summary refs log tree commit diff
path: root/malloc/tst-malloc-fork-deadlock.c
blob: 30d3df3b087f433c7fb51e811dacf7edb710c45a (plain) (blame)
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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
/* Test concurrent fork, getline, and fflush (NULL).
   Copyright (C) 2016-2017 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   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; see the file COPYING.LIB.  If
   not, see <http://www.gnu.org/licenses/>.  */

#include <sys/wait.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <pthread.h>
#include <stdbool.h>
#include <stdlib.h>
#include <malloc.h>
#include <time.h>
#include <string.h>
#include <signal.h>

#include <support/xthread.h>
#include <support/temp_file.h>
#include <support/test-driver.h>

enum {
  /* Number of threads which call fork.  */
  fork_thread_count = 4,
  /* Number of threads which call getline (and, indirectly,
     malloc).  */
  read_thread_count = 8,
};

static bool termination_requested;

static void *
fork_thread_function (void *closure)
{
  while (!__atomic_load_n (&termination_requested, __ATOMIC_RELAXED))
    {
      pid_t pid = fork ();
      if (pid < 0)
        {
          printf ("error: fork: %m\n");
          abort ();
        }
      else if (pid == 0)
        _exit (17);

      int status;
      if (waitpid (pid, &status, 0) < 0)
        {
          printf ("error: waitpid: %m\n");
          abort ();
        }
      if (!WIFEXITED (status) || WEXITSTATUS (status) != 17)
        {
          printf ("error: waitpid returned invalid status: %d\n", status);
          abort ();
        }
    }
  return NULL;
}

static char *file_to_read;

static void *
read_thread_function (void *closure)
{
  FILE *f = fopen (file_to_read, "r");
  if (f == NULL)
    {
      printf ("error: fopen (%s): %m\n", file_to_read);
      abort ();
    }

  while (!__atomic_load_n (&termination_requested, __ATOMIC_RELAXED))
    {
      rewind (f);
      char *line = NULL;
      size_t line_allocated = 0;
      ssize_t ret = getline (&line, &line_allocated, f);
      if (ret < 0)
        {
          printf ("error: getline: %m\n");
          abort ();
        }
      free (line);
    }
  fclose (f);

  return NULL;
}

static void *
flushall_thread_function (void *closure)
{
  while (!__atomic_load_n (&termination_requested, __ATOMIC_RELAXED))
    if (fflush (NULL) != 0)
      {
        printf ("error: fflush (NULL): %m\n");
        abort ();
      }
  return NULL;
}

static void
create_threads (pthread_t *threads, size_t count, void *(*func) (void *))
{
  for (size_t i = 0; i < count; ++i)
    threads[i] = xpthread_create (NULL, func, NULL);
}

static void
join_threads (pthread_t *threads, size_t count)
{
  for (size_t i = 0; i < count; ++i)
    xpthread_join (threads[i]);
}

/* Create a file which consists of a single long line, and assigns
   file_to_read.  The hope is that this triggers an allocation in
   getline which needs a lock.  */
static void
create_file_with_large_line (void)
{
  int fd = create_temp_file ("bug19431-large-line", &file_to_read);
  if (fd < 0)
    {
      printf ("error: create_temp_file: %m\n");
      abort ();
    }
  FILE *f = fdopen (fd, "w+");
  if (f == NULL)
    {
      printf ("error: fdopen: %m\n");
      abort ();
    }
  for (int i = 0; i < 50000; ++i)
    fputc ('x', f);
  fputc ('\n', f);
  if (ferror (f))
    {
      printf ("error: fputc: %m\n");
      abort ();
    }
  if (fclose (f) != 0)
    {
      printf ("error: fclose: %m\n");
      abort ();
    }
}

static int
do_test (void)
{
  /* Make sure that we do not exceed the arena limit with the number
     of threads we configured.  */
  if (mallopt (M_ARENA_MAX, 400) == 0)
    {
      printf ("error: mallopt (M_ARENA_MAX) failed\n");
      return 1;
    }

  /* Leave some room for shutting down all threads gracefully.  */
  int timeout = 3;
  if (timeout > DEFAULT_TIMEOUT)
    timeout = DEFAULT_TIMEOUT - 1;

  create_file_with_large_line ();

  pthread_t fork_threads[fork_thread_count];
  create_threads (fork_threads, fork_thread_count, fork_thread_function);
  pthread_t read_threads[read_thread_count];
  create_threads (read_threads, read_thread_count, read_thread_function);
  pthread_t flushall_threads[1];
  create_threads (flushall_threads, 1, flushall_thread_function);

  struct timespec ts = {timeout, 0};
  if (nanosleep (&ts, NULL))
    {
      printf ("error: error: nanosleep: %m\n");
      abort ();
    }

  __atomic_store_n (&termination_requested, true, __ATOMIC_RELAXED);

  join_threads (flushall_threads, 1);
  join_threads (read_threads, read_thread_count);
  join_threads (fork_threads, fork_thread_count);

  free (file_to_read);

  return 0;
}

#include <support/test-driver.c>