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  1. 6th March 2006, 14:27 #1
    yellowmat
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    Default Re: Architecture problem using threads, custom events and signals/slots

    Using qDebug helped me to see what is happening and understand that my application does not blocks but seems to be lost. Let's my explain, many times I see that the serialDataFrameDecoded function is called but never returned. I say that because I can read the following messages :
    Qt Code: 
    1. qDebug("In CSerialDataFrameDecoder::serialDataFrameDecoded. Before : QApplication::postEvent(objectOwner, ce);");
    2. qDebug("In CSerialDataFrameDecoder::serialDataFrameDecoded. After : QApplication::postEvent(objectOwner, ce);");
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    When my application seems to be blocked, I see that the message that should be writen after the serialDataFrameDecoded function call is never writen. Why ? That is what I do not understand. So if someone could help me to understand I whould be great. thanks.

    Here is the code of the run() reimplementation function of my thread, and also the serialDataFrameDecoded fnuction which trigger the custom event :
    Qt Code: 
    1. void CSerialDataFrameDecoder::run()
    2. {
    3. 	int bytesToRead = -1;
    4. 	Q_LONG bytesRead = 0;
    5.  
    6. 	int startSequenceIndex = -1;
    7. 	int stopSequenceIndex = -1;
    8.  
    9. 	QString buffer("");
    10. 	QString frame("");
    11.  
    12. 	while( bMustDecode == true )
    13. 	{
    14. 		qDebug("In CSerialDataFrameDecoder. After : while( bMustDecode == true )");
    15. 		// TO DO
    16. 		// ... read the com port buffer
    17. 		// ... decode frames
    18. 		// ... trigger a custom events each time a complete frame is decoded
    19. 		if( comPort != 0 )
    20. 		{
    21. 			qDebug("In CSerialDataFrameDecoder::run(). After : if( comPort != 0 )");
    22. 			if( comPort->isOpen() )
    23. 			{
    24. 				qDebug("In CSerialDataFrameDecoder::run(). After : if( comPort->isOpen() )");
    25. 				// Get the number of bytes to read
    26. 				bytesToRead = comPort->bytesWaiting();
    27. 				qDebug("In CSerialDataFrameDecoder::run(). After : bytesToRead = comPort->bytesWaiting();");
    28.  
    29. 				if( bytesToRead != 0 )
    30. 				{
    31. 					// Here we can do some stuff
    32. 					char* buffData = 0;
    33. 					buffData = new char[bytesToRead+1];
    34. 					qDebug("In CSerialDataFrameDecoder::run(). After : buffData = new char[bytesToRead+1];");
    35.  
    36. 					bytesRead = comPort->readBlock(buffData, bytesToRead);
    37. 					qDebug("In CSerialDataFrameDecoder::run(). After : bytesRead = comPort->readBlock(buffData, bytesToRead);");
    38. 					buffData[bytesRead] = '\0';
    39. 					comPort->flush();
    40. 					qDebug("In CSerialDataFrameDecoder::run(). After : comPort->flush();");
    41.  
    42. 					buffer = buffData;
    43.  
    44. 					while( (buffer.length() != 0) && (bMustDecode == true) )
    45. 					{
    46. 						qDebug("In CSerialDataFrameDecoder::run(). After : while( (buffer.length() != 0) && (bMustDecode == true) )");
    47.  
    48. 						startSequenceIndex = buffer.find(startSequence, 0, false);
    49. 						stopSequenceIndex = buffer.find(stopSequence, 0, false);
    50. 						qDebug("In CSerialDataFrameDecoder::run(). startSequenceIndex=%d, stopSequenceIndex=%d", startSequenceIndex, stopSequenceIndex);
    51. 						// Check previous indexes to determine if the frame is complete or not
    52. 						// CASE 1 : start and stop indexex are found, stop index is greather than start index
    53. 						// !!! A complete frame can be extracted !!!
    54.  
    55. 						// CASE 2 and CASE 5 : stop index is found but not start index
    56. 						// !!! An incomplete frame can be extracted, its beginning is missing !!!
    57.  
    58. 						// CASE 3 : start index is found but not stop
    59. 						// !!! An incomplete frame can be extracted, its ending is missing
    60.  
    61. 						// CASE 4 : start index neither stop are found
    62. 						// !!! An incomplete frame can be extracted, its beginning and ending are missing
    63.  
    64. 						// CASE 1
    65. 						if( (startSequenceIndex == 0) && (stopSequenceIndex != -1) && (stopSequenceIndex>startSequenceIndex) )
    66. 						{
    67. 							qDebug("In CSerialDataFrameDecoder::run(). Entry : CASE1");
    68. 							frame = buffer.mid(startSequenceIndex, (stopSequenceIndex-startSequenceIndex)+1);
    69. 							buffer.remove(0, stopSequenceIndex+stopSequence.length());
    70.  
    71. 							CSerialDataFrame aFrame;
    72. 							aFrame.setSerialDataFrameValue(frame);
    73. 							aFrame.setSerialDataFrameStatus(CSerialDataFrame::SerialDataFrameStatusComplete);
