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author | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2013-01-18 01:52:42 +0000 |
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committer | patacongo <patacongo@42af7a65-404d-4744-a932-0658087f49c3> | 2013-01-18 01:52:42 +0000 |
commit | 76753ad9cb67133892000f19de10f93de78bb525 (patch) | |
tree | 1eae1d92a03b0a2cbd1e83b45704a24d8662cf17 /nuttx/sched/task_reparent.c | |
parent | 2f653578c632ec95e94f67306af24c7d82700d28 (diff) | |
download | px4-firmware-76753ad9cb67133892000f19de10f93de78bb525.tar.gz px4-firmware-76753ad9cb67133892000f19de10f93de78bb525.tar.bz2 px4-firmware-76753ad9cb67133892000f19de10f93de78bb525.zip |
Add internal API task_reparent(), used in posix_spawn(). Move libc/spawn/lib_ps.c to sched/task_posixspawn.c; Move libc/spawn/spawn.h to include/nuttx/spawn.h
git-svn-id: http://svn.code.sf.net/p/nuttx/code/trunk@5531 42af7a65-404d-4744-a932-0658087f49c3
Diffstat (limited to 'nuttx/sched/task_reparent.c')
-rw-r--r-- | nuttx/sched/task_reparent.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/nuttx/sched/task_reparent.c b/nuttx/sched/task_reparent.c new file mode 100644 index 000000000..9daa0743b --- /dev/null +++ b/nuttx/sched/task_reparent.c @@ -0,0 +1,145 @@ +/***************************************************************************** + * sched/task_reparent.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 <errno.h> + +#include "os_internal.h" + +#ifdef CONFIG_SCHED_HAVE_PARENT + +/***************************************************************************** + * Private Functions + *****************************************************************************/ + +/***************************************************************************** + * Public Functions + *****************************************************************************/ + +/***************************************************************************** + * Name: task_reparent + * + * Description: + * Change the parent of a task. + * + * Parameters: + * oldpid - PID of the old parent task (0 if this task) + * newpid - PID ot the new parent task (0 for the parent of this task) + * chpid - PID of the child to be reparented. + * + * Return Value: + * 0 (OK) on success; A negated errno value on failure. + * + *****************************************************************************/ + +int task_reparent(pid_t oldpid, pid_t newpid, pid_t chpid) +{ + _TCB *oldtcb; + _TCB *newtcb; + _TCB *chtcb; + irqstate_t flags; + int ret; + + /* If oldpid is zero, then we are parent task. */ + + if (oldpid == 0) + { + oldpid = getpid(); + } + + /* Get the current parent task's TCB */ + + oldtcb = sched_gettcb(oldpid); + if (!oldtcb) + { + return -ESRCH; + } + + /* Disable interrupts so that nothing can change from this point */ + + flags = irqsave(); + + /* If newpid is zero, then new is the parent of oldpid. */ + + if (newpid == 0) + { + newpid = oldtcb->parent; + } + + /* Get the new parent task's TCB */ + + newtcb = sched_gettcb(newpid); + if (!newtcb) + { + ret = -ESRCH; + goto errout_with_ints; + } + + /* Get the child tasks TCB */ + + chtcb = sched_gettcb(chpid); + if (!chtcb) + { + ret = -ECHILD; + goto errout_with_ints; + } + + /* Verify that oldpid is the parent of chpid */ + + if (chtcb->parent != oldpid) + { + ret = -ECHILD; + goto errout_with_ints; + } + + /* Okay, reparent the child */ + + DEBUGASSERT(oldtcb->nchildren > 0); + chtcb->parent = newpid; + oldtcb->nchildren--; + newtcb->nchildren++; + ret = OK; + +errout_with_ints: + irqrestore(flags); + return ret; +} + +#endif /* CONFIG_SCHED_HAVE_PARENT */ |