1 | /* Bug 22830: malloc_stats fails to re-enable cancellation on exit. |
2 | Copyright (C) 2018 Free Software Foundation. |
3 | Copying and distribution of this file, with or without modification, |
4 | are permitted in any medium without royalty provided the copyright |
5 | notice and this notice are preserved. This file is offered as-is, |
6 | without any warranty. */ |
7 | |
8 | #include <errno.h> |
9 | #include <stdio.h> |
10 | #include <string.h> |
11 | |
12 | #include <pthread.h> |
13 | #include <sys/stat.h> |
14 | #include <sys/types.h> |
15 | #include <fcntl.h> |
16 | #include <unistd.h> |
17 | |
18 | #include <malloc.h> |
19 | |
20 | static void * |
21 | test_threadproc (void *gatep) |
22 | { |
23 | /* When we are released from the barrier, there is a cancellation |
24 | request pending for this thread. N.B. pthread_barrier_wait is |
25 | not itself a cancellation point (oddly enough). */ |
26 | pthread_barrier_wait (barrier: (pthread_barrier_t *)gatep); |
27 | malloc_stats (); |
28 | fputs ("this call should trigger cancellation\n" , stderr); |
29 | return 0; |
30 | } |
31 | |
32 | /* We cannot replace stderr with a memstream because writes to memstreams |
33 | do not trigger cancellation. Instead, main swaps out fd 2 to point to |
34 | a pipe, and this thread reads from the pipe and writes to a memstream |
35 | until EOF, then returns the data accumulated in the memstream. main |
36 | can't do that itself because, when the test thread gets cancelled, |
37 | it doesn't close the pipe. */ |
38 | |
39 | struct buffer_tp_args |
40 | { |
41 | int ifd; |
42 | FILE *real_stderr; |
43 | }; |
44 | |
45 | static void * |
46 | buffer_threadproc (void *argp) |
47 | { |
48 | struct buffer_tp_args *args = argp; |
49 | int ifd = args->ifd; |
50 | char block[BUFSIZ], *p; |
51 | ssize_t nread; |
52 | size_t nwritten; |
53 | |
54 | char *obuf = 0; |
55 | size_t obufsz = 0; |
56 | FILE *ofp = open_memstream (bufloc: &obuf, sizeloc: &obufsz); |
57 | if (!ofp) |
58 | { |
59 | fprintf (args->real_stderr, |
60 | "buffer_threadproc: open_memstream: %s\n" , strerror (errno)); |
61 | return 0; |
62 | } |
63 | |
64 | while ((nread = read (ifd, block, BUFSIZ)) > 0) |
65 | { |
66 | p = block; |
67 | do |
68 | { |
69 | nwritten = fwrite_unlocked (p, 1, nread, ofp); |
70 | if (nwritten == 0) |
71 | { |
72 | fprintf (args->real_stderr, |
73 | "buffer_threadproc: fwrite_unlocked: %s\n" , |
74 | strerror (errno)); |
75 | return 0; |
76 | } |
77 | nread -= nwritten; |
78 | p += nwritten; |
79 | } |
80 | while (nread > 0); |
81 | } |
82 | if (nread == -1) |
83 | { |
84 | fprintf (args->real_stderr, "buffer_threadproc: read: %s\n" , |
85 | strerror (errno)); |
86 | return 0; |
87 | } |
88 | close (fd: ifd); |
89 | fclose (ofp); |
90 | return obuf; |
91 | } |
92 | |
93 | |
94 | static int |
95 | do_test (void) |
96 | { |
97 | int result = 0, err, real_stderr_fd, bufpipe[2]; |
98 | pthread_t t_thr, b_thr; |
99 | pthread_barrier_t gate; |
100 | void *rv; |
101 | FILE *real_stderr; |
102 | char *obuf; |
103 | void *obuf_v; |
104 | struct buffer_tp_args b_args; |
105 | |
106 | real_stderr_fd = dup (fd: 2); |
107 | if (real_stderr_fd == -1) |
108 | { |
109 | perror ("dup" ); |
110 | return 2; |
111 | } |
112 | real_stderr = fdopen(real_stderr_fd, "w" ); |
