diff options
Diffstat (limited to 'nuttx/sched/sched_waitid.c')
| -rw-r--r-- | nuttx/sched/sched_waitid.c | 408 |
1 files changed, 0 insertions, 408 deletions
diff --git a/nuttx/sched/sched_waitid.c b/nuttx/sched/sched_waitid.c deleted file mode 100644 index 9c24189c4..000000000 --- a/nuttx/sched/sched_waitid.c +++ /dev/null @@ -1,408 +0,0 @@ -/***************************************************************************** - * sched/sched_waitid.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 <sys/wait.h> -#include <signal.h> -#include <errno.h> - -#include <nuttx/sched.h> - -#include "os_internal.h" -#include "group_internal.h" - -#if defined(CONFIG_SCHED_WAITPID) && defined(CONFIG_SCHED_HAVE_PARENT) - -/***************************************************************************** - * Private Functions - *****************************************************************************/ - -/***************************************************************************** - * Name: exited_child - * - * Description: - * Handle the case where a child exited properlay was we (apparently) lost - * the detch of child signal. - * - *****************************************************************************/ - -#ifdef CONFIG_SCHED_CHILD_STATUS -static void exited_child(FAR _TCB *rtcb, FAR struct child_status_s *child, - FAR siginfo_t *info) -{ - /* The child has exited. Return the saved exit status (and some fudged - * information. - */ - - info->si_signo = SIGCHLD; - info->si_code = CLD_EXITED; - info->si_value.sival_ptr = NULL; - info->si_pid = child->ch_pid; - info->si_status = child->ch_status; - - /* Discard the child entry */ - - (void)group_removechild(rtcb->group, child->ch_pid); - group_freechild(child); -} -#endif - -/***************************************************************************** - * Public Functions - *****************************************************************************/ - -/***************************************************************************** - * Name: waitid - * - * Description: - * The waitid() function suspends the calling thread until one child of - * the process containing the calling thread changes state. It records the - * current state of a child in the structure pointed to by 'info'. If a - * child process changed state prior to the call to waitid(), waitid() - * returns immediately. If more than one thread is suspended in wait() or - * waitpid() waiting termination of the same process, exactly one thread - * will return the process status at the time of the target process - * termination - * - * The idtype and id arguments are used to specify which children waitid() - * will wait for. - * - * If idtype is P_PID, waitid() will wait for the child with a process - * ID equal to (pid_t)id. - * - * If idtype is P_PGID, waitid() will wait for any child with a process - * group ID equal to (pid_t)id. - * - * If idtype is P_ALL, waitid() will wait for any children and id is - * ignored. - * - * The options argument is used to specify which state changes waitid() - * will will wait for. It is formed by OR-ing together one or more of the - * following flags: - * - * WEXITED - Wait for processes that have exited. - * WSTOPPED - Status will be returned for any child that has stopped - * upon receipt of a signal. - * WCONTINUED - Status will be returned for any child that was stopped - * and has been continued. - * WNOHANG - Return immediately if there are no children to wait for. - * WNOWAIT - Keep the process whose status is returned in 'info' in a - * waitable state. This will not affect the state of the process; the - * process may be waited for again after this call completes. - * - * The 'info' argument must point to a siginfo_t structure. If waitid() - * returns because a child process was found that satisfied the conditions - * indicated by the arguments idtype and options, then the structure pointed - * to by 'info' will be filled in by the system with the status of the - * process. The si_signo member will always be equal to SIGCHLD. - * - * Input Parameters: - * See description. - * - * Returned Value: - * If waitid() returns due to the change of state of one of its children, - * 0 is returned. Otherwise, -1 is returned and errno is set to indicate - * the error. - * - * The waitid() function will fail if: - * - * ECHILD - The calling process has no existing unwaited-for child - * processes. - * EINTR - The waitid() function was interrupted by a signal. - * EINVAL - An invalid value was specified for options, or idtype and id - * specify an invalid set of processes. - * - *****************************************************************************/ - -int waitid(idtype_t idtype, id_t id, FAR siginfo_t *info, int options) -{ - FAR _TCB *rtcb = (FAR _TCB *)g_readytorun.head; - FAR _TCB *ctcb; -#ifdef CONFIG_SCHED_CHILD_STATUS - FAR struct child_status_s *child; - bool retains; -#endif - sigset_t sigset; - int err; - int ret; - - /* MISSING LOGIC: If WNOHANG is provided in the options, then this function - * should returned immediately. However, there is no mechanism available now - * know if the thread has child: The children remember