1 | /* Test support for single-thread optimizations. With threads. |
2 | Copyright (C) 2020-2024 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library; if not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <stddef.h> |
20 | #include <stdio.h> |
21 | #include <support/check.h> |
22 | #include <support/namespace.h> |
23 | #include <support/xdlfcn.h> |
24 | #include <support/xthread.h> |
25 | #include <sys/single_threaded.h> |
26 | |
27 | /* First barrier synchronizes main thread, thread 1, thread 2. */ |
28 | static pthread_barrier_t barrier1; |
29 | |
30 | /* Second barrier synchronizes main thread, thread 2. */ |
31 | static pthread_barrier_t barrier2; |
32 | |
33 | /* Defined in tst-single-threaded-mod1.so. */ |
34 | _Bool single_threaded_1 (void); |
35 | |
36 | /* Initialized via dlsym. */ |
37 | static _Bool (*single_threaded_2) (void); |
38 | static _Bool (*single_threaded_3) (void); |
39 | static _Bool (*single_threaded_4) (void); |
40 | |
41 | static void * |
42 | threadfunc (void *closure) |
43 | { |
44 | TEST_VERIFY (!__libc_single_threaded); |
45 | TEST_VERIFY (!single_threaded_1 ()); |
46 | TEST_VERIFY (!single_threaded_2 ()); |
47 | |
48 | /* Wait until the main thread loads more functions. */ |
49 | xpthread_barrier_wait (barrier: &barrier1); |
50 | |
51 | TEST_VERIFY (!__libc_single_threaded); |
52 | TEST_VERIFY (!single_threaded_1 ()); |
53 | TEST_VERIFY (!single_threaded_2 ()); |
54 | TEST_VERIFY (!single_threaded_3 ()); |
55 | TEST_VERIFY (!single_threaded_4 ()); |
56 | |
57 | /* Second thread waits on second barrier, too. */ |
58 | if (closure != NULL) |
59 | xpthread_barrier_wait (barrier: &barrier2); |
60 | TEST_VERIFY (!__libc_single_threaded); |
61 | TEST_VERIFY (!single_threaded_1 ()); |
62 | TEST_VERIFY (!single_threaded_2 ()); |
63 | TEST_VERIFY (!single_threaded_3 ()); |
64 | TEST_VERIFY (!single_threaded_4 ()); |
65 | |
66 | return NULL; |
67 | } |
68 | |
69 | /* Used for closure arguments to the subprocess function. */ |
70 | static char expected_false = 0; |
71 | static char expected_true = 1; |
72 | |
73 | /* A subprocess inherits currently inherits the single-threaded state |
74 | of the parent process. */ |
75 | static void |
76 | subprocess (void *closure) |
77 | { |
78 | const char *expected = closure; |
79 | TEST_COMPARE (__libc_single_threaded, *expected); |
80 | TEST_COMPARE (single_threaded_1 (), *expected); |
81 | if (single_threaded_2 != NULL) |
82 | TEST_COMPARE (single_threaded_2 (), *expected); |
83 | if (single_threaded_3 != NULL) |
84 | TEST_COMPARE (single_threaded_3 (), *expected); |
85 | if (single_threaded_4 != NULL) |
86 | TEST_VERIFY (!single_threaded_4 ()); |
87 | } |
88 | |
89 | static int |
90 | do_test (void) |
91 | { |
92 | printf (format: "info: main __libc_single_threaded address: %p\n" , |
93 | &__libc_single_threaded); |
94 | TEST_VERIFY (__libc_single_threaded); |
95 | TEST_VERIFY (single_threaded_1 ()); |
96 | support_isolate_in_subprocess (callback: subprocess, closure: &expected_true); |
97 | |
98 | void *handle_mod2 = xdlopen (filename: "tst-single_threaded-mod2.so" , RTLD_LAZY); |
99 | single_threaded_2 = xdlsym (handle: handle_mod2, symbol: "single_threaded_2" ); |
100 | TEST_VERIFY (single_threaded_2 ()); |
101 | |
102 | /* Two threads plus main thread. */ |
103 | xpthread_barrier_init (barrier: &barrier1, NULL, count: 3); |
