X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/8f3905e6e13d9511eb3002f9bdeb30e147e76056..9cc1089f9aa108b9b8b32cc42c7afca7c45dc593:/src/xbt/parmap.c

diff --git a/src/xbt/parmap.c b/src/xbt/parmap.c
index d9f5a9d5b1..90a0b8101f 100644
--- a/src/xbt/parmap.c
+++ b/src/xbt/parmap.c
@@ -3,7 +3,7 @@
 
 /* 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 "gras_config.h"
+#include "internal_config.h"
 #include <unistd.h>
 
 #ifndef _XBT_WIN32
@@ -12,6 +12,7 @@
 
 #ifdef HAVE_FUTEX_H
 #include <linux/futex.h>
+#include <limits.h>
 #endif
 
 #include "xbt/parmap.h"
@@ -20,59 +21,88 @@
 #include "xbt/dynar.h"
 #include "xbt/xbt_os_thread.h"
 #include "xbt/sysdep.h"
+#include "simix/smx_private.h"
 
 XBT_LOG_NEW_DEFAULT_SUBCATEGORY(xbt_parmap, xbt, "parmap: parallel map");
-XBT_LOG_NEW_SUBCATEGORY(xbt_parmap_unit, xbt_parmap, "parmap unit testing");
 
 typedef enum {
-  XBT_PARMAP_WORK = 0,
+  XBT_PARMAP_WORK,
   XBT_PARMAP_DESTROY
 } e_xbt_parmap_flag_t;
 
 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode);
 static void *xbt_parmap_worker_main(void *parmap);
+static void xbt_parmap_work(xbt_parmap_t parmap);
 
-static void xbt_parmap_posix_start(xbt_parmap_t parmap);
-static void xbt_parmap_posix_end(xbt_parmap_t parmap);
-static void xbt_parmap_posix_signal(xbt_parmap_t parmap);
-static void xbt_parmap_posix_wait(xbt_parmap_t parmap);
+static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap);
+static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap);
+static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap);
+static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round);
 
 #ifdef HAVE_FUTEX_H
-static void xbt_parmap_futex_start(xbt_parmap_t parmap);
-static void xbt_parmap_futex_end(xbt_parmap_t parmap);
-static void xbt_parmap_futex_signal(xbt_parmap_t parmap);
-static void xbt_parmap_futex_wait(xbt_parmap_t parmap);
-static void futex_wait(int *uaddr, int val);
-static void futex_wake(int *uaddr, int val);
+static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap);
+static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap);
+static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap);
+static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round);
+static void futex_wait(unsigned *uaddr, unsigned val);
+static void futex_wake(unsigned *uaddr, unsigned val);
 #endif
 
-static void xbt_parmap_busy_start(xbt_parmap_t parmap);
-static void xbt_parmap_busy_end(xbt_parmap_t parmap);
-static void xbt_parmap_busy_signal(xbt_parmap_t parmap);
-static void xbt_parmap_busy_wait(xbt_parmap_t parmap);
+static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap);
+static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap);
+static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap);
+static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round);
 
+#ifdef HAVE_MC
+static void xbt_parmap_mc_work(xbt_parmap_t parmap, int worker_id);
+static void *xbt_parmap_mc_worker_main(void *arg);
+#endif
 
 /**
  * \brief Parallel map structure
  */
 typedef struct s_xbt_parmap {
   e_xbt_parmap_flag_t status;      /**< is the parmap active or being destroyed? */
-  int work;                        /**< index of the current round (1 is the first) */
-  int done;                        /**< number of rounds already done (futexes only) */
-  unsigned int thread_counter;     /**< number of threads currently working */
+  unsigned work;                   /**< index of the current round */
+  unsigned thread_counter;         /**< number of workers that have done the work */
+
   unsigned int num_workers;        /**< total number of worker threads including the controller */
   void_f_pvoid_t fun;              /**< function to run in parallel on each element of data */
   xbt_dynar_t data;                /**< parameters to pass to fun in parallel */
   unsigned int index;              /**< index of the next element of data to pick */
 
