git.m6w6.name Git - m6w6/libmemcached/blob - libtest/signal.cc

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   3  *  uTest, libtest
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  36
  37 #include <libtest/common.h>
  38
  39 #include <pthread.h>
  40 #include <semaphore.h>
  41 #include <csignal>
  42
  43 #include <libtest/signal.h>
  44
  45 using namespace libtest;
  46
  47 struct context_st {
  48   sigset_t set;
  49   sem_t lock;
  50
  51   context_st()
  52   {
  53     sigemptyset(&set);
  54     sigaddset(&set, SIGQUIT);
  55     sigaddset(&set, SIGINT);
  56
  57     sem_init(&lock, 0, 0);
  58   }
  59
  60   void test()
  61   {
  62     assert(sigismember(&set, SIGQUIT));
  63     assert(sigismember(&set, SIGINT));
  64   }
  65
  66   int wait(int& sig)
  67   {
  68     return sigwait(&set, &sig);
  69   }
  70
  71   ~context_st()
  72   {
  73     sem_destroy(&lock);
  74   }
  75 };
  76
  77 static volatile shutdown_t __shutdown;
  78 static pthread_mutex_t shutdown_mutex;
  79 static pthread_t thread;
  80
  81 bool is_shutdown()
  82 {
  83   bool ret;
  84   pthread_mutex_lock(&shutdown_mutex);
  85   ret= bool(__shutdown != SHUTDOWN_RUNNING);
  86   pthread_mutex_unlock(&shutdown_mutex);
  87
  88   return ret;
  89 }
  90
  91 void set_shutdown(shutdown_t arg)
  92 {
  93   pthread_mutex_lock(&shutdown_mutex);
  94   __shutdown= arg;
  95   pthread_mutex_unlock(&shutdown_mutex);
  96
  97   if (arg == SHUTDOWN_GRACEFUL)
  98   {
  99     pthread_kill(thread, SIGQUIT);
 100
 101     void *retval;
 102     pthread_join(thread, &retval);
 103   }
 104 }
 105
 106 shutdown_t get_shutdown()
 107 {
 108   shutdown_t local;
 109   pthread_mutex_lock(&shutdown_mutex);
 110   local= __shutdown;
 111   pthread_mutex_unlock(&shutdown_mutex);
 112
 113   return local;
 114 }
 115
 116 extern "C" {
 117
 118 static void *sig_thread(void *arg)
 119 {
 120   context_st *context= (context_st*)arg;
 121   assert(context);
 122
 123   context->test();
 124   sem_post(&context->lock);
 125
 126   while (get_shutdown() == SHUTDOWN_RUNNING)
 127   {
 128     int sig;
 129
 130     if (context->wait(sig) == -1)
 131     {
 132       Error << "sigwait() returned errno:" << strerror(errno);
 133       continue;
 134     }
 135
 136     switch (sig)
 137     {
 138     case SIGINT:
 139     case SIGQUIT:
 140       if (is_shutdown() == false)
 141       {
 142         Error << "Signal handling thread got signal " <<  strsignal(sig);
 143         set_shutdown(SHUTDOWN_FORCED);
 144       }
 145       break;
 146
 147     default:
 148       Error << "Signal handling thread got unexpected signal " <<  strsignal(sig);
 149       break;
 150     }
 151   }
 152
 153   delete context;
 154
 155   return NULL;
 156 }
 157
 158 }
 159
 160 void setup_signals()
 161 {
 162   pthread_mutex_init(&shutdown_mutex, NULL);
 163   set_shutdown(SHUTDOWN_RUNNING);
 164
 165   context_st *context= new context_st;
 166
 167   assert(context);
 168
 169   sigset_t old_set;
 170   sigemptyset(&old_set);
 171   pthread_sigmask(SIG_BLOCK, NULL, &old_set);
 172
 173   if (sigismember(&old_set, SIGQUIT))
 174   {
 175     Error << strsignal(SIGQUIT) << " has been previously set.";
 176   }
 177   if (sigismember(&old_set, SIGINT))
 178   {
 179     Error << strsignal(SIGINT) << " has been previously set.";
 180   }
 181
 182   int error;
 183   if ((error= pthread_sigmask(SIG_BLOCK, &context->set, NULL)) != 0)
 184   {
 185     Error << "pthread_sigmask() died during pthread_sigmask(" << strerror(error) << ")";
 186     exit(EXIT_FAILURE);
 187   }
 188
 189   if ((error= pthread_create(&thread, NULL, &sig_thread, (void *) &context->set)) != 0)
 190   {
 191     Error << "pthread_create() died during pthread_create(" << strerror(error) << ")";
 192     exit(EXIT_FAILURE);
 193   }
 194
 195   sem_wait(&context->lock);
 196 }