system/luaserver: Terminate Lua script when luaclient dies.

src/gui/luainstance.cpp

@@ -480,6 +480,16 @@ void CLuaInstance::runScript(const char *fileName, const char *arg0, ...)
 	args.clear();
 }
 
+static void abortHook(lua_State *lua, lua_Debug *)
+{
+	luaL_error(lua, "aborted");
+}
+
+void CLuaInstance::abortScript()
+{
+	lua_sethook(lua, &abortHook, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1);
+}
+
 const luaL_Reg CLuaInstance::methods[] =
 {
 	{ "PaintBox", CLuaInstance::PaintBox },

src/gui/luainstance.h

@@ -176,6 +176,7 @@ public:
 	CLuaInstance();
 	~CLuaInstance();
 	void runScript(const char *fileName, std::vector<std::string> *argv = NULL, std::string *result_code = NULL, std::string *result_string = NULL, std::string *error_string = NULL);
+	void abortScript();
 
 	// Example: runScript(fileName, "Arg1", "Arg2", "Arg3", ..., NULL);
 	//	Type of all parameters: const char*

src/system/luaserver.cpp

@@ -114,7 +114,10 @@ bool CLuaServer::Block(const neutrino_msg_t msg, const neutrino_msg_data_t data)
 class luaserver_data
 {
 	public:
+		CLuaInstance *lua;
+		bool died;
 		int fd;
+
 		std::vector<std::string> argv;
 		std::string script;
 
@@ -122,6 +125,7 @@ class luaserver_data
 			fd = dup(_fd);
 			fcntl(fd, F_SETFD, FD_CLOEXEC);
 			script = _script;
+			died = false;
 		}
 		~luaserver_data(void) {
 			close(fd);
@@ -138,6 +142,21 @@ void CLuaServer::UnLock(void)
 	pthread_mutex_unlock(&mutex);
 }
 
+void *CLuaServer::luaclient_watchdog(void *arg) {
+	set_threadname(__func__);
+	pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, NULL);
+
+	luaserver_data *lsd = (class luaserver_data *)arg;
+
+	struct pollfd pfd;
+	pfd.fd = lsd->fd;
+	pfd.events = pfd.revents = 0;
+	poll(&pfd, 1, -1);
+	lsd->lua->abortScript();
+	lsd->died = true;
+	pthread_exit(NULL);
+}
+
 void *CLuaServer::luaserver_thread(void *arg) {
 	set_threadname(__func__);
 	Lock();
@@ -149,28 +168,35 @@ void *CLuaServer::luaserver_thread(void *arg) {
 
 	luaserver_data *lsd = (class luaserver_data *)arg;
 
+	pthread_t wdthr;
+	pthread_create (&wdthr, NULL, luaclient_watchdog, (void *) lsd);
+
 	CLuaInstance lua;
+	lsd->lua = &lua;
 	std::string result_code;
 	std::string result_string;
 	std::string error_string;
 	lua.runScript(lsd->script.c_str(), &lsd->argv, &result_code, &result_string, &error_string);
-	size_t result_code_len = result_code.length() + 1;
-	size_t result_string_len = result_string.length() + 1;
-	size_t error_string_len = error_string.length() + 1;
-	size_t size = result_code_len + result_string_len + error_string_len;
-	char result[size + sizeof(size)];
-	char *rp = result;
-	memcpy(rp, &size, sizeof(size));
-	rp += sizeof(size);
-	size += sizeof(size);
-	memcpy(rp, result_code.c_str(), result_code_len);
-	rp += result_code_len;
-	memcpy(rp, result_string.c_str(), result_string_len);
-	rp += result_string_len;
-	memcpy(rp, error_string.c_str(), error_string_len);
-	rp += error_string_len;
-	CBasicServer::send_data(lsd->fd, result, size);
-
+	pthread_cancel(wdthr);
+	pthread_join(wdthr, NULL);
+	if (!lsd->died) {
+		size_t result_code_len = result_code.length() + 1;
+		size_t result_string_len = result_string.length() + 1;
+		size_t error_string_len = error_string.length() + 1;
+		size_t size = result_code_len + result_string_len + error_string_len;
+		char result[size + sizeof(size)];
+		char *rp = result;
+		memcpy(rp, &size, sizeof(size));
+		rp += sizeof(size);
+		size += sizeof(size);
+		memcpy(rp, result_code.c_str(), result_code_len);
+		rp += result_code_len;
+		memcpy(rp, result_string.c_str(), result_string_len);
+		rp += result_string_len;
+		memcpy(rp, error_string.c_str(), error_string_len);
+		rp += error_string_len;
+		CBasicServer::send_data(lsd->fd, result, size);
+	}
 	delete lsd;
 	Lock();
 	if (instance) {

src/system/luaserver.h

@@ -32,6 +32,7 @@ class CLuaServer
 
 		static void *luaserver_thread(void *arg);
 		static void *luaserver_main_thread(void *);
+		static void *luaclient_watchdog(void *);
 		static bool luaserver_parse_command(CBasicMessage::Header &rmsg, int connfd);
 		static void Lock();
 		static void UnLock();