+#ifdef HAVE_MC
+  int finish;
+  void* ref_snapshot;
+  int_f_pvoid_pvoid_t snapshot_compare;
+  unsigned int length;
+  void* mc_data;
+#endif
+
+  /* posix only */
+  xbt_os_cond_t ready_cond;
+  xbt_os_mutex_t ready_mutex;
+  xbt_os_cond_t done_cond;
+  xbt_os_mutex_t done_mutex;
+
   /* fields that depend on the synchronization mode */
   e_xbt_parmap_mode_t mode;        /**< synchronization mode */
-  void (*start_f)(xbt_parmap_t);   /**< initializes the worker threads */
-  void (*end_f)(xbt_parmap_t);     /**< finalizes the worker threads */
-  void (*signal_f)(xbt_parmap_t);  /**< wakes the workers threads to process tasks */
-  void (*wait_f)(xbt_parmap_t);    /**< waits for more work */
+  void (*master_wait_f)(xbt_parmap_t);    /**< wait for the workers to have done the work */
+  void (*worker_signal_f)(xbt_parmap_t);  /**< signal the master that a worker has done the work */
+  void (*master_signal_f)(xbt_parmap_t);  /**< wakes the workers threads to process tasks */
+  void (*worker_wait_f)(xbt_parmap_t, unsigned); /**< waits for more work */
 } s_xbt_parmap_t;
 
+/**
+ * \brief Thread data transmission structure
+ */
+typedef struct s_xbt_parmap_thread_data{
+  xbt_parmap_t parmap;
+  int worker_id;
+} s_xbt_parmap_thread_data_t;
+
+typedef s_xbt_parmap_thread_data_t *xbt_parmap_thread_data_t;
+
 /**
  * \brief Creates a parallel map object
  * \param num_workers number of worker threads to create
@@ -94,13 +124,50 @@ xbt_parmap_t xbt_parmap_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
   xbt_parmap_set_mode(parmap, mode);
 
   /* Create the pool of worker threads */
-  for (i = 0; i < num_workers - 1; i++) {
-    worker = xbt_os_thread_create(NULL, xbt_parmap_worker_main, parmap, NULL);
+  xbt_parmap_thread_data_t data;
+  for (i = 1; i < num_workers; i++) {
+    data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
+    data->parmap = parmap;
+    data->worker_id = i;
+    worker = xbt_os_thread_create(NULL, xbt_parmap_worker_main, data, NULL);
+    xbt_os_thread_detach(worker);
+  }
+  return parmap;
+}
+
+#ifdef HAVE_MC
+/**
+ * \brief Creates a parallel map object
+ * \param num_workers number of worker threads to create
+ * \param mode how to synchronize the worker threads
+ * \return the parmap created
+ */
+xbt_parmap_t xbt_parmap_mc_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
+{
+  unsigned int i;
+  xbt_os_thread_t worker = NULL;
+
+  XBT_DEBUG("Create new parmap (%u workers)", num_workers);
+
+  /* Initialize the thread pool data structure */
+  xbt_parmap_t parmap = xbt_new0(s_xbt_parmap_t, 1);
+
+  parmap->num_workers = num_workers;
+  parmap->status = XBT_PARMAP_WORK;
+  xbt_parmap_set_mode(parmap, mode);
+
+  /* Create the pool of worker threads */
+  xbt_parmap_thread_data_t data;
+  for (i = 1; i < num_workers; i++) {
+    data = xbt_new0(s_xbt_parmap_thread_data_t, 1);
+    data->parmap = parmap;
+    data->worker_id = i;
+    worker = xbt_os_thread_create(NULL, xbt_parmap_mc_worker_main, data, NULL);
     xbt_os_thread_detach(worker);
   }
-  parmap->start_f(parmap);
   return parmap;
 }
+#endif
 
 /**
  * \brief Destroys a parmap
@@ -108,8 +175,19 @@ xbt_parmap_t xbt_parmap_new(unsigned int num_workers, e_xbt_parmap_mode_t mode)
  */
 void xbt_parmap_destroy(xbt_parmap_t parmap)
 {
+  if (!parmap) {
+    return;
+  }
+
   parmap->status = XBT_PARMAP_DESTROY;
-  parmap->signal_f(parmap);
+  parmap->master_signal_f(parmap);
+  parmap->master_wait_f(parmap);
+
+  xbt_os_cond_destroy(parmap->ready_cond);
+  xbt_os_mutex_destroy(parmap->ready_mutex);
+  xbt_os_cond_destroy(parmap->done_cond);
+  xbt_os_mutex_destroy(parmap->done_mutex);
+
   xbt_free(parmap);
 }
 
