Add atomic reference counting and port DBI (bug 5876 part 3, r=ds).

--HG--
extra : rebase_source : a6defaf477e7a856ce91f92d5f3143f12c141da3

extensions/mysql/mysql/MyBasicResults.cpp

@@ -306,7 +306,6 @@ DBResult MyBasicResults::CopyBlob(unsigned int columnId, void *buffer, size_t ma
 MyQuery::MyQuery(MyDatabase *db, MYSQL_RES *res)
 : m_pParent(db), m_rs(res)
 {
-	m_pParent->IncReferenceCount();
 	m_InsertID = m_pParent->GetInsertID();
 	m_AffectedRows = m_pParent->GetAffectedRows();
 }
@@ -371,9 +370,6 @@ void MyQuery::Destroy()
 		mysql_free_result(m_rs.m_pRes);
 	}
 
-	/* Tell our parent we're done */
-	m_pParent->Close();
-
 	/* Self destruct */
 	delete this;
 }

extensions/mysql/mysql/MyBasicResults.h

@@ -1,5 +1,5 @@
 /**
- * vim: set ts=4 :
+ * vim: set ts=4 sw=4 tw=99 noet :
  * =============================================================================
  * SourceMod MySQL Extension
  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
@@ -91,7 +91,7 @@ public: // Used by the driver to implement GetInsertIDForQuery()/GetAffectedRows
 	unsigned int GetInsertID();
 	unsigned int GetAffectedRows();
 private:
-	MyDatabase *m_pParent;
+	ke::Ref<MyDatabase> m_pParent;
 	MyBasicResults m_rs;
 	unsigned int m_InsertID;
 	unsigned int m_AffectedRows;

extensions/mysql/mysql/MyDatabase.cpp

@@ -1,5 +1,5 @@
 /**
- * vim: set ts=4 :
+ * vim: set ts=4 sw=4 tw=99 noet :
  * =============================================================================
  * SourceMod MySQL Extension
  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
@@ -87,7 +87,7 @@ DBType GetOurType(enum_field_types type)
 }
 
 MyDatabase::MyDatabase(MYSQL *mysql, const DatabaseInfo *info, bool persistent)
-: m_mysql(mysql), m_refcount(1), m_pFullLock(NULL), m_bPersistent(persistent)
+: m_mysql(mysql), m_bPersistent(persistent)
 {
 	m_Host.assign(info->host);
 	m_Database.assign(info->database);
@@ -101,50 +101,24 @@ MyDatabase::MyDatabase(MYSQL *mysql, const DatabaseInfo *info, bool persistent)
 	m_Info.driver = NULL;
 	m_Info.maxTimeout = info->maxTimeout;
 	m_Info.port = info->port;
-
-	m_pRefLock = threader->MakeMutex();
 }
 
 MyDatabase::~MyDatabase()
 {
+	/* Remove us from the search list */
+	if (m_bPersistent)
+		g_MyDriver.RemoveFromList(this, true);
 	mysql_close(m_mysql);
-	m_mysql = NULL;
-
-	m_pRefLock->DestroyThis();
-	if (m_pFullLock)
-	{
-		m_pFullLock->DestroyThis();
-	}
 }
 
 void MyDatabase::IncReferenceCount()
 {
-	m_pRefLock->Lock();
+	AddRef();
-	m_refcount++;
-	m_pRefLock->Unlock();
 }
 
 bool MyDatabase::Close()
 {
-	m_pRefLock->Lock();
+	return !Release();
-	if (m_refcount > 1)
-	{
-		m_refcount--;
-		m_pRefLock->Unlock();
-		return false;
-	}
-	m_pRefLock->Unlock();
-
-	/* Remove us from the search list */
-	if (m_bPersistent)
-	{
-		g_MyDriver.RemoveFromList(this, true);
-	}
-
-	/* Finally, free our resource(s) */
-	delete this;
-
-	return true;
 }
 
 const DatabaseInfo &MyDatabase::GetInfo()
@@ -300,26 +274,17 @@ IPreparedQuery *MyDatabase::PrepareQuery(const char *query, char *error, size_t
 
 bool MyDatabase::LockForFullAtomicOperation()
 {
-	if (!m_pFullLock)
+	if (!m_FullLock)
-	{
+		m_FullLock = new ke::Mutex();
-		m_pFullLock = threader->MakeMutex();
-		if (!m_pFullLock)
-		{
-			return false;
-		}
-	}
-
-	m_pFullLock->Lock();
 
