Fixed bug #1721186: thread-safe reference counting.

3 files changed, 306 insertions, 130 deletions

diff --git a/src/object.cpp b/src/object.cpp
index 651aa1e1..c03653e9 100644
--- a/src/object.cpp
+++ b/src/object.cpp
@@ -33,13 +33,13 @@ namespace vmime
 
 
 object::object()
-	: m_refMgr(new utility::refManager(this))
+	: m_refMgr(utility::refManager::create(this))
 {
 }
 
 
 object::object(const object&)
-	: m_refMgr(new utility::refManager(this))
+	: m_refMgr(utility::refManager::create(this))
 {
 }
 
diff --git a/src/utility/smartPtr.cpp b/src/utility/smartPtr.cpp
index 16249df8..08a8f57c 100644
--- a/src/utility/smartPtr.cpp
+++ b/src/utility/smartPtr.cpp
@@ -29,135 +29,10 @@ namespace vmime {
 namespace utility {
 
 
-// refManager
-
-refManager::refManager(object* obj)
-	: m_object(obj), m_strongCount(1), m_weakCount(1)
-{
-}
-
-
-refManager::~refManager()
-{
-}
-
-
-const bool refManager::addStrong()
-{
-	if (m_strongCount <= 0)
-		return false;
-
-	m_strongCount.increment();
-	m_weakCount.increment();
-
-	return true;
-}
-
-
-void refManager::releaseStrong()
-{
-	m_strongCount.decrement();
-
-	if (m_strongCount.compareExchange(0, -424242) == 0)  // prevent from adding strong refs later
-		deleteObject();
-
-	releaseWeak();
-}
-
-
-void refManager::addWeak()
-{
-	m_weakCount.increment();
-}
-
-
-void refManager::releaseWeak()
-{
-	if (m_weakCount.decrement() == 0)
-		deleteManager();
-}
-
-
-object* refManager::getObject()
-{
-	return m_object;
-}
-
-
-void refManager::deleteManager()
-{
-	delete this;
-}
-
-
-void refManager::deleteObject()
-{
-	try
-	{
-		m_object->setRefManager(0);
-		delete m_object;
-	}
-	catch (...)
-	{
-		// Exception in destructor
-	}
-
-	m_object = 0;
-}
-
-
-const long refManager::getStrongRefCount() const
-{
-	return m_strongCount;
-}
-
-
-const long refManager::getWeakRefCount() const
-{
-	return m_weakCount;
-}
-
-
-
-// refCounter
-
-refCounter::refCounter(const long initialValue)
-	: m_value(initialValue)
-{
-}
-
-
-refCounter::~refCounter()
-{
-}
-
-
-const long refCounter::increment()
-{
-	return ++m_value;
-}
-
-
-const long refCounter::decrement()
-{
-	return --m_value;
-}
-
-
-const long refCounter::compareExchange(const long compare, const long exchangeWith)
-{
-	const int prev = m_value;
-
-	if (m_value == compare)
-		m_value = exchangeWith;
-
-	return prev;
-}
-
-
-refCounter::operator long() const
+void refManager::deleteObjectImpl(object* obj)
 {
-	return m_value;
+	obj->setRefManager(0);
+	delete obj;
 }
 
