2 files changed, 90 insertions, 0 deletions

diff --git a/src/ByteBuffer.cpp b/src/ByteBuffer.cpp
index 6406a2625..acda8a839 100644
--- a/src/ByteBuffer.cpp
+++ b/src/ByteBuffer.cpp
@@ -109,6 +109,47 @@ public:
 
 
 
+#ifdef _DEBUG
+
+	/** Simple RAII class that is used for checking that no two threads are using an object simultanously.
+	It requires the monitored object to provide the storage for a thread ID.
+	It uses that storage to check if the thread ID of consecutive calls is the same all the time. */
+	class cSingleThreadAccessChecker
+	{
+	public:
+		cSingleThreadAccessChecker(std::thread::id * a_ThreadID) :
+			m_ThreadID(a_ThreadID)
+		{
+			ASSERT(
+				(*a_ThreadID == std::this_thread::get_id()) ||  // Either the object is used by current thread...
+				(*a_ThreadID == std::thread::id())              // ... or by no thread at all
+			);
+
+			// Mark as being used by this thread:
+			*m_ThreadID = std::this_thread::get_id();
+		}
+
+		~cSingleThreadAccessChecker()
+		{
+			// Mark as not being used by any thread:
+			*m_ThreadID = std::thread::id();
+		}
+
+	protected:
+		/** Points to the storage used for ID of the thread using the object. */
+		std::thread::id * m_ThreadID;
+	};
+
+#define CHECK_THREAD cSingleThreadAccessChecker Checker(&m_ThreadID);
+
+#else
+ #define CHECK_THREAD
+#endif
+
+
+
+
+
 ////////////////////////////////////////////////////////////////////////////////
 // cByteBuffer:
 
@@ -140,6 +181,7 @@ cByteBuffer::~cByteBuffer()
 
 bool cByteBuffer::Write(const void * a_Bytes, size_t a_Count)
 {
+	CHECK_THREAD
 	CheckValid();
 
 	// Store the current free space for a check after writing:
@@ -186,6 +228,7 @@ bool cByteBuffer::Write(const void * a_Bytes, size_t a_Count)
 
 size_t cByteBuffer::GetFreeSpace(void) const
 {
+	CHECK_THREAD
 	CheckValid();
 	if (m_WritePos >= m_DataStart)
 	{
@@ -207,6 +250,7 @@ size_t cByteBuffer::GetFreeSpace(void) const
 /// Returns the number of bytes that are currently in the ringbuffer. Note GetReadableBytes()
 size_t cByteBuffer::GetUsedSpace(void) const
 {
+	CHECK_THREAD
 	CheckValid();
 	ASSERT(m_BufferSize >= GetFreeSpace());
 	ASSERT((m_BufferSize - GetFreeSpace()) >= 1);
@@ -220,6 +264,7 @@ size_t cByteBuffer::GetUsedSpace(void) const
 /// Returns the number of bytes that are currently available for reading (may be less than UsedSpace due to some data having been read already)
 size_t cByteBuffer::GetReadableSpace(void) const
 {
+	CHECK_THREAD
 	CheckValid();
 	if (m_ReadPos > m_WritePos)
 	{
@@ -238,6 +283,7 @@ size_t cByteBuffer::GetReadableSpace(void) const
 
 bool cByteBuffer::CanReadBytes(size_t a_Count) const
 {
+	CHECK_THREAD
 	CheckValid();
 	return (a_Count <= GetReadableSpace());
 }
@@ -248,6 +294,7 @@ bool cByteBuffer::CanReadBytes(size_t a_Count) const
 
 bool cByteBuffer::CanWriteBytes(size_t a_Count) const
 {
+	CHECK_THREAD
 	CheckValid();
 	return (a_Count <= GetFreeSpace());
 }
@@ -258,6 +305,7 @@ bool cByteBuffer::CanWriteBytes(size_t a_Count) const
 
