X-Git-Url: https://oss.titaniummirror.com/gitweb?a=blobdiff_plain;f=libgomp%2Fteam.c;fp=libgomp%2Fteam.c;h=44ffd56095ffb425da26579a4696775db67a7e0a;hb=6fed43773c9b0ce596dca5686f37ac3fc0fa11c0;hp=0000000000000000000000000000000000000000;hpb=27b11d56b743098deb193d510b337ba22dc52e5c;p=msp430-gcc.git

diff --git a/libgomp/team.c b/libgomp/team.c
new file mode 100644
index 00000000..44ffd560
--- /dev/null
+++ b/libgomp/team.c
@@ -0,0 +1,555 @@
+/* Copyright (C) 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+   Contributed by Richard Henderson <rth@redhat.com>.
+
+   This file is part of the GNU OpenMP Library (libgomp).
+
+   Libgomp is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
+   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+   FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+   more details.
+
+   Under Section 7 of GPL version 3, you are granted additional
+   permissions described in the GCC Runtime Library Exception, version
+   3.1, as published by the Free Software Foundation.
+
+   You should have received a copy of the GNU General Public License and
+   a copy of the GCC Runtime Library Exception along with this program;
+   see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+/* This file handles the maintainence of threads in response to team
+   creation and termination.  */
+
+#include "libgomp.h"
+#include <stdlib.h>
+#include <string.h>
+
+/* This attribute contains PTHREAD_CREATE_DETACHED.  */
+pthread_attr_t gomp_thread_attr;
+
+/* This key is for the thread destructor.  */
+pthread_key_t gomp_thread_destructor;
+
+
+/* This is the libgomp per-thread data structure.  */
+#ifdef HAVE_TLS
+__thread struct gomp_thread gomp_tls_data;
+#else
+pthread_key_t gomp_tls_key;
+#endif
+
+
+/* This structure is used to communicate across pthread_create.  */
+
+struct gomp_thread_start_data
+{
+  void (*fn) (void *);
+  void *fn_data;
+  struct gomp_team_state ts;
+  struct gomp_task *task;
+  struct gomp_thread_pool *thread_pool;
+  bool nested;
+};
+
+
+/* This function is a pthread_create entry point.  This contains the idle
+   loop in which a thread waits to be called up to become part of a team.  */
+
+static void *
+gomp_thread_start (void *xdata)
+{
+  struct gomp_thread_start_data *data = xdata;
+  struct gomp_thread *thr;
+  struct gomp_thread_pool *pool;
+  void (*local_fn) (void *);
+  void *local_data;
+
+#ifdef HAVE_TLS
+  thr = &gomp_tls_data;
+#else
+  struct gomp_thread local_thr;
+  thr = &local_thr;
+  pthread_setspecific (gomp_tls_key, thr);
+#endif
+  gomp_sem_init (&thr->release, 0);
+
+  /* Extract what we need from data.  */
+  local_fn = data->fn;
+  local_data = data->fn_data;
+  thr->thread_pool = data->thread_pool;
+  thr->ts = data->ts;
+  thr->task = data->task;
+
+  thr->ts.team->ordered_release[thr->ts.team_id] = &thr->release;
+
+  /* Make thread pool local. */
+  pool = thr->thread_pool;
+
+  if (data->nested)
+    {
+      struct gomp_team *team = thr->ts.team;
+      struct gomp_task *task = thr->task;
+
+      gomp_barrier_wait (&team->barrier);
+
+      local_fn (local_data);
+      gomp_team_barrier_wait (&team->barrier);
+      gomp_finish_task (task);
