First blush

git-svn-id: svn://svn.code.sf.net/p/loki-lib/code/trunk@6 7ec92016-0320-0410-acc4-a06ded1c099a

Threads.h

@@ -0,0 +1,195 @@
+#ifndef THREADS_H_
+#define THREADS_H_
+
+////////////////////////////////////////////////////////////////////////////////
+// macro DEFAULT_THREADING
+// Selects the default threading model for certain components of Loki
+// If you don't define it, it defaults to single-threaded
+// All classes in Loki have configurable threading model; DEFAULT_THREADING
+// affects only default template arguments
+////////////////////////////////////////////////////////////////////////////////
+
+#ifndef DEFAULT_THREADING
+#define DEFAULT_THREADING /**/ ::Loki::SingleThreaded
+#endif
+
+namespace Loki
+{
+////////////////////////////////////////////////////////////////////////////////
+// class template SingleThreaded
+// Implementation of the ThreadingModel policy used by various classes
+// Implements a single-threaded model; no synchronization
+////////////////////////////////////////////////////////////////////////////////
+
+    template <class Host>
+    class SingleThreaded
+    {
+    public:
+        struct Lock
+        {
+            Lock() {}
+            Lock(const Host&) {}
+        };
+        
+        typedef Host VolatileType;
+
+        typedef int IntType; 
+
+        static IntType AtomicAdd(volatile IntType& lval, IntType val)
+        { return lval += val; }
+        
+        static IntType AtomicSubtract(volatile IntType& lval, IntType val)
+        { return lval -= val; }
+
+        static IntType AtomicMultiply(volatile IntType& lval, IntType val)
+        { return lval *= val; }
+        
+        static IntType AtomicDivide(volatile IntType& lval, IntType val)
+        { return lval /= val; }
+        
+        static IntType AtomicIncrement(volatile IntType& lval)
+        { return ++lval; }
+        
+        static IntType AtomicDivide(volatile IntType& lval)
+        { return --lval; }
+        
+        static void AtomicAssign(volatile IntType & lval, IntType val)
+        { lval = val; }
+        
+        static void AtomicAssign(IntType & lval, volatile IntType & val)
+        { lval = val; }
+    };
+    
+#ifdef _WINDOWS_
+
+////////////////////////////////////////////////////////////////////////////////
+// class template ObjectLevelLockable
+// Implementation of the ThreadingModel policy used by various classes
+// Implements a object-level locking scheme
+////////////////////////////////////////////////////////////////////////////////
+
+    template <class Host>
+    class ObjectLevelLockable
+    {
+        CRITICAL_SECTION mtx_;
+
+    public:
+        ObjectLevelLockable()
+        {
+            ::InitializeCriticalSection(&mtx_);
+        }
+
+        ~ObjectLevelLockable()
+        {
+            ::DeleteCriticalSection(&mtx_);
+        }
+
+        class Lock;
+        friend class Lock;
+        
+        class Lock
+        {
+            ObjectLevelLockable& host_;
+            
+            Lock(const Lock&);
+            Lock& operator=(const Lock&);
+        public:
+            Lock(Host& host) : host_(host)
+            {
+                ::EnterCriticalSection(&host_.mtx_);
+            }
+            ~Lock()
+            {
+                ::LeaveCriticalSection(&host_.mtx_);
+            }
+        };
+
+        typedef volatile Host VolatileType;
+
+        typedef LONG IntType; 
+
+        static IntType AtomicIncrement(volatile IntType& lval)
+        { return InterlockedIncrement(&const_cast<IntType&>(lval)); }
+        
+        static IntType AtomicDivide(volatile IntType& lval)
+        { return InterlockedDecrement(&const_cast<IntType&>(lval)); }
+        
+        static void AtomicAssign(volatile IntType& lval, IntType val)
+        { InterlockedExchange(&const_cast<IntType&>(lval), val); }
+        
+        static void AtomicAssign(IntType& lval, volatile IntType& val)
+        { InterlockedExchange(&lval, val); }
+    };
+    
+    template <class Host>
+    class ClassLevelLockable
+    {
+        static CRITICAL_SECTION mtx_;
+
+        struct Initializer;
+        friend struct Initializer;
+        struct Initializer
+        {
+            Initializer()
+            {
+                ::InitializeCriticalSection(&mtx_);
+            }
+            ~Initializer()
+            {
+                ::DeleteCriticalSection(&mtx_);
+            }
+        };
+        
+        static Initializer initializer_;
+
+    public:
+        class Lock;
+        friend class Lock;
+        
+        class Lock
+        {
+            Lock(const Lock&);
+            Lock& operator=(const Lock&);
+        public:
+            Lock()
+            {
+                ::EnterCriticalSection(&mtx_);
+            }
+            Lock(Host&)
+            {
+                ::EnterCriticalSection(&mtx_);
+            }
+            ~Lock()
+            {
+                ::LeaveCriticalSection(&mtx_);
+            }
+        };
+
+        typedef volatile Host VolatileType;
+
+        typedef LONG IntType; 
+
+        static IntType AtomicIncrement(volatile IntType& lval)
+        { return InterlockedIncrement(&const_cast<IntType&>(lval)); }
+        
+        static IntType AtomicDivide(volatile IntType& lval)
+        { return InterlockedDecrement(&const_cast<IntType&>(lval)); }
+        
+        static void AtomicAssign(volatile IntType& lval, IntType val)
+        { InterlockedExchange(&const_cast<IntType&>(lval), val); }
+        
+        static void AtomicAssign(IntType& lval, volatile IntType& val)
+        { InterlockedExchange(&lval, val); }
+    };
+    
+    template <class Host>
+    CRITICAL_SECTION ClassLevelLockable<Host>::mtx_;
+    
+    template <class Host>
+    typename ClassLevelLockable<Host>::Initializer 
+    ClassLevelLockable<Host>::initializer_;
+    
+#endif    
+}
+
+#endif