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28 
29 #include "utils/signals/interrupts.hpp"
30 
31 extern "C" {
32 #include <signal.h>
33 #include <unistd.h>
34 }
35 
36 #include <cstdlib>
37 #include <iostream>
38 
39 #include <atf-c++.hpp>
40 
41 #include "utils/format/macros.hpp"
42 #include "utils/fs/path.hpp"
43 #include "utils/process/child.ipp"
44 #include "utils/process/status.hpp"
45 #include "utils/signals/exceptions.hpp"
46 #include "utils/signals/programmer.hpp"
47 
48 namespace fs = utils::fs;
49 namespace process = utils::process;
50 namespace signals = utils::signals;
51 
52 
53 namespace {
54 
55 
56 /// Set to the signal that fired; -1 if none.
57 static volatile int fired_signal = -1;
58 
59 
60 /// Test handler for signals.
61 ///
62 /// \post fired_signal is set to the signal that triggered the handler.
63 ///
64 /// \param signo The signal that triggered the handler.
65 static void
66 signal_handler(const int signo)
67 {
68     PRE(fired_signal == -1 || fired_signal == signo);
69     fired_signal = signo;
70 }
71 
72 
73 /// Child process that pauses waiting to be killed.
74 static void
75 pause_child(void)
76 {
77     sigset_t mask;
78     sigemptyset(&mask);
79     // We loop waiting for signals because we want the parent process to send us
80     // a SIGKILL that we cannot handle, not just any non-deadly signal.
81     for (;;) {
82         std::cerr << F("Waiting for any signal; pid=%s\n") % ::getpid();
83         ::sigsuspend(&mask);
84         std::cerr << F("Signal received; pid=%s\n") % ::getpid();
85     }
86 }
87 
88 
89 /// Checks that interrupts_handler() handles a particular signal.
90 ///
91 /// This indirectly checks the check_interrupt() function, which is not part of
92 /// the class but is tightly related.
93 ///
94 /// \param signo The signal to check.
95 /// \param explicit_unprogram Whether to call interrupts_handler::unprogram()
96 ///     explicitly before letting the object go out of scope.
97 static void
98 check_interrupts_handler(const int signo, const bool explicit_unprogram)
99 {
100     fired_signal = -1;
101 
102     signals::programmer test_handler(signo, signal_handler);
103 
104     {
105         signals::interrupts_handler interrupts;
106 
107         // No pending interrupts at first.
108         signals::check_interrupt();
109 
110         // Send us an interrupt and check for it.
111         ::kill(getpid(), signo);
112         ATF_REQUIRE_THROW_RE(signals::interrupted_error,
113                              F("Interrupted by signal %s") % signo,
114                              signals::check_interrupt());
115 
116         // Interrupts should have been cleared now, so this should not throw.
117         signals::check_interrupt();
118 
119         // Check to see if a second interrupt is detected.
120         ::kill(getpid(), signo);
121         ATF_REQUIRE_THROW_RE(signals::interrupted_error,
122                              F("Interrupted by signal %s") % signo,
123                              signals::check_interrupt());
124 
125         // And ensure the interrupt was cleared again.
126         signals::check_interrupt();
127 
128         if (explicit_unprogram) {
129             interrupts.unprogram();
130         }
131     }
132 
133     ATF_REQUIRE_EQ(-1, fired_signal);
134     ::kill(getpid(), signo);
135     ATF_REQUIRE_EQ(signo, fired_signal);
136 
137     test_handler.unprogram();
138 }
139 
140 
141 /// Checks that interrupts_inhibiter() handles a particular signal.
142 ///
143 /// \param signo The signal to check.
144 static void
145 check_interrupts_inhibiter(const int signo)
146 {
147     signals::programmer test_handler(signo, signal_handler);
148 
149     {
150         signals::interrupts_inhibiter inhibiter;
151         {
152             signals::interrupts_inhibiter nested_inhibiter;
153             ::kill(::getpid(), signo);
154             ATF_REQUIRE_EQ(-1, fired_signal);
155         }
156         ::kill(::getpid(), signo);
157         ATF_REQUIRE_EQ(-1, fired_signal);
158     }
159     ATF_REQUIRE_EQ(signo, fired_signal);
160 
161     test_handler.unprogram();
162 }
163 
164 
165 }  // anonymous namespace
166 
167 
168 ATF_TEST_CASE_WITHOUT_HEAD(interrupts_handler__sighup);
169 ATF_TEST_CASE_BODY(interrupts_handler__sighup)
170 {
171     // We run this twice in sequence to ensure that we can actually program two
172     // interrupts handlers in a row.
