fix: solve runtime issues with emscripten build

Signed-off-by: Jason Dellaluce <jasondellaluce@gmail.com>
Co-authored-by: Rohith Raju <rohithraju488@gmail.com>

userspace/falco/CMakeLists.txt

@@ -167,6 +167,7 @@ target_include_directories(falco PUBLIC ${FALCO_INCLUDE_DIRECTORIES})
 
 if (EMSCRIPTEN)
 	target_compile_options(falco PRIVATE "-sDISABLE_EXCEPTION_CATCHING=0")
+  target_link_options(falco PRIVATE "-sALLOW_MEMORY_GROWTH=1")
 	target_link_options(falco PRIVATE "-sDISABLE_EXCEPTION_CATCHING=0")
 	target_link_options(falco PRIVATE "-sEXPORTED_FUNCTIONS=['_main','_htons','_ntohs']")
 endif()

userspace/falco/app/actions/load_plugins.cpp

@@ -25,7 +25,7 @@ falco::app::run_result falco::app::actions::load_plugins(falco::app::state& s)
 #if !defined(MUSL_OPTIMIZED) and !defined(__EMSCRIPTEN__)
 	if (!s.config->m_plugins.empty())
 	{
-		return run_result::fatal("Loading plugins dynamic libraries is not supported with this Falco build");
+		return run_result::fatal("Loading plugins dynamic libraries is not supported by this Falco build");
 	}
 #endif
 	// Initialize the set of loaded event sources. 

userspace/falco/app/actions/process_events.cpp

@@ -493,6 +493,13 @@ falco::app::run_result falco::app::actions::process_events(falco::app::state& s)
 	{
 		print_enabled_event_sources(s);
 
+#ifdef __EMSCRIPTEN__
+		if(s.enabled_sources.size() > 1)
+		{
+			return run_result::fatal("enabling multiple event sources is not supported by this Falco build");
+		}
+#endif
+
 		// start event processing for all enabled sources
 		falco::semaphore termination_sem(s.enabled_sources.size());
 		std::vector<live_context> ctxs;

userspace/falco/falco_outputs.cpp

@@ -64,13 +64,16 @@ falco_outputs::falco_outputs(
 	{
 		add_output(output);
 	}
-
+#ifndef __EMSCRIPTEN__
 	m_worker_thread = std::thread(&falco_outputs::worker, this);
+#endif
 }
 
 falco_outputs::~falco_outputs()
 {
+#ifndef __EMSCRIPTEN__
 	this->stop_worker();
+#endif
 	for(auto o : m_outputs)
 	{
 		delete o;
@@ -274,6 +277,11 @@ inline void falco_outputs::push(const ctrl_msg& cmsg)
 		fprintf(stderr, "Fatal error: Output queue reached maximum capacity. Exiting.\n");
 		exit(EXIT_FAILURE);
 	}
+#else
+	for (auto o : m_outputs)
+	{
+		process_msg(o, cmsg);
+	}
 #endif
 }
 
@@ -297,11 +305,24 @@ void falco_outputs::worker() noexcept
 		m_queue.pop(cmsg);
 #endif
 
-		for(const auto o : m_outputs)
+		for(auto o : m_outputs)
 		{
 			wd.set_timeout(timeout, o->get_name());
 			try
 			{
+				process_msg(o, cmsg);
+			}
+			catch(const std::exception &e)
+			{
+				falco_logger::log(LOG_ERR, o->get_name() + ": " + std::string(e.what()) + "\n");
+			}
+		}
+		wd.cancel_timeout();
+	} while(cmsg.type != ctrl_msg_type::CTRL_MSG_STOP);
+}
+
+inline void falco_outputs::process_msg(falco::outputs::abstract_output* o, const ctrl_msg& cmsg)
+{
 	switch(cmsg.type)
 	{
 		case ctrl_msg_type::CTRL_MSG_OUTPUT:
@@ -317,12 +338,4 @@ void falco_outputs::worker() noexcept
 		default:
 			falco_logger::log(LOG_DEBUG, "Outputs worker received an unknown message type\n");
 	}
-			}
-			catch(const std::exception &e)
-			{
-				falco_logger::log(LOG_ERR, o->get_name() + ": " + std::string(e.what()) + "\n");
-			}
-		}
-		wd.cancel_timeout();
-	} while(cmsg.type != ctrl_msg_type::CTRL_MSG_STOP);
 }

userspace/falco/falco_outputs.h

@@ -118,4 +118,5 @@ private:
 	void worker() noexcept;
 	void stop_worker();
 	void add_output(falco::outputs::config oc);
+	inline void process_msg(falco::outputs::abstract_output* o, const ctrl_msg& cmsg);
 };