signal_test.cpp revision aa0ebdafc71e1ceac78e0929b94f3bb117d0c8e9 
1/*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <gtest/gtest.h>
18
19#include <errno.h>
20#include <signal.h>
21
22#include "ScopedSignalHandler.h"
23
24static size_t SIGNAL_MIN() {
25  return 1; // Signals start at 1 (SIGHUP), not 0.
26}
27
28static size_t SIGNAL_MAX() {
29  size_t result = SIGRTMAX;
30
31#if defined(__BIONIC__) && !defined(__mips__) && !defined(__LP64__)
32  // 32-bit bionic's sigset_t is too small for ARM and x86: 32 bits instead of 64.
33  // This means you can't refer to any of the real-time signals.
34  // See http://b/3038348 and http://b/5828899.
35  result = 32;
36#else
37  // Otherwise, C libraries should be perfectly capable of using their largest signal.
38  if (sizeof(sigset_t) * 8 < static_cast<size_t>(SIGRTMAX)) {
39    abort();
40  }
41#endif
42
43  return result;
44}
45
46template <typename Fn>
47static void TestSigSet1(Fn fn) {
48  // NULL sigset_t*.
49  sigset_t* set_ptr = NULL;
50  errno = 0;
51  ASSERT_EQ(-1, fn(set_ptr));
52  ASSERT_EQ(EINVAL, errno);
53
54  // Non-NULL.
55  sigset_t set;
56  errno = 0;
57  ASSERT_EQ(0, fn(&set));
58  ASSERT_EQ(0, errno);
59}
60
61template <typename Fn>
62static void TestSigSet2(Fn fn) {
63  // NULL sigset_t*.
64  sigset_t* set_ptr = NULL;
65  errno = 0;
66  ASSERT_EQ(-1, fn(set_ptr, SIGSEGV));
67  ASSERT_EQ(EINVAL, errno);
68
69  sigset_t set;
70  sigemptyset(&set);
71
72  // Bad signal number: too small.
73  errno = 0;
74  ASSERT_EQ(-1, fn(&set, 0));
75  ASSERT_EQ(EINVAL, errno);
76
77  // Bad signal number: too high.
78  errno = 0;
79  ASSERT_EQ(-1, fn(&set, SIGNAL_MAX() + 1));
80  ASSERT_EQ(EINVAL, errno);
81
82  // Good signal numbers, low and high ends of range.
83  errno = 0;
84  ASSERT_EQ(0, fn(&set, SIGNAL_MIN()));
85  ASSERT_EQ(0, errno);
86  ASSERT_EQ(0, fn(&set, SIGNAL_MAX()));
87  ASSERT_EQ(0, errno);
88}
89
90TEST(signal, sigismember_invalid) {
91  TestSigSet2(sigismember);
92}
93
94TEST(signal, sigaddset_invalid) {
95  TestSigSet2(sigaddset);
96}
97
98TEST(signal, sigdelset_invalid) {
99  TestSigSet2(sigdelset);
100}
101
102TEST(signal, sigemptyset_invalid) {
103  TestSigSet1(sigemptyset);
104}
105
106TEST(signal, sigfillset_invalid) {
107  TestSigSet1(sigfillset);
108}
109
110TEST(signal, raise_invalid) {
111  errno = 0;
112  ASSERT_EQ(-1, raise(-1));
113  ASSERT_EQ(EINVAL, errno);
114}
115
116static void raise_in_signal_handler_helper(int signal_number) {
117  ASSERT_EQ(SIGALRM, signal_number);
118  static int count = 0;
119  if (++count == 1) {
120    raise(SIGALRM);
121  }
122}
123
124TEST(signal, raise_in_signal_handler) {
125  ScopedSignalHandler ssh(SIGALRM, raise_in_signal_handler_helper);
126  raise(SIGALRM);
127}
128
129static void HandleSIGALRM(int signal_number) {
130  ASSERT_EQ(SIGALRM, signal_number);
131}
132
133TEST(signal, sigwait) {
134  ScopedSignalHandler ssh(SIGALRM, HandleSIGALRM);
135
136  sigset_t wait_set;
137  sigemptyset(&wait_set);
138  sigaddset(&wait_set, SIGALRM);
139
140  alarm(1);
141
142  int received_signal;
143  errno = 0;
144  ASSERT_EQ(0, sigwait(&wait_set, &received_signal));
145  ASSERT_EQ(0, errno);
146  ASSERT_EQ(SIGALRM, received_signal);
147}
148
149static int gSigSuspendTestHelperCallCount = 0;
150
151static void SigSuspendTestHelper(int) {
152  ++gSigSuspendTestHelperCallCount;
153}
154
155TEST(signal, sigsuspend_sigpending) {
156  // Block SIGALRM.