+      gomp_barrier_wait_last (&team->barrier);
+    }
+  else
+    {
+      pool->threads[thr->ts.team_id] = thr;
+
+      gomp_barrier_wait (&pool->threads_dock);
+      do
+	{
+	  struct gomp_team *team = thr->ts.team;
+	  struct gomp_task *task = thr->task;
+
+	  local_fn (local_data);
+	  gomp_team_barrier_wait (&team->barrier);
+	  gomp_finish_task (task);
+
+	  gomp_barrier_wait (&pool->threads_dock);
+
+	  local_fn = thr->fn;
+	  local_data = thr->data;
+	  thr->fn = NULL;
+	}
+      while (local_fn);
+    }
+
+  gomp_sem_destroy (&thr->release);
+  return NULL;
+}
+
+
+/* Create a new team data structure.  */
+
+struct gomp_team *
+gomp_new_team (unsigned nthreads)
+{
+  struct gomp_team *team;
+  size_t size;
+  int i;
+
+  size = sizeof (*team) + nthreads * (sizeof (team->ordered_release[0])
+				      + sizeof (team->implicit_task[0]));
+  team = gomp_malloc (size);
+
+  team->work_share_chunk = 8;
+#ifdef HAVE_SYNC_BUILTINS
+  team->single_count = 0;
+#else
+  gomp_mutex_init (&team->work_share_list_free_lock);
+#endif
+  gomp_init_work_share (&team->work_shares[0], false, nthreads);
+  team->work_shares[0].next_alloc = NULL;
+  team->work_share_list_free = NULL;
+  team->work_share_list_alloc = &team->work_shares[1];
+  for (i = 1; i < 7; i++)
+    team->work_shares[i].next_free = &team->work_shares[i + 1];
+  team->work_shares[i].next_free = NULL;
+
+  team->nthreads = nthreads;
+  gomp_barrier_init (&team->barrier, nthreads);
+
+  gomp_sem_init (&team->master_release, 0);
+  team->ordered_release = (void *) &team->implicit_task[nthreads];
+  team->ordered_release[0] = &team->master_release;
+
+  gomp_mutex_init (&team->task_lock);
+  team->task_queue = NULL;
+  team->task_count = 0;
+  team->task_running_count = 0;
+
+  return team;
+}
+
+
+/* Free a team data structure.  */
+
+static void
+free_team (struct gomp_team *team)
+{
+  gomp_barrier_destroy (&team->barrier);
+  gomp_mutex_destroy (&team->task_lock);
+  free (team);
+}
+
+/* Allocate and initialize a thread pool. */
+
+static struct gomp_thread_pool *gomp_new_thread_pool (void)
+{
+  struct gomp_thread_pool *pool
+    = gomp_malloc (sizeof(struct gomp_thread_pool));
+  pool->threads = NULL;
+  pool->threads_size = 0;
+  pool->threads_used = 0;
+  pool->last_team = NULL;
+  return pool;
+}
+
+static void
+gomp_free_pool_helper (void *thread_pool)
+{
+  struct gomp_thread_pool *pool
+    = (struct gomp_thread_pool *) thread_pool;
+  gomp_barrier_wait_last (&pool->threads_dock);
+  gomp_sem_destroy (&gomp_thread ()->release);
+  pthread_exit (NULL);
+}
+
+/* Free a thread pool and release its threads. */
+
+static void
+gomp_free_thread (void *arg __attribute__((unused)))
+{
+  struct gomp_thread *thr = gomp_thread ();
+  struct gomp_thread_pool *pool = thr->thread_pool;
+  if (pool)
+    {
+      if (pool->threads_used > 0)
+	{
+	  int i;
+	  for (i = 1; i < pool->threads_used; i++)
+	    {
+	      struct gomp_thread *nthr = pool->threads[i];
+	      nthr->fn = gomp_free_pool_helper;
+	      nthr->data = pool;
+	    }
+	  /* This barrier undocks threads docked on pool->threads_dock.  */
+	  gomp_barrier_wait (&pool->threads_dock);
+	  /* And this waits till all threads have called gomp_barrier_wait_last