    74. 							qDebug("In CSerialDataFrameDecoder::run(). Before : this->serialDataFrameDecoded(aFrame);");
    75. 							this->serialDataFrameDecoded(aFrame);
    76. 							qDebug("In CSerialDataFrameDecoder::run(). After : this->serialDataFrameDecoded(aFrame);");
    77. 						}
    78. 						// CASE 2
    79. 						else if( (startSequenceIndex == -1) && (stopSequenceIndex != -1) )
    80. 						{
    81. 							qDebug("In CSerialDataFrameDecoder::run(). Entry : CASE2");
    82. 							frame = buffer.left(stopSequenceIndex+1);
    83. 							buffer.remove(0, stopSequenceIndex+stopSequence.length());
    84.  
    85. 							CSerialDataFrame aFrame;
    86. 							aFrame.setSerialDataFrameValue(frame);
    87. 							aFrame.setSerialDataFrameStatus(CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheEndingPart);
    88. 							qDebug("In CSerialDataFrameDecoder::run(). Before : this->serialDataFrameDecoded(aFrame);");
    89. 							this->serialDataFrameDecoded(aFrame);
    90. 							qDebug("In CSerialDataFrameDecoder::run(). After : this->serialDataFrameDecoded(aFrame);");
    91. 						}
    92. 						// CASE 3
    93. 						else if( (startSequenceIndex != -1) && (stopSequenceIndex == -1) )
    94. 						{
    95. 							qDebug("In CSerialDataFrameDecoder::run(). Entry : CASE3");
    96. 							frame = buffer.mid(0, buffer.length());
    97. 							buffer.remove(0, buffer.length());
    98.  
    99. 							CSerialDataFrame aFrame;
    100. 							aFrame.setSerialDataFrameValue(frame);
    101. 							aFrame.setSerialDataFrameStatus(CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheBeginningPart);
    102. 							qDebug("In CSerialDataFrameDecoder::run(). Before : this->serialDataFrameDecoded(aFrame);");
    103. 							this->serialDataFrameDecoded(aFrame);
    104. 							qDebug("In CSerialDataFrameDecoder::run(). After : this->serialDataFrameDecoded(aFrame);");
    105. 						}
    106. 						// CASE 4
    107. 						else if( (startSequenceIndex == -1) && (stopSequenceIndex == -1) )
    108. 						{
    109. 							qDebug("In CSerialDataFrameDecoder::run(). Entry : CASE4");
    110. 							frame = buffer;
    111. 							buffer.remove(frame);
    112.  
    113. 							CSerialDataFrame aFrame;
    114. 							aFrame.setSerialDataFrameValue(frame);
    115. 							aFrame.setSerialDataFrameStatus(CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheMiddlePart);
    116. 							qDebug("In CSerialDataFrameDecoder::run(). Before : this->serialDataFrameDecoded(aFrame);");
    117. 							this->serialDataFrameDecoded(aFrame);
    118. 							qDebug("In CSerialDataFrameDecoder::run(). After this->serialDataFrameDecoded(aFrame);");
    119. 						}
    120. 						// CASE 5
    121. 						else if( (startSequenceIndex != -1) && (stopSequenceIndex != -1) && (stopSequenceIndex<startSequenceIndex) )
    122. 						{
    123. 							qDebug("In CSerialDataFrameDecoder::run(). Entry : CASE5");
    124. 							frame = buffer.left(stopSequenceIndex+1);
    125. 							buffer.remove(0, stopSequenceIndex+stopSequence.length());
    126.  
    127. 							CSerialDataFrame aFrame;
    128. 							aFrame.setSerialDataFrameValue(frame);
    129. 							aFrame.setSerialDataFrameStatus(CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheEndingPart);
    130. 							qDebug("In CSerialDataFrameDecoder::run(). Before : this->serialDataFrameDecoded(aFrame);");
    131. 							this->serialDataFrameDecoded(aFrame);
    132. 							qDebug("In CSerialDataFrameDecoder::run(). After : this->serialDataFrameDecoded(aFrame);");
    133. 						}
    134. 					}
    135. 				}
    136. 			}
    137. 		}
    138. 	}
    139. }
    140.  
    141.  
    142. void CSerialDataFrameDecoder::serialDataFrameDecoded(const CSerialDataFrame& frame)
    143. {
    144. 	// Allocate some memory for the data
    145. 	CSerialDataFrame* data = 0;
    146. 	data = new CSerialDataFrame(frame);
    147. 	// The allocated memory for the data MUST by freed by the receiver
    148.  
    149. 	// Allocate some memory for the custom event
    150. 	QCustomEvent* ce = 0;
    151. 	ce = new QCustomEvent(1002);
    152. 	ce->setData(data);
    153.  
    154. 	// Send the event
    155. 	qDebug("In CSerialDataFrameDecoder::serialDataFrameDecoded. Before : QApplication::postEvent(objectOwner, ce);");
    156. 	QApplication::postEvent(objectOwner, ce);
    157. 	qDebug("In CSerialDataFrameDecoder::serialDataFrameDecoded. After : QApplication::postEvent(objectOwner, ce);");
    158. 	// The allocated memory for the custum event is freed by Qt so the receiver neither the sender MUST NOT free it
    159. }
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  2. 6th March 2006, 15:32 #2
    jacek
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    Default Re: Architecture problem using threads, custom events and signals/slots

