Forgot to add a file needed in the last commit

sched/group/group_waiter.c

+/****************************************************************************
+ * sched/group/group_waiter.c
+ *
+ *   Copyright (C) 2015 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 <sys/types.h>
+
+#include <assert.h>
+
+#include "nuttx/sched.h"
+#include "group/group.h"
+
+#if defined(CONFIG_SCHED_WAITPID) && !defined(CONFIG_SCHED_HAVE_PARENT)
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name:  group_addwaiter
+ *
+ * Description:
+ *   Increment the number of instances of waitpid that are waiting for this
+ *   group to exit.
+ *
+ * Assumptions:
+ *   Caller has assured mutually exclusive access to the group.
+ *
+ ****************************************************************************/
+
+void group_addwaiter(FAR struct task_group_s *group)
+{
+  group->tg_nwaiters++;
+  DEBUGASSERT(group->tg_nwaiters > 0);
+}
+
+/****************************************************************************
+ * Name:  group_addwaiter
+ *
+ * Description:
+ *   Decrement the number of instances of waitpid that are waiting for this
+ *   group to exit.  If the count goes to zero and deletion is pending, the
+ *   call group_free to release the dangling resources.
+ *
+ * Assumptions:
+ *   Caller has assured mutually exclusive access to the group.
+ *
+ ****************************************************************************/
+
+void group_delwaiter(FAR struct task_group_s *group)
+{
+  DEBUGASSERT(group->tg_nwaiters > 0);
+  group->tg_nwaiters--;
+  if (group->tg_nwaiters == 0 && (group->tg_flags & GROUP_FLAG_DELETED) != 0)
+    {
+      /* Release the group container (all other resources have already been
+       * freed).
+       */
+
+      sched_kfree(group);
+    }
+}
+
+#endif  /* CONFIG_SCHED_WAITPID && !CONFIG_SCHED_HAVE_PARENT */