+	m_FullLock->Lock();
 	return true;
 }
 
 void MyDatabase::UnlockFromFullAtomicOperation()
 {
-	if (m_pFullLock)
+	if (m_FullLock)
-	{
+		m_FullLock->Unlock();
-		m_pFullLock->Unlock();
-	}
 }
 
 IDBDriver *MyDatabase::GetDriver()
@@ -330,4 +295,4 @@ IDBDriver *MyDatabase::GetDriver()
 bool MyDatabase::SetCharacterSet(const char *characterset)
 {
 	return mysql_set_character_set(m_mysql, characterset) == 0 ? true : false;
-}
+}

extensions/mysql/mysql/MyDatabase.h

@@ -1,5 +1,5 @@
 /**
- * vim: set ts=4 :
+ * vim: set ts=4 sw=4 tw=99 noet :
  * =============================================================================
  * SourceMod MySQL Extension
  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
@@ -32,13 +32,16 @@
 #ifndef _INCLUDE_SM_MYSQL_DATABASE_H_
 #define _INCLUDE_SM_MYSQL_DATABASE_H_
 
+#include <am-thread-utils.h>
+#include <am-refcounting-threadsafe.h>
 #include "MyDriver.h"
-#include <IThreader.h>
 
 class MyQuery;
 class MyStatement;
 
-class MyDatabase : public IDatabase
+class MyDatabase
+	: public IDatabase,
+	  public ke::RefcountedThreadsafe<MyDatabase>
 {
 	friend class MyQuery;
 	friend class MyStatement;
@@ -67,9 +70,7 @@ public:
 	const DatabaseInfo &GetInfo();
 private:
 	MYSQL *m_mysql;
-	unsigned int m_refcount;
+	ke::AutoPtr<ke::Mutex> m_FullLock;
-	IMutex *m_pFullLock;
-	IMutex *m_pRefLock;
 
 	/* ---------- */
 	DatabaseInfo m_Info;

extensions/mysql/mysql/MyDriver.cpp

@@ -1,5 +1,5 @@
 /**
- * vim: set ts=4 :
+ * vim: set ts=4 sw=4 tw=99 noet :
  * =============================================================================
  * SourceMod MySQL Extension
  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
@@ -154,6 +154,8 @@ bool CompareField(const char *str1, const char *str2)
 
 IDatabase *MyDriver::Connect(const DatabaseInfo *info, bool persistent, char *error, size_t maxlength)
 {
+	ke::AutoLock lock(&m_Lock);
+
 	if (persistent)
 	{
 		/* Try to find a matching persistent connection */
@@ -194,6 +196,7 @@ IDatabase *MyDriver::Connect(const DatabaseInfo *info, bool persistent, char *er
 
 void MyDriver::RemoveFromList(MyDatabase *pdb, bool persistent)
 {
+	ke::AutoLock lock(&m_Lock);
 	if (persistent)
 	{
 		m_PermDbs.remove(pdb);

extensions/mysql/mysql/MyDriver.h

@@ -1,5 +1,5 @@
 /**
- * vim: set ts=4 :
+ * vim: set ts=4 sw=4 tw=99 noet :
  * =============================================================================
  * SourceMod MySQL Extension
  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
@@ -32,6 +32,7 @@
 #ifndef _INCLUDE_SM_MYSQL_DRIVER_H_
 #define _INCLUDE_SM_MYSQL_DRIVER_H_
 
+#define SOURCEMOD_SQL_DRIVER_CODE
 #include <IDBDriver.h>
 #include <sm_platform.h>
 #if defined PLATFORM_WINDOWS
@@ -46,6 +47,7 @@
 
 #include <sh_string.h>
 #include <sh_list.h>
+#include <am-thread-utils.h>
 
 using namespace SourceMod;
 using namespace SourceHook;
@@ -71,6 +73,7 @@ public:
 	void Shutdown();
 	void RemoveFromList(MyDatabase *pdb, bool persistent);
 private:
+	ke::Mutex m_Lock;
 	Handle_t m_MyHandle;
 	List<MyDatabase *> m_TempDbs;
 	List<MyDatabase *> m_PermDbs;

extensions/mysql/mysql/MyStatement.cpp

@@ -48,8 +48,6 @@ MyStatement::MyStatement(MyDatabase *db, MYSQL_STMT *stmt)
 		m_bind = NULL;
 	}
 
