1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
/* Copyright (C) 2002, 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sysdep.h>
#include <libio/libioP.h>
#include <tls.h>
#include "fork.h"
#include <bits/stdio-lock.h>
#include <assert.h>
unsigned long int *__fork_generation_pointer;
lll_lock_t __fork_lock = LLL_LOCK_INITIALIZER;
LIST_HEAD (__fork_prepare_list);
LIST_HEAD (__fork_parent_list);
LIST_HEAD (__fork_child_list);
static void
fresetlockfiles (void)
{
_IO_ITER i;
for (i = _IO_iter_begin(); i != _IO_iter_end(); i = _IO_iter_next(i))
_IO_lock_init (*((_IO_lock_t *) _IO_iter_file(i)->_lock));
}
pid_t
__libc_fork (void)
{
pid_t pid;
list_t *runp;
/* Get the lock so that the set of registered handlers is not
inconsistent or changes beneath us. */
lll_lock (__fork_lock);
/* Run all the registered preparation handlers. In reverse order. */
list_for_each_prev (runp, &__fork_prepare_list)
{
struct fork_handler *curp;
curp = list_entry (runp, struct fork_handler, list);
curp->handler ();
}
_IO_list_lock ();
#ifndef NDEBUG
pid_t ppid = THREAD_GETMEM (THREAD_SELF, tid);
#endif
#ifdef ARCH_FORK
pid = ARCH_FORK ();
#else
# error "ARCH_FORK must be defined so that the CLONE_SETTID flag is used"
pid = INLINE_SYSCALL (fork, 0);
#endif
if (pid == 0)
{
assert (THREAD_GETMEM (THREAD_SELF, tid) != ppid);
if (__fork_generation_pointer != NULL)
*__fork_generation_pointer += 4;
/* Reset the file list. These are recursive mutexes. */
fresetlockfiles ();
/* Reset locks in the I/O code. */
_IO_list_resetlock ();
/* Run the handlers registered for the child. */
list_for_each (runp, &__fork_child_list)
{
struct fork_handler *curp;
curp = list_entry (runp, struct fork_handler, list);
curp->handler ();
}
/* Initialize the fork lock. */
__fork_lock = (lll_lock_t) LLL_LOCK_INITIALIZER;
}
else
{
assert (THREAD_GETMEM (THREAD_SELF, tid) == ppid);
/* We execute this even if the 'fork' call failed. */
_IO_list_unlock ();
/* Run the handlers registered for the parent. */
list_for_each (runp, &__fork_parent_list)
{
struct fork_handler *curp;
curp = list_entry (runp, struct fork_handler, list);
curp->handler ();
}
/* Release the for lock. */
lll_unlock (__fork_lock);
}
return pid;
}
weak_alias (__libc_fork, __fork)
libc_hidden_def (__fork)
weak_alias (__libc_fork, fork)
|
