fixed SF# 1985180: Poco::Net::DNS multithreading issue

Net/include/Poco/Net/DNS.h

@@ -1,7 +1,7 @@
 //
 // DNS.h
 //
-// $Id: //poco/svn/Net/include/Poco/Net/DNS.h#2 $
+// $Id: //poco/Main/Net/include/Poco/Net/DNS.h#3 $
 //
 // Library: Net
 // Package: NetCore
@@ -59,7 +59,7 @@ class Net_API DNS
 	/// An internal DNS cache is used to speed up name lookups.
 {
 public:
-	static const HostEntry& hostByName(const std::string& hostname);
+	static HostEntry hostByName(const std::string& hostname);
 		/// Returns a HostEntry object containing the DNS information
 		/// for the host with the given name.
 		///
@@ -73,7 +73,7 @@ public:
 		///
 		/// Throws an IOException in case of any other error.
 		
-	static const HostEntry& hostByAddress(const IPAddress& address);
+	static HostEntry hostByAddress(const IPAddress& address);
 		/// Returns a HostEntry object containing the DNS information
 		/// for the host with the given IP address.
 		///
@@ -84,7 +84,7 @@ public:
 		///
 		/// Throws an IOException in case of any other error.
 
-	static const HostEntry& resolve(const std::string& address);
+	static HostEntry resolve(const std::string& address);
 		/// Returns a HostEntry object containing the DNS information
 		/// for the host with the given IP address or host name.
 		///
@@ -102,7 +102,7 @@ public:
 		/// Convenience method that calls resolve(address) and returns 
 		/// the first address from the HostInfo.
 
-	static const HostEntry& thisHost();
+	static HostEntry thisHost();
 		/// Returns a HostEntry object containing the DNS information
 		/// for this host.
 		///

Net/include/Poco/Net/HostEntry.h

@@ -1,7 +1,7 @@
 //
 // HostEntry.h
 //
-// $Id: //poco/svn/Net/include/Poco/Net/HostEntry.h#2 $
+// $Id: //poco/Main/Net/include/Poco/Net/HostEntry.h#3 $
 //
 // Library: Net
 // Package: NetCore
@@ -43,6 +43,8 @@
 #include "Poco/Net/Net.h"
 #include "Poco/Net/SocketDefs.h"
 #include "Poco/Net/IPAddress.h"
+#include "Poco/RefCountedObject.h"
+#include "Poco/AutoPtr.h"
 #include <vector>
 
 
@@ -50,14 +52,60 @@ namespace Poco {
 namespace Net {
 
 
+class Net_API HostEntryImpl: public Poco::RefCountedObject
+	/// This class stores information about a host
+	/// such as host name, alias names and a list
+	/// of IP addresses.
+	///
+	/// This class is used internally by HostEntry and is not
+	/// intended for public use.
+{
+protected:
+	typedef std::vector<std::string> AliasList;
+	typedef std::vector<IPAddress>   AddressList;
+	
+	HostEntryImpl();
+		/// Creates an empty HostEntry.
+		
+	HostEntryImpl(struct hostent* entry);
+		/// Creates the HostEntry from the data in a hostent structure.
+
+#if defined(_WIN32) && defined(POCO_HAVE_IPv6)
+	HostEntryImpl(struct addrinfo* info);
+		/// Creates the HostEntry from the data in a Windows addrinfo structure.
+#endif
+
+	~HostEntryImpl();
+		/// Destroys the HostEntryImpl.
+
+	const std::string& name() const;
+		/// Returns the canonical host name.
+
+	const AliasList& aliases() const;
+		/// Returns a vector containing alias names for
+		/// the host name.
+
+	const AddressList& addresses() const;
+		/// Returns a vector containing the IPAddresses
+		/// for the host.
+
+private:
+	std::string _name;
+	AliasList   _aliases;
+	AddressList _addresses;
+	
+	friend class HostEntry;
+};
+
+
 class Net_API HostEntry
 	/// This class stores information about a host
 	/// such as host name, alias names and a list
 	/// of IP addresses.
 {
 public:
-	typedef std::vector<std::string> AliasList;
+	typedef HostEntryImpl::AliasList   AliasList;
-	typedef std::vector<IPAddress>   AddressList;
+	typedef HostEntryImpl::AddressList AddressList;
 	
 	HostEntry();
 		/// Creates an empty HostEntry.
@@ -94,33 +142,55 @@ public:
 		/// for the host.
 
 private:
-	std::string _name;
+	Poco::AutoPtr<HostEntryImpl> _pImpl;
-	AliasList   _aliases;
-	AddressList _addresses;
 };
 
 
 //
 // inlines
 //
-inline const std::string& HostEntry::name() const
+inline const std::string& HostEntryImpl::name() const
 {
 	return _name;
 }
 
 
-inline const HostEntry::AliasList& HostEntry::aliases() const
+inline const HostEntryImpl::AliasList& HostEntryImpl::aliases() const
 {
 	return _aliases;
 }
 
 
-inline const HostEntry::AddressList& HostEntry::addresses() const
+inline const HostEntryImpl::AddressList& HostEntryImpl::addresses() const
 {
 	return _addresses;
 }
 
