// 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());
}
}
}
// 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");
}