-	m_pParent->IncReferenceCount();
-
 	m_pRes = mysql_stmt_result_metadata(stmt);
 	m_Results = false;
 }
@@ -75,9 +73,6 @@ MyStatement::~MyStatement()
 		mysql_free_result(m_pRes);
 	}
 	mysql_stmt_close(m_stmt);
-
-	/* Tell the parent database that we're done referencing it */
-	m_pParent->Close();
 }
 
 void MyStatement::Destroy()

extensions/mysql/mysql/MyStatement.h

@@ -1,5 +1,5 @@
 /**
- * vim: set ts=4 :
+ * vim: set ts=4 sw=4 tw=99 noet :
  * =============================================================================
  * SourceMod MySQL Extension
  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
@@ -69,7 +69,7 @@ private:
 	void *CopyBlob(unsigned int param, const void *blobptr, size_t length);
 private:
 	MYSQL *m_mysql;
-	MyDatabase *m_pParent;
+	ke::Ref<MyDatabase> m_pParent;
 	MYSQL_STMT *m_stmt;
 	MYSQL_BIND *m_bind;
 	MYSQL_RES *m_pRes;

extensions/mysql/sdk/smsdk_config.h

@@ -67,6 +67,6 @@
 //#define SMEXT_ENABLE_MEMUTILS
 //#define SMEXT_ENABLE_GAMEHELPERS
 //#define SMEXT_ENABLE_TIMERSYS
-#define SMEXT_ENABLE_THREADER
+//#define SMEXT_ENABLE_THREADER
 
 #endif // _INCLUDE_SOURCEMOD_EXTENSION_CONFIG_H_

extensions/sqlite/driver/SqDatabase.cpp

@@ -1,5 +1,5 @@
 /**
- * vim: set ts=4 :
+ * vim: set ts=4 sw=4 tw=99 noet :
  * =============================================================================
  * SourceMod SQLite Extension
  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
@@ -34,47 +34,25 @@
 #include "SqQuery.h"
 
 SqDatabase::SqDatabase(sqlite3 *sq3, bool persistent) : 
-	m_sq3(sq3), m_refcount(1), m_pFullLock(NULL), m_Persistent(persistent)
+	m_sq3(sq3), m_Persistent(persistent)
 {
-	m_pRefLock = threader->MakeMutex();
 }
 
 SqDatabase::~SqDatabase()
 {
-	m_pRefLock->DestroyThis();
+	if (m_Persistent)
-	if (m_pFullLock)
+		g_SqDriver.RemovePersistent(this);
-	{
-		m_pFullLock->DestroyThis();
-	}
 	sqlite3_close(m_sq3);
 }
 
 void SqDatabase::IncReferenceCount()
 {
-	m_pRefLock->Lock();
+	AddRef();
-	m_refcount++;
-	m_pRefLock->Unlock();
 }
 
 bool SqDatabase::Close()
 {
-	m_pRefLock->Lock();
+	return !Release();
-	if (m_refcount > 1)
-	{
-		m_refcount--;
-		m_pRefLock->Unlock();
-		return false;
-	}
-	m_pRefLock->Unlock();
-
-	if (m_Persistent)
-	{
-		g_SqDriver.RemovePersistent(this);
-	}
-
-	delete this;
-
-	return true;
 }
 
 const char *SqDatabase::GetError(int *errorCode/* =NULL */)
@@ -84,26 +62,17 @@ const char *SqDatabase::GetError(int *errorCode/* =NULL */)
 
 bool SqDatabase::LockForFullAtomicOperation()
 {
-	if (!m_pFullLock)
+	if (!m_FullLock)
-	{
+		m_FullLock = new ke::Mutex();
-		m_pFullLock = threader->MakeMutex();
-		if (!m_pFullLock)
-		{
-			return false;
-		}
-	}
-
-	m_pFullLock->Lock();
 
