diff --git a/libs/client_server/piclientserver_server.cpp b/libs/client_server/piclientserver_server.cpp
index 7984d36f..4a6ec693 100644
--- a/libs/client_server/piclientserver_server.cpp
+++ b/libs/client_server/piclientserver_server.cpp
@@ -90,6 +90,18 @@ void PIClientServer::Server::listen(PINetworkAddress addr) {
 }
 
 
+void PIClientServer::Server::closeAll() {
+	clients_mutex.lock();
+	for (auto c: clients) {
+		c->aboutDelete();
+		c->destroy();
+		delete c;
+	}
+	clients.clear();
+	clients_mutex.unlock();
+}
+
+
 void PIClientServer::Server::setMaxClients(int new_max_clients) {
 	max_clients = new_max_clients;
 }
diff --git a/libs/main/client_server/piclientserver_server.h b/libs/main/client_server/piclientserver_server.h
index 37a380d1..784fa125 100644
--- a/libs/main/client_server/piclientserver_server.h
+++ b/libs/main/client_server/piclientserver_server.h
@@ -49,6 +49,8 @@ public:
 	void listen(PINetworkAddress addr);
 	void listenAll(ushort port) { listen({0, port}); }
 
+	void closeAll();
+
 	int getMaxClients() const { return max_clients; }
 	void setMaxClients(int new_max_clients);
 	int clientsCount() const;
diff --git a/libs/main/system/pisignals.cpp b/libs/main/system/pisignals.cpp
index c4518dd8..57fdc146 100644
--- a/libs/main/system/pisignals.cpp
+++ b/libs/main/system/pisignals.cpp
@@ -60,6 +60,33 @@ void PISignals::grabSignals(PIFlags<PISignals::Signal> signals_) {
 }
 
 
+void PISignals::releaseSignals(PIFlags<Signal> signals_) {
+	if (signals_[PISignals::Interrupt]) signal(signalCode(PISignals::Interrupt), SIG_DFL);
+	if (signals_[PISignals::Illegal]) signal(signalCode(PISignals::Illegal), SIG_DFL);
+	if (signals_[PISignals::Abort]) signal(signalCode(PISignals::Abort), SIG_DFL);
+	if (signals_[PISignals::FPE]) signal(signalCode(PISignals::FPE), SIG_DFL);
+	if (signals_[PISignals::SegFault]) signal(signalCode(PISignals::SegFault), SIG_DFL);
+	if (signals_[PISignals::Termination]) signal(signalCode(PISignals::Termination), SIG_DFL);
+#ifndef CC_VC
+	if (signals_[PISignals::UserDefined1]) signal(signalCode(PISignals::UserDefined1), SIG_DFL);
+	if (signals_[PISignals::UserDefined2]) signal(signalCode(PISignals::UserDefined2), SIG_DFL);
+#endif
+#ifndef WINDOWS
+	if (signals_[PISignals::Hangup]) signal(signalCode(PISignals::Hangup), SIG_DFL);
+	if (signals_[PISignals::Quit]) signal(signalCode(PISignals::Quit), SIG_DFL);
+	if (signals_[PISignals::Kill]) signal(signalCode(PISignals::Kill), SIG_DFL);
+	if (signals_[PISignals::BrokenPipe]) signal(signalCode(PISignals::BrokenPipe), SIG_DFL);
+	if (signals_[PISignals::Timer]) signal(signalCode(PISignals::Timer), SIG_DFL);
+	if (signals_[PISignals::ChildStopped]) signal(signalCode(PISignals::ChildStopped), SIG_DFL);
+	if (signals_[PISignals::Continue]) signal(signalCode(PISignals::Continue), SIG_DFL);
+	if (signals_[PISignals::StopProcess]) signal(signalCode(PISignals::StopProcess), SIG_DFL);
+	if (signals_[PISignals::StopTTY]) signal(signalCode(PISignals::StopTTY), SIG_DFL);
+	if (signals_[PISignals::StopTTYInput]) signal(signalCode(PISignals::StopTTYInput), SIG_DFL);
+	if (signals_[PISignals::StopTTYOutput]) signal(signalCode(PISignals::StopTTYOutput), SIG_DFL);
+#endif
+}
+
+
 void PISignals::raiseSignal(PISignals::Signal signal) {
 	raise(signalCode(signal));
 }
@@ -90,7 +117,7 @@ int PISignals::signalCode(PISignals::Signal signal) {
 	case PISignals::StopTTYInput: return SIGTTIN;
 	case PISignals::StopTTYOutput: return SIGTTOU;
 #endif
-	default:;
+	default: break;
 	}
 	return 0;
 }
@@ -121,13 +148,13 @@ PISignals::Signal PISignals::signalFromCode(int signal) {
 	case SIGTTIN: return PISignals::StopTTYInput;
 	case SIGTTOU: return PISignals::StopTTYOutput;
 #endif
-	default:;
+	default: break;
 	}
 	return PISignals::Termination;
 }
 
 
 void PISignals::signal_event(int signal) {
-	if (PISignals::ret_func == 0) return;
+	if (!PISignals::ret_func) return;
 	PISignals::ret_func(PISignals::signalFromCode(signal));
 }
diff --git a/libs/main/system/pisignals.h b/libs/main/system/pisignals.h
index d6064587..b9aad0e6 100644
--- a/libs/main/system/pisignals.h
+++ b/libs/main/system/pisignals.h
@@ -59,6 +59,7 @@ public:
 	// slot is any function format "void(PISignals::Signal)"
 	static void setSlot(SignalEvent slot) { ret_func = slot; }
 	static void grabSignals(PIFlags<PISignals::Signal> signals_);
+	static void releaseSignals(PIFlags<PISignals::Signal> signals_);
 	static void raiseSignal(PISignals::Signal signal);
 
 private: