Example #1
0
// This gets it's own thread, and polls the client once per second to see if
// there is a signal, i.e., if the user has pressed Ctrl-C, etc. If there is a
// signal, it is passed as an interrupt to the proxy in an attempt to get other
// threads in the sandbox to stop.
//
// If another thread in the sandbox fails to stop and consume the signal then
// it will be passed to the dummy sandbox instead.
void DebuggerProxy::pollSignal() {
  TRACE(2, "DebuggerProxy::pollSignal\n");
  while (!m_stopped) {
    sleep(1);

    // after 1 second that no active thread picks up the signal, we send it
    // to dummy sandbox
    if (m_signum != CmdSignal::SignalNone && m_dummySandbox) {
      Lock lock(m_signumMutex);
      if (m_signum != CmdSignal::SignalNone) {
        m_dummySandbox->notifySignal(m_signum);
        m_signum = CmdSignal::SignalNone;
      }
    }

    Lock lock(m_signalMutex);

    // Send CmdSignal over to the client and wait for a response.
    CmdSignal cmd;
    if (!cmd.onServer(this)) break; // on socket error

    DebuggerCommandPtr res;
    while (!DebuggerCommand::Receive(m_thrift, res,
                                     "DebuggerProxy::pollSignal()")) {
      // We will wait forever until DebuggerClient sends us something.
    }
    if (!res) break;

    CmdSignalPtr sig = dynamic_pointer_cast<CmdSignal>(res);
    if (!sig) {
      Logger::Error("bad response from signal polling: %d", res->getType());
      break;
    }

    m_signum = sig->getSignal();

    if (m_signum != CmdSignal::SignalNone) {
      Debugger::RequestInterrupt(shared_from_this());
    }
  }
}
Example #2
0
// This gets it's own thread, and polls the client once per second to see if
// there is a signal, i.e., if the user has pressed Ctrl-C, etc. If there is a
// signal, it is passed as an interrupt to the proxy in an attempt to get other
// threads in the sandbox to stop.
//
// If another thread in the sandbox fails to stop and consume the signal then
// it will be passed to the dummy sandbox instead.
void DebuggerProxy::pollSignal() {
  TRACE_RB(2, "DebuggerProxy::pollSignal: starting\n");
  int signalTimeout = RuntimeOption::DebuggerSignalTimeout;
  while (!m_stopped) {
    sleep(1);

    // Block any threads that might be interrupting from communicating with the
    // client until we're done with this poll.
    Lock lock(m_signalMutex);

    // After DebuggerSignalTimeout seconds that no active thread picks
    // up the signal, we send it to dummy sandbox.
    if ((m_signum != CmdSignal::SignalNone) && m_dummySandbox &&
        (--signalTimeout <= 0)) {
      TRACE_RB(2, "DebuggerProxy::pollSignal: sending to dummy sandbox\n");
      m_dummySandbox->notifySignal(m_signum);
      m_signum = CmdSignal::SignalNone;
    }

    // Don't actually poll if another thread is already in a command
    // processing loop with the client.
    if (!m_okayToPoll) continue;

    // Send CmdSignal over to the client and wait for a response.
    CmdSignal cmd;
    if (!cmd.onServer(*this)) {
      TRACE_RB(2, "DebuggerProxy::pollSignal: "
               "Failed to send CmdSignal to client\n");
      break;
    }

    // We've sent the client a command, and we expect an immediate
    // response. Wait 10 times to give it a chance on especially
    // overloaded computers.
    DebuggerCommandPtr res;
    for (int i = 0; i < 10; i++) {
      if (DebuggerCommand::Receive(m_thrift, res,
                                   "DebuggerProxy::pollSignal()")) break;
      if (m_stopped) {
        TRACE_RB(2, "DebuggerProxy::pollSignal: "
                 "signal thread asked to stop while waiting "
                 "for CmdSignal back from the client\n");
        break;
      }
    }
    if (!res) {
      if (!m_stopped) {
        TRACE_RB(2, "DebuggerProxy::pollSignal: "
                 "Failed to get CmdSignal back from client\n");
      }
      break;
    }

    CmdSignalPtr sig = dynamic_pointer_cast<CmdSignal>(res);
    if (!sig) {
      TRACE_RB(2, "DebuggerProxy::pollSignal: "
               "bad response from signal polling: %d", res->getType());
      break;
    }

    auto newSignum = sig->getSignal();

    if (newSignum != CmdSignal::SignalNone) {
      TRACE_RB(2, "DebuggerProxy::pollSignal: "
               "got interrupt signal from client\n");
      m_signum = newSignum;
      signalTimeout = RuntimeOption::DebuggerSignalTimeout;
      Debugger::RequestInterrupt(shared_from_this());
    }
  }
  if (!m_stopped) {
    // We've noticed that the socket has closed. Stop and destory this proxy.
    TRACE_RB(2, "DebuggerProxy::pollSignal: "
             "lost communication with the client, stopping proxy\n");
    Debugger::UsageLog("server", getSandboxId(), "ProxyError", "Signal poll");
    stop();
  }
  TRACE_RB(2, "DebuggerProxy::pollSignal: ended\n");
}