+	m_FullLock->Lock();
 	return true;
 }
 
 void SqDatabase::UnlockFromFullAtomicOperation()
 {
-	if (m_pFullLock)
+	if (m_FullLock)
-	{
+		m_FullLock->Unlock();
-		m_pFullLock->Unlock();
-	}
 }
 
 IDBDriver *SqDatabase::GetDriver()
@@ -259,4 +228,4 @@ bool SqDatabase::SetCharacterSet(const char *characterset)
 {
 	// sqlite only supports utf8 and utf16 - by the time the database is created. It's too late here.
 	return false;
-}
+}

extensions/sqlite/driver/SqDatabase.h

@@ -1,5 +1,5 @@
 /**
- * vim: set ts=4 :
+ * vim: set ts=4 sw=4 tw=99 noet :
  * =============================================================================
  * SourceMod SQLite Extension
  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
@@ -32,10 +32,13 @@
 #ifndef _INCLUDE_SQLITE_SOURCEMOD_DATABASE_H_
 #define _INCLUDE_SQLITE_SOURCEMOD_DATABASE_H_
 
-#include <IThreader.h>
+#include <am-refcounting-threadsafe.h>
+#include <am-thread-utils.h>
 #include "SqDriver.h"
 
-class SqDatabase : public IDatabase
+class SqDatabase
+	: public IDatabase,
+	  public ke::RefcountedThreadsafe<SqDatabase>
 {
 public:
 	SqDatabase(sqlite3 *sq3, bool persistent);
@@ -63,9 +66,7 @@ public:
 	sqlite3 *GetDb();
 private:
 	sqlite3 *m_sq3;
-	unsigned int m_refcount;
+	ke::AutoPtr<ke::Mutex> m_FullLock;
-	IMutex *m_pFullLock;
-	IMutex *m_pRefLock;
 	bool m_Persistent;
 	String m_LastError;
 	int m_LastErrorCode;

extensions/sqlite/driver/SqDriver.cpp

@@ -1,5 +1,5 @@
 /**
- * vim: set ts=4 :
+ * vim: set ts=4 sw=4 tw=99 noet :
  * =============================================================================
  * SourceMod SQLite Extension
  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
@@ -66,24 +66,16 @@ int busy_handler(void *unused1, int unused2)
 SqDriver::SqDriver()
 {
 	m_Handle = BAD_HANDLE;
-	m_pOpenLock = NULL;
 	m_bThreadSafe = false;
 }
 
 void SqDriver::Initialize()
 {
-	m_pOpenLock = threader->MakeMutex();
-
 	InitializeThreadSafety();
 }
 
 void SqDriver::Shutdown()
 {
-	if (m_pOpenLock)
-	{
-		m_pOpenLock->DestroyThis();
-	}
-
 	if (m_bThreadSafe)
 	{
 		sqlite3_enable_shared_cache(0);
@@ -158,8 +150,7 @@ inline bool IsPathSepChar(char c)
 
 IDatabase *SqDriver::Connect(const DatabaseInfo *info, bool persistent, char *error, size_t maxlength)
 {
-	/* We wrap most of the open process in a mutex just to be safe */
+	ke::AutoLock lock(&m_OpenLock);
-	m_pOpenLock->Lock();
 
 	/* Format our path */
 	char path[PLATFORM_MAX_PATH];
@@ -189,7 +180,6 @@ IDatabase *SqDriver::Connect(const DatabaseInfo *info, bool persistent, char *er
 			if (!libsys->CreateFolder(fullpath))
 			{
 				strncopy(error, "Could not create or open \"data\" folder\"", maxlength);
-				m_pOpenLock->Unlock();
 				return NULL;
 			}
 		}
@@ -237,7 +227,6 @@ IDatabase *SqDriver::Connect(const DatabaseInfo *info, bool persistent, char *er
 			if ((*iter).path.compare(fullpath) == 0)
 			{
 				(*iter).db->IncReferenceCount();
-				m_pOpenLock->Unlock();
 				return (*iter).db;
 			}
 		}
@@ -250,7 +239,6 @@ IDatabase *SqDriver::Connect(const DatabaseInfo *info, bool persistent, char *er
 	{
 		strncopy(error, sqlite3_errmsg(sql), maxlength);
 		sqlite3_close(sql);
-		m_pOpenLock->Unlock();
 		return NULL;
 	}
 
