text: /*  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
   *
   *  Data Differential YATL (i.e. libtest)  library
   *
   *  Copyright (C) 2012 Data Differential, http://datadifferential.com/
   *
   *  Redistribution and use in source and binary forms, with or without
   *  modification, are permitted provided that the following conditions are
   *  met:
   *
   *      * Redistributions of source code must retain the above copyright
   *  notice, this list of conditions and the following disclaimer.
   *
   *      * Redistributions in binary form must reproduce the above
   *  copyright notice, this list of conditions and the following disclaimer
   *  in the documentation and/or other materials provided with the
   *  distribution.
   *
   *      * The names of its contributors may not be used to endorse or
   *  promote products derived from this software without specific prior
   *  written permission.
   *
   *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   *  OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   */
  
  #include "libtest/yatlcon.h"
  #include <libtest/common.h>
  
  #include <fcntl.h>
  #include <semaphore.h>
  #include <unistd.h>
  
  #include <csignal>
  
  #include <libtest/signal.h>
  
  using namespace libtest;
  
  #define MAGIC_MEMORY 123569
  
  bool SignalThread::is_shutdown()
  {
    bool ret;
    pthread_mutex_lock(&shutdown_mutex);
    ret= bool(__shutdown != SHUTDOWN_RUNNING);
    pthread_mutex_unlock(&shutdown_mutex);
  
    return ret;
  }
  
  void SignalThread::set_shutdown(shutdown_t arg)
  {
    pthread_mutex_lock(&shutdown_mutex);
    __shutdown= arg;
    pthread_mutex_unlock(&shutdown_mutex);
  
    if (arg == SHUTDOWN_GRACEFUL)
    {
      if (pthread_kill(thread, SIGUSR2) == 0)
      {
        void *retval;
        pthread_join(thread, &retval);
      }
    }
  }
  
  shutdown_t SignalThread::get_shutdown()
  {
    shutdown_t local;
    pthread_mutex_lock(&shutdown_mutex);
    local= __shutdown;
    pthread_mutex_unlock(&shutdown_mutex);
  
    return local;
  }
  
  void SignalThread::post()
  {
    sem_post(lock);
  }
  
  void SignalThread::test()
  {
    fatal_assert(magic_memory == MAGIC_MEMORY);
  
    if (bool(getenv("LIBTEST_IN_GDB")) == false)
    {
      assert(sigismember(&set, SIGALRM));
      assert(sigismember(&set, SIGABRT));
      assert(sigismember(&set, SIGQUIT));
      assert(sigismember(&set, SIGINT));
      assert(sigismember(&set, SIGVTALRM));
    }
    assert(sigismember(&set, SIGUSR2));
  }
  
  bool SignalThread::unblock()
  {
    int error;
    if ((error= pthread_sigmask(SIG_UNBLOCK, &set, NULL)) != 0)
    {
      Error << "While trying to reset signal mask to original set, pthread_sigmask() died during pthread_sigmask(" << strerror(error) << ")";
      return false;
    }
  
    return true;
  }
  
  SignalThread::~SignalThread()
  {
    if (is_shutdown() == false)
    {
      set_shutdown(SHUTDOWN_GRACEFUL);
    }
  
  #if 0
    if (pthread_equal(thread, pthread_self()) != 0 and (pthread_kill(thread, 0) == ESRCH) == true)
    {
      void *retval;
      pthread_join(thread, &retval);
    }
  #endif
    sem_close(lock);
  
    unblock();
  }
  
  extern "C" {
  
  static void *sig_thread(void *arg)
  {   
    SignalThread *context= (SignalThread*)arg;
  
    context->test();
    context->post();
  
    while (context->get_shutdown() == SHUTDOWN_RUNNING)
    {
      int sig;
  
      if (context->wait(sig) == -1)
      {
        Error << "sigwait() returned errno:" << strerror(errno);
        continue;
      }
  
      switch (sig)
      {
      case SIGALRM:
      case SIGVTALRM:
        Error << strsignal(sig);
        if (gdb_is_caller())
        {
          abort();
        }
        exit(EXIT_FAILURE);
  
      case SIGABRT:
      case SIGUSR2:
      case SIGINT:
      case SIGQUIT:
        if (context->is_shutdown() == false)
        {
          context->set_shutdown(SHUTDOWN_FORCED);
        }
        break;
      case SIGPIPE:
        {
          Error << "Ignoring SIGPIPE";
        }
        break;
  
      case 0:
        Error << "Inside of gdb";
        break;
  
      default:
        Error << "Signal handling thread got unexpected signal " <<  strsignal(sig);
        break;
      }
    }
  
    return NULL;
  }
  
  }
  
  SignalThread::SignalThread() :
    magic_memory(MAGIC_MEMORY),
    thread(pthread_self())
  {
    pthread_mutex_init(&shutdown_mutex, NULL);
    sigemptyset(&set);
    if (bool(getenv("LIBTEST_IN_GDB")) == false)
    {
      sigaddset(&set, SIGALRM);
      sigaddset(&set, SIGABRT);
      sigaddset(&set, SIGQUIT);
      sigaddset(&set, SIGINT);
      sigaddset(&set, SIGVTALRM);
    }
    sigaddset(&set, SIGPIPE);
  
    sigaddset(&set, SIGUSR2);
  
    strcpy(lock_name, "/XXXXXXXX");
    mktemp(lock_name);
  
    sigemptyset(&original_set);
    pthread_sigmask(SIG_BLOCK, NULL, &original_set);
  }
  
  
  bool SignalThread::setup()
  {
    set_shutdown(SHUTDOWN_RUNNING);
    lock = sem_open(lock_name, O_CREAT|O_EXCL);
    if (lock == SEM_FAILED)
    {
      Error << strerror(errno) << " when opening lock.";
    }
  
  
    if (sigismember(&original_set, SIGQUIT))
    {
      Error << strsignal(SIGQUIT) << " has been previously set.";
    }
  
    if (sigismember(&original_set, SIGINT))
    {
      Error << strsignal(SIGINT) << " has been previously set.";
    }
  
    if (sigismember(&original_set, SIGVTALRM))
    {
      Error << strsignal(SIGVTALRM) << " has been previously set.";
    }
  
    if (sigismember(&original_set, SIGUSR2))
    {
      Error << strsignal(SIGUSR2) << " has been previously set.";
    }
  
    int error;
    if ((error= pthread_sigmask(SIG_BLOCK, &set, NULL)) != 0)
    {
      Error << "pthread_sigmask() died during pthread_sigmask(" << strerror(error) << ")";
      return false;
    }
  
    if ((error= pthread_create(&thread, NULL, &sig_thread, this)) != 0)
    {
      Error << "pthread_create() died during pthread_create(" << strerror(error) << ")";
      return false;
    }
  
    sem_wait(lock);
  
    return true;
  }
  