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402ecba4 ZW |
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 ((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 (&obuf, &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 (ifd); | |
89 | fclose (ofp); | |
90 | return obuf; | |
91 | } | |
92 | ||
93 | ||
94 | int | |
95 | main (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 (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 (real_stderr, 0, _IOLBF, 0)) | |
119 | { | |
120 | perror ("setvbuf(real_stderr)"); | |
121 | return 2; | |
122 | } | |
123 | ||
124 | if (pipe (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 (bufpipe[1], 2) == -1) | |
133 | { | |
134 | fprintf (real_stderr, "dup2: %s\n", strerror (errno)); | |
135 | return 2; | |
136 | } | |
137 | close (bufpipe[1]); | |
138 | ||
139 | b_args.ifd = bufpipe[0]; | |
140 | b_args.real_stderr = real_stderr; | |
141 | err = pthread_create (&b_thr, 0, buffer_threadproc, &b_args); | |
142 | if (err) | |
143 | { | |
144 | fprintf (real_stderr, "pthread_create(buffer_thr): %s\n", | |
145 | strerror (err)); | |
146 | return 2; | |
147 | } | |
148 | ||
149 | err = pthread_barrier_init (&gate, 0, 2); | |
150 | if (err) | |
151 | { | |
152 | fprintf (real_stderr, "pthread_barrier_init: %s\n", strerror (err)); | |
153 | return 2; | |
154 | } | |
155 | ||
156 | err = pthread_create (&t_thr, 0, test_threadproc, &gate); | |
157 | if (err) | |
158 | { | |
159 | fprintf (real_stderr, "pthread_create(test_thr): %s\n", strerror (err)); | |
160 | return 2; | |
161 | } | |
162 | ||
163 | err = pthread_cancel (t_thr); | |
164 | if (err) | |
165 | { | |
166 | fprintf (real_stderr, "pthread_cancel: %s\n", strerror (err)); | |
167 | return 2; | |
168 | } | |
169 | ||
170 | pthread_barrier_wait (&gate); /* cannot fail */ | |
171 | ||
172 | err = pthread_join (t_thr, &rv); | |
173 | if (err) | |
174 | { | |
175 | fprintf (real_stderr, "pthread_join(test_thr): %s\n", strerror (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 (b_thr, &obuf_v); | |
183 | if (err) | |
184 | { | |
185 | fprintf (real_stderr, "pthread_join(buffer_thr): %s\n", strerror (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 | } |