157  sigset_t just_SIGALRM;
158  sigemptyset(&just_SIGALRM);
159  sigaddset(&just_SIGALRM, SIGALRM);
160  sigset_t original_set;
161  ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &just_SIGALRM, &original_set));
162
163  ScopedSignalHandler ssh(SIGALRM, SigSuspendTestHelper);
164
165  // There should be no pending signals.
166  sigset_t pending;
167  sigemptyset(&pending);
168  ASSERT_EQ(0, sigpending(&pending));
169  for (size_t i = SIGNAL_MIN(); i <= SIGNAL_MAX(); ++i) {
170    EXPECT_FALSE(sigismember(&pending, i)) << i;
171  }
172
173  // Raise SIGALRM and check our signal handler wasn't called.
174  raise(SIGALRM);
175  ASSERT_EQ(0, gSigSuspendTestHelperCallCount);
176
177  // We should now have a pending SIGALRM but nothing else.
178  sigemptyset(&pending);
179  ASSERT_EQ(0, sigpending(&pending));
180  for (size_t i = SIGNAL_MIN(); i <= SIGNAL_MAX(); ++i) {
181    EXPECT_EQ((i == SIGALRM), sigismember(&pending, i));
182  }
183
184  // Use sigsuspend to block everything except SIGALRM...
185  sigset_t not_SIGALRM;
186  sigfillset(&not_SIGALRM);
187  sigdelset(&not_SIGALRM, SIGALRM);
188  ASSERT_EQ(-1, sigsuspend(&not_SIGALRM));
189  ASSERT_EQ(EINTR, errno);
190  // ...and check that we now receive our pending SIGALRM.
191  ASSERT_EQ(1, gSigSuspendTestHelperCallCount);
192
193  // Restore the original set.
194  ASSERT_EQ(0, sigprocmask(SIG_SETMASK, &original_set, NULL));
195}
196
197static void EmptySignalHandler(int) {}
198static void EmptySignalAction(int, siginfo_t*, void*) {}
199
200TEST(signal, sigaction) {
201  // See what's currently set for SIGALRM.
202  struct sigaction original_sa;
203  memset(&original_sa, 0, sizeof(original_sa));
204  ASSERT_EQ(0, sigaction(SIGALRM, NULL, &original_sa));
205  ASSERT_TRUE(original_sa.sa_handler == NULL);
206  ASSERT_TRUE(original_sa.sa_sigaction == NULL);
207  ASSERT_TRUE(original_sa.sa_flags == 0);
208
209  // Set a traditional sa_handler signal handler.
210  struct sigaction sa;
211  memset(&sa, 0, sizeof(sa));
212  sigaddset(&sa.sa_mask, SIGALRM);
213  sa.sa_flags = SA_ONSTACK;
214  sa.sa_handler = EmptySignalHandler;
215  ASSERT_EQ(0, sigaction(SIGALRM, &sa, NULL));
216
217  // Check that we can read it back.
218  memset(&sa, 0, sizeof(sa));
219  ASSERT_EQ(0, sigaction(SIGALRM, NULL, &sa));
220  ASSERT_TRUE(sa.sa_handler == EmptySignalHandler);
221  ASSERT_TRUE((void*) sa.sa_sigaction == (void*) sa.sa_handler);
222  ASSERT_TRUE(sa.sa_flags == SA_ONSTACK);
223
224  // Set a new-style sa_sigaction signal handler.
225  memset(&sa, 0, sizeof(sa));
226  sigaddset(&sa.sa_mask, SIGALRM);
227  sa.sa_flags = SA_ONSTACK | SA_SIGINFO;
228  sa.sa_sigaction = EmptySignalAction;
229  ASSERT_EQ(0, sigaction(SIGALRM, &sa, NULL));
230
231  // Check that we can read it back.
232  memset(&sa, 0, sizeof(sa));
233  ASSERT_EQ(0, sigaction(SIGALRM, NULL, &sa));
234  ASSERT_TRUE(sa.sa_sigaction == EmptySignalAction);
235  ASSERT_TRUE((void*) sa.sa_sigaction == (void*) sa.sa_handler);
236  ASSERT_TRUE(sa.sa_flags == (SA_ONSTACK | SA_SIGINFO));
237
238  // Put everything back how it was.
239  ASSERT_EQ(0, sigaction(SIGALRM, &original_sa, NULL));
240}
241
242TEST(signal, sys_signame) {
243#if defined(__BIONIC__) && !defined(__LP64__)
244  ASSERT_TRUE(sys_signame[0] == NULL);
245  ASSERT_STREQ("HUP", sys_signame[SIGHUP]);
246#else
247  GTEST_LOG_(INFO) << "This test does nothing.\n";
248#endif
249}
250
251TEST(signal, sys_siglist) {
252  ASSERT_TRUE(sys_siglist[0] == NULL);
253  ASSERT_STREQ("Hangup", sys_siglist[SIGHUP]);
254}
255