their parents (if - * CONFIG_SCHED_HAVE_PARENT) but the parents do not remember their children. - */ - - /* None of the options are supported except for WEXITED (which must be - * provided. Currently SIGCHILD always reports CLD_EXITED so we cannot - * distinguish any other events. - */ - -#ifdef CONFIG_DEBUG - if (options != WEXITED) - { - set_errno(ENOSYS); - return ERROR; - } -#endif - - /* Create a signal set that contains only SIGCHLD */ - - (void)sigemptyset(&sigset); - (void)sigaddset(&sigset, SIGCHLD); - - /* Disable pre-emption so that nothing changes while the loop executes */ - - sched_lock(); - - /* Verify that this task actually has children and that the the requested - * TCB is actually a child of this task. - */ - -#ifdef CONFIG_SCHED_CHILD_STATUS - /* Does this task retain child status? */ - - retains = ((rtcb->group->tg_flags && GROUP_FLAG_NOCLDWAIT) == 0); - - if (rtcb->group->tg_children == NULL && retains) - { - /* There are no children */ - - err = ECHILD; - goto errout_with_errno; - } - else if (idtype == P_PID) - { - /* Get the TCB corresponding to this PID and make sure it is our child. */ - - ctcb = sched_gettcb((pid_t)id); -#ifdef HAVE_GROUP_MEMBERS - if (!ctcb || ctcb->group->tg_pgid != rtcb->group->tg_gid) -#else - if (!ctcb || ctcb->ppid != rtcb->pid) -#endif - { - err = ECHILD; - goto errout_with_errno; - } - - /* Does this task retain child status? */ - - if (retains) - { - /* Check if this specific pid has allocated child status? */ - - if (group_findchild(rtcb->group, (pid_t)id) == NULL) - { - /* This specific pid is not a child */ - - err = ECHILD; - goto errout_with_errno; - } - } - } -#else - if (rtcb->nchildren == 0) - { - /* There are no children */ - - err = ECHILD; - goto errout_with_errno; - } - else if (idtype == P_PID) - { - /* Get the TCB corresponding to this PID and make sure it is our child. */ - - ctcb = sched_gettcb((pid_t)id); -#ifdef HAVE_GROUP_MEMBERS - if (!ctcb || ctcb->group->tg_pgid != rtcb->group->tg_gid) -#else - if (!ctcb || ctcb->ppid != rtcb->pid) -#endif - { - err = ECHILD; - goto errout_with_errno; - } - } -#endif - - /* Loop until the child that we are waiting for dies */ - - for (;;) - { -#ifdef CONFIG_SCHED_CHILD_STATUS - /* Check if the task has already died. Signals are not queued in - * NuttX. So a possibility is that the child has died and we - * missed the death of child signal (we got some other signal - * instead). - */ - - DEBUGASSERT(!retains || rtcb->group->tg_children); - if (idtype == P_ALL) - { - /* We are waiting for any child to exit */ - - if (retains && (child = group_exitchild(rtcb->group)) != NULL) - { - /* A child has exited. Apparently we missed the signal. - * Return the exit status and break out of the loop. - */ - - exited_child(rtcb, child, info); - break; - } - } - - /* We are waiting for a specific PID. Does this task retain child status? */ - - else if (retains) - { - /* Yes ... Get the current status of the child task. */ - - child = group_findchild(rtcb->group, (pid_t)id); - DEBUGASSERT(child); - - /* Did the child exit? */ - - if ((child->ch_flags & CHILD_FLAG_EXITED) != 0) - { - /* The child has exited. Return the exit status and break out - * of the loop. - */ - - exited_child(rtcb, child, info); - break; - } - } - else - { - /* We can use kill() with signal number 0 to determine if that - * task is still alive. - */ - - ret = kill((pid_t)id, 0); - if (ret < 0) - { - /* It is no longer running. We know that the child task - * was running okay when we started, so we must have lost - * the signal. In this case, we know that the task exit'ed, - * but we do not know its exit status. It would be better - * to reported ECHILD than bogus status. - */ - - err = ECHILD; - goto errout_with_errno; - } - } -#else - /* Check if the task has already died. Signals are not queued in - * NuttX. So a possibility is that the child has died and we - * missed the death of child signal (we got some other signal - * instead). - */ - - if (rtcb->nchildren == 0 || - (idtype == P_PID && (ret = kill((pid_t)id, 0)) < 0)) - { - /* We know that the child task was running okay we stared, - * so we must have lost the signal. What can we do? - * Let's claim we were interrupted by a signal. - */ - - err = EINTR; - goto errout_with_errno; - } -#endif - - /* Wait for any death-of-child signal */ - - ret = sigwaitinfo(&sigset, info); - if (ret < 0) - { - goto errout; - } - - /* Make there this was SIGCHLD */ - - if (info->si_signo == SIGCHLD) - { - /* Yes.. Are we waiting for the death of a specific child? */ - - if (idtype == P_PID) - { - /* Was this the death of the thread we were waiting for? */ - - if (info->si_pid == (pid_t)id) - { - /* Yes... return success */ - - break; - } - } - - /* Are we waiting for any child to change state? */ - - else if (idtype == P_ALL) - { - /* Return success */ - - break; - } - - /* Other ID types are not supported */ - - else /* if (idtype == P_PGID) */ - { - set_errno(ENOSYS); - goto errout; - } - } - } - - sched_unlock(); - return OK; - -errout_with_errno: - set_errno(err); -errout: - sched_unlock(); - return ERROR; -} - -#endif /* CONFIG_SCHED_WAITPID && CONFIG_SCHED_HAVE_PARENT*/ |