113 | if (!real_stderr) |
114 | { |
115 | perror ("fdopen" ); |
116 | return 2; |
117 | } |
118 | if (setvbuf (stream: real_stderr, buf: 0, _IOLBF, n: 0)) |
119 | { |
120 | perror ("setvbuf(real_stderr)" ); |
121 | return 2; |
122 | } |
123 | |
124 | if (pipe (pipedes: bufpipe)) |
125 | { |
126 | perror ("pipe" ); |
127 | return 2; |
128 | } |
129 | |
130 | /* Below this point, nobody other than the test_threadproc should use |
131 | the normal stderr. */ |
132 | if (dup2 (fd: bufpipe[1], fd2: 2) == -1) |
133 | { |
134 | fprintf (real_stderr, "dup2: %s\n" , strerror (errno)); |
135 | return 2; |
136 | } |
137 | close (fd: bufpipe[1]); |
138 | |
139 | b_args.ifd = bufpipe[0]; |
140 | b_args.real_stderr = real_stderr; |
141 | err = pthread_create (newthread: &b_thr, attr: 0, start_routine: buffer_threadproc, arg: &b_args); |
142 | if (err) |
143 | { |
144 | fprintf (real_stderr, "pthread_create(buffer_thr): %s\n" , |
145 | strerror (errnum: err)); |
146 | return 2; |
147 | } |
148 | |
149 | err = pthread_barrier_init (barrier: &gate, attr: 0, count: 2); |
150 | if (err) |
151 | { |
152 | fprintf (real_stderr, "pthread_barrier_init: %s\n" , strerror (errnum: err)); |
153 | return 2; |
154 | } |
155 | |
156 | err = pthread_create (newthread: &t_thr, attr: 0, start_routine: test_threadproc, arg: &gate); |
157 | if (err) |
158 | { |
159 | fprintf (real_stderr, "pthread_create(test_thr): %s\n" , strerror (errnum: err)); |
160 | return 2; |
161 | } |
162 | |
163 | err = pthread_cancel (th: t_thr); |
164 | if (err) |
165 | { |
166 | fprintf (real_stderr, "pthread_cancel: %s\n" , strerror (errnum: err)); |
167 | return 2; |
168 | } |
169 | |
170 | pthread_barrier_wait (barrier: &gate); /* cannot fail */ |
171 | |
172 | err = pthread_join (th: t_thr, thread_return: &rv); |
173 | if (err) |
174 | { |
175 | fprintf (real_stderr, "pthread_join(test_thr): %s\n" , strerror (errnum: err)); |
176 | return 2; |
177 | } |
178 | |
179 | /* Closing the normal stderr releases the buffer_threadproc from its |
180 | loop. */ |
181 | fclose (stderr); |
182 | err = pthread_join (th: b_thr, thread_return: &obuf_v); |
183 | if (err) |
184 | { |
185 | fprintf (real_stderr, "pthread_join(buffer_thr): %s\n" , strerror (errnum: err)); |
186 | return 2; |
187 | } |
188 | obuf = obuf_v; |
189 | if (obuf == 0) |
190 | return 2; /* error within buffer_threadproc, already reported */ |
191 | |
192 | if (rv != PTHREAD_CANCELED) |
193 | { |
194 | fputs ("FAIL: thread was not cancelled\n" , real_stderr); |
195 | result = 1; |
196 | } |
197 | /* obuf should have received all of the text printed by malloc_stats, |
198 | but not the text printed by the final call to fputs. */ |
199 | if (!strstr (obuf, "max mmap bytes" )) |
200 | { |
201 | fputs ("FAIL: malloc_stats output incomplete\n" , real_stderr); |
202 | result = 1; |
203 | } |
204 | if (strstr (obuf, "this call should trigger cancellation" )) |
205 | { |
206 | fputs ("FAIL: fputs produced output\n" , real_stderr); |
207 | result = 1; |
208 | } |
209 | |
210 | if (result == 1) |
211 | { |
212 | fputs ("--- output from thread below ---\n" , real_stderr); |
213 | fputs (obuf, real_stderr); |
214 | } |
215 | return result; |
216 | } |
217 | |
218 | #include <support/test-driver.c> |
219 | |