[Blockable] add global set of all blocked contexts for debugging

This feature must be activated using the blocked_context_set meson option.

emper/Blockable.hpp

@@ -9,7 +9,11 @@
 #include "Context.hpp"
 #include "ContextManager.hpp"
 #include "Debug.hpp"
+#include "Emper.hpp"
 #include "Runtime.hpp"
+#include "lib/adt/LockedSet.hpp"
+
+static emper::lib::adt::LockedSet<Context*> blockedContexts;
 
 template <LogSubsystem logSubsystem>
 class Blockable : public Logger<logSubsystem> {
@@ -29,12 +33,21 @@ class Blockable : public Logger<logSubsystem> {
 		assert(Runtime::inRuntime());
 
 		LOGD("block() blockedContext is " << Context::getCurrentContext());
+
+		if constexpr (emper::BLOCKED_CONTEXT_SET) {
+			blockedContexts.insert(Context::getCurrentContext());
+		}
+
 		contextManager.saveAndStartNew(std::move(freshContextHook));
 	}
 
 	template <CallerEnvironment callerEnvironment = CallerEnvironment::EMPER>
 	void unblock(Context* context) {
 		assert(context != nullptr);
+		if constexpr (emper::BLOCKED_CONTEXT_SET) {
+			blockedContexts.erase(context);
+		}
+
 		// cppcheck-suppress unsafeClassCanLeak
 		Fiber* unblockFiber =
 				Fiber::from([this, context]() { contextManager.discardAndResume(context); });

emper/Emper.hpp

@@ -65,4 +65,12 @@ static const bool OVERFLOW_QUEUE =
 		;
 
 auto getFullVersion() -> std::string;
+
+static const bool BLOCKED_CONTEXT_SET =
+#ifdef EMPER_BLOCKED_CONTEXT_SET
+		DEBUG
+#else
+		false
+#endif
+		;
 }	 // namespace emper

emper/lib/adt/LockedSet.hpp

+// SPDX-License-Identifier: LGPL-3.0-or-later
+// Copyright © 2020 Florian Fischer
+#pragma once
+
+#include <iterator>
+#include <mutex>
+#include <set>
+
+namespace emper::lib::adt {
+
+template <class Key, class Compare = std::less<Key>, class Allocator = std::allocator<Key>>
+class LockedSet {
+ private:
+	std::mutex _mutex;
+	std::set<Key, Compare, Allocator> _set;
+
+ public:
+	auto insert(const Key& item)
+			-> std::pair<typename std::set<Key, Compare, Allocator>::iterator, bool> {
+		std::lock_guard<std::mutex> lock(_mutex);
+		return _set.insert(item);
+	}
+
+	template <class InputIt>
+	void insert(InputIt first, InputIt last) {
+		std::lock_guard<std::mutex> lock(_mutex);
+		_set.insert(first, last);
+	}
+
+	size_t erase(const Key& key) {
+		std::lock_guard<std::mutex> lock(_mutex);
+		return _set.erase(key);
+	}
+};
+}	 // namespace emper::lib::adt

meson.build

@@ -32,6 +32,7 @@ conf_data.set('EMPER_OVERFLOW_QUEUE', get_option('overflow_queue'))
 conf_data.set('EMPER_LOCKED_MPSC_QUEUE', get_option('locked_mpsc_queue'))
 conf_data.set('EMPER_STATS', get_option('stats'))
 conf_data.set('EMPER_OVERFLOW_QUEUE', get_option('overflow_queue'))
+conf_data.set('EMPER_BLOCKED_CONTEXT_SET', get_option('blocked_context_set'))
 
 default_scheduling_strategy = get_option('default_scheduling_strategy')
 conf_data.set('EMPER_DEFAULT_SCHEDULING_STRATEGY_' + default_scheduling_strategy.to_upper(), true)

meson_options.txt

@@ -10,6 +10,12 @@ option(
   choices: ['automatic', 'OFF', 'Error', 'Warning', 'Info', 'Debug', 'FineDebug', 'FinerDebug', 'FinestDebug', 'ALL'],
   value: 'automatic',
 )
+option(
+  'blocked_context_set',
+  type: 'boolean',
+  value: false,
+  description: 'Store all currently blocked contexts for debugging in the set Blockable<LogLevel>::blocked'
+)
 option(
   'log_timestamp',
   type: 'boolean',