 
diff --git a/src/utility/smartPtrInt.cpp b/src/utility/smartPtrInt.cpp
new file mode 100644
index 00000000..a3036310
--- /dev/null
+++ b/src/utility/smartPtrInt.cpp
@@ -0,0 +1,301 @@
+//
+// VMime library (http://www.vmime.org)
+// Copyright (C) 2002-2007 Vincent Richard <[email protected]>
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of
+// the License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with this program; if not, write to the Free Software Foundation, Inc.,
+// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+//
+// Linking this library statically or dynamically with other modules is making
+// a combined work based on this library.  Thus, the terms and conditions of
+// the GNU General Public License cover the whole combination.
+//
+
+#include "vmime/utility/smartPtrInt.hpp"
+#include "vmime/object.hpp"
+
+#if defined(_WIN32)
+#	include <windows.h>
+#elif defined(VMIME_HAVE_PTHREAD)
+#	include <pthread.h>
+#endif
+
+
+namespace vmime {
+namespace utility {
+
+
+// static
+refManager* refManager::create(object* obj)
+{
+	return new refManagerImpl(obj);
+}
+
+
+//
+// refManager
+//
+
+refManagerImpl::refManagerImpl(object* obj)
+	: m_object(obj), m_strongCount(1), m_weakCount(1)
+{
+}
+
+
+refManagerImpl::~refManagerImpl()
+{
+}
+
+
+const bool refManagerImpl::addStrong()
+{
+	if (m_strongCount <= 0)
+		return false;
+
+	m_strongCount.increment();
+	m_weakCount.increment();
+
+	return true;
+}
+
+
+void refManagerImpl::releaseStrong()
+{
+	if (m_strongCount.decrement() <= 0)
+		deleteObject();
+
+	releaseWeak();
+}
+
+
+void refManagerImpl::addWeak()
+{
+	m_weakCount.increment();
+}
+
+
+void refManagerImpl::releaseWeak()
+{
+	if (m_weakCount.decrement() <= 0)
+		deleteManager();
+}
+
+
+object* refManagerImpl::getObject()
+{
+	return m_object;
+}
+
+
+void refManagerImpl::deleteManager()
+{
+	delete this;
+}
+
+
+void refManagerImpl::deleteObject()
+{
+	try
+	{
+		deleteObjectImpl(m_object);
+	}
+	catch (...)
+	{
+		// Exception in destructor
+	}
+
+	m_object = 0;
+}
+
+
+const long refManagerImpl::getStrongRefCount() const
+{
+	return m_strongCount;
+}
+
+
+const long refManagerImpl::getWeakRefCount() const
+{
+	return m_weakCount;
+}
+
+
+
+//
+// refCounter
+//
+
+#ifdef _WIN32
+
+
+refCounter::refCounter(const long initialValue)
+	: m_value(initialValue)
+{
+}
+
+
+refCounter::~refCounter()
+{
+}
+
+
+const long refCounter::increment()
+{
+	return InterlockedIncrement(&m_value);
+}
+
+
+const long refCounter::decrement()
+{
+	return InterlockedDecrement(&m_value);
+}
+
+
+refCounter::operator long() const
+{
+	return m_value;
+}
+
+
+#elif defined(__GNUC__) && defined(__GLIBCPP__)
+
+
+refCounter::refCounter(const long initialValue)
+	: m_value(static_cast <int>(initialValue))
+{
+}
+
+
+refCounter::~refCounter()
+{
+}
+
+
+const long refCounter::increment()
+{
+#if __GNUC_MINOR__ < 4 && __GNUC__ < 4
+	return __exchange_and_add(&m_value, 1) + 1;
+#else
+	return __gnu_cxx::__exchange_and_add(&m_value, 1) + 1;
+#endif
+}
+
+
+const long refCounter::decrement()
+{
+#if __GNUC_MINOR__ < 4 && __GNUC__ < 4
+	return __exchange_and_add(&m_value, -1) - 1;
+#else
+	return __gnu_cxx::__exchange_and_add(&m_value, -1) - 1;
+#endif
+}
+
+
+refCounter::operator long() const
+{
+#if __GNUC_MINOR__ < 4 && __GNUC__ < 4
+	return static_cast <long>(__exchange_and_add(&m_value, 0));
+#else
+	return static_cast <long>(__gnu_cxx::__exchange_and_add(&m_value, 0));
+#endif
+}
+
+
+#elif defined(VMIME_HAVE_PTHREAD)
+
+
+refCounter::refCounter(const long initialValue)
+	: m_value(initialValue)
+{
+	pthread_mutexattr_t attr;
+	pthread_mutexattr_init(&attr);
+	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_NORMAL);
+	pthread_mutex_init(&m_mutex, &attr);
+	pthread_mutexattr_destroy(&attr);
+}
+
+
+refCounter::~refCounter()
+{
+	pthread_mutex_destroy(&m_mutex);
+}
+
+
+const long refCounter::increment()
+{
+	long value;
+
+	pthread_mutex_lock(&m_mutex);
+	value = ++m_value;
+	pthread_mutex_unlock(&m_mutex);
+
+	return value;
+}
+
+
+const long refCounter::decrement()
+{
+	long value;
+
+	pthread_mutex_lock(&m_mutex);
+	value = --m_value;
+	pthread_mutex_unlock(&m_mutex);
+
+	return value;
+}
+
+
+refCounter::operator long() const
+{
+	return m_value;
+}
+
+
+#else  // not thread-safe implementation
+
+
+refCounter::refCounter(const long initialValue)
+	: m_value(initialValue)
+{
+}
+
+
+refCounter::~refCounter()
+{
+}
+
+
+const long refCounter::increment()
+{
+	return ++m_value;
+}
+
+
+const long refCounter::decrement()
+{
+	return --m_value;
+}
+
+
+refCounter::operator long() const
+{
+	return m_value;
+}
+
+
+#endif
+
+
+} // utility
+} // vmime
+