@@ -266,13 +254,13 @@ IDatabase *SqDriver::Connect(const DatabaseInfo *info, bool persistent, char *er
 		m_Cache.push_back(pinfo);
 	}
 
-	m_pOpenLock->Unlock();
-
 	return pdb;
 }
 
 void SqDriver::RemovePersistent(IDatabase *pdb)
 {
+	ke::AutoLock lock(&m_OpenLock);
+
 	List<SqDbInfo>::iterator iter;
 	for (iter = m_Cache.begin(); iter != m_Cache.end(); iter++)
 	{

extensions/sqlite/driver/SqDriver.h

@@ -1,5 +1,5 @@
 /**
- * vim: set ts=4 :
+ * vim: set ts=4 sw=4 tw=99 noet :
  * =============================================================================
  * SourceMod SQLite Extension
  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
@@ -32,10 +32,11 @@
 #ifndef _INCLUDE_SQLITE_SOURCEMOD_DRIVER_H_
 #define _INCLUDE_SQLITE_SOURCEMOD_DRIVER_H_
 
+#define SOURCEMOD_SQL_DRIVER_CODE
 #include <IDBDriver.h>
-#include <IThreader.h>
 #include <sh_list.h>
 #include <sh_string.h>
+#include <am-thread-utils.h>
 #include "sqlite-source/sqlite3.h"
 
 using namespace SourceMod;
@@ -70,7 +71,7 @@ public:
 	void RemovePersistent(IDatabase *pdb);
 private:
 	Handle_t m_Handle;
-	IMutex *m_pOpenLock;
+	ke::Mutex m_OpenLock;
 	List<SqDbInfo> m_Cache;
 	bool m_bThreadSafe;
 };

extensions/sqlite/driver/SqQuery.cpp

@@ -36,14 +36,12 @@ SqQuery::SqQuery(SqDatabase *parent, sqlite3_stmt *stmt) :
 {
 	m_ParamCount = sqlite3_bind_parameter_count(m_pStmt);
 	m_ColCount = sqlite3_column_count(m_pStmt);
-	m_pParent->IncReferenceCount();
 }
 
 SqQuery::~SqQuery()
 {
 	delete m_pResults;
 	sqlite3_finalize(m_pStmt);
-	m_pParent->Close();
 }
 
 IResultSet *SqQuery::GetResultSet()

extensions/sqlite/driver/SqQuery.h

@@ -1,5 +1,5 @@
 /**
- * vim: set ts=4 :
+ * vim: set ts=4 sw=4 tw=99 noet :
  * =============================================================================
  * SourceMod SQLite Extension
  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
@@ -32,6 +32,7 @@
 #ifndef _INCLUDE_SQLITE_SOURCEMOD_QUERY_H_
 #define _INCLUDE_SQLITE_SOURCEMOD_QUERY_H_
 
+#include <am-refcounting.h>
 #include "SqDatabase.h"
 #include "SqResults.h"
 
@@ -81,7 +82,7 @@ public: //IResultRow
 public:
 	sqlite3_stmt *GetStmt();
 private:
-	SqDatabase *m_pParent;
+	ke::Ref<SqDatabase> m_pParent;
 	sqlite3_stmt *m_pStmt;
 	SqResults *m_pResults;
 	unsigned int m_ParamCount;

extensions/sqlite/extension.h

@@ -37,6 +37,7 @@
  * @brief Sample extension code header.
  */
 
+#define SOURCEMOD_SQL_DRIVER_CODE
 #include "smsdk_ext.h"
 
 

extensions/sqlite/sdk/smsdk_config.h

@@ -67,7 +67,7 @@
 //#define SMEXT_ENABLE_MEMUTILS
 //#define SMEXT_ENABLE_GAMEHELPERS
 //#define SMEXT_ENABLE_TIMERSYS
-#define SMEXT_ENABLE_THREADER
+//#define SMEXT_ENABLE_THREADER
 #define SMEXT_ENABLE_LIBSYS
 
 #endif // _INCLUDE_SOURCEMOD_EXTENSION_CONFIG_H_

public/IDBDriver.h

@@ -608,6 +608,7 @@ namespace SourceMod
 		 */
 		virtual bool SetCharacterSet(const char *characterset) =0;
 