 bool cByteBuffer::ReadChar(char & a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	NEEDBYTES(1);
 	ReadBuf(&a_Value, 1);
@@ -270,6 +318,7 @@ bool cByteBuffer::ReadChar(char & a_Value)
 
 bool cByteBuffer::ReadByte(unsigned char & a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	NEEDBYTES(1);
 	ReadBuf(&a_Value, 1);
@@ -282,6 +331,7 @@ bool cByteBuffer::ReadByte(unsigned char & a_Value)
 
 bool cByteBuffer::ReadBEShort(short & a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	NEEDBYTES(2);
 	ReadBuf(&a_Value, 2);
@@ -295,6 +345,7 @@ bool cByteBuffer::ReadBEShort(short & a_Value)
 
 bool cByteBuffer::ReadBEInt(int & a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	NEEDBYTES(4);
 	ReadBuf(&a_Value, 4);
@@ -308,6 +359,7 @@ bool cByteBuffer::ReadBEInt(int & a_Value)
 
 bool cByteBuffer::ReadBEInt64(Int64 & a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	NEEDBYTES(8);
 	ReadBuf(&a_Value, 8);
@@ -321,6 +373,7 @@ bool cByteBuffer::ReadBEInt64(Int64 & a_Value)
 
 bool cByteBuffer::ReadBEFloat(float & a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	NEEDBYTES(4);
 	ReadBuf(&a_Value, 4);
@@ -334,6 +387,7 @@ bool cByteBuffer::ReadBEFloat(float & a_Value)
 
 bool cByteBuffer::ReadBEDouble(double & a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	NEEDBYTES(8);
 	ReadBuf(&a_Value, 8);
@@ -347,6 +401,7 @@ bool cByteBuffer::ReadBEDouble(double & a_Value)
 
 bool cByteBuffer::ReadBool(bool & a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	NEEDBYTES(1);
 	char Value = 0;
@@ -361,6 +416,7 @@ bool cByteBuffer::ReadBool(bool & a_Value)
 
 bool cByteBuffer::ReadBEUTF16String16(AString & a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	short Length;
 	if (!ReadBEShort(Length))
@@ -381,6 +437,7 @@ bool cByteBuffer::ReadBEUTF16String16(AString & a_Value)
 
 bool cByteBuffer::ReadVarInt(UInt32 & a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	UInt32 Value = 0;
 	int Shift = 0;
@@ -402,6 +459,7 @@ bool cByteBuffer::ReadVarInt(UInt32 & a_Value)
 
 bool cByteBuffer::ReadVarUTF8String(AString & a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	UInt32 Size = 0;
 	if (!ReadVarInt(Size))
@@ -421,6 +479,7 @@ bool cByteBuffer::ReadVarUTF8String(AString & a_Value)
 
 bool cByteBuffer::ReadLEInt(int & a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	NEEDBYTES(4);
 	ReadBuf(&a_Value, 4);
@@ -439,6 +498,7 @@ bool cByteBuffer::ReadLEInt(int & a_Value)
 
 bool cByteBuffer::ReadPosition(int & a_BlockX, int & a_BlockY, int & a_BlockZ)
 {
+	CHECK_THREAD
 	Int64 Value;
 	if (!ReadBEInt64(Value))
 	{
@@ -463,6 +523,7 @@ bool cByteBuffer::ReadPosition(int & a_BlockX, int & a_BlockY, int & a_BlockZ)
 
 bool cByteBuffer::WriteChar(char a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	PUTBYTES(1);
 	return WriteBuf(&a_Value, 1);
@@ -474,6 +535,7 @@ bool cByteBuffer::WriteChar(char a_Value)
 
 bool cByteBuffer::WriteByte(unsigned char a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	PUTBYTES(1);
 	return WriteBuf(&a_Value, 1);
@@ -485,6 +547,7 @@ bool cByteBuffer::WriteByte(unsigned char a_Value)
 
 bool cByteBuffer::WriteBEShort(short a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	PUTBYTES(2);
 	u_short Converted = htons((u_short)a_Value);
@@ -497,6 +560,7 @@ bool cByteBuffer::WriteBEShort(short a_Value)
 