104 | |
105 | /* Main thread and second thread. */ |
106 | xpthread_barrier_init (barrier: &barrier2, NULL, count: 2); |
107 | |
108 | pthread_t thr1 = xpthread_create (NULL, thread_func: threadfunc, NULL); |
109 | TEST_VERIFY (!__libc_single_threaded); |
110 | TEST_VERIFY (!single_threaded_1 ()); |
111 | TEST_VERIFY (!single_threaded_2 ()); |
112 | support_isolate_in_subprocess (callback: subprocess, closure: &expected_false); |
113 | |
114 | pthread_t thr2 = xpthread_create (NULL, thread_func: threadfunc, closure: &thr2); |
115 | TEST_VERIFY (!__libc_single_threaded); |
116 | TEST_VERIFY (!single_threaded_1 ()); |
117 | TEST_VERIFY (!single_threaded_2 ()); |
118 | support_isolate_in_subprocess (callback: subprocess, closure: &expected_false); |
119 | |
120 | /* Delayed library load, while already multi-threaded. */ |
121 | void *handle_mod3 = xdlopen (filename: "tst-single_threaded-mod3.so" , RTLD_LAZY); |
122 | single_threaded_3 = xdlsym (handle: handle_mod3, symbol: "single_threaded_3" ); |
123 | TEST_VERIFY (!__libc_single_threaded); |
124 | TEST_VERIFY (!single_threaded_1 ()); |
125 | TEST_VERIFY (!single_threaded_2 ()); |
126 | TEST_VERIFY (!single_threaded_3 ()); |
127 | support_isolate_in_subprocess (callback: subprocess, closure: &expected_false); |
128 | |
129 | /* Same with dlmopen. */ |
130 | void *handle_mod4 = dlmopen (LM_ID_NEWLM, file: "tst-single_threaded-mod4.so" , |
131 | RTLD_LAZY); |
132 | single_threaded_4 = xdlsym (handle: handle_mod4, symbol: "single_threaded_4" ); |
133 | TEST_VERIFY (!__libc_single_threaded); |
134 | TEST_VERIFY (!single_threaded_1 ()); |
135 | TEST_VERIFY (!single_threaded_2 ()); |
136 | TEST_VERIFY (!single_threaded_3 ()); |
137 | TEST_VERIFY (!single_threaded_4 ()); |
138 | support_isolate_in_subprocess (callback: subprocess, closure: &expected_false); |
139 | |
140 | /* Run the newly loaded functions from the other threads as |
141 | well. */ |
142 | xpthread_barrier_wait (barrier: &barrier1); |
143 | TEST_VERIFY (!__libc_single_threaded); |
144 | TEST_VERIFY (!single_threaded_1 ()); |
145 | TEST_VERIFY (!single_threaded_2 ()); |
146 | TEST_VERIFY (!single_threaded_3 ()); |
147 | TEST_VERIFY (!single_threaded_4 ()); |
148 | support_isolate_in_subprocess (callback: subprocess, closure: &expected_false); |
149 | |
150 | /* Join first thread. This should not bring us back into |
151 | single-threaded mode. */ |
152 | xpthread_join (thr: thr1); |
153 | TEST_VERIFY (!__libc_single_threaded); |
154 | TEST_VERIFY (!single_threaded_1 ()); |
155 | TEST_VERIFY (!single_threaded_2 ()); |
156 | TEST_VERIFY (!single_threaded_3 ()); |
157 | TEST_VERIFY (!single_threaded_4 ()); |
158 | support_isolate_in_subprocess (callback: subprocess, closure: &expected_false); |
159 | |
160 | /* We may be back in single-threaded mode after joining both |
161 | threads, but this is not guaranteed. */ |
162 | xpthread_barrier_wait (barrier: &barrier2); |
163 | xpthread_join (thr: thr2); |
164 | printf (format: "info: __libc_single_threaded after joining all threads: %d\n" , |
165 | __libc_single_threaded); |
166 | |
167 | xdlclose (handle: handle_mod4); |
168 | xdlclose (handle: handle_mod3); |
169 | xdlclose (handle: handle_mod2); |
170 | |
171 | return 0; |
172 | } |
173 | |
174 | #include <support/test-driver.c> |
175 | |