    What member variables does CSerialDataFrame contain? Maybe it uses some Qt classes with implicit sharing?
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  3. 6th March 2006, 15:40 #3
    yellowmat
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    Default Re: Architecture problem using threads, custom events and signals/slots

    Here is the declaration of my CSerialDataFrame class
    Qt Code: 
    1. #ifndef _SERIAL_DATA_FRAME_H
    2. #define _SERIAL_DATA_FRAME_H
    3.  
    4. #include <qstring.h>
    5.  
    6. class CSerialDataFrame
    7. {
    8. 	// Constructor / Destructor
    9. public:
    10. 	CSerialDataFrame(QString data="");
    11. 	CSerialDataFrame(const CSerialDataFrame&);
    12.  
    13. 	const CSerialDataFrame& operator+=	(const CSerialDataFrame&);
    14. 	const CSerialDataFrame&	operator=	(const CSerialDataFrame&);
    15. 	bool					operator==	(const CSerialDataFrame&);
    16.  
    17.  
    18. 	// Functions
    19. 	void		setSerialDataFrameValue(QString);
    20. 	QString		getSerialDataFrameValue() const;
    21.  
    22. 	void		setSerialDataFrameStatus(int);
    23. 	int			getSerialDataFrameStatus() const;
    24.  
    25. 	// Members
    26. public:
    27. 	static const int SerialDataFrameStatusNotDefined;
    28. 	static const int SerialDataFrameStatusComplete;
    29. 	static const int SerialDataFrameStatusIncompleteHasJustTheBeginningPart;
    30. 	static const int SerialDataFrameStatusIncompleteHasJustTheEndingPart;
    31. 	static const int SerialDataFrameStatusIncompleteHasJustTheMiddlePart;
    32.  
    33. private:
    34. 	QString serialDataFrameValue;
    35. 	int		serialDataFrameStatus;
    36. };
    37.  
    38. #endif
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    and the implementation
    Qt Code: 
    1. #include "SerialDataFrame.h"
    2.  
    3. const int CSerialDataFrame::SerialDataFrameStatusNotDefined								=	-1;
    4. const int CSerialDataFrame::SerialDataFrameStatusComplete								=	0;
    5. const int CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheBeginningPart		=	1;
    6. const int CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheEndingPart			=	2;
    7. const int CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheMiddlePart			=	3;
    8.  
    9.  
    10. // Constructor / Destructor
    11. CSerialDataFrame::CSerialDataFrame(QString data):
    12. serialDataFrameValue(data),
    13. serialDataFrameStatus(SerialDataFrameStatusNotDefined)
    14. {
    15. }
    16.  
    17.  
    18. CSerialDataFrame::CSerialDataFrame(const CSerialDataFrame& frame)
    19. {
    20. 	this->serialDataFrameValue		=	frame.serialDataFrameValue;
    21. 	this->serialDataFrameStatus		=	frame.serialDataFrameStatus;
    22. }
    23.  
    24.  
    25. const CSerialDataFrame& CSerialDataFrame::operator+=(const CSerialDataFrame& frame)
    26. {
    27. 	this->serialDataFrameValue		+=	frame.serialDataFrameValue;
    28.  
    29. 	// Beginnig part + middle part = beginning part
    30. 	if( (this->serialDataFrameStatus == CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheBeginningPart) && (frame.serialDataFrameStatus == CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheMiddlePart) )
    31. 	{
    32. 		this->serialDataFrameStatus = CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheBeginningPart;
    33. 	}
    34. 	// Beginning part + ending part = complete part
    35. 	else if(  (this->serialDataFrameStatus == CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheBeginningPart) && (frame.serialDataFrameStatus == CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheEndingPart) )
    36. 	{
    37. 		this->serialDataFrameStatus = CSerialDataFrame::SerialDataFrameStatusComplete;
