diff options
Diffstat (limited to 'nuttx/sched/task_exithook.c')
| -rw-r--r-- | nuttx/sched/task_exithook.c | 114 |
1 files changed, 112 insertions, 2 deletions
diff --git a/nuttx/sched/task_exithook.c b/nuttx/sched/task_exithook.c index 3bde8fb7a..1813c12ed 100644 --- a/nuttx/sched/task_exithook.c +++ b/nuttx/sched/task_exithook.c @@ -1,7 +1,7 @@ /**************************************************************************** * sched/task_exithook.c * - * Copyright (C) 2011-2012 Gregory Nutt. All rights reserved. + * Copyright (C) 2011-2013 Gregory Nutt. All rights reserved. * Author: Gregory Nutt <gnutt@nuttx.org> * * Redistribution and use in source and binary forms, with or without @@ -41,6 +41,7 @@ #include <stdlib.h> #include <unistd.h> +#include <signal.h> #include <debug.h> #include <errno.h> @@ -188,6 +189,105 @@ static inline void task_onexit(FAR _TCB *tcb, int status) #endif /**************************************************************************** + * Name: task_sigchild + * + * Description: + * Send the SIGCHILD signal to the parent thread + * + ****************************************************************************/ + +#ifdef CONFIG_SCHED_HAVE_PARENT +static inline void task_sigchild(FAR _TCB *tcb, int status) +{ + FAR _TCB *ptcb; + siginfo_t info; + + /* Only exiting tasks should generate SIGCHLD. pthreads use other + * mechansims. + */ + + if ((tcb->flags & TCB_FLAG_TTYPE_MASK) == TCB_FLAG_TTYPE_TASK) + { + /* Keep things stationary through the following */ + + sched_lock(); + + /* Get the TCB of the receiving task */ + + ptcb = sched_gettcb(tcb->parent); + if (!ptcb) + { + /* The parent no longer exists... bail */ + + sched_unlock(); + return; + } + +#ifdef CONFIG_SCHED_CHILD_STATUS + /* Check if the parent task has suppressed retention of child exit + * status information. Only 'tasks' report exit status, not pthreads. + * pthreads have a different mechanism. + */ + + if ((ptcb->flags & TCB_FLAG_NOCLDWAIT) == 0) + { + FAR struct child_status_s *child; + + /* No.. Find the exit status entry for this task in the parent TCB */ + + child = task_findchild(ptcb, getpid()); + DEBUGASSERT(child); + if (child) + { + /* Mark that the child has exit'ed */ + + child->ch_flags |= CHILD_FLAG_EXITED; + + /* Save the exit status */ + + child->ch_status = status; + } + } +#else + /* Decrement the number of children from this parent */ + + DEBUGASSERT(ptcb->nchildren > 0); + ptcb->nchildren--; +#endif + + /* Set the parent to an impossible PID. We do this because under + * certain conditions, task_exithook() can be called multiple times. + * If this function is called again, sched_gettcb() will fail on the + * invalid parent PID above, nchildren will be decremented once and + * all will be well. + */ + + tcb->parent = INVALID_PROCESS_ID; + + /* Create the siginfo structure. We don't actually know the cause. + * That is a bug. Let's just say that the child task just exit-ted + * for now. + */ + + info.si_signo = SIGCHLD; + info.si_code = CLD_EXITED; + info.si_value.sival_ptr = NULL; + info.si_pid = tcb->pid; + info.si_status = status; + + /* Send the signal. We need to use this internal interface so that we + * can provide the correct si_code value with the signal. + */ + + (void)sig_received(ptcb, &info); + sched_unlock(); + } +} +#else +# define task_sigchild(tcb,status) +#endif + +/**************************************************************************** * Name: task_exitwakeup * * Description: @@ -195,7 +295,7 @@ static inline void task_onexit(FAR _TCB *tcb, int status) * ****************************************************************************/ -#ifdef CONFIG_SCHED_WAITPID +#if defined(CONFIG_SCHED_WAITPID) && !defined(CONFIG_SCHED_HAVE_PARENT) static inline void task_exitwakeup(FAR _TCB *tcb, int status) { /* Wakeup any tasks waiting for this task to exit */ @@ -263,6 +363,10 @@ void task_exithook(FAR _TCB *tcb, int status) task_onexit(tcb, status); + /* Send SIGCHLD to the parent of the exit-ing task */ + + task_sigchild(tcb, status); + /* Wakeup any tasks waiting for this task to exit */ task_exitwakeup(tcb, status); @@ -275,6 +379,12 @@ void task_exithook(FAR _TCB *tcb, int status) (void)lib_flushall(tcb->streams); #endif + /* Discard any un-reaped child status (no zombies here!) */ + +#if defined(CONFIG_SCHED_HAVE_PARENT) && defined(CONFIG_SCHED_CHILD_STATUS) + task_removechildren(tcb); +#endif + /* Free all file-related resources now. This gets called again * just be be certain when the TCB is delallocated. However, we * really need to close files as soon as possible while we still |