@@ -120,29 +198,60 @@ void xbt_parmap_destroy(xbt_parmap_t parmap)
  */
 static void xbt_parmap_set_mode(xbt_parmap_t parmap, e_xbt_parmap_mode_t mode)
 {
+  if (mode == XBT_PARMAP_DEFAULT) {
+#ifdef HAVE_FUTEX_H
+    mode = XBT_PARMAP_FUTEX;
+#else
+    mode = XBT_PARMAP_POSIX;
+#endif
+  }
   parmap->mode = mode;
 
   switch (mode) {
 
     case XBT_PARMAP_POSIX:
-      parmap->start_f = xbt_parmap_posix_start;
-      parmap->end_f = xbt_parmap_posix_end;
-      parmap->signal_f = xbt_parmap_posix_signal;
-      parmap->wait_f = xbt_parmap_posix_wait;
+      parmap->master_wait_f = xbt_parmap_posix_master_wait;
+      parmap->worker_signal_f = xbt_parmap_posix_worker_signal;
+      parmap->master_signal_f = xbt_parmap_posix_master_signal;
+      parmap->worker_wait_f = xbt_parmap_posix_worker_wait;
+
+      parmap->ready_cond = xbt_os_cond_init();
+      parmap->ready_mutex = xbt_os_mutex_init();
+      parmap->done_cond = xbt_os_cond_init();
+      parmap->done_mutex = xbt_os_mutex_init();
       break;
 
+
     case XBT_PARMAP_FUTEX:
-      parmap->start_f = xbt_parmap_futex_start;
-      parmap->end_f = xbt_parmap_futex_end;
-      parmap->signal_f = xbt_parmap_futex_signal;
-      parmap->wait_f = xbt_parmap_futex_wait;
+#ifdef HAVE_FUTEX_H
+      parmap->master_wait_f = xbt_parmap_futex_master_wait;
+      parmap->worker_signal_f = xbt_parmap_futex_worker_signal;
+      parmap->master_signal_f = xbt_parmap_futex_master_signal;
+      parmap->worker_wait_f = xbt_parmap_futex_worker_wait;
+
+      xbt_os_cond_destroy(parmap->ready_cond);
+      xbt_os_mutex_destroy(parmap->ready_mutex);
+      xbt_os_cond_destroy(parmap->done_cond);
+      xbt_os_mutex_destroy(parmap->done_mutex);
       break;
+#else
+      xbt_die("Futex is not available on this OS.");
+#endif
 
     case XBT_PARMAP_BUSY_WAIT:
-      parmap->start_f = xbt_parmap_busy_start;
-      parmap->end_f = xbt_parmap_busy_end;
-      parmap->signal_f = xbt_parmap_busy_signal;
-      parmap->wait_f = xbt_parmap_busy_wait;
+      parmap->master_wait_f = xbt_parmap_busy_master_wait;
+      parmap->worker_signal_f = xbt_parmap_busy_worker_signal;
+      parmap->master_signal_f = xbt_parmap_busy_master_signal;
+      parmap->worker_wait_f = xbt_parmap_busy_worker_wait;
+
+      xbt_os_cond_destroy(parmap->ready_cond);
+      xbt_os_mutex_destroy(parmap->ready_mutex);
+      xbt_os_cond_destroy(parmap->done_cond);
+      xbt_os_mutex_destroy(parmap->done_mutex);
+      break;
+
+    case XBT_PARMAP_DEFAULT:
+      THROW_IMPOSSIBLE;
       break;
   }
 }
@@ -159,7 +268,9 @@ void xbt_parmap_apply(xbt_parmap_t parmap, void_f_pvoid_t fun, xbt_dynar_t data)
   parmap->fun = fun;
   parmap->data = data;
   parmap->index = 0;
-  parmap->signal_f(parmap);
+  parmap->master_signal_f(parmap);
+  xbt_parmap_work(parmap);
+  parmap->master_wait_f(parmap);
   XBT_DEBUG("Job done");
 }
 