173     check_interrupts_handler(SIGHUP, true);
174     check_interrupts_handler(SIGHUP, false);
175 }
176 
177 
178 ATF_TEST_CASE_WITHOUT_HEAD(interrupts_handler__sigint);
179 ATF_TEST_CASE_BODY(interrupts_handler__sigint)
180 {
181     // We run this twice in sequence to ensure that we can actually program two
182     // interrupts handlers in a row.
183     check_interrupts_handler(SIGINT, true);
184     check_interrupts_handler(SIGINT, false);
185 }
186 
187 
188 ATF_TEST_CASE_WITHOUT_HEAD(interrupts_handler__sigterm);
189 ATF_TEST_CASE_BODY(interrupts_handler__sigterm)
190 {
191     // We run this twice in sequence to ensure that we can actually program two
192     // interrupts handlers in a row.
193     check_interrupts_handler(SIGTERM, true);
194     check_interrupts_handler(SIGTERM, false);
195 }
196 
197 
198 ATF_TEST_CASE(interrupts_handler__kill_children);
199 ATF_TEST_CASE_HEAD(interrupts_handler__kill_children)
200 {
201     set_md_var("timeout", "10");
202 }
203 ATF_TEST_CASE_BODY(interrupts_handler__kill_children)
204 {
205     std::auto_ptr< process::child > child1(process::child::fork_files(
206          pause_child, fs::path("/dev/stdout"), fs::path("/dev/stderr")));
207     std::auto_ptr< process::child > child2(process::child::fork_files(
208          pause_child, fs::path("/dev/stdout"), fs::path("/dev/stderr")));
209 
210     signals::interrupts_handler interrupts;
211 
212     // Our children pause until the reception of a signal.  Interrupting
213     // ourselves will cause the signal to be re-delivered to our children due to
214     // the interrupts_handler semantics.  If this does not happen, the wait
215     // calls below would block indefinitely and cause our test to time out.
216     ::kill(::getpid(), SIGHUP);
217 
218     const process::status status1 = child1->wait();
219     ATF_REQUIRE(status1.signaled());
220     ATF_REQUIRE_EQ(SIGKILL, status1.termsig());
221     const process::status status2 = child2->wait();
222     ATF_REQUIRE(status2.signaled());
223     ATF_REQUIRE_EQ(SIGKILL, status2.termsig());
224 }
225 
226 
227 ATF_TEST_CASE_WITHOUT_HEAD(interrupts_inhibiter__sigalrm);
228 ATF_TEST_CASE_BODY(interrupts_inhibiter__sigalrm)
229 {
230     check_interrupts_inhibiter(SIGALRM);
231 }
232 
233 
234 ATF_TEST_CASE_WITHOUT_HEAD(interrupts_inhibiter__sighup);
235 ATF_TEST_CASE_BODY(interrupts_inhibiter__sighup)
236 {
237     check_interrupts_inhibiter(SIGHUP);
238 }
239 
240 
241 ATF_TEST_CASE_WITHOUT_HEAD(interrupts_inhibiter__sigint);
242 ATF_TEST_CASE_BODY(interrupts_inhibiter__sigint)
243 {
244     check_interrupts_inhibiter(SIGINT);
245 }
246 
247 
248 ATF_TEST_CASE_WITHOUT_HEAD(interrupts_inhibiter__sigterm);
249 ATF_TEST_CASE_BODY(interrupts_inhibiter__sigterm)
250 {
251     check_interrupts_inhibiter(SIGTERM);
252 }
253 
254 
255 ATF_INIT_TEST_CASES(tcs)
256 {
257     ATF_ADD_TEST_CASE(tcs, interrupts_handler__sighup);
258     ATF_ADD_TEST_CASE(tcs, interrupts_handler__sigint);
259     ATF_ADD_TEST_CASE(tcs, interrupts_handler__sigterm);
260     ATF_ADD_TEST_CASE(tcs, interrupts_handler__kill_children);
261 
262     ATF_ADD_TEST_CASE(tcs, interrupts_inhibiter__sigalrm);
263     ATF_ADD_TEST_CASE(tcs, interrupts_inhibiter__sighup);
264     ATF_ADD_TEST_CASE(tcs, interrupts_inhibiter__sigint);
265     ATF_ADD_TEST_CASE(tcs, interrupts_inhibiter__sigterm);
266 }
267