signal_test.cpp revision 1f5af926fa626734981d6b4dcc0ab54e520032a9 
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
22template <typename Fn>
23static void TestSigSet1(Fn fn) {
24  // NULL sigset_t*.
25  sigset_t* set_ptr = NULL;
26  errno = 0;
27  ASSERT_EQ(-1, fn(set_ptr));
28  ASSERT_EQ(EINVAL, errno);
29
30  // Non-NULL.
31  sigset_t set;
32  errno = 0;
33  ASSERT_EQ(0, fn(&set));
34  ASSERT_EQ(0, errno);
35}
36
37template <typename Fn>
38static void TestSigSet2(Fn fn) {
39  // NULL sigset_t*.
40  sigset_t* set_ptr = NULL;
41  errno = 0;
42  ASSERT_EQ(-1, fn(set_ptr, SIGSEGV));
43  ASSERT_EQ(EINVAL, errno);
44
45  sigset_t set;
46  sigemptyset(&set);
47
48  int min_signal = SIGHUP;
49  int max_signal = SIGRTMAX;
50
51#if defined(__BIONIC__) && !defined(__mips__)
52  // bionic's sigset_t is too small for ARM and x86: 32 bits instead of 64.
53  // This means you can't refer to any of the real-time signals.
54  // See http://b/3038348 and http://b/5828899.
55  max_signal = 32;
56#else
57  // Other C libraries (or bionic for MIPS) are perfectly capable of using their largest signal.
58  ASSERT_GE(sizeof(sigset_t) * 8, static_cast<size_t>(SIGRTMAX));
59#endif
60
61  // Bad signal number: too small.
62  errno = 0;
63  ASSERT_EQ(-1, fn(&set, 0));
64  ASSERT_EQ(EINVAL, errno);
65
66  // Bad signal number: too high.
67  errno = 0;
68  ASSERT_EQ(-1, fn(&set, max_signal + 1));
69  ASSERT_EQ(EINVAL, errno);
70
71  // Good signal numbers, low and high ends of range.
72  errno = 0;
73  ASSERT_EQ(0, fn(&set, min_signal));
74  ASSERT_EQ(0, errno);
75  ASSERT_EQ(0, fn(&set, max_signal));
76  ASSERT_EQ(0, errno);
77}
78
79class ScopedSignalHandler {
80 public:
81  ScopedSignalHandler(int signal_number, void (*handler)(int)) : signal_number_(signal_number) {
82    sigemptyset(&action_.sa_mask);
83    action_.sa_flags = 0;
84    action_.sa_handler = handler;
85    sigaction(signal_number_, &action_, &old_action_);
86  }
87
88  ~ScopedSignalHandler() {
89    sigaction(signal_number_, &old_action_, NULL);
90  }
91
92 private:
93  struct sigaction action_;
94  struct sigaction old_action_;
95  const int signal_number_;
96};
97
98TEST(signal, sigismember_invalid) {
99  TestSigSet2(sigismember);
100}
101
102TEST(signal, sigaddset_invalid) {
103  TestSigSet2(sigaddset);
104}
105
106TEST(signal, sigdelset_invalid) {
107  TestSigSet2(sigdelset);
108}
109
110TEST(signal, sigemptyset_invalid) {
111  TestSigSet1(sigemptyset);
112}
113
114TEST(signal, sigfillset_invalid) {
115  TestSigSet1(sigfillset);
116}
117
118TEST(signal, raise_invalid) {
119  errno = 0;
120  ASSERT_EQ(-1, raise(-1));
121  ASSERT_EQ(EINVAL, errno);
122}
123
124static void raise_in_signal_handler_helper(int signal_number) {
125  ASSERT_EQ(SIGALRM, signal_number);
126  static int count = 0;
127  if (++count == 1) {
128    raise(SIGALRM);
129  }
130}
131
132TEST(signal, raise_in_signal_handler) {
133  ScopedSignalHandler ssh(SIGALRM, raise_in_signal_handler_helper);
134  raise(SIGALRM);
135}
136
137static void HandleSIGALRM(int signal_number) {
138  ASSERT_EQ(SIGALRM, signal_number);
139}
140
141TEST(signal, sigwait) {
142  ScopedSignalHandler ssh(SIGALRM, HandleSIGALRM);
143
144  sigset_t wait_set;
145  sigemptyset(&wait_set);
146  sigaddset(&wait_set, SIGALRM);
147
148  alarm(1);
149
150  int received_signal;
151  errno = 0;
152  ASSERT_EQ(0, sigwait(&wait_set, &received_signal));
153  ASSERT_EQ(0, errno);
154  ASSERT_EQ(SIGALRM, received_signal);
155}
156
157static int gSigSuspendTestHelperCallCount = 0;
158
159static void SigSuspendTestHelper(int) {
160  ++gSigSuspendTestHelperCallCount;
161}
162
163TEST(signal, sigsuspend) {
164  ScopedSignalHandler ssh(SIGALRM, SigSuspendTestHelper);
165
166  // Block SIGALRM.
167  sigset_t just_SIGALRM;
168  sigemptyset(&just_SIGALRM);
169  sigaddset(&just_SIGALRM, SIGALRM);
170  sigset_t original_set;
171  ASSERT_EQ(0, sigprocmask(SIG_BLOCK, &just_SIGALRM, &original_set));
172
173  // Raise SIGALRM and check our signal handler wasn't called.
174  raise(SIGALRM);
175  ASSERT_EQ(0, gSigSuspendTestHelperCallCount);
176
177  // Use sigsuspend to block everything except SIGALRM...
178  sigset_t not_SIGALRM;
179  sigfillset(&not_SIGALRM);
180  sigdelset(&not_SIGALRM, SIGALRM);
181  ASSERT_EQ(-1, sigsuspend(&not_SIGALRM));
182  ASSERT_EQ(EINTR, errno);
183  // ...and check that we now receive our pending SIGALRM.
184  ASSERT_EQ(1, gSigSuspendTestHelperCallCount);
185
186  // Restore the original set.
187  assert(0 == sigprocmask(SIG_SETMASK, &original_set, NULL));
188}
189