@@ -179,72 +290,215 @@ void* xbt_parmap_next(xbt_parmap_t parmap)
   return NULL;
 }
 
+static void xbt_parmap_work(xbt_parmap_t parmap)
+{
+  unsigned index;
+  while ((index = __sync_fetch_and_add(&parmap->index, 1))
+         < xbt_dynar_length(parmap->data))
+    parmap->fun(xbt_dynar_get_as(parmap->data, index, void*));
+}
+
 /**
  * \brief Main function of a worker thread.
  * \param arg the parmap
  */
 static void *xbt_parmap_worker_main(void *arg)
 {
-  xbt_parmap_t parmap = (xbt_parmap_t) arg;
+  xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
+  xbt_parmap_t parmap = data->parmap;
+  unsigned round = 0;
+  smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL);
+  SIMIX_context_set_current(context);
 
   XBT_DEBUG("New worker thread created");
 
   /* Worker's main loop */
   while (1) {
-    parmap->wait_f(parmap);
+    parmap->worker_wait_f(parmap, ++round);
     if (parmap->status == XBT_PARMAP_WORK) {
 
-      XBT_DEBUG("Worker got a job");
+      XBT_DEBUG("Worker %d got a job", data->worker_id);
 
-      void* work = xbt_parmap_next(parmap);
-      while (work != NULL) {
-        parmap->fun(work);
-        work = xbt_parmap_next(parmap);
-      }
+      xbt_parmap_work(parmap);
+      parmap->worker_signal_f(parmap);
 
-      XBT_DEBUG("Worker has finished");
+      XBT_DEBUG("Worker %d has finished", data->worker_id);
 
     /* We are destroying the parmap */
     } else {
-      parmap->end_f(parmap);
-      XBT_DEBUG("Shutting down worker");
+      xbt_free(data);
+      parmap->worker_signal_f(parmap);
       return NULL;
     }
   }
 }
 
+#ifdef HAVE_MC
+
+/**
+ * \brief Applies a list of tasks in parallel.
+ * \param parmap a parallel map object
+ * \param fun the function to call in parallel
+ * \param data each element of this dynar will be passed as an argument to fun
+ */
+int xbt_parmap_mc_apply(xbt_parmap_t parmap, int_f_pvoid_pvoid_t fun, 
+                         void* data, unsigned int length,  void* ref_snapshot)
+{
+  /* Assign resources to worker threads */
+  parmap->snapshot_compare = fun;
+  parmap->mc_data = data;
+  parmap->index = 0;
+  parmap->finish = -1;
+  parmap->length = length;
+  parmap->ref_snapshot = ref_snapshot;
+  parmap->master_signal_f(parmap);
+  xbt_parmap_mc_work(parmap, 0);
+  parmap->master_wait_f(parmap);
+  XBT_DEBUG("Job done");
+  return parmap->finish;
+}
+
+static void xbt_parmap_mc_work(xbt_parmap_t parmap, int worker_id)
+{
+  unsigned int data_size = (parmap->length / parmap->num_workers) +
+    ((parmap->length % parmap->num_workers) ? 1 :0);
+  void* start = (char*)parmap->mc_data + (data_size*worker_id*sizeof(void*));
+  void* end = MIN((char *)start + data_size* sizeof(void*), (char*)parmap->mc_data + parmap->length*sizeof(void*));
+  
+  //XBT_CRITICAL("Worker %d : %p -> %p (%d)", worker_id, start, end, data_size);
+
+  while ( start < end && parmap->finish == -1) {
+    //XBT_CRITICAL("Starting with %p", start);
+    int res = parmap->snapshot_compare(*(void**)start, parmap->ref_snapshot);
+    start = (char *)start + sizeof(start);
+    if (!res){
+    
+      parmap->finish = ((char*)start - (char*)parmap->mc_data) / sizeof(void*);
+      //XBT_CRITICAL("Find good one %p (%p)", start, parmap->mc_data);
+      break;
+    }
+  }
+}
+
+/**
+ * \brief Main function of a worker thread.
+ * \param arg the parmap
+ */
+static void *xbt_parmap_mc_worker_main(void *arg)
+{
+  xbt_parmap_thread_data_t data = (xbt_parmap_thread_data_t) arg;
+  xbt_parmap_t parmap = data->parmap;
+  unsigned round = 0;
+  /* smx_context_t context = SIMIX_context_new(NULL, 0, NULL, NULL, NULL); */
+  /* SIMIX_context_set_current(context); */
+
+  XBT_DEBUG("New worker thread created");
+
+  /* Worker's main loop */
+  while (1) {
+    parmap->worker_wait_f(parmap, ++round);
+    if (parmap->status == XBT_PARMAP_WORK) {
+
+      XBT_DEBUG("Worker %d got a job", data->worker_id);
+
+      xbt_parmap_mc_work(parmap, data->worker_id);
+      parmap->worker_signal_f(parmap);
+
+      XBT_DEBUG("Worker %d has finished", data->worker_id);
+
+    /* We are destroying the parmap */
+    } else {
+      xbt_free(data);
+      parmap->worker_signal_f(parmap);
+      return NULL;
+    }
+  }
+}
+#endif
+
 #ifdef HAVE_FUTEX_H
-static void futex_wait(int *uaddr, int val)
+static void futex_wait(unsigned *uaddr, unsigned val)
 {
   XBT_VERB("Waiting on futex %p", uaddr);
   syscall(SYS_futex, uaddr, FUTEX_WAIT_PRIVATE, val, NULL, NULL, 0);
 }
 