+	     in gomp_free_pool_helper.  */
+	  gomp_barrier_wait (&pool->threads_dock);
+	  /* Now it is safe to destroy the barrier and free the pool.  */
+	  gomp_barrier_destroy (&pool->threads_dock);
+	}
+      free (pool->threads);
+      if (pool->last_team)
+	free_team (pool->last_team);
+      free (pool);
+      thr->thread_pool = NULL;
+    }
+  if (thr->task != NULL)
+    {
+      struct gomp_task *task = thr->task;
+      gomp_end_task ();
+      free (task);
+    }
+}
+
+/* Launch a team.  */
+
+void
+gomp_team_start (void (*fn) (void *), void *data, unsigned nthreads,
+		 struct gomp_team *team)
+{
+  struct gomp_thread_start_data *start_data;
+  struct gomp_thread *thr, *nthr;
+  struct gomp_task *task;
+  struct gomp_task_icv *icv;
+  bool nested;
+  struct gomp_thread_pool *pool;
+  unsigned i, n, old_threads_used = 0;
+  pthread_attr_t thread_attr, *attr;
+
+  thr = gomp_thread ();
+  nested = thr->ts.team != NULL;
+  if (__builtin_expect (thr->thread_pool == NULL, 0))
+    {
+      thr->thread_pool = gomp_new_thread_pool ();
+      pthread_setspecific (gomp_thread_destructor, thr);
+    }
+  pool = thr->thread_pool;
+  task = thr->task;
+  icv = task ? &task->icv : &gomp_global_icv;
+
+  /* Always save the previous state, even if this isn't a nested team.
+     In particular, we should save any work share state from an outer
+     orphaned work share construct.  */
+  team->prev_ts = thr->ts;
+
+  thr->ts.team = team;
+  thr->ts.team_id = 0;
+  ++thr->ts.level;
+  if (nthreads > 1)
+    ++thr->ts.active_level;
+  thr->ts.work_share = &team->work_shares[0];
+  thr->ts.last_work_share = NULL;
+#ifdef HAVE_SYNC_BUILTINS
+  thr->ts.single_count = 0;
+#endif
+  thr->ts.static_trip = 0;
+  thr->task = &team->implicit_task[0];
+  gomp_init_task (thr->task, task, icv);
+
+  if (nthreads == 1)
+    return;
+
+  i = 1;
+
+  /* We only allow the reuse of idle threads for non-nested PARALLEL
+     regions.  This appears to be implied by the semantics of
+     threadprivate variables, but perhaps that's reading too much into
+     things.  Certainly it does prevent any locking problems, since
+     only the initial program thread will modify gomp_threads.  */
+  if (!nested)
+    {
+      old_threads_used = pool->threads_used;
+
+      if (nthreads <= old_threads_used)
+	n = nthreads;
+      else if (old_threads_used == 0)
+	{
+	  n = 0;
+	  gomp_barrier_init (&pool->threads_dock, nthreads);
+	}
+      else
+	{
+	  n = old_threads_used;
+
+	  /* Increase the barrier threshold to make sure all new
+	     threads arrive before the team is released.  */
+	  gomp_barrier_reinit (&pool->threads_dock, nthreads);
+	}
+
+      /* Not true yet, but soon will be.  We're going to release all
+	 threads from the dock, and those that aren't part of the
+	 team will exit.  */
+      pool->threads_used = nthreads;
+
+      /* Release existing idle threads.  */
+      for (; i < n; ++i)
+	{
+	  nthr = pool->threads[i];
+	  nthr->ts.team = team;
+	  nthr->ts.work_share = &team->work_shares[0];
+	  nthr->ts.last_work_share = NULL;
+	  nthr->ts.team_id = i;
+	  nthr->ts.level = team->prev_ts.level + 1;
+	  nthr->ts.active_level = thr->ts.active_level;
