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: svn://svn.code.sf.net/p/nuttx/code/trunk@5531 42af7a65-404d-4744-a932-0658087f49c3

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 */