Annotation of prex-old/usr/server/proc/fork.c, Revision 1.1.1.1.2.1
1.1 nbrk 1: /*
2: * Copyright (c) 2005-2006, 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: * fork.c - fork() support
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 <stdlib.h>
41: #include <string.h>
42:
43: #include "proc.h"
44:
1.1.1.1.2.1! nbrk 45: static int vfork_start(struct proc *);
1.1 nbrk 46:
47: /*
48: * fork() support.
49: *
50: * It creates new process data and update all process relations.
1.1.1.1.2.1! nbrk 51: * The task creation and the thread creation are done by the
! 52: * fork() library stub.
1.1 nbrk 53: */
54: int
55: proc_fork(struct msg *msg)
56: {
57: struct proc *p;
58: struct pgrp *pgrp;
59: task_t child;
60: pid_t pid;
1.1.1.1.2.1! nbrk 61: int vfork_flag;
1.1 nbrk 62:
63: if (curproc == NULL)
64: return EINVAL;
65:
66: child = (task_t)msg->data[0];
1.1.1.1.2.1! nbrk 67: vfork_flag = msg->data[1];
1.1 nbrk 68:
1.1.1.1.2.1! nbrk 69: DPRINTF(("fork: parent=%x child=%x vfork=%d\n", msg->hdr.task,
! 70: child, vfork_flag));
1.1 nbrk 71:
72: if (task_to_proc(child) != NULL)
73: return EINVAL; /* Process already exists */
74:
75: if ((pid = pid_assign()) == 0)
76: return EAGAIN; /* Too many processes */
77:
78: if ((p = malloc(sizeof(struct proc))) == NULL)
79: return ENOMEM;
80:
1.1.1.1.2.1! nbrk 81: p->p_parent = curproc;
! 82: p->p_pgrp = curproc->p_pgrp;
! 83: p->p_stat = SRUN;
! 84: p->p_exitcode = 0;
! 85: p->p_pid = pid;
! 86: p->p_task = child;
! 87: list_init(&p->p_children);
1.1 nbrk 88: proc_add(p);
1.1.1.1.2.1! nbrk 89: list_insert(&curproc->p_children, &p->p_sibling);
! 90: pgrp = p->p_pgrp;
! 91: list_insert(&pgrp->pg_members, &p->p_pgrp_link);
! 92: list_insert(&allproc, &p->p_link);
1.1 nbrk 93:
1.1.1.1.2.1! nbrk 94: if (vfork_flag)
1.1 nbrk 95: vfork_start(curproc);
96:
1.1.1.1.2.1! nbrk 97: DPRINTF(("fork: new pid=%d\n", p->p_pid));
! 98: msg->data[0] = (int)p->p_pid;
1.1 nbrk 99: return 0;
100: }
101:
102: /*
103: * Clean up all resource created by fork().
104: */
105: void
1.1.1.1.2.1! nbrk 106: proc_cleanup(struct proc *p)
1.1 nbrk 107: {
108: struct proc *pp;
109:
1.1.1.1.2.1! nbrk 110: pp = p->p_parent;
! 111: list_remove(&p->p_sibling);
! 112: list_remove(&p->p_pgrp_link);
! 113: proc_remove(p);
! 114: list_remove(&p->p_link);
! 115: free(p);
1.1 nbrk 116: }
117:
118: static int
1.1.1.1.2.1! nbrk 119: vfork_start(struct proc *p)
1.1 nbrk 120: {
121: void *stack;
122:
123: /*
124: * Save parent's stack
125: */
1.1.1.1.2.1! nbrk 126: if (vm_allocate(p->p_task, &stack, USTACK_SIZE, 1) != 0)
1.1 nbrk 127: return ENOMEM;
128:
1.1.1.1.2.1! nbrk 129: memcpy(stack, p->p_stackbase, USTACK_SIZE);
! 130: p->p_stacksaved = stack;
1.1 nbrk 131:
1.1.1.1.2.1! nbrk 132: p->p_vforked = 1;
! 133: DPRINTF(("vfork_start: saved=%x org=%x\n", stack, p->p_stackbase));
1.1 nbrk 134: return 0;
135: }
136:
137: void
1.1.1.1.2.1! nbrk 138: vfork_end(struct proc *p)
1.1 nbrk 139: {
140:
1.1.1.1.2.1! nbrk 141: DPRINTF(("vfork_end: org=%x saved=%x\n", p->p_stackbase,
! 142: p->p_stacksaved));
1.1 nbrk 143: /*
144: * Restore parent's stack
145: */
1.1.1.1.2.1! nbrk 146: memcpy(p->p_stackbase, p->p_stacksaved, USTACK_SIZE);
! 147: vm_free(p->p_task, p->p_stacksaved);
1.1 nbrk 148:
149: /*
150: * Resume parent
151: */
1.1.1.1.2.1! nbrk 152: p->p_vforked = 0;
! 153: task_resume(p->p_task);
1.1 nbrk 154: }
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