 bool cByteBuffer::WriteBEUShort(unsigned short a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	PUTBYTES(2);
 	u_short Converted = htons((u_short)a_Value);
@@ -509,6 +573,7 @@ bool cByteBuffer::WriteBEUShort(unsigned short a_Value)
 
 bool cByteBuffer::WriteBEInt(int a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	PUTBYTES(4);
 	UInt32 Converted = HostToNetwork4(&a_Value);
@@ -521,6 +586,7 @@ bool cByteBuffer::WriteBEInt(int a_Value)
 
 bool cByteBuffer::WriteBEInt64(Int64 a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	PUTBYTES(8);
 	UInt64 Converted = HostToNetwork8(&a_Value);
@@ -533,6 +599,7 @@ bool cByteBuffer::WriteBEInt64(Int64 a_Value)
 
 bool cByteBuffer::WriteBEFloat(float a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	PUTBYTES(4);
 	UInt32 Converted = HostToNetwork4(&a_Value);
@@ -545,6 +612,7 @@ bool cByteBuffer::WriteBEFloat(float a_Value)
 
 bool cByteBuffer::WriteBEDouble(double a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	PUTBYTES(8);
 	UInt64 Converted = HostToNetwork8(&a_Value);
@@ -558,6 +626,7 @@ bool cByteBuffer::WriteBEDouble(double a_Value)
 
 bool cByteBuffer::WriteBool(bool a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	return WriteChar(a_Value ? 1 : 0);
 }
@@ -568,6 +637,7 @@ bool cByteBuffer::WriteBool(bool a_Value)
 
 bool cByteBuffer::WriteVarInt(UInt32 a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	
 	// A 32-bit integer can be encoded by at most 5 bytes:
@@ -588,6 +658,7 @@ bool cByteBuffer::WriteVarInt(UInt32 a_Value)
 
 bool cByteBuffer::WriteVarUTF8String(const AString & a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	PUTBYTES(a_Value.size() + 1);  // This is a lower-bound on the bytes that will be actually written. Fail early.
 	bool res = WriteVarInt((UInt32)(a_Value.size()));
@@ -604,6 +675,7 @@ bool cByteBuffer::WriteVarUTF8String(const AString & a_Value)
 
 bool cByteBuffer::WriteLEInt(int a_Value)
 {
+	CHECK_THREAD
 	CheckValid();
 	#ifdef IS_LITTLE_ENDIAN
 		return WriteBuf((const char *)&a_Value, 4);
@@ -619,6 +691,7 @@ bool cByteBuffer::WriteLEInt(int a_Value)
 
 bool cByteBuffer::WritePosition(int a_BlockX, int a_BlockY, int a_BlockZ)
 {
+	CHECK_THREAD
 	return WriteBEInt64(((Int64)a_BlockX & 0x3FFFFFF) << 38 | ((Int64)a_BlockY & 0xFFF) << 26 | ((Int64)a_BlockZ & 0x3FFFFFF));
 }
 
@@ -628,6 +701,7 @@ bool cByteBuffer::WritePosition(int a_BlockX, int a_BlockY, int a_BlockZ)
 
 bool cByteBuffer::ReadBuf(void * a_Buffer, size_t a_Count)
 {
+	CHECK_THREAD
 	CheckValid();
 	NEEDBYTES(a_Count);
 	char * Dst = (char *)a_Buffer;  // So that we can do byte math
@@ -660,6 +734,7 @@ bool cByteBuffer::ReadBuf(void * a_Buffer, size_t a_Count)
 
 bool cByteBuffer::WriteBuf(const void * a_Buffer, size_t a_Count)
 {
+	CHECK_THREAD
 	CheckValid();
 	PUTBYTES(a_Count);
 	char * Src = (char *)a_Buffer;  // So that we can do byte math
@@ -689,6 +764,7 @@ bool cByteBuffer::WriteBuf(const void * a_Buffer, size_t a_Count)
 
