1 |
|
---|
2 | // Application to show a possible problem of Boost condition variables in
|
---|
3 | // combination with a POSIX timer and signals
|
---|
4 |
|
---|
5 | #include <unistd.h>
|
---|
6 | #include <getopt.h>
|
---|
7 |
|
---|
8 | #include <signal.h>
|
---|
9 | #include "boost/thread/condition_variable.hpp"
|
---|
10 | #include "boost/date_time/posix_time/posix_time.hpp"
|
---|
11 | #include <boost/interprocess/sync/interprocess_semaphore.hpp>
|
---|
12 |
|
---|
13 | struct sigaction timerSigAction;
|
---|
14 | struct sigaction oldSigAction;
|
---|
15 | timer_t timer;
|
---|
16 | int timerCount = 0;
|
---|
17 |
|
---|
18 | #define SIGNAL_IN_USE (SIGRTMIN)
|
---|
19 |
|
---|
20 | /* handler installed to handle signals generated by the timer */
|
---|
21 | static void timerHandler(int signo)
|
---|
22 | {
|
---|
23 | if (signo != SIGNAL_IN_USE)
|
---|
24 | {
|
---|
25 | return;
|
---|
26 | }
|
---|
27 | timerCount++;
|
---|
28 | return;
|
---|
29 | }
|
---|
30 |
|
---|
31 | /* restores signal handlers and removes timer */
|
---|
32 | static void stopTimer()
|
---|
33 | {
|
---|
34 | timer_delete(timer);
|
---|
35 | sigaction(SIGNAL_IN_USE, &oldSigAction, NULL);
|
---|
36 | }
|
---|
37 |
|
---|
38 | /* timer initializer */
|
---|
39 | static void startTimer()
|
---|
40 | {
|
---|
41 | struct sigevent signalEvent;
|
---|
42 | struct itimerspec timerSpec;
|
---|
43 | sigset_t blockedSignals;
|
---|
44 |
|
---|
45 | sigemptyset(&blockedSignals);
|
---|
46 | timerSigAction.sa_handler = timerHandler;
|
---|
47 | timerSigAction.sa_flags = SA_RESTART;
|
---|
48 | timerSigAction.sa_mask = blockedSignals;
|
---|
49 | if (sigaction(SIGNAL_IN_USE, &timerSigAction, &oldSigAction))
|
---|
50 | {
|
---|
51 | return;
|
---|
52 | }
|
---|
53 |
|
---|
54 | signalEvent.sigev_notify = SIGEV_SIGNAL;
|
---|
55 | signalEvent.sigev_signo = SIGNAL_IN_USE;
|
---|
56 |
|
---|
57 | if (timer_create(CLOCK_REALTIME, &signalEvent, &timer))
|
---|
58 | {
|
---|
59 | stopTimer(); // restore signal handler
|
---|
60 | return;
|
---|
61 | }
|
---|
62 |
|
---|
63 | timerSpec = (struct itimerspec){ {(time_t)0, 50000000L}, {(time_t)0, 50000000L} };
|
---|
64 | if (timer_settime(timer, 0, &timerSpec, NULL))
|
---|
65 | {
|
---|
66 | stopTimer(); // clean up timer and restore signal handler
|
---|
67 | return;
|
---|
68 | }
|
---|
69 | }
|
---|
70 |
|
---|
71 | void BoostConditionVar()
|
---|
72 | {
|
---|
73 | boost::mutex m;
|
---|
74 | boost::unique_lock<boost::mutex> lk(m);
|
---|
75 | boost::condition_variable cond;
|
---|
76 | cond.timed_wait(lk, boost::posix_time::millisec(1000));
|
---|
77 | }
|
---|
78 |
|
---|
79 | void OwnConditionVar()
|
---|
80 | {
|
---|
81 | pthread_mutex_t m_mutex;
|
---|
82 | pthread_cond_t m_cond;
|
---|
83 |
|
---|
84 | pthread_mutexattr_t mutexattr;
|
---|
85 | pthread_mutexattr_init(&mutexattr);
|
---|
86 | pthread_mutexattr_settype(&mutexattr, PTHREAD_MUTEX_RECURSIVE);
|
---|
87 | pthread_mutex_init(&m_mutex, &mutexattr);
|
---|
88 | pthread_mutexattr_destroy(&mutexattr);
|
---|
89 |
|
---|
90 | pthread_condattr_t condattr;
|
---|
91 | pthread_condattr_init(&condattr);
|
---|
92 | pthread_condattr_setclock(&condattr, CLOCK_MONOTONIC);
|
---|
93 | pthread_cond_init(&m_cond, &condattr);