-static void futex_wake(int *uaddr, int val)
+static void futex_wake(unsigned *uaddr, unsigned val)
 {
   XBT_VERB("Waking futex %p", uaddr);
   syscall(SYS_futex, uaddr, FUTEX_WAKE_PRIVATE, val, NULL, NULL, 0);
 }
 #endif
 
-static void xbt_parmap_posix_start(xbt_parmap_t parmap)
+/**
+ * \brief Starts the parmap: waits for all workers to be ready and returns.
+ *
+ * This function is called by the controller thread.
+ *
+ * \param parmap a parmap
+ */
+static void xbt_parmap_posix_master_wait(xbt_parmap_t parmap)
 {
-  THROW_UNIMPLEMENTED;
+  xbt_os_mutex_acquire(parmap->done_mutex);
+  if (parmap->thread_counter < parmap->num_workers) {
+    /* wait for all workers to be ready */
+    xbt_os_cond_wait(parmap->done_cond, parmap->done_mutex);
+  }
+  xbt_os_mutex_release(parmap->done_mutex);
 }
 
-static void xbt_parmap_posix_end(xbt_parmap_t parmap)
+/**
+ * \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).
+ *
+ * \param parmap a parmap
+ */
+static void xbt_parmap_posix_worker_signal(xbt_parmap_t parmap)
 {
-  THROW_UNIMPLEMENTED;
+  xbt_os_mutex_acquire(parmap->done_mutex);
+  if (++parmap->thread_counter == parmap->num_workers) {
+    /* all workers have finished, wake the controller */
+    xbt_os_cond_signal(parmap->done_cond);
+  }
+  xbt_os_mutex_release(parmap->done_mutex);
 }
 
-static void xbt_parmap_posix_signal(xbt_parmap_t parmap)
+/**
+ * \brief Wakes all workers and waits for them to finish the tasks.
+ *
+ * This function is called by the controller thread.
+ *
+ * \param parmap a parmap
+ */
+static void xbt_parmap_posix_master_signal(xbt_parmap_t parmap)
 {
-  THROW_UNIMPLEMENTED;
+  xbt_os_mutex_acquire(parmap->ready_mutex);
+  parmap->thread_counter = 1;
+  parmap->work++;
+  /* wake all workers */
+  xbt_os_cond_broadcast(parmap->ready_cond);
+  xbt_os_mutex_release(parmap->ready_mutex);
 }
 