+#if !defined(SOURCEMOD_SQL_DRIVER_CODE)
 		/**
 		 * @brief Wrapper around IncReferenceCount(), for ke::Ref.
 		 */
@@ -621,6 +622,7 @@ namespace SourceMod
 		void Release() {
 			Close();
 		}
+#endif
 	};
 
 	/** 

public/amtl/am-atomics.h

@@ -0,0 +1,100 @@
+// vim: set sts=8 ts=2 sw=2 tw=99 et:
+//
+// Copyright (C) 2013, David Anderson and AlliedModders LLC
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+// 
+//  * Redistributions of source code must retain the above copyright notice, this
+//    list of conditions and the following disclaimer.
+//  * Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//  * Neither the name of AlliedModders LLC nor the names of its contributors
+//    may be used to endorse or promote products derived from this software
+//    without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef _include_amtl_atomics_h_
+#define _include_amtl_atomics_h_
+
+#include <am-utility.h>
+
+namespace ke {
+
+#if defined(_MSC_VER)
+extern "C" {
+  long __cdecl _InterlockedIncrement(long volatile *dest);
+  long __cdecl _InterlockedDecrement(long volatile *dest);
+}
+# pragma intrinsic(_InterlockedIncrement);
+# pragma intrinsic(_InterlockedDecrement);
+#endif
+
+template <size_t Width>
+struct AtomicOps;
+
+template <>
+struct AtomicOps<4>
+{
+  typedef int Type;
+
+#if defined(_MSC_VER)
+  static int Increment(int *ptr) {
+    return _InterlockedIncrement(ptr);
+  }
+  static int Decrement(int *ptr) {
+    return _InterlockedDecrement(ptr);
+  };
+#elif defined(__GNUC__)
+  // x86/x64 notes: When using GCC < 4.8, this will compile to a spinlock.
+  // On 4.8+, or when using Clang, we'll get the more optimal "lock addl"
+  // variant.
+  static int Increment(int *ptr) {
+    return __sync_add_and_fetch(ptr, 1);
+  }
+  static int Decrement(int *ptr) {
+    return __sync_sub_and_fetch(ptr, 1);
+  }
+#endif
+};
+
+class AtomicRefCount
+{
+  typedef AtomicOps<sizeof(uintptr_t)> Ops;
+
+ public:
+  AtomicRefCount(uintptr_t value)
+   : value_(value)
+  {
+  }
+
+  void increment() {
+    Ops::Increment(&value_);
+  }
+
+  // Return false if all references are gone.
+  bool decrement() {
+    return Ops::Decrement(&value_) != 0;
+  }
+
+ private:
+  Ops::Type value_;
+};
+
+}
+
+#endif // _include_amtl_atomics_h_
+

public/amtl/am-refcounting-threadsafe.h

@@ -0,0 +1,68 @@
+// vim: set sts=8 ts=2 sw=2 tw=99 et:
+//
+// Copyright (C) 2013, David Anderson and AlliedModders LLC
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+// 
+//  * Redistributions of source code must retain the above copyright notice, this
+//    list of conditions and the following disclaimer.
+//  * Redistributions in binary form must reproduce the above copyright notice,
+//    this list of conditions and the following disclaimer in the documentation
+//    and/or other materials provided with the distribution.
+//  * Neither the name of AlliedModders LLC nor the names of its contributors
+//    may be used to endorse or promote products derived from this software
+//    without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef _include_amtl_ts_refcounting_h_
+#define _include_amtl_ts_refcounting_h_
+
+#include <am-refcounting.h>
+#include <am-atomics.h>
+
+namespace ke {
+
+template <typename T>
+class RefcountedThreadsafe
+{
+  public:
+    RefcountedThreadsafe()
+     : refcount_(1)
+    {
+    }
+
+    void AddRef() {
+      refcount_.increment();
+    }
+    bool Release() {
+        if (!refcount_.decrement()) {
+            delete static_cast<T *>(this);
+            return false;
+        }
+        return true;
+    }
+
+  protected:
+    ~RefcountedThreadsafe() {
+    }
+
+  private:
+    AtomicRefCount refcount_;
+};
+
+} // namespace ke
+
+#endif // _include_amtl_ts_refcounting_h_