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

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   2  *
   3  *  uTest, libtest
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  36
  37 #include <libtest/common.h>
  38
  39 #include <pthread.h>
  40 #include <semaphore.h>
  41 #include <signal.h>
  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, SIGABRT);
  55     sigaddset(&set, SIGINT);
  56     sigaddset(&set, SIGUSR2);
  57
  58     sem_init(&lock, 0, 0);
  59   }
  60
  61   void test()
  62   {
  63     assert(sigismember(&set, SIGABRT));
  64     assert(sigismember(&set, SIGINT));
  65     assert(sigismember(&set, SIGUSR2));
  66   }
  67
  68   int wait(int& sig)
  69   {
  70     return sigwait(&set, &sig);
  71   }
  72
  73   ~context_st()
  74   {
  75     sem_destroy(&lock);
  76   }
  77 };
  78
  79 static volatile shutdown_t __shutdown;
  80 static pthread_mutex_t shutdown_mutex;
  81 static pthread_t thread;
  82
  83 bool is_shutdown()
  84 {
  85   bool ret;
  86   pthread_mutex_lock(&shutdown_mutex);
  87   ret= bool(__shutdown != SHUTDOWN_RUNNING);
  88   pthread_mutex_unlock(&shutdown_mutex);
  89
  90   return ret;
  91 }
  92
  93 void set_shutdown(shutdown_t arg)
  94 {
  95   pthread_mutex_lock(&shutdown_mutex);
  96   __shutdown= arg;
  97   pthread_mutex_unlock(&shutdown_mutex);
  98
  99   if (arg == SHUTDOWN_GRACEFUL)
 100   {
 101     pthread_kill(thread, SIGUSR2);
 102
 103     void *retval;
 104     pthread_join(thread, &retval);
 105   }
 106 }
 107
 108 shutdown_t get_shutdown()
 109 {
 110   shutdown_t local;
 111   pthread_mutex_lock(&shutdown_mutex);
 112   local= __shutdown;
 113   pthread_mutex_unlock(&shutdown_mutex);
 114
 115   return local;
 116 }
 117
 118 extern "C" {
 119
 120 static void *sig_thread(void *arg)
 121 {
 122   context_st *context= (context_st*)arg;
 123   assert(context);
 124
 125   context->test();
 126   sem_post(&context->lock);
 127
 128   while (get_shutdown() == SHUTDOWN_RUNNING)
 129   {
 130     int sig;
 131
 132     if (context->wait(sig) == -1)
 133     {
 134       Error << "sigwait() returned errno:" << strerror(errno);
 135       continue;
 136     }
 137
 138     switch (sig)
 139     {
 140     case SIGABRT:
 141     case SIGINT:
 142       Error << "Signal handling thread got signal " <<  strsignal(sig);
 143       set_shutdown(SHUTDOWN_FORCED);
 144       break;
 145
 146       // Signal thread is being told that a graceful shutdown is occuring
 147     case SIGUSR2:
 148       break;
 149
 150     default:
 151       Error << "Signal handling thread got unexpected signal " <<  strsignal(sig);
 152       break;
 153     }
 154   }
 155
 156   delete context;
 157
 158   return NULL;
 159 }
 160
 161 }
 162
 163 void setup_signals()
 164 {
 165   pthread_mutex_init(&shutdown_mutex, NULL);
 166   set_shutdown(SHUTDOWN_RUNNING);
 167
 168   context_st *context= new context_st;
 169
 170   assert(context);
 171
 172   int error;
 173   if ((error= pthread_sigmask(SIG_BLOCK, &context->set, NULL)) != 0)
 174   {
 175     Error << "pthread_sigmask() died during pthread_sigmask(" << strerror(error) << ")";
 176     exit(EXIT_FAILURE);
 177   }
 178
 179   if ((error= pthread_create(&thread, NULL, &sig_thread, (void *) &context->set)) != 0)
 180   {
 181     Error << "pthread_create() died during pthread_create(" << strerror(error) << ")";
 182     exit(EXIT_FAILURE);
 183   }
 184
 185   sem_wait(&context->lock);
 186 }