From 38bb6b72da1d3f5cfa4c72d8bc9597229423c0e3 Mon Sep 17 00:00:00 2001
From: Lubos Dolezel <lubos@dolezel.info>
Date: Tue, 7 Jul 2015 23:08:03 +0200
Subject: Partial lock rework in t_phone (#17). If the app starts crashing or
 freezing, this commit is probably to blame.

---
 src/threads/mutex.cpp | 37 +++++++++++++++++++++++++++++++++++++
 src/threads/mutex.h   | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+)

(limited to 'src/threads')

diff --git a/src/threads/mutex.cpp b/src/threads/mutex.cpp
index 0ae2a99..159f887 100644
--- a/src/threads/mutex.cpp
+++ b/src/threads/mutex.cpp
@@ -20,6 +20,7 @@
 #include <iostream>
 #include "mutex.h"
 #include "thread.h"
+#include <stdexcept>
 
 using namespace std;
 
@@ -88,3 +89,39 @@ t_mutex_guard::t_mutex_guard(t_mutex &mutex) : mutex_(mutex) {
 t_mutex_guard::~t_mutex_guard() {
 	mutex_.unlock();
 }
+
+
+///////////////////////////
+// t_rwmutex
+///////////////////////////
+
+t_rwmutex::t_rwmutex()
+{
+	int ret = pthread_rwlock_init(&_lock, nullptr);
+	if (ret != 0) throw string(
+		"t_rwmutex::t_rwmutex failed to create a r/w mutex.");
+}
+
+t_rwmutex::~t_rwmutex()
+{
+	pthread_rwlock_destroy(&_lock);
+}
+
+void t_rwmutex::lockRead()
+{
+	int err = pthread_rwlock_rdlock(&_lock);
+	if (err != 0)
+		throw std::logic_error("Mutex lock failed");
+}
+
+void t_rwmutex::lockWrite()
+{
+	int err = pthread_rwlock_wrlock(&_lock);
+	if (err != 0)
+		throw std::logic_error("Mutex lock failed");
+}
+
+void t_rwmutex::unlock()
+{
+	pthread_rwlock_unlock(&_lock);
+}
diff --git a/src/threads/mutex.h b/src/threads/mutex.h
index 9970e08..16f314d 100644
--- a/src/threads/mutex.h
+++ b/src/threads/mutex.h
@@ -21,6 +21,7 @@
 
 #include <errno.h>
 #include <pthread.h>
+// #include <iostream>
 
 /**
  * @file
@@ -83,4 +84,45 @@ public:
 	~t_mutex_guard();
 };
 
+class t_rwmutex {
+protected:
+	pthread_rwlock_t _lock;
+public:
+	t_rwmutex();
+	~t_rwmutex();
+
+	void lockRead();
+	void lockWrite();
+	void unlock();
+};
+
+class t_rwmutex_reader {
+private:
+	t_rwmutex& _mutex;
+public:
+	t_rwmutex_reader(t_rwmutex& mutex) : _mutex(mutex) {
+		// std::cout << "mtx rd lock " << (void*)&_mutex << std::endl;
+		_mutex.lockRead();
+	}
+	~t_rwmutex_reader() {
+		// std::cout << "mtx rd unlock " << (void*)&_mutex << std::endl;
+		_mutex.unlock();
+	}
+};
+
+class t_rwmutex_writer {
+private:
+	t_rwmutex& _mutex;
+public:
+	t_rwmutex_writer(t_rwmutex& mutex) : _mutex(mutex) {
+		// std::cout << "mtx wr lock " << (void*)&_mutex << std::endl;
+		_mutex.lockWrite();
+	}
+	~t_rwmutex_writer() {
+		// std::cout << "mtx wr unlock " << (void*)&_mutex << std::endl;
+		_mutex.unlock();
+	}
+};
+
+
 #endif
-- 
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