1 files changed, 125 insertions, 0 deletions
diff --git a/nuttx/sched/group_find.c b/nuttx/sched/group_find.c
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+/*****************************************************************************
+ * sched/group_find.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Included Files
+ *****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sched.h>
+#include <assert.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/kmalloc.h>
+
+#include "group_internal.h"
+#include "env_internal.h"
+
+#ifdef HAVE_TASK_GROUP
+
+/*****************************************************************************
+ * Pre-processor Definitions
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Private Types
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Private Data
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Public Data
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Private Functions
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Public Functions
+ *****************************************************************************/
+
+/*****************************************************************************
+ * Name: group_find
+ *
+ * Description:
+ *   Given a group ID, find the group task structure with that ID.  IDs are
+ *   used instead of pointers to group structures.  This is done because a 
+ *   group can disappear at any time leaving a stale pointer; an ID is cleaner
+ *   because if the group disappears, this function will fail gracefully.
+ *
+ * Parameters:
+ *   gid - The group ID to find.
+ *
+ * Return Value:
+ *   On success, a pointer to the group task structure is returned.  This
+ *   function can fail only if there is no group that corresponds to the
+ *   groupd ID.
+ *
+ * Assumptions:
+ *   Called during when signally tasks in a safe context.  No special
+ *   precautions should be required here.  However, extra care is taken when
+ *   accessing the global g_grouphead list.
+ *
+ *****************************************************************************/
+
+#ifdef HAVE_GROUP_MEMBERS
+FAR struct task_group_s *group_find(gid_t gid)
+{
+  FAR struct task_group_s *group;
+  irqstate_t flags;
+
+  /* Find the status structure with the matching PID  */
+
+  flags = irqsave();
+  for (group = g_grouphead; group; group = group->flink)
+    {
+      if (group->tg_gid == gid)
+        {
+          irqrestore(flags);
+          return group;
+        }
+    }
+
+  irqrestore(flags);
+  return NULL;
+}
+#endif
+
+#endif /* HAVE_TASK_GROUP */