+#ifdef HAVE_SYNC_BUILTINS
+	  nthr->ts.single_count = 0;
+#endif
+	  nthr->ts.static_trip = 0;
+	  nthr->task = &team->implicit_task[i];
+	  gomp_init_task (nthr->task, task, icv);
+	  nthr->fn = fn;
+	  nthr->data = data;
+	  team->ordered_release[i] = &nthr->release;
+	}
+
+      if (i == nthreads)
+	goto do_release;
+
+      /* If necessary, expand the size of the gomp_threads array.  It is
+	 expected that changes in the number of threads are rare, thus we
+	 make no effort to expand gomp_threads_size geometrically.  */
+      if (nthreads >= pool->threads_size)
+	{
+	  pool->threads_size = nthreads + 1;
+	  pool->threads
+	    = gomp_realloc (pool->threads,
+			    pool->threads_size
+			    * sizeof (struct gomp_thread_data *));
+	}
+    }
+
+  if (__builtin_expect (nthreads > old_threads_used, 0))
+    {
+      long diff = (long) nthreads - (long) old_threads_used;
+
+      if (old_threads_used == 0)
+	--diff;
+
+#ifdef HAVE_SYNC_BUILTINS
+      __sync_fetch_and_add (&gomp_managed_threads, diff);
+#else
+      gomp_mutex_lock (&gomp_remaining_threads_lock);
+      gomp_managed_threads += diff;
+      gomp_mutex_unlock (&gomp_remaining_threads_lock);
+#endif
+    }
+
+  attr = &gomp_thread_attr;
+  if (__builtin_expect (gomp_cpu_affinity != NULL, 0))
+    {
+      size_t stacksize;
+      pthread_attr_init (&thread_attr);
+      pthread_attr_setdetachstate (&thread_attr, PTHREAD_CREATE_DETACHED);
+      if (! pthread_attr_getstacksize (&gomp_thread_attr, &stacksize))
+	pthread_attr_setstacksize (&thread_attr, stacksize);
+      attr = &thread_attr;
+    }
+
+  start_data = gomp_alloca (sizeof (struct gomp_thread_start_data)
+			    * (nthreads-i));
+
+  /* Launch new threads.  */
+  for (; i < nthreads; ++i, ++start_data)
+    {
+      pthread_t pt;
+      int err;
+
+      start_data->fn = fn;
+      start_data->fn_data = data;
+      start_data->ts.team = team;
+      start_data->ts.work_share = &team->work_shares[0];
+      start_data->ts.last_work_share = NULL;
+      start_data->ts.team_id = i;
+      start_data->ts.level = team->prev_ts.level + 1;
+      start_data->ts.active_level = thr->ts.active_level;
+#ifdef HAVE_SYNC_BUILTINS
+      start_data->ts.single_count = 0;
+#endif
+      start_data->ts.static_trip = 0;
+      start_data->task = &team->implicit_task[i];
+      gomp_init_task (start_data->task, task, icv);
+      start_data->thread_pool = pool;
+      start_data->nested = nested;
+
+      if (gomp_cpu_affinity != NULL)
+	gomp_init_thread_affinity (attr);
+
+      err = pthread_create (&pt, attr, gomp_thread_start, start_data);
+      if (err != 0)
+	gomp_fatal ("Thread creation failed: %s", strerror (err));
+    }
+
+  if (__builtin_expect (gomp_cpu_affinity != NULL, 0))
+    pthread_attr_destroy (&thread_attr);
+
+ do_release:
+  gomp_barrier_wait (nested ? &team->barrier : &pool->threads_dock);
+
+  /* Decrease the barrier threshold to match the number of threads
+     that should arrive back at the end of this team.  The extra
+     threads should be exiting.  Note that we arrange for this test
+     to never be true for nested teams.  */
+  if (__builtin_expect (nthreads < old_threads_used, 0))
+    {