    38. 	}
    39. 	// Middle part + middle part = middle part
    40. 	else if(  (this->serialDataFrameStatus == CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheMiddlePart) && (frame.serialDataFrameStatus == CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheMiddlePart) )
    41. 	{
    42. 		this->serialDataFrameStatus = CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheMiddlePart;
    43. 	}
    44. 	// Middle part + ending part = ending part
    45. 	else if(  (this->serialDataFrameStatus == CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheMiddlePart) && (frame.serialDataFrameStatus == CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheEndingPart) )
    46. 	{
    47. 		this->serialDataFrameStatus = CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheEndingPart;
    48. 	}
    49. 	// Other cases are not defined
    50. 	else
    51. 		this->serialDataFrameStatus = CSerialDataFrame::SerialDataFrameStatusNotDefined;
    52.  
    53.  	return *this;
    54. }
    55.  
    56.  
    57. const CSerialDataFrame& CSerialDataFrame::operator=(const CSerialDataFrame& frame)
    58. {
    59. 	this->serialDataFrameValue		=	frame.serialDataFrameValue;
    60. 	this->serialDataFrameStatus		=	frame.serialDataFrameStatus;
    61.  
    62. 	return *this;
    63. }
    64.  
    65.  
    66. bool CSerialDataFrame::operator==(const CSerialDataFrame& frame)
    67. {
    68. 	if( (this->serialDataFrameValue == frame.serialDataFrameValue) && (this->serialDataFrameStatus == frame.serialDataFrameStatus) )
    69. 		return true;
    70. 	else
    71. 		return false;
    72. }
    73.  
    74.  
    75. // Functions
    76. void CSerialDataFrame::setSerialDataFrameValue(QString value)
    77. {
    78. 	serialDataFrameValue = value;
    79. }
    80.  
    81.  
    82. QString	CSerialDataFrame::getSerialDataFrameValue() const
    83. {
    84. 	return serialDataFrameValue;
    85. }
    86.  
    87.  
    88. void CSerialDataFrame::setSerialDataFrameStatus(int value)
    89. {
    90. 	serialDataFrameStatus = value;
    91. }
    92.  
    93.  
    94. int CSerialDataFrame::getSerialDataFrameStatus() const
    95. {
    96. 	return serialDataFrameStatus;
    97. }
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    All the afternoon I was looking logs delivered by qDebug. What happening is sometime strange. Sometime I can see that my class CSerialDataFrameDecoder is at a particular code line and the next step it is at a previous code line ... and it is not possible
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  4. 6th March 2006, 15:48 #4
    yellowmat
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    Default Re: Architecture problem using threads, custom events and signals/slots

    An example of a very strange log :
    Sometime qDebug trace tell me that
    Qt Code: 
    1. qDebug("In CSerialDataFrameDecoder::run(). Entry : CASE1");
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    and the next trace tell me
    Qt Code: 
    1. qDebug("In CSerialDataFrameDecoder::run(). After : while( (buffer.length() != 0) && (bMustDecode == true) )");
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    I don't understand what is going on and what's wrong with my code ... I thought what I was coding was not that difficult.
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  5. 6th March 2006, 15:59 #5
    jacek
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    Default Re: Architecture problem using threads, custom events and signals/slots

    Quote Originally Posted by yellowmat
    QString serialDataFrameValue;
    QString data is implicitly shared.