-static void xbt_parmap_posix_wait(xbt_parmap_t parmap)
+/**
+ * \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 parmap a parmap
+ * \param round  the expected round number
+ */
+static void xbt_parmap_posix_worker_wait(xbt_parmap_t parmap, unsigned round)
 {
-  THROW_UNIMPLEMENTED;
+  xbt_os_mutex_acquire(parmap->ready_mutex);
+  /* wait for more work */
+  if (parmap->work != round) {
+    xbt_os_cond_wait(parmap->ready_cond, parmap->ready_mutex);
+  }
+  xbt_os_mutex_release(parmap->ready_mutex);
 }
 
 #ifdef HAVE_FUTEX_H
@@ -255,13 +509,13 @@ static void xbt_parmap_posix_wait(xbt_parmap_t parmap)
  *
  * \param parmap a parmap
  */
-static void xbt_parmap_futex_start(xbt_parmap_t parmap)
+static void xbt_parmap_futex_master_wait(xbt_parmap_t parmap)
 {
-  int myflag = parmap->done;
-  __sync_fetch_and_add(&parmap->thread_counter, 1);
-  if (parmap->thread_counter < parmap->num_workers) {
+  unsigned count = parmap->thread_counter;
+  while (count < parmap->num_workers) {
     /* wait for all workers to be ready */
-    futex_wait(&parmap->done, myflag);
+    futex_wait(&parmap->thread_counter, count);
+    count = parmap->thread_counter;
   }
 }
 
@@ -273,15 +527,12 @@ static void xbt_parmap_futex_start(xbt_parmap_t parmap)
  *
  * \param parmap a parmap
  */
-static void xbt_parmap_futex_end(xbt_parmap_t parmap)
+static void xbt_parmap_futex_worker_signal(xbt_parmap_t parmap)
 {
-  unsigned int mycount;
-
-  mycount = __sync_add_and_fetch(&parmap->thread_counter, 1);
-  if (mycount == parmap->num_workers) {
+  unsigned count = __sync_add_and_fetch(&parmap->thread_counter, 1);
+  if (count == parmap->num_workers) {
     /* all workers have finished, wake the controller */
-    parmap->done++;
-    futex_wake(&parmap->done, 1);
+    futex_wake(&parmap->thread_counter, INT_MAX);
   }
 }
 
@@ -292,29 +543,12 @@ static void xbt_parmap_futex_end(xbt_parmap_t parmap)
  *
  * \param parmap a parmap
  */
-static void xbt_parmap_futex_signal(xbt_parmap_t parmap)
+static void xbt_parmap_futex_master_signal(xbt_parmap_t parmap)
 {
-  int myflag = parmap->done;
-  parmap->thread_counter = 0;
-  parmap->work++;
-
+  parmap->thread_counter = 1;
+  __sync_add_and_fetch(&parmap->work, 1);
   /* wake all workers */
-  futex_wake(&parmap->work, parmap->num_workers);
-
-  if (parmap->status == XBT_PARMAP_WORK) {
-    /* also work myself */
-    void* work = xbt_parmap_next(parmap);
-    while (work != NULL) {
-      parmap->fun(work);
-      work = xbt_parmap_next(parmap);
-    }
-  }
-
-  unsigned int mycount = __sync_add_and_fetch(&parmap->thread_counter, 1);
-  if (mycount < parmap->num_workers) {
-    /* some workers have not finished yet */
-    futex_wait(&parmap->done, myflag);
-  }
+  futex_wake(&parmap->work, INT_MAX);
 }
 
 /**
@@ -324,22 +558,16 @@ static void xbt_parmap_futex_signal(xbt_parmap_t parmap)
  * when it has no more work to do.
  *
  * \param parmap a parmap
+ * \param round  the expected round number
  */
-static void xbt_parmap_futex_wait(xbt_parmap_t parmap)
+static void xbt_parmap_futex_worker_wait(xbt_parmap_t parmap, unsigned round)
 {
-  int myflag;
-  unsigned int mycount;
-
-  myflag = parmap->work;
-  mycount = __sync_add_and_fetch(&parmap->thread_counter, 1);
-  if (mycount == parmap->num_workers) {
-    /* all workers have finished, wake the controller */
-    parmap->done++;
-    futex_wake(&parmap->done, 1);
-  }
-
+  unsigned work = parmap->work;
   /* wait for more work */
-  futex_wait(&parmap->work, myflag);
+  while (work != round) {
+    futex_wait(&parmap->work, work);
+    work = parmap->work;
+  }
 }
 #endif
 
