From 004d01981905f420287bb0c61045d957553c0ac3 Mon Sep 17 00:00:00 2001
From: Dario <dario.rekowski@gmx.de>
Date: Fri, 5 Jun 2020 13:20:00 +0200
Subject: [PATCH] Update mutex, now using std::shared_mutex allowing reload of
 word list while server is running

---
 src/cpp/Crypto/mnemonic.cpp |  9 +++++++--
 src/cpp/Crypto/mnemonic.h   | 17 ++++++++++++-----
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/src/cpp/Crypto/mnemonic.cpp b/src/cpp/Crypto/mnemonic.cpp
index 53393ad3c..e9147ae99 100644
--- a/src/cpp/Crypto/mnemonic.cpp
+++ b/src/cpp/Crypto/mnemonic.cpp
@@ -4,6 +4,7 @@
 #include <memory>
 #include <cstring>
 #include <assert.h>
+#include <mutex> 
 #include "../dependencies/tinf/src/tinf.h"
 
 #include "DRRandom.h"
@@ -23,7 +24,7 @@ Mnemonic::~Mnemonic()
 
 int Mnemonic::init(void(*fill_words_func)(unsigned char*), unsigned int original_size, unsigned int compressed_size)
 {
-	Poco::Mutex::ScopedLock _lock(mWorkingMutex, 500);
+	std::unique_lock<std::shared_mutex> _lock(mWorkingMutex);
 	clear();
 
 	unsigned char* buffer = (unsigned char*)malloc(compressed_size);
@@ -152,8 +153,9 @@ int Mnemonic::init(void(*fill_words_func)(unsigned char*), unsigned int original
 	return -5;
 }
 
-short Mnemonic::getWordIndex(const char* word) const 
+short Mnemonic::getWordIndex(const char* word) 
 { 
+	std::shared_lock<std::shared_mutex> _lock(mWorkingMutex);
 	DHASH word_hash = DRMakeStringHash(word); 
 	auto it = mWordHashIndices.find(word_hash);
 	if (it != mWordHashIndices.end()) {
@@ -193,6 +195,7 @@ void Mnemonic::clear()
 
 std::string Mnemonic::getCompleteWordList()
 {
+	std::shared_lock<std::shared_mutex> _lock(mWorkingMutex);
 	std::string result("");
 	for (int i = 0; i < 2048; i++) {
 		if (mWords[i]) {
@@ -207,6 +210,7 @@ std::string Mnemonic::getCompleteWordList()
 
 void Mnemonic::printToFile(const char* filename)
 {
+	std::shared_lock<std::shared_mutex> _lock(mWorkingMutex);
 	FILE* f = fopen(filename, "wt");
 	auto words = getCompleteWordList();
 	fwrite(words.data(), 1, words.size(), f);
@@ -215,6 +219,7 @@ void Mnemonic::printToFile(const char* filename)
 
 Poco::JSON::Array Mnemonic::getSortedWordList()
 {
+	std::shared_lock<std::shared_mutex> _lock(mWorkingMutex);
 	std::list<std::string> words;
 	for (auto it = mWordHashIndices.begin(); it != mWordHashIndices.end(); it++) {
 		words.push_back(mWords[it->second]);
diff --git a/src/cpp/Crypto/mnemonic.h b/src/cpp/Crypto/mnemonic.h
index 216e122ee..afc708ac1 100644
--- a/src/cpp/Crypto/mnemonic.h
+++ b/src/cpp/Crypto/mnemonic.h
@@ -12,8 +12,8 @@
  */
 
 #include "../lib/DRHashList.h"
-#include "Poco/Mutex.h"
 #include <string>
+#include <shared_mutex>
 #include <map>
 #include <list>
 
@@ -30,9 +30,16 @@ public:
 
 	int init(void(*fill_words_func)(unsigned char*), unsigned int original_size, unsigned int compressed_size);
 
-	inline const char* getWord(short index) const {  if (index < 2048 && index >= 0) return mWords[index]; return nullptr; }
-	short getWordIndex(const char* word) const;
-	inline bool isWordExist(const std::string& word) const { return getWordIndex(word.data()) != -1; }
+	inline const char* getWord(short index) { 
+		std::shared_lock<std::shared_mutex> _lock(mWorkingMutex); 
+		if (index < 2048 && index >= 0) return mWords[index]; 
+		return nullptr; 
+	}
+	short getWordIndex(const char* word);
+	inline bool isWordExist(const std::string& word) {
+		std::shared_lock<std::shared_mutex> _lock(mWorkingMutex);
+		return getWordIndex(word.data()) != -1; 
+	}
 	// using only for debugging
 	std::string getCompleteWordList();
 
@@ -55,7 +62,7 @@ protected:
 	typedef std::pair<std::string, unsigned short> HashCollideWordEntry;
 	std::map<DHASH, unsigned short> mWordHashIndices;
 	std::map<DHASH, std::map<std::string, unsigned short>> mHashCollisionWords;
-	Poco::Mutex mWorkingMutex;
+	std::shared_mutex mWorkingMutex;
 
 };