    Try this:
    Qt Code: 
    1. CSerialDataFrame::CSerialDataFrame( const CSerialDataFrame& frame )
    2. {
    3.     serialDataFrameValue  = QDeepCopy<QString>( frame.serialDataFrameValue );
    4.     serialDataFrameStatus = frame.serialDataFrameStatus;
    5. }
    6.  
    7. const CSerialDataFrame& CSerialDataFrame::operator=(const CSerialDataFrame& frame)
    8. {
    9.     serialDataFrameValue  = QDeepCopy<QString>( frame.serialDataFrameValue );
    10.     serialDataFrameStatus = frame.serialDataFrameStatus;
    11.     return *this;
    12. }
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    Quote Originally Posted by yellowmat
    Sometime I can see that my class CSerialDataFrameDecoder is at a particular code line and the next step it is at a previous code line ... and it is not possible
    I'm not sure if qDebug() is thread safe.
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  6. 6th March 2006, 16:07 #6
    yellowmat
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    Default Re: Architecture problem using threads, custom events and signals/slots

    The same problem occurs despite the modifucation you proposed me to implement.

    Could I post you the source code of my CSerialDataFrameDecoder and CSerialPort ? There must be something that is not architecturaly clear and clean ?
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  7. 6th March 2006, 16:09 #7
    yellowmat
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    Default Re: Architecture problem using threads, custom events and signals/slots

    Sorry, I forget to ask but, why should I use QDeepCopy in my CSerialDataFrame code ? Maybe I should use it somewhere else to because I use QString quite often in my code ?

    Another question, what should I use instead of qDebug to keep a trace of what (should) going on ?
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  8. 6th March 2006, 16:15 #8
    jacek
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    Default Re: Architecture problem using threads, custom events and signals/slots

    Quote Originally Posted by yellowmat
    why should I use QDeepCopy in my CSerialDataFrame code ?
    Because you are passing a implicitly shared object (i.e. QString) between two threads.

    http://doc.trolltech.com/3.3/threads.html#9
    http://doc.trolltech.com/3.3/shclass.html

    Quote Originally Posted by yellowmat
    Another question, what should I use instead of qDebug to keep a trace of what (should) going on ?
    First you check whether you can use qDebug() or not, but you can always try writing messages to a text file.
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  9. 6th March 2006, 17:27 #9
    yellowmat
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    Default Re: Architecture problem using threads, custom events and signals/slots

    Sorry Jacek, I know that I should find out by myself but I don't manage to ... so I need some more help please.

    I have modified the source code of my CSerialDataFrame in order to make a deep copy when I call the copy constructor, the equal operator but also the setSerialDataFrameValue. Here I am sure that the copy is deep.

    I have analysed my code and I don't know what could be wrong but I'm sure there is something wrong ... it is starting to drive me crazy

