 template <typename T> void* Parmap<T>::worker_main(void* arg)
 {
@@ -312,59 +305,47 @@ 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);
-  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
@@ -382,25 +363,25 @@ 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);
+  __atomic_store_n(&this->parmap.thread_counter, 1, __ATOMIC_SEQ_CST);
+  __atomic_add_fetch(&this->parmap.work_round, 1, __ATOMIC_SEQ_CST);
   /* 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 = __atomic_load_n(&this->parmap.thread_counter, __ATOMIC_SEQ_CST);
   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 = __atomic_load_n(&this->parmap.thread_counter, __ATOMIC_SEQ_CST);
   }
 }
 
 template <typename T> void Parmap<T>::FutexSynchro::worker_signal()
 {
-  unsigned count = __sync_add_and_fetch(&this->parmap.thread_counter, 1);
+  unsigned count = __atomic_add_fetch(&this->parmap.thread_counter, 1, __ATOMIC_SEQ_CST);
   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 +390,42 @@ 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 = __atomic_load_n(&this->parmap.work_round, __ATOMIC_SEQ_CST);
   /* wait for more work */
   while (work_round != round) {
     futex_wait(&this->parmap.work_round, work_round);
-    work_round = this->parmap.work_round;
+    work_round = __atomic_load_n(&this->parmap.work_round, __ATOMIC_SEQ_CST);
   }
 }
 #endif
 
 template <typename T> void Parmap<T>::BusyWaitSynchro::master_signal()
 {
-  this->parmap.thread_counter = 1;
-  __sync_add_and_fetch(&this->parmap.work_round, 1);
+  __atomic_store_n(&this->parmap.thread_counter, 1, __ATOMIC_SEQ_CST);
+  __atomic_add_fetch(&this->parmap.work_round, 1, __ATOMIC_SEQ_CST);
 }
 
 template <typename T> void Parmap<T>::BusyWaitSynchro::master_wait()
 {
-  while (this->parmap.thread_counter < this->parmap.num_workers) {
-    xbt_os_thread_yield();
+  while (__atomic_load_n(&this->parmap.thread_counter, __ATOMIC_SEQ_CST) < 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);
+  __atomic_add_fetch(&this->parmap.thread_counter, 1, __ATOMIC_SEQ_CST);
 }
 
 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 (__atomic_load_n(&this->parmap.work_round, __ATOMIC_SEQ_CST) != round) {
+    std::this_thread::yield();
   }
 }
 
-/** \} */
+/** @} */
 }
 }