From 675695cde136139554fe35072bf2b2010006268f Mon Sep 17 00:00:00 2001
From: Akash Mozumdar <akashmozumdar@gmail.com>
Date: Sat, 5 Jun 2021 02:58:53 -0600
Subject: [PATCH] prevent write starvation

---
 GUI/extenwindow.cpp         | 7 +++----
 extensions/regexfilter.cpp  | 4 ++--
 extensions/replacer.cpp     | 4 ++--
 extensions/threadlinker.cpp | 4 ++--
 include/common.h            | 2 +-
 5 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/GUI/extenwindow.cpp b/GUI/extenwindow.cpp
index 76c5e80..07ab793 100644
--- a/GUI/extenwindow.cpp
+++ b/GUI/extenwindow.cpp
@@ -1,6 +1,5 @@
 #include "extenwindow.h"
 #include "ui_extenwindow.h"
-#include <concrt.h>
 #include <QMenu>
 #include <QFileDialog>
 #include <QDragEnterEvent>
@@ -44,7 +43,7 @@ namespace
 			{
 				if (auto callback = (decltype(Extension::callback))GetProcAddress(module, "OnNewSentence"))
 				{
-					std::scoped_lock writeLock(extenMutex);
+					std::scoped_lock lock(extenMutex);
 					extensions.push_back({ S(extenName), callback });
 					return true;
 				}
@@ -63,7 +62,7 @@ namespace
 
 	void Reorder(QStringList extenNames)
 	{
-		std::scoped_lock writeLock(extenMutex);
+		std::scoped_lock lock(extenMutex);
 		std::vector<Extension> extensions;
 		for (auto extenName : extenNames)
 			extensions.push_back(*std::find_if(::extensions.begin(), ::extensions.end(), [&](Extension extension) { return extension.name == S(extenName); }));
@@ -128,7 +127,7 @@ bool DispatchSentenceToExtensions(std::wstring& sentence, const InfoForExtension
 
 void CleanupExtensions()
 {
-	std::scoped_lock writeLock(extenMutex);
+	std::scoped_lock lock(extenMutex);
 	for (auto extension : extensions) FreeLibrary(GetModuleHandleW((extension.name + L".xdll").c_str()));
 	extensions.clear();
 }
diff --git a/extensions/regexfilter.cpp b/extensions/regexfilter.cpp
index 69560f9..2ba237b 100644
--- a/extensions/regexfilter.cpp
+++ b/extensions/regexfilter.cpp
@@ -13,7 +13,7 @@ const char* REGEX_SAVE_FILE = "SavedRegexFilters.txt";
 
 std::optional<std::wregex> regex;
 std::wstring replace = L"$1";
-std::shared_mutex m;
+concurrency::reader_writer_lock m;
 DWORD (*GetSelectedProcessId)() = nullptr;
 
 class Window : public QDialog, Localizer
@@ -66,7 +66,7 @@ bool ProcessSentence(std::wstring& sentence, SentenceInfo sentenceInfo)
 		while (auto read = savedFilters.Next()) if (read->at(0) == processName) regexes.push_back(std::move(read->at(1)));
 		if (!regexes.empty()) QMetaObject::invokeMethod(&window, std::bind(&Window::SetRegex, &window, S(regexes.back())), Qt::BlockingQueuedConnection);
 	}
-	std::shared_lock lock(m);
+	concurrency::reader_writer_lock::scoped_lock_read readLock(m);
 	if (regex) sentence = std::regex_replace(sentence, regex.value(), replace);
 	return true;
 }
diff --git a/extensions/replacer.cpp b/extensions/replacer.cpp
index 03ae8dc..6d5fa33 100644
--- a/extensions/replacer.cpp
+++ b/extensions/replacer.cpp
@@ -10,7 +10,7 @@ extern const wchar_t* REPLACER_INSTRUCTIONS;
 constexpr auto REPLACE_SAVE_FILE = u8"SavedReplacements.txt";
 
 std::atomic<std::filesystem::file_time_type> replaceFileLastWrite = {};
-std::shared_mutex m;
+concurrency::reader_writer_lock m;
 
 class Trie
 {
@@ -121,7 +121,7 @@ bool ProcessSentence(std::wstring& sentence, SentenceInfo)
 {
 	UpdateReplacements();
 
-	std::shared_lock lock(m);
+	concurrency::reader_writer_lock::scoped_lock_read readLock(m);
 	sentence = trie.Replace(sentence);
 	return true;
 }
diff --git a/extensions/threadlinker.cpp b/extensions/threadlinker.cpp
index fb4ff00..0fc5230 100644
--- a/extensions/threadlinker.cpp
+++ b/extensions/threadlinker.cpp
@@ -10,7 +10,7 @@ extern const char* THREAD_LINK_TO;
 extern const char* HEXADECIMAL;
 
 std::unordered_map<int64_t, std::unordered_set<int64_t>> linkedTextHandles;
-std::shared_mutex m;
+concurrency::reader_writer_lock m;
 
 class Window : public QDialog, Localizer
 {
@@ -68,7 +68,7 @@ private:
 
 bool ProcessSentence(std::wstring& sentence, SentenceInfo sentenceInfo)
 {
-	std::shared_lock lock(m);
+	concurrency::reader_writer_lock::scoped_lock_read readLock(m);
 	auto links = linkedTextHandles.find(sentenceInfo["text number"]);
 	if (links != linkedTextHandles.end()) for (auto link : links->second)
 		((void(*)(int64_t, const wchar_t*))sentenceInfo["void (*AddText)(int64_t number, const wchar_t* text)"])(link, sentence.c_str());
diff --git a/include/common.h b/include/common.h
index 32e6d0a..ec37f27 100644
--- a/include/common.h
+++ b/include/common.h
@@ -2,6 +2,7 @@
 
 #define WIN32_LEAN_AND_MEAN
 #include <Windows.h>
+#include <concrt.h>
 #include <string>
 #include <vector>
 #include <deque>
@@ -15,7 +16,6 @@
 #include <optional>
 #include <thread>
 #include <mutex>
-#include <shared_mutex>
 #include <atomic>
 #include <filesystem>
 #include <cstdint>