Improve segfault handling with better error messages, and add segfaul…

…t command (simulation only) for testing

src/Werk/Application/ApplicationContext.cpp

@@ -31,6 +31,7 @@
 #include <unistd.h>
 
 #include "Werk/Commands/CommandAlias.hpp"
+#include "Werk/Commands/SegfaultCommand.hpp"
 #include "Werk/Commands/WriteCommandLogAction.hpp"
 #include "Werk/Console/ConsoleCommandReceiver.hpp"
 #include "Werk/Console/IpcConsoleServer.hpp"
@@ -231,6 +232,12 @@ ApplicationContext::ApplicationContext(const std::string &configPath) :
 	_commandManager->add("quit", new ActionCommand(
 		quitAction,
 		"Quits the application cleanly."));
+
+	//Some commands are only available in simulation
+	if (_simulation) {
+		_commandManager->add("segfault", new SegfaultCommand(_log));
+	}
+
 	_log->logRaw(LogLevel::SUCCESS, "<CommandManager> Initialized.");
 
 	//Setup command aliases configured like so:
@@ -385,7 +392,7 @@ int ApplicationContext::run(Action *mainAction)
 		"Number of times the main thread can miss the watchdog");
 	//TODO: configurable watchdog action
 	Watchdog *watchdog = new Watchdog("Watchdog", &_backgroundThread.backgroundClock(),
-		new LogAction("WatchdogWarning", new StringLoggable("Main thread missed watchdog!", LogLevel::WARNING), _log),
+		new LogAction("WatchdogWarning", new StringLoggable("Main thread missed watchdog timer! It may be hung or dead.", LogLevel::ERROR), _log),
 		watchdogInterval, watchdogAllowedMisses);
 
 	if (0 != watchdogInterval) {

src/Werk/Commands/SegfaultCommand.hpp

@@ -0,0 +1,57 @@
+
+/*
+ * Copyright (c) 2015-2020 Agalmic Ventures LLC (www.agalmicventures.com)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#pragma once
+
+#include <signal.h>
+
+#include "Werk/Logging/Log.hpp"
+
+#include "Command.hpp"
+
+namespace werk
+{
+
+/**
+ * Command to intentionally cause a segfault -- useful for debugging the handler.
+ */
+class SegfaultCommand : public Command
+{
+public:
+
+	SegfaultCommand(Log *log) :
+		Command("Segfaults the program (useful for testing)."),
+		_log(log) { }
+
+	bool execute(const std::vector<std::string> &arguments) override {
+		//Join all but the first argument since the command name needn't be echoed
+		_log->logRaw(LogLevel::WARNING, "Intentionally segfaulting...");
+		raise(SIGSEGV);
+		return true;
+	}
+
+private:
+	Log *_log;
+};
+
+}

src/Werk/OS/Signals.cpp

@@ -49,6 +49,7 @@ static void handleBusError(int /*signal*/, siginfo_t *info, void * /*context*/)
 		<< "Cause: " << cause << "(" << info->si_code << ")" << std::endl;
 
 	//Sleep before aborting to allow logging to finish
+	std::cout << std::endl << "Sleeping 5 to allow other threads to finish (e.g. logging)..." << std::endl;
 	sleep(5);
 	std::abort();
 }
@@ -67,6 +68,7 @@ static void handleSegfault(int /*signal*/, siginfo_t *info, void * /*context*/)
 		<< "Cause: " << cause << "(" << info->si_code << ")" << std::endl;
 
 	//Sleep before aborting to allow logging to finish
+	std::cout << std::endl << "Sleeping 5 to allow other threads to finish (e.g. logging)..." << std::endl;
 	sleep(5);
 	std::abort();
 }