 
+inline const std::string& HostEntry::name() const
+{
+	return _pImpl->name();
+}
+
+
+inline const HostEntry::AliasList& HostEntry::aliases() const
+{
+	return _pImpl->aliases();
+}
+
+
+inline const HostEntry::AddressList& HostEntry::addresses() const
+{
+	return _pImpl->addresses();
+}
+
+
+inline void HostEntry::swap(HostEntry& other)
+{
+	_pImpl.swap(other._pImpl);
+}
+
+
 inline void swap(HostEntry& h1, HostEntry& h2)
 {
 	h1.swap(h2);

Net/src/DNS.cpp

@@ -1,7 +1,7 @@
 //
 // DNS.cpp
 //
-// $Id: //poco/svn/Net/src/DNS.cpp#2 $
+// $Id: //poco/Main/Net/src/DNS.cpp#9 $
 //
 // Library: Net
 // Package: NetCore
@@ -82,7 +82,7 @@ DNS::DNSCache DNS::_cache;
 Poco::FastMutex DNS::_mutex;
 
 
-const HostEntry& DNS::hostByName(const std::string& hostname)
+HostEntry DNS::hostByName(const std::string& hostname)
 {
 	FastMutex::ScopedLock lock(_mutex);
 	
@@ -118,7 +118,7 @@ const HostEntry& DNS::hostByName(const std::string& hostname)
 }
 
 
-const HostEntry& DNS::hostByAddress(const IPAddress& address)
+HostEntry DNS::hostByAddress(const IPAddress& address)
 {
 	FastMutex::ScopedLock lock(_mutex);
 
@@ -158,7 +158,7 @@ const HostEntry& DNS::hostByAddress(const IPAddress& address)
 }
 
 
-const HostEntry& DNS::resolve(const std::string& address)
+HostEntry DNS::resolve(const std::string& address)
 {
 	IPAddress ip;
 	if (IPAddress::tryParse(address, ip))
@@ -170,7 +170,7 @@ const HostEntry& DNS::resolve(const std::string& address)
 
 IPAddress DNS::resolveOne(const std::string& address)
 {
-	const HostEntry& entry = resolve(address);
+	HostEntry entry = resolve(address);
 	if (!entry.addresses().empty())
 		return entry.addresses()[0];
 	else
@@ -178,7 +178,7 @@ IPAddress DNS::resolveOne(const std::string& address)
 }
 
 
-const HostEntry& DNS::thisHost()
+HostEntry DNS::thisHost()
 {
 	return hostByName(Environment::nodeName());
 }

Net/src/HostEntry.cpp

@@ -1,7 +1,7 @@
 //
 // HostEntry.cpp
 //
-// $Id: //poco/svn/Net/src/HostEntry.cpp#2 $
+// $Id: //poco/Main/Net/src/HostEntry.cpp#8 $
 //
 // Library: Net
 // Package: NetCore
@@ -43,12 +43,17 @@ namespace Poco {
 namespace Net {
 
 
-HostEntry::HostEntry()
+//
+// HostEntryImpl
+//
+
+
+HostEntryImpl::HostEntryImpl()
 {
 }
 
 	
-HostEntry::HostEntry(struct hostent* entry)
+HostEntryImpl::HostEntryImpl(struct hostent* entry)
 {
 	poco_check_ptr (entry);
 	
@@ -77,7 +82,7 @@ HostEntry::HostEntry(struct hostent* entry)
 #if defined(_WIN32) && defined(POCO_HAVE_IPv6)
 
 
-HostEntry::HostEntry(struct addrinfo* ainfo)
+HostEntryImpl::HostEntryImpl(struct addrinfo* ainfo)
 {
 	poco_check_ptr (ainfo);
 	
@@ -94,37 +99,53 @@ HostEntry::HostEntry(struct addrinfo* ainfo)
 #endif
 
 
-HostEntry::HostEntry(const HostEntry& entry):
+HostEntryImpl::~HostEntryImpl()
-	_name(entry._name),
-	_aliases(entry._aliases),
-	_addresses(entry._addresses)
 {
 }
 
 
-HostEntry& HostEntry::operator = (const HostEntry& entry)
+//
+// HostEntry
+//
+
+
+HostEntry::HostEntry():
+	_pImpl(new HostEntryImpl)
 {
-	if (&entry != this)
-	{
-		_name          = entry._name;
-		_aliases       = entry._aliases;
-		_addresses     = entry._addresses;
-	}
-	return *this;
 }
 
 	
-void HostEntry::swap(HostEntry& hostEntry)
+HostEntry::HostEntry(struct hostent* entry):
+	_pImpl(new HostEntryImpl(entry))
 {
-	std::swap(_name, hostEntry._name);
-	std::swap(_aliases, hostEntry._aliases);
-	std::swap(_addresses, hostEntry._addresses);
 }
 
 
+#if defined(_WIN32) && defined(POCO_HAVE_IPv6)
+HostEntry::HostEntry(struct addrinfo* info):
+	_pImpl(new HostEntryImpl(info))
+{
+}
+#endif
+
+
 HostEntry::~HostEntry()
 {
 }
 
 
+HostEntry::HostEntry(const HostEntry& entry):
+	_pImpl(entry._pImpl)
+{
+}
+
+
+HostEntry& HostEntry::operator = (const HostEntry& entry)
+{
+	HostEntry tmp(entry);
+	tmp.swap(*this);
+	return *this;
+}
+
+
 } } // namespace Poco::Net