sergiotarxz/nuttx
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

waitpid(): Corrects two problems when CONFIG_SCHED_HAVE_PARENT+CONFIG_SCHED_CHILD_STATUS are enabled: (1) Was erroring out if the waited for task had already exited, and (2) was not freeing resources when a wait was completed.

Browse Source
This commit is contained in:
Boris Astardzhiev 2017-09-04 17:10:37 -06:00 committed by Gregory Nutt
parent 7fe3625382
commit 087a0cf2c7
1 changed files with 27 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

37
sched/sched/sched_waitpid.c
View File

@ -1,7 +1,7 @@
/****************************************************************************
* sched/sched/sched_waitpid.c
*
* Copyright (C) 2011-2013, 2015 Gregory Nutt. All rights reserved.
* Copyright (C) 2011-2013, 2015, 2017 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
@ -355,27 +355,33 @@ pid_t waitpid(pid_t pid, int *stat_loc, int options)
}
else if (pid != (pid_t)-1)
{
/* Get the TCB corresponding to this PID and make sure that the
* thread it is our child.
/* Get the TCB corresponding to this PID. NOTE: If the child has
* already exited, then the PID will not map to a valid TCB.
*/
ctcb = sched_gettcb(pid);
if (ctcb != NULL)
{
/* Make sure that the thread it is our child. */
#ifdef HAVE_GROUP_MEMBERS
if (ctcb == NULL || ctcb->group->tg_pgid != rtcb->group->tg_gid)
if (ctcb->group->tg_pgid != rtcb->group->tg_gid)
#else
if (ctcb == NULL || ctcb->group->tg_ppid != rtcb->pid)
if (ctcb->group->tg_ppid != rtcb->pid)
#endif
{
errcode = ECHILD;
goto errout_with_errno;
{
errcode = ECHILD;
goto errout_with_errno;
}
}
/* Does this task retain child status? */
/* The child task is ours or it is no longer active. Does the parent
* task retain child status?
*/
if (retains)
{
/* Check if this specific pid has allocated child status? */
/* Yes.. Check if this specific pid has allocated child status? */
if (group_findchild(rtcb->group, pid) == NULL)
{
@ -537,6 +543,17 @@ pid_t waitpid(pid_t pid, int *stat_loc, int options)
*stat_loc = info.si_status << 8;
pid = info.si_pid;
#ifdef CONFIG_SCHED_CHILD_STATUS
if (retains)
{
/* Discard the child entry */
(void)group_removechild(rtcb->group, child->ch_pid);
group_freechild(child);
}
#endif /* CONFIG_SCHED_CHILD_STATUS */
break;
}
}