Initial community commit

Src/replicant/nu/AutoLock.h

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+#ifndef AUTOLOCKH
+#define AUTOLOCKH
+
+#ifdef _WIN32
+#pragma warning (disable:4786)
+#include <windows.h>
+#elif defined(__linux__) || defined(__APPLE__)
+#include <pthread.h>
+#else
+#error port me!!
+#endif
+
+/*
+NULLSOFT_LOCK_OUTPUT_STATUS turns on/off debugging output
+this can be VERY useful if you are trying to find a deadlock
+each time the guard is locked or unlocked, it outputs a list of
+any threads using the mutex, and their function stack
+*/ 
+//#define NULLSOFT_LOCK_OUTPUT_STATS
+
+#ifdef NULLSOFT_LOCK_OUTPUT_STATS
+
+#include <string> // we save each function name as a string
+#include <deque> // we make a list of the recursive function stack for each thread
+#include <map> // and map
+#include <iostream> // we output to std::cerr
+#include <windows.h>
+
+
+/*****
+Description:
+	This class uses scoping to wrap a critical section (lightweight in-process mutex)
+	The constructor enters the mutex and the destructor leaves it.  This allows it to
+	take advantage of automatic scoping in C++, because C++ automatically calls the destructor
+	when an object leaves scope. 
+ 
+	This is _especially_ useful when you have multiple return paths, since you don't have to
+	repeat mutex-leaving code.
+ 
+To use:
+	Make a LockGuard for a resource you want to protect.  The guard is shared, so make it part 
+	of your class, or a global, or whatever.  The LockGuard is essentially a "token", equivalent
+	to your mutex handle or critical section handle.
+	
+	Make an AutoLock object on the stack to lock.  It will unlock automatically when the object
+	leaves scope.  
+	
+		Note: You'll want to make an object on the stack - don't use a heap object (new/delete)
+		unless you have weird requirements and know what you are doing.
+ 
+	Example:
+ 
+	class MyClass
+	{
+		LockGuard fileGuard;
+		fstream file;
+		void DumpSomeData() // 
+		{
+			AutoLock lock(fileGuard);
+			file << GetData();
+		}
+ 
+		void CALLBACK NewData() // potentially called by another thread
+		{
+			AutoLock lock(fileGuard)
+			file << newData;
+		}
+	};
+ 
+ 
+	Tip: You can use "false scoping" to tweak the mutex lifetime, for example:
+ 
+	void DoStuff()
+	{
+		a = GetData();
+		{ // false scope
+			AutoLock lock(dataGuard);
+			DoCalculationsWith(a);
+		} // mutex will release here
+		SetData(a);
+	}
+	
+	Tip: A common mistake is making a temporary object.
+	i.e.
+	CORRECT:  AutoLock lock(fileGuard); // an AutoLock object called "lock" is put on the stack
+	INCORRECT: AutoLock(fileGuard); // An unnamed temporary is created which will be destroyed IMMEDIATELY
+ 
+*******/
+#define MANUALLOCKNAME(x) x
+#define LOCKNAME(x) ,x
+#define GUARDNAME(x) (x)
+namespace Nullsoft
+{
+	namespace Utility
+	{
+		/* the token which represents a resource to be locked */
+		class LockGuard
+		{
+		public:
+			inline LockGuard(const char *name = "Unnamed Guard")
+			{
+				lockName = name;
+				InitializeCriticalSection(&cerr_cs);
+				InitializeCriticalSection(&map_cs);
+				InitializeCriticalSection(&m_cs);
+			}
+
+			inline ~LockGuard()
+			{
+				DeleteCriticalSection(&cerr_cs);
+				DeleteCriticalSection(&map_cs);
+				DeleteCriticalSection(&m_cs);
+			}
+
+			inline void Lock()
+			{
+				EnterCriticalSection(&m_cs);
+			}
+
+			inline void Unlock()
+			{
+				LeaveCriticalSection(&m_cs);
+			}
+
+			int ThreadCount()
+			{
+				EnterCriticalSection(&map_cs);
+				int count = 0;
+				for (ThreadMap::iterator itr = threads.begin(); itr != threads.end(); itr++)
+				{
+					if (!itr->second.empty())
+						count++;
+				}
+
+				LeaveCriticalSection(&map_cs);
+				return count;
+			}
+
+			void Display()
+			{
+				EnterCriticalSection(&map_cs);
+				EnterCriticalSection(&cerr_cs);
+
+				if (ThreadCount() > 1 && owner)
+				{
+					std::cerr << "Guard: " << lockName << std::endl;
+					for (ThreadMap::iterator itr = threads.begin(); itr != threads.end(); itr++)
+					{
+						if (itr->second.empty())
+							continue;
+
+						std::cerr << "  Thread ID: " << std::hex << itr->first << std::dec;
+						if (owner == itr->first)
+							std::cerr << " [holding the mutex] *****";
+						else
+							std::cerr << " [blocked]";
+						std::cerr << std::endl;
+						for (FunctionStack::iterator fitr = itr->second.begin(); fitr != itr->second.end(); fitr++)
+						{
+							std::cerr << "    " << *fitr << "();" << std::endl;
+						}
+					}
+				}
+				LeaveCriticalSection(&cerr_cs);
+				LeaveCriticalSection(&map_cs);
+			}
+
+			void In(DWORD thread, const char *functionName)
+			{
+				EnterCriticalSection(&map_cs);
+				threads[thread].push_back(functionName);
