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Diffstat (limited to 'nuttx/sched/group_find.c')
-rw-r--r-- | nuttx/sched/group_find.c | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/nuttx/sched/group_find.c b/nuttx/sched/group_find.c new file mode 100644 index 000000000..eb3989223 --- /dev/null +++ b/nuttx/sched/group_find.c @@ -0,0 +1,125 @@ +/***************************************************************************** + * 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 */ |