@@ -350,9 +578,8 @@ static void xbt_parmap_futex_wait(xbt_parmap_t parmap)
  *
  * \param parmap a parmap
  */
-static void xbt_parmap_busy_start(xbt_parmap_t parmap)
+static void xbt_parmap_busy_master_wait(xbt_parmap_t parmap)
 {
-  __sync_fetch_and_add(&parmap->thread_counter, 1);
   while (parmap->thread_counter < parmap->num_workers) {
     xbt_os_thread_yield();
   }
@@ -365,7 +592,7 @@ static void xbt_parmap_busy_start(xbt_parmap_t parmap)
  *
  * \param parmap a parmap
  */
-static void xbt_parmap_busy_end(xbt_parmap_t parmap)
+static void xbt_parmap_busy_worker_signal(xbt_parmap_t parmap)
 {
   __sync_add_and_fetch(&parmap->thread_counter, 1);
 }
@@ -377,25 +604,10 @@ static void xbt_parmap_busy_end(xbt_parmap_t parmap)
  *
  * \param parmap a parmap
  */
-static void xbt_parmap_busy_signal(xbt_parmap_t parmap)
+static void xbt_parmap_busy_master_signal(xbt_parmap_t parmap)
 {
-  parmap->thread_counter = 0;
-  parmap->work++;
-
-  if (parmap->status == XBT_PARMAP_WORK) {
-    /* also work myself */
-    void* work = xbt_parmap_next(parmap);
-    while (work != NULL) {
-      parmap->fun(work);
-      work = xbt_parmap_next(parmap);
-    }
-  }
-
-  /* I have finished, wait for the others */
-  __sync_add_and_fetch(&parmap->thread_counter, 1);
-  while (parmap->thread_counter < parmap->num_workers) {
-    xbt_os_thread_yield();
-  }
+  parmap->thread_counter = 1;
+  __sync_add_and_fetch(&parmap->work, 1);
 }
 
 /**
@@ -405,55 +617,12 @@ static void xbt_parmap_busy_signal(xbt_parmap_t parmap)
  * when it has no more work to do.
  *
  * \param parmap a parmap
+ * \param round  the expected round number
  */
-static void xbt_parmap_busy_wait(xbt_parmap_t parmap)
+static void xbt_parmap_busy_worker_wait(xbt_parmap_t parmap, unsigned round)
 {
-  int work = parmap->work;
-  __sync_add_and_fetch(&parmap->thread_counter, 1);
-
   /* wait for more work */
-  while (parmap->work == work) {
+  while (parmap->work != round) {
     xbt_os_thread_yield();
   }
 }
-
-#ifdef SIMGRID_TEST
-#include "xbt.h"
-#include "xbt/ex.h"
-
-XBT_TEST_SUITE("parmap", "Parallel Map");
-XBT_LOG_EXTERNAL_DEFAULT_CATEGORY(xbt_parmap_unit);
-
-xbt_parmap_t parmap;
-
-void fun(void *arg);
-
-void fun(void *arg)
-{
-  //XBT_INFO("I'm job %lu", (unsigned long)arg);
-}
-
-XBT_TEST_UNIT("basic", test_parmap_basic, "Basic usage")
-{
-  xbt_test_add("Create the parmap");
-
-  unsigned long i, j;
-  xbt_dynar_t data = xbt_dynar_new(sizeof(void *), NULL);
-
-  /* Create the parallel map */
-  parmap = xbt_parmap_new(10);
-
-  for (j = 0; j < 100; j++) {
-    xbt_dynar_push_as(data, void *, (void *)j);
-  }
-
-  for (i = 0; i < 5; i++) {
-    xbt_parmap_apply(parmap, fun, data);
-  }
-
-  /* Destroy the parmap */
-  xbt_parmap_destroy(parmap);
-  xbt_dynar_free(&data);
-}
-
-#endif /* SIMGRID_TEST */