+				LeaveCriticalSection(&map_cs);
+			}
+
+			void Out(DWORD thread)
+			{
+				EnterCriticalSection(&map_cs);
+				threads[thread].pop_back();
+				LeaveCriticalSection(&map_cs);
+			}
+			std::string lockName;
+			CRITICAL_SECTION cerr_cs, map_cs;
+			typedef std::deque<std::string> FunctionStack; // this typedef reduce ugly c++ <>::<>::<> overkill
+			typedef std::map<DWORD, FunctionStack> ThreadMap;
+			ThreadMap threads;
+
+			DWORD owner;
+		private:
+			CRITICAL_SECTION m_cs;
+
+		};
+
+		/* an AutoLock locks a resource (represented by a LockGuard) for the duration of its lifetime */
+		class AutoLock
+		{
+		public:
+			/*
+			@param functionName The function name which wants the mutex
+				we pass it in as a char * even though it'll be converted to a std::string
+				to reduce overhead when OUTPUT_STATS is off
+			 */
+			inline AutoLock(LockGuard &_guard, const char *functionName = "function name not passed") : guard(&_guard)
+			{
+				ManualLock(functionName);
+			}
+			inline void ManualLock(char *functionName = "manual lock")
+			{
+				thisThread = GetCurrentThreadId();
+				guard->In(thisThread, functionName);
+				guard->Display();
+				guard->Lock();
+				guard->owner = thisThread;
+				guard->Display();
+			}
+
+			inline void ManualUnlock()
+			{
+				guard->Display();
+				guard->Unlock();
+
+				InterlockedCompareExchange((LONG volatile *)&guard->owner, 0, (LONG)thisThread);
+				/* above line is functionally equivalent to:
+				if (guard->owner == thisThread) 
+					guard->owner=0;
+				*/
+				guard->Out(thisThread);
+				guard->Display();
+			}
+
+			inline ~AutoLock()
+			{
+				ManualUnlock();
+			}
+
+			LockGuard *guard;
+			DWORD thisThread;
+		};
+
+	}
+}
+
+
+#else
+#define MANUALLOCKNAME(x)
+#define LOCKNAME(x)
+#define GUARDNAME(x)
+namespace nu
+{
+		/* the token which represents a resource to be locked */
+		class LockGuard
+		{
+		public:
+			inline LockGuard(const char *guardName = "")
+			{
+      #ifdef _WIN32
+					InitializeCriticalSection(&m_cs);
+#elif defined(__linux__)
+           pthread_mutexattr_t mtxattr;
+           pthread_mutexattr_init(&mtxattr);
+           pthread_mutexattr_settype(&mtxattr,  PTHREAD_MUTEX_RECURSIVE_NP );           
+           pthread_mutex_init(&mtx, &mtxattr);
+           pthread_mutexattr_destroy(&mtxattr);
+#elif defined(__APPLE__)
+                pthread_mutexattr_t mtxattr;
+                pthread_mutexattr_init(&mtxattr);
+                pthread_mutexattr_settype(&mtxattr,  PTHREAD_MUTEX_RECURSIVE);           
+                pthread_mutex_init(&mtx, &mtxattr);
+                pthread_mutexattr_destroy(&mtxattr);
+           #else
+           #error port me
+          #endif
+			}
+			inline ~LockGuard()
+			{
+      #ifdef _WIN32
+				DeleteCriticalSection(&m_cs);
+      #elif defined(__linux__) || defined(__APPLE__)
+      pthread_mutex_destroy(&mtx);
+      #else
+      #error port me!
+      #endif
+      }
+			inline void Lock()
+			{
+      #ifdef _WIN32
+				EnterCriticalSection(&m_cs);
+      #elif defined(__linux__) || defined(__APPLE__)
+        pthread_mutex_lock(&mtx);
+        #else
+        #error por tme!
+      #endif
+      }
+
+			inline void Unlock()
+			{
+      #ifdef _WIN32
+				LeaveCriticalSection(&m_cs);
+      #elif defined(__linux__) || defined(__APPLE__)
+        pthread_mutex_unlock(&mtx);
+        #else
+        #error port me!
+      #endif
+      }
+		private:
+    #ifdef _WIN32
+			CRITICAL_SECTION m_cs;
+      #elif defined(__linux__) || defined(__APPLE__)
+			pthread_mutex_t mtx;
+			        #else
+        #error port me!
+    #endif
+    };
+
+		/* an AutoLock locks a resource (represented by a LockGuard) for the duration of its lifetime */
+		class AutoLock
+		{
+		public:
+			inline AutoLock(LockGuard &_guard) : guard(&_guard)
+			{
+				guard->Lock();
+			}
+			
+			inline AutoLock(LockGuard *_guard) : guard(_guard)
+			{
+				guard->Lock();
+			}
+			inline void ManualLock()
+			{
+				guard->Lock();
+			}
+
+			inline void ManualUnlock()
+			{
+				guard->Unlock();
+
+			}
+			inline ~AutoLock()
+			{
+				guard->Unlock();
+			}
+			LockGuard *guard;
+		};
+
+		// will lock anything that implements Lock() and Unlock()
+		template <class LockGuard_t>
+		class AutoLockT
+		{
+		public:
+			inline AutoLockT(LockGuard_t &_guard) : guard(&_guard)
+			{
+				guard->Lock();
+			}
+			
+			inline AutoLockT(LockGuard_t *_guard) : guard(_guard)
+			{
+				guard->Lock();
+			}
+			inline void ManualLock()
+			{
+				guard->Lock();
+			}
+
+			inline void ManualUnlock()
+			{
+				guard->Unlock();
+
+			}
+			inline ~AutoLockT()
+			{
+				guard->Unlock();
+			}
+			LockGuard_t *guard;
+		};
+}
+#endif
+
+#endif