Annotation of prex/usr/server/proc/exit.c, Revision 1.1
1.1 ! nbrk 1: /*
! 2: * Copyright (c) 2005-2008, Kohsuke Ohtani
! 3: * All rights reserved.
! 4: *
! 5: * Redistribution and use in source and binary forms, with or without
! 6: * modification, are permitted provided that the following conditions
! 7: * are met:
! 8: * 1. Redistributions of source code must retain the above copyright
! 9: * notice, this list of conditions and the following disclaimer.
! 10: * 2. Redistributions in binary form must reproduce the above copyright
! 11: * notice, this list of conditions and the following disclaimer in the
! 12: * documentation and/or other materials provided with the distribution.
! 13: * 3. Neither the name of the author nor the names of any co-contributors
! 14: * may be used to endorse or promote products derived from this software
! 15: * without specific prior written permission.
! 16: *
! 17: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
! 18: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 19: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 20: * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
! 21: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 22: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 23: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 24: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 25: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 26: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 27: * SUCH DAMAGE.
! 28: */
! 29:
! 30: /*
! 31: * exit.c - process exit and wait
! 32: */
! 33:
! 34: #include <prex/prex.h>
! 35: #include <server/proc.h>
! 36: #include <sys/list.h>
! 37:
! 38: #include <unistd.h>
! 39: #include <errno.h>
! 40: #include <signal.h>
! 41:
! 42: #include "proc.h"
! 43:
! 44: /*
! 45: * Exit process.
! 46: *
! 47: * process_exit() sets the process state to zombie state, and it
! 48: * saves the exit code for waiting process.
! 49: */
! 50: int
! 51: proc_exit(struct msg *msg)
! 52: {
! 53: int exitcode;
! 54: struct proc *child, *parent;
! 55: list_t head, n;
! 56:
! 57: if (curproc == NULL)
! 58: return EINVAL;
! 59:
! 60: exitcode = msg->data[0];
! 61: DPRINTF(("exit pid=%d task=%x code=%x\n", curproc->p_pid,
! 62: msg->hdr.task, exitcode));
! 63:
! 64: if (curproc->p_stat == SZOMB)
! 65: return EBUSY;
! 66:
! 67: curproc->p_stat = SZOMB;
! 68: curproc->p_exitcode = exitcode;
! 69:
! 70: /*
! 71: * Set the parent pid of all child processes to 1 (init).
! 72: */
! 73: head = &curproc->p_children;
! 74: n = list_first(head);
! 75: while (n != head) {
! 76: child = list_entry(n, struct proc, p_sibling);
! 77: n = list_next(n);
! 78:
! 79: child->p_parent = &initproc;
! 80: list_remove(&child->p_sibling);
! 81: list_insert(&initproc.p_children, &child->p_sibling);
! 82: }
! 83:
! 84: /*
! 85: * Resume parent process which is wating in vfork.
! 86: */
! 87: parent = curproc->p_parent;
! 88: if (parent != NULL && parent->p_vforked) {
! 89: vfork_end(parent);
! 90:
! 91: /*
! 92: * The child task loses its stack data.
! 93: * So, it can not run anymore.
! 94: */
! 95: task_terminate(curproc->p_task);
! 96: }
! 97:
! 98: /* Send a signal to the parent process. */
! 99: exception_raise(curproc->p_parent->p_task, SIGCHLD);
! 100: return 0;
! 101: }
! 102:
! 103: /*
! 104: * Stop process.
! 105: *
! 106: * This is similar with exit(), but it does not update the parent
! 107: * pid of any child processes.
! 108: */
! 109: int
! 110: proc_stop(struct msg *msg)
! 111: {
! 112: int code;
! 113:
! 114: if (curproc == NULL)
! 115: return EINVAL;
! 116:
! 117: code = msg->data[0];
! 118: DPRINTF(("stop task=%x code=%x\n", msg->hdr.task, code));
! 119:
! 120: if (curproc->p_stat == SZOMB)
! 121: return EBUSY;
! 122:
! 123: curproc->p_stat = SSTOP;
! 124: curproc->p_exitcode = code;
! 125:
! 126: /* Send a signal to the parent process. */
! 127: exception_raise(curproc->p_parent->p_task, SIGCHLD);
! 128: return 0;
! 129: }
! 130:
! 131: /*
! 132: * Find the zombie process in the child processes. It just
! 133: * returns the pid and exit code if it find at least one zombie
! 134: * process.
! 135: *
! 136: * The library stub for waitpid() will wait the SIGCHLD signal in
! 137: * the stub code if there is no zombie process in child process.
! 138: * This signal is sent by proc_exit() or proc_stop() routines in
! 139: * the process server.
! 140: */
! 141: int
! 142: proc_waitpid(struct msg *msg)
! 143: {
! 144: pid_t pid, pid_child;
! 145: int options, code, match;
! 146: struct proc *p;
! 147: list_t head, n;
! 148:
! 149: if (curproc == NULL)
! 150: return EINVAL;
! 151:
! 152: pid = (pid_t)msg->data[0];
! 153: options = msg->data[1];
! 154: DPRINTF(("wait task=%x pid=%d options=%x\n", msg->hdr.task,
! 155: pid, options));
! 156:
! 157: if (list_empty(&curproc->p_children))
! 158: return ECHILD; /* No child process */
! 159:
! 160: /* Set the default pid and exit code */
! 161: pid_child = 0;
! 162: code = 0;
! 163:
! 164: /*
! 165: * Check all processes.
! 166: */
! 167: p = NULL;
! 168: head = &curproc->p_children;
! 169: for (n = list_first(head); n != head; n = list_next(n)) {
! 170: p = list_entry(n, struct proc, p_sibling);
! 171:
! 172: /*
! 173: * Check if pid matches.
! 174: */
! 175: match = 0;
! 176: if (pid > 0) {
! 177: /*
! 178: * Wait a specific child process.
! 179: */
! 180: if (p->p_pid == pid)
! 181: match = 1;
! 182: } else if (pid == 0) {
! 183: /*
! 184: * Wait a process who has same pgid.
! 185: */
! 186: if (p->p_pgrp->pg_pgid == curproc->p_pgrp->pg_pgid)
! 187: match = 1;
! 188: } else if (pid != -1) {
! 189: /*
! 190: * Wait a specific pgid.
! 191: */
! 192: if (p->p_pgrp->pg_pgid == -pid)
! 193: match = 1;
! 194: } else {
! 195: /*
! 196: * pid = -1 means wait any child process.
! 197: */
! 198: match = 1;
! 199: }
! 200: if (match) {
! 201: /*
! 202: * Get the exit code.
! 203: */
! 204: if (p->p_stat == SSTOP) {
! 205: pid_child = p->p_pid;
! 206: code = p->p_exitcode;
! 207: break;
! 208: } else if (p->p_stat == SZOMB) {
! 209: pid_child = p->p_pid;
! 210: code = p->p_exitcode;
! 211: proc_cleanup(p);
! 212: break;
! 213: }
! 214: }
! 215: }
! 216: msg->data[0] = pid_child;
! 217: msg->data[1] = code;
! 218: return 0;
! 219: }
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