File: [local] / prex / usr / server / proc / exit.c (download)
Revision 1.1.1.1 (vendor branch), Tue Aug 19 12:47:01 2008 UTC (16 years, 1 month ago) by nbrk
Branch: MAIN, KOHSUKE
CVS Tags: PREX_0_8_BASE, HEAD Changes since 1.1: +0 -0 lines
Initial import of Prex, Portable Real-time Embedded POSIX microkernel system.
I have totally new directions in my development (more focused on real hardware, not virtual one).
Old hacks are available in prex-old module. They will be carefully re-designed and merged soon.
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/*
* Copyright (c) 2005-2008, Kohsuke Ohtani
* All rights reserved.
*
* 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 of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*/
/*
* exit.c - process exit and wait
*/
#include <prex/prex.h>
#include <server/proc.h>
#include <sys/list.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include "proc.h"
/*
* Exit process.
*
* process_exit() sets the process state to zombie state, and it
* saves the exit code for waiting process.
*/
int
proc_exit(struct msg *msg)
{
int exitcode;
struct proc *child, *parent;
list_t head, n;
if (curproc == NULL)
return EINVAL;
exitcode = msg->data[0];
DPRINTF(("exit pid=%d task=%x code=%x\n", curproc->p_pid,
msg->hdr.task, exitcode));
if (curproc->p_stat == SZOMB)
return EBUSY;
curproc->p_stat = SZOMB;
curproc->p_exitcode = exitcode;
/*
* Set the parent pid of all child processes to 1 (init).
*/
head = &curproc->p_children;
n = list_first(head);
while (n != head) {
child = list_entry(n, struct proc, p_sibling);
n = list_next(n);
child->p_parent = &initproc;
list_remove(&child->p_sibling);
list_insert(&initproc.p_children, &child->p_sibling);
}
/*
* Resume parent process which is wating in vfork.
*/
parent = curproc->p_parent;
if (parent != NULL && parent->p_vforked) {
vfork_end(parent);
/*
* The child task loses its stack data.
* So, it can not run anymore.
*/
task_terminate(curproc->p_task);
}
/* Send a signal to the parent process. */
exception_raise(curproc->p_parent->p_task, SIGCHLD);
return 0;
}
/*
* Stop process.
*
* This is similar with exit(), but it does not update the parent
* pid of any child processes.
*/
int
proc_stop(struct msg *msg)
{
int code;
if (curproc == NULL)
return EINVAL;
code = msg->data[0];
DPRINTF(("stop task=%x code=%x\n", msg->hdr.task, code));
if (curproc->p_stat == SZOMB)
return EBUSY;
curproc->p_stat = SSTOP;
curproc->p_exitcode = code;
/* Send a signal to the parent process. */
exception_raise(curproc->p_parent->p_task, SIGCHLD);
return 0;
}
/*
* Find the zombie process in the child processes. It just
* returns the pid and exit code if it find at least one zombie
* process.
*
* The library stub for waitpid() will wait the SIGCHLD signal in
* the stub code if there is no zombie process in child process.
* This signal is sent by proc_exit() or proc_stop() routines in
* the process server.
*/
int
proc_waitpid(struct msg *msg)
{
pid_t pid, pid_child;
int options, code, match;
struct proc *p;
list_t head, n;
if (curproc == NULL)
return EINVAL;
pid = (pid_t)msg->data[0];
options = msg->data[1];
DPRINTF(("wait task=%x pid=%d options=%x\n", msg->hdr.task,
pid, options));
if (list_empty(&curproc->p_children))
return ECHILD; /* No child process */
/* Set the default pid and exit code */
pid_child = 0;
code = 0;
/*
* Check all processes.
*/
p = NULL;
head = &curproc->p_children;
for (n = list_first(head); n != head; n = list_next(n)) {
p = list_entry(n, struct proc, p_sibling);
/*
* Check if pid matches.
*/
match = 0;
if (pid > 0) {
/*
* Wait a specific child process.
*/
if (p->p_pid == pid)
match = 1;
} else if (pid == 0) {
/*
* Wait a process who has same pgid.
*/
if (p->p_pgrp->pg_pgid == curproc->p_pgrp->pg_pgid)
match = 1;
} else if (pid != -1) {
/*
* Wait a specific pgid.
*/
if (p->p_pgrp->pg_pgid == -pid)
match = 1;
} else {
/*
* pid = -1 means wait any child process.
*/
match = 1;
}
if (match) {
/*
* Get the exit code.
*/
if (p->p_stat == SSTOP) {
pid_child = p->p_pid;
code = p->p_exitcode;
break;
} else if (p->p_stat == SZOMB) {
pid_child = p->p_pid;
code = p->p_exitcode;
proc_cleanup(p);
break;
}
}
}
msg->data[0] = pid_child;
msg->data[1] = code;
return 0;
}