+      long diff = (long) nthreads - (long) old_threads_used;
+
+      gomp_barrier_reinit (&pool->threads_dock, nthreads);
+
+#ifdef HAVE_SYNC_BUILTINS
+      __sync_fetch_and_add (&gomp_managed_threads, diff);
+#else
+      gomp_mutex_lock (&gomp_remaining_threads_lock);
+      gomp_managed_threads += diff;
+      gomp_mutex_unlock (&gomp_remaining_threads_lock);
+#endif
+    }
+}
+
+
+/* Terminate the current team.  This is only to be called by the master
+   thread.  We assume that we must wait for the other threads.  */
+
+void
+gomp_team_end (void)
+{
+  struct gomp_thread *thr = gomp_thread ();
+  struct gomp_team *team = thr->ts.team;
+
+  /* This barrier handles all pending explicit threads.  */
+  gomp_team_barrier_wait (&team->barrier);
+  gomp_fini_work_share (thr->ts.work_share);
+
+  gomp_end_task ();
+  thr->ts = team->prev_ts;
+
+  if (__builtin_expect (thr->ts.team != NULL, 0))
+    {
+#ifdef HAVE_SYNC_BUILTINS
+      __sync_fetch_and_add (&gomp_managed_threads, 1L - team->nthreads);
+#else
+      gomp_mutex_lock (&gomp_remaining_threads_lock);
+      gomp_managed_threads -= team->nthreads - 1L;
+      gomp_mutex_unlock (&gomp_remaining_threads_lock);
+#endif
+      /* This barrier has gomp_barrier_wait_last counterparts
+	 and ensures the team can be safely destroyed.  */
+      gomp_barrier_wait (&team->barrier);
+    }
+
+  if (__builtin_expect (team->work_shares[0].next_alloc != NULL, 0))
+    {
+      struct gomp_work_share *ws = team->work_shares[0].next_alloc;
+      do
+	{
+	  struct gomp_work_share *next_ws = ws->next_alloc;
+	  free (ws);
+	  ws = next_ws;
+	}
+      while (ws != NULL);
+    }
+  gomp_sem_destroy (&team->master_release);
+#ifndef HAVE_SYNC_BUILTINS
+  gomp_mutex_destroy (&team->work_share_list_free_lock);
+#endif
+
+  if (__builtin_expect (thr->ts.team != NULL, 0)
+      || __builtin_expect (team->nthreads == 1, 0))
+    free_team (team);
+  else
+    {
+      struct gomp_thread_pool *pool = thr->thread_pool;
+      if (pool->last_team)
+	free_team (pool->last_team);
+      pool->last_team = team;
+    }
+}
+
+
+/* Constructors for this file.  */
+
+static void __attribute__((constructor))
+initialize_team (void)
+{
+  struct gomp_thread *thr;
+
+#ifndef HAVE_TLS
+  static struct gomp_thread initial_thread_tls_data;
+
+  pthread_key_create (&gomp_tls_key, NULL);
+  pthread_setspecific (gomp_tls_key, &initial_thread_tls_data);
+#endif
+
+  if (pthread_key_create (&gomp_thread_destructor, gomp_free_thread) != 0)
+    gomp_fatal ("could not create thread pool destructor.");
+
+#ifdef HAVE_TLS
+  thr = &gomp_tls_data;
+#else
+  thr = &initial_thread_tls_data;
+#endif
+  gomp_sem_init (&thr->release, 0);
+}
+
+static void __attribute__((destructor))
+team_destructor (void)
+{
+  /* Without this dlclose on libgomp could lead to subsequent
+     crashes.  */
+  pthread_key_delete (gomp_thread_destructor);
+}
+
+struct gomp_task_icv *
+gomp_new_icv (void)
+{
+  struct gomp_thread *thr = gomp_thread ();
+  struct gomp_task *task = gomp_malloc (sizeof (struct gomp_task));
+  gomp_init_task (task, NULL, &gomp_global_icv);
+  thr->task = task;
+  pthread_setspecific (gomp_thread_destructor, thr);
+  return &task->icv;
+}