mutex ctor can have a type, class has tryLock method

include/Mutex.hpp

@@ -5,12 +5,15 @@
 
 class Mutex 
 {
+
 public:
-	Mutex();
+
+  Mutex(int type = PTHREAD_MUTEX_DEFAULT);
   ~Mutex();
 
   void lock();
   void unlock();
+  bool tryLock(int interval = 0);
 
 private:
 

src/Mutex.cpp

@@ -1,26 +1,60 @@
 #include "Mutex.hpp"
 
+#include <assert.h>
+#include <time.h>
 
-Mutex::Mutex()
+
+Mutex::Mutex(int type)
 {
-	pthread_mutex_init( &m_mutex, 0 );
+  int ret;
+  if ( type == PTHREAD_MUTEX_DEFAULT ) {
+    ret = pthread_mutex_init( &m_mutex, 0 );
+  } else {
+    pthread_mutexattr_t attr;
+    pthread_mutexattr_init(&attr);
+    pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK);
+    ret = pthread_mutex_init( &m_mutex, &attr );
+  }
+  assert( ret == 0 );
 }
 
 
 Mutex::~Mutex()
 {
-	pthread_mutex_destroy ( &m_mutex );
+  int ret = pthread_mutex_destroy ( &m_mutex );
+  assert( ret == 0);
 }
 
 
 void Mutex::lock()
 {
-	pthread_mutex_lock( &m_mutex );
+  int ret = pthread_mutex_lock( &m_mutex );
+  assert( ret == 0);
 }
 
 
 void Mutex::unlock()
 {
-	pthread_mutex_unlock ( &m_mutex );
+  int ret = pthread_mutex_unlock ( &m_mutex );
+  assert( ret == 0);
+}
+
+
+bool Mutex::tryLock(int interval)
+{
+  if ( interval == 0 ) {
+    int result = pthread_mutex_trylock ( &m_mutex );
+    return result == 0;
+  } else {
+    timespec abs_time;
+    clock_gettime ( CLOCK_REALTIME, &abs_time );
+    abs_time.tv_nsec += interval * 1000000;
+    if ( abs_time.tv_nsec >= 1000000000 ) {
+      abs_time.tv_nsec -= 1000000000;
+      abs_time.tv_sec += 1;
+    }
+    int result = pthread_mutex_timedlock ( &m_mutex, &abs_time );
+    return result == 0;
+  }
 }
 

test/main_Mutex.cpp

@@ -1,3 +1,5 @@
+//  g++ -Wall -Wextra src/*.cpp test/main_Mutex.cpp -Iinclude -lpthread -lrt
+
 #include <iostream>
 #include <pthread.h>
 
@@ -26,6 +28,14 @@ int main()
   pthread_join( thread1, 0 );
   pthread_join( thread2, 0 );
 
+  Mutex m2(PTHREAD_MUTEX_ERRORCHECK);
+
+  m2.lock();
+  m2.unlock();
+
+  m2.unlock();
+  m2.unlock();
+
     return 0;
 }