diff --git a/src/core/sync/condition.d b/src/core/sync/condition.d
index c86220883a4..68afb94ba00 100644
--- a/src/core/sync/condition.d
+++ b/src/core/sync/condition.d
@@ -570,8 +570,8 @@ version( unittest )
             synchronized( mutex )
             {
                 waiting    = true;
-                alertedOne = condReady.wait( 10_000_000 ); // 1s
-                alertedTwo = condReady.wait( 10_000_000 ); // 1s
+                alertedOne = condReady.wait( dur!"seconds"(1) );
+                alertedTwo = condReady.wait( dur!"seconds"(1) );
             }
         }
 
diff --git a/src/core/sync/exception.d b/src/core/sync/exception.d
index 89077d34ce9..c5661b6af29 100644
--- a/src/core/sync/exception.d
+++ b/src/core/sync/exception.d
@@ -20,8 +20,13 @@ module core.sync.exception;
  */
 class SyncException : Exception
 {
-    this( string msg )
+    this(string msg, string file = __FILE__, size_t line = __LINE__, Throwable next = null)
     {
-        super( msg );
+        super(msg, file, line, next);
+    }
+
+    this(string msg, Throwable next, string file = __FILE__, size_t line = __LINE__)
+    {
+        super(msg, file, line, next);
     }
 }
diff --git a/src/core/sync/mutex.d b/src/core/sync/mutex.d
index 4fa18d04ff4..35515a08151 100644
--- a/src/core/sync/mutex.d
+++ b/src/core/sync/mutex.d
@@ -62,8 +62,16 @@ class Mutex :
         }
         else version( Posix )
         {
-            int rc = pthread_mutex_init( &m_hndl, &sm_attr );
-            if( rc )
+            pthread_mutexattr_t attr = void;
+
+            if( pthread_mutexattr_init( &attr ) )
+                throw new SyncException( "Unable to initialize mutex" );
+            scope(exit) pthread_mutexattr_destroy( &attr );
+
+            if( pthread_mutexattr_settype( &attr, PTHREAD_MUTEX_RECURSIVE ) )
+                throw new SyncException( "Unable to initialize mutex" );
+
+            if( pthread_mutex_init( &m_hndl, &attr ) )
                 throw new SyncException( "Unable to initialize mutex" );
         }
         m_proxy.link = this;
@@ -177,26 +185,6 @@ class Mutex :
     }
 
 
-    version( Posix )
-    {
-        shared static this()
-        {
-            int rc = pthread_mutexattr_init( &sm_attr );
-            assert( !rc );
-
-            rc = pthread_mutexattr_settype( &sm_attr, PTHREAD_MUTEX_RECURSIVE );
-            assert( !rc );
-        }
-
-
-        shared static ~this()
-        {
-            int rc = pthread_mutexattr_destroy( &sm_attr );
-            assert( !rc );
-        }
-    }
-
-
 private:
     version( Win32 )
     {
@@ -204,8 +192,6 @@ private:
     }
     else version( Posix )
     {
-        __gshared pthread_mutexattr_t   sm_attr;
-
         pthread_mutex_t     m_hndl;
     }
 
diff --git a/src/core/sync/semaphore.d b/src/core/sync/semaphore.d
index e88200e7a0f..3eb497d2aac 100644
--- a/src/core/sync/semaphore.d
+++ b/src/core/sync/semaphore.d
@@ -493,8 +493,8 @@ version( unittest )
             {
                 waiting    = true;
             }
-            alertedOne = semReady.wait( 10_000_000 ); // 100ms
-            alertedTwo = semReady.wait( 10_000_000 ); // 100ms
+            alertedOne = semReady.wait( dur!"msecs"(200) );
+            alertedTwo = semReady.wait( dur!"msecs"(200) );
         }
 
         auto thread = new Thread( &waiter );
diff --git a/src/core/thread.d b/src/core/thread.d
index a3173062138..9ef2372570d 100644
--- a/src/core/thread.d
+++ b/src/core/thread.d
@@ -33,9 +33,14 @@ version = StackGrowsDown;
  */
 class ThreadException : Exception
 {
-    this( string msg )
+    this(string msg, string file = __FILE__, size_t line = __LINE__, Throwable next = null)
     {
-        super( msg );
+        super(msg, file, line, next);
+    }
+
+    this(string msg, Throwable next, string file = __FILE__, size_t line = __LINE__)
+    {
+        super(msg, file, line, next);
     }
 }
 
@@ -45,15 +50,22 @@ class ThreadException : Exception
  */
 class FiberException : Exception
 {
-    this( string msg )
+    this(string msg, string file = __FILE__, size_t line = __LINE__, Throwable next = null)
     {
-        super( msg );
+        super(msg, file, line, next);
+    }
+
+    this(string msg, Throwable next, string file = __FILE__, size_t line = __LINE__)
+    {
+        super(msg, file, line, next);
     }
 }
 
 
 private
 {
+    import core.sync.mutex;
+
     //
     // from core.memory
     //
@@ -1577,9 +1589,21 @@ private:
     //
     // All use of the global lists should synchronize on this lock.
     //
-    static Object slock()
+    static Mutex slock()
     {
-        return Thread.classinfo;
+        static Mutex m = null;
+
+        if( m !is null )
+            return m;
+        else
+        {
+            auto ci = Mutex.classinfo;
+            auto p  = malloc( ci.init.length );
+            (cast(byte*) p)[0 .. ci.init.length] = ci.init[];
+            m = cast(Mutex) p;
+            m.__ctor();
+            return m;
+        }
     }
 
 
@@ -2105,6 +2129,11 @@ extern (C) void thread_joinAll()
 
         foreach( t; Thread )
         {
+            if( !t.isRunning )
+            {
+                Thread.remove( t );
+                continue;
+            }
             if( !t.isDaemon )
             {
                 nonDaemon = t;
@@ -2338,7 +2367,8 @@ extern (C) void thread_suspendAll()
             suspend( Thread.getThis() );
         return;
     }
-    synchronized( Thread.slock )
+
+    Thread.slock.lock();
     {
         if( ++suspendDepth > 1 )
             return;
@@ -2462,7 +2492,8 @@ body
             resume( Thread.getThis() );
         return;
     }
-    synchronized( Thread.slock )
+    
+    scope(exit) Thread.slock.unlock();
     {
         if( --suspendDepth > 0 )
             return;
diff --git a/src/object_.d b/src/object_.d
index 53b95b3c96b..2c408274bed 100644
--- a/src/object_.d
+++ b/src/object_.d
@@ -1328,6 +1328,7 @@ class Exception : Throwable
     {
         super(msg, file, line, next);
     }
+
     this(string msg, Throwable next, string file = __FILE__, size_t line = __LINE__)
     {
         super(msg, file, line, next);