 bool cByteBuffer::ReadString(AString & a_String, size_t a_Count)
 {
+	CHECK_THREAD
 	CheckValid();
 	NEEDBYTES(a_Count);
 	a_String.clear();
@@ -723,6 +799,7 @@ bool cByteBuffer::ReadString(AString & a_String, size_t a_Count)
 bool cByteBuffer::ReadUTF16String(AString & a_String, size_t a_NumChars)
 {
 	// Reads 2 * a_NumChars bytes and interprets it as a UTF16 string, converting it into UTF8 string a_String
+	CHECK_THREAD
 	CheckValid();
 	AString RawData;
 	if (!ReadString(RawData, a_NumChars * 2))
@@ -739,6 +816,7 @@ bool cByteBuffer::ReadUTF16String(AString & a_String, size_t a_NumChars)
 
 bool cByteBuffer::SkipRead(size_t a_Count)
 {
+	CHECK_THREAD
 	CheckValid();
 	if (!CanReadBytes(a_Count))
 	{
@@ -754,6 +832,7 @@ bool cByteBuffer::SkipRead(size_t a_Count)
 
 void cByteBuffer::ReadAll(AString & a_Data)
 {
+	CHECK_THREAD
 	CheckValid();
 	ReadString(a_Data, GetReadableSpace());
 }
@@ -764,6 +843,7 @@ void cByteBuffer::ReadAll(AString & a_Data)
 
 bool cByteBuffer::ReadToByteBuffer(cByteBuffer & a_Dst, size_t a_NumBytes)
 {
+	CHECK_THREAD
 	if (!a_Dst.CanWriteBytes(a_NumBytes) || !CanReadBytes(a_NumBytes))
 	{
 		// There's not enough source bytes or space in the dest BB
@@ -788,6 +868,7 @@ bool cByteBuffer::ReadToByteBuffer(cByteBuffer & a_Dst, size_t a_NumBytes)
 
 void cByteBuffer::CommitRead(void)
 {
+	CHECK_THREAD
 	CheckValid();
 	m_DataStart = m_ReadPos;
 }
@@ -798,6 +879,7 @@ void cByteBuffer::CommitRead(void)
 
 void cByteBuffer::ResetRead(void)
 {
+	CHECK_THREAD
 	CheckValid();
 	m_ReadPos = m_DataStart;
 }
@@ -810,6 +892,7 @@ void cByteBuffer::ReadAgain(AString & a_Out)
 {
 	// Return the data between m_DataStart and m_ReadPos (the data that has been read but not committed)
 	// Used by ProtoProxy to repeat communication twice, once for parsing and the other time for the remote party
+	CHECK_THREAD
 	CheckValid();
 	size_t DataStart = m_DataStart;
 	if (m_ReadPos < m_DataStart)
@@ -829,6 +912,7 @@ void cByteBuffer::ReadAgain(AString & a_Out)
 
 void cByteBuffer::AdvanceReadPos(size_t a_Count)
 {
+	CHECK_THREAD
 	CheckValid();
 	m_ReadPos += a_Count;
 	if (m_ReadPos >= m_BufferSize)
diff --git a/src/ByteBuffer.h b/src/ByteBuffer.h
index e80763772..2a316fa32 100644
--- a/src/ByteBuffer.h
+++ b/src/ByteBuffer.h
@@ -133,6 +133,12 @@ protected:
 	size_t m_DataStart;  // Where the data starts in the ringbuffer
 	size_t m_WritePos;   // Where the data ends in the ringbuffer
 	size_t m_ReadPos;    // Where the next read will start in the ringbuffer
+
+	#ifdef _DEBUG
+		/** The ID of the thread currently accessing the object.
+		Used for checking that only one thread accesses the object at a time, via cSingleThreadAccessChecker. */
+		mutable std::thread::id m_ThreadID;
+	#endif
 	
 	/** Advances the m_ReadPos by a_Count bytes */
 	void AdvanceReadPos(size_t a_Count);