|
---|
94 | pthread_condattr_destroy(&condattr);
|
---|
95 |
|
---|
96 | struct timespec t1;
|
---|
97 | clock_gettime(CLOCK_MONOTONIC, &t1);
|
---|
98 | t1.tv_sec += 1;
|
---|
99 | pthread_mutex_lock(&m_mutex);
|
---|
100 | pthread_cond_timedwait(&m_cond, &m_mutex, &t1);
|
---|
101 |
|
---|
102 | pthread_mutex_destroy(&m_mutex);
|
---|
103 | pthread_cond_destroy(&m_cond);
|
---|
104 | }
|
---|
105 |
|
---|
106 | int kbhit()
|
---|
107 | {
|
---|
108 | struct timeval tv;
|
---|
109 | fd_set fds;
|
---|
110 | tv.tv_sec = 0;
|
---|
111 | tv.tv_usec = 0;
|
---|
112 | FD_ZERO(&fds);
|
---|
113 | FD_SET(STDIN_FILENO, &fds); //STDIN_FILENO is 0
|
---|
114 | select(STDIN_FILENO+1, &fds, NULL, NULL, &tv);
|
---|
115 | return FD_ISSET(STDIN_FILENO, &fds);
|
---|
116 | }
|
---|
117 |
|
---|
118 | int main(int argc, char *argv[])
|
---|
119 | {
|
---|
120 | bool useSignals = false;
|
---|
121 | bool useBoost = false;
|
---|
122 | static struct option long_options[] =
|
---|
123 | {
|
---|
124 | {"signals", no_argument, 0, 's'},
|
---|
125 | {"boost", no_argument, 0, 'b'},
|
---|
126 | {0, 0, 0, 0 }
|
---|
127 | };
|
---|
128 |
|
---|
129 | int option_index = 0;
|
---|
130 | int opt;
|
---|
131 | while ((opt = getopt_long(argc, argv, "sb", long_options, &option_index)) != -1)
|
---|
132 | {
|
---|
133 | switch (opt) {
|
---|
134 | case 's':
|
---|
135 | fprintf(stderr, "Generating POSIX signals\n");
|
---|
136 | useSignals = 1;
|
---|
137 | break;
|
---|
138 | case 'b':
|
---|
139 | fprintf(stderr, "Using Boost condition variables\n");
|
---|
140 | useBoost = 1;
|
---|
141 | break;
|
---|
142 | default: /* '?' */
|
---|
143 | fprintf(stderr, "Usage: %s [-b] [-s] \n", argv[0]);
|
---|
144 | fprintf(stderr, "-b --boost: use boost condition variable\n");
|
---|
145 | fprintf(stderr, "-s --signals: generate POSIX signals\n");
|
---|
146 | exit(EXIT_FAILURE);
|
---|
147 | }
|
---|
148 | }
|
---|
149 |
|
---|
150 | if(useSignals)
|
---|
151 | {
|
---|
152 | startTimer();
|
---|
153 | }
|
---|
154 |
|
---|
155 | printf("Press ENTER to stop\n");
|
---|
156 |
|
---|
157 | sem_t sem;
|
---|
158 | if (sem_init(&sem, 0, 1) == -1) {
|
---|
159 | if(useSignals)
|
---|
160 | {
|
---|
161 | stopTimer();
|
---|
162 | }
|
---|
163 | perror("sem_init");
|
---|
164 | exit(EXIT_FAILURE);
|
---|
165 | }
|
---|
166 |
|
---|
167 | struct timespec t1;
|
---|
168 | struct timespec t2;
|
---|
169 |
|
---|
170 | while(kbhit() == false)
|
---|
171 | {
|
---|
172 | if (useBoost)
|
---|
173 | {
|
---|
174 | BoostConditionVar();
|
---|
175 | }
|
---|
176 | else
|
---|
177 | {
|
---|
178 | OwnConditionVar();
|
---|
179 | }
|
---|
180 | boost::posix_time::ptime now = boost::posix_time::second_clock::local_time();
|
---|
181 | std::string output = to_simple_string(now);
|
---|
182 | int retval1 = clock_gettime(CLOCK_REALTIME, &t1);
|
---|
183 | int retval2 = clock_gettime(CLOCK_MONOTONIC, &t2);
|
---|
184 | printf("%s %d %d.%9.9d %d %d.%9.9d %d\n", output.c_str(), retval1,
|
---|
185 | t1.tv_sec, t1.tv_nsec, retval2, t2.tv_sec, t2.tv_nsec,
|
---|
186 | timerCount);
|
---|
187 | }
|
---|
188 |
|
---|
189 | if(useSignals)
|
---|
190 | {
|
---|
191 | stopTimer();
|
---|
192 | }
|
---|
193 | }
|
---|