    First, the CSerialDataDecoder code looks fine
    Qt Code: 
    1. void CSerialDataFrameDecoder::run()
    2. {
    3. 	int bytesToRead = -1;
    4. 	Q_LONG bytesRead = 0;
    5.  
    6. 	int startSequenceIndex = -1;
    7. 	int stopSequenceIndex = -1;
    8.  
    9. 	QString buffer("");
    10. 	QString frame("");
    11.  
    12. 	while( bMustDecode == true )
    13. 	{
    14. 		msleep(1);
    15. 		// TO DO
    16. 		// ... read the com port buffer
    17. 		// ... decode frames
    18. 		// ... trigger a custom events each time a complete frame is decoded
    19. 		if( comPort != 0 )
    20. 		{
    21. 			if( comPort->isOpen() )
    22. 			{
    23. 				// Get the number of bytes to read
    24. 				bytesToRead = comPort->bytesWaiting();
    25.  
    26. 				if( bytesToRead != 0 )
    27. 				{
    28. 					// Here we can do some stuff
    29. 					char* buffData = 0;
    30. 					buffData = new char[bytesToRead+1];
    31.  
    32. 					bytesRead = comPort->readBlock(buffData, bytesToRead);
    33. 					buffData[bytesRead] = '\0';
    34. 					comPort->flush();
    35.  
    36. 					buffer = buffData;
    37.  
    38. 					while( (buffer.length() != 0) && (bMustDecode == true) )
    39. 					{
    40. 						msleep(1);
    41.  
    42. 						startSequenceIndex = buffer.find(startSequence, 0, false);
    43. 						stopSequenceIndex = buffer.find(stopSequence, 0, false);
    44. 						// Check previous indexes to determine if the frame is complete or not
    45. 						// CASE 1 : start and stop indexex are found, stop index is greather than start index
    46. 						// !!! A complete frame can be extracted !!!
    47.  
    48. 						// CASE 2 and CASE 5 : stop index is found but not start index
    49. 						// !!! An incomplete frame can be extracted, its beginning is missing !!!
    50.  
    51. 						// CASE 3 : start index is found but not stop
    52. 						// !!! An incomplete frame can be extracted, its ending is missing
    53.  
    54. 						// CASE 4 : start index neither stop are found
    55. 						// !!! An incomplete frame can be extracted, its beginning and ending are missing
    56.  
    57. 						// CASE 1
    58. 						if( (startSequenceIndex == 0) && (stopSequenceIndex != -1) && (stopSequenceIndex>startSequenceIndex) )
    59. 						{
    60. 							frame = buffer.mid(startSequenceIndex, (stopSequenceIndex-startSequenceIndex)+1);
    61. 							buffer.remove(0, stopSequenceIndex+stopSequence.length());
    62.  
    63. 							CSerialDataFrame aFrame;
    64. 							aFrame.setSerialDataFrameValue(frame);
    65. 							aFrame.setSerialDataFrameStatus(CSerialDataFrame::SerialDataFrameStatusComplete);
    66. 							this->serialDataFrameDecoded(aFrame);
    67. 						}
    68. 						// CASE 2
    69. 						else if( (startSequenceIndex == -1) && (stopSequenceIndex != -1) )
    70. 						{
    71. 							frame = buffer.left(stopSequenceIndex+1);
    72. 							buffer.remove(0, stopSequenceIndex+stopSequence.length());
    73.  
    74. 							CSerialDataFrame aFrame;
    75. 							aFrame.setSerialDataFrameValue(frame);
    76. 							aFrame.setSerialDataFrameStatus(CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheEndingPart);
    77. 							this->serialDataFrameDecoded(aFrame);
    78. 						}
    79. 						// CASE 3
    80. 						else if( (startSequenceIndex != -1) && (stopSequenceIndex == -1) )
    81. 						{
    82. 							frame = buffer.mid(0, buffer.length());
    83. 							buffer.remove(0, buffer.length());
    84.  
    85. 							CSerialDataFrame aFrame;
    86. 							aFrame.setSerialDataFrameValue(frame);
    87. 							aFrame.setSerialDataFrameStatus(CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheBeginningPart);
    88. 							this->serialDataFrameDecoded(aFrame);
    89. 						}
    90. 						// CASE 4
    91. 						else if( (startSequenceIndex == -1) && (stopSequenceIndex == -1) )
    92. 						{
    93. 							frame = buffer;
    94. 							buffer.remove(frame);
    95.  
    96. 							CSerialDataFrame aFrame;
    97. 							aFrame.setSerialDataFrameValue(frame);
    98. 							aFrame.setSerialDataFrameStatus(CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheMiddlePart);
    99. 							this->serialDataFrameDecoded(aFrame);
    100. 						}
    101. 						// CASE 5
    102. 						else if( (startSequenceIndex != -1) && (stopSequenceIndex != -1) && (stopSequenceIndex<startSequenceIndex) )
    103. 						{
    104. 							frame = buffer.left(stopSequenceIndex+1);
    105. 							buffer.remove(0, stopSequenceIndex+stopSequence.length());
    106.  
    107. 							CSerialDataFrame aFrame;
    108. 							aFrame.setSerialDataFrameValue(frame);
    109. 							aFrame.setSerialDataFrameStatus(CSerialDataFrame::SerialDataFrameStatusIncompleteHasJustTheEndingPart);
    110. 							this->serialDataFrameDecoded(aFrame);
    111. 						}
    112. 					}
    113. 				}
    114. 			}
    115. 		}
    116. 	}
    117. }
    118.  
    119.  
    120. void CSerialDataFrameDecoder::serialDataFrameDecoded(const CSerialDataFrame& frame)
    121. {
    122. 	// Allocate some memory for the data
    123. 	CSerialDataFrame* data = 0;
    124. 	data = new CSerialDataFrame(frame);
    125. 	// The allocated memory for the data MUST by freed by the receiver
    126.  
    127. 	// Allocate some memory for the custom event
    128. 	QCustomEvent* ce = 0;
    129. 	ce = new QCustomEvent(1002);
    130. 	ce->setData(data);
    131.  
    132. 	// Send the event
    133. 	QApplication::postEvent(objectOwner, ce);
    134. 	// The allocated memory for the custum event is freed by Qt so the receiver neither the sender MUST NOT free it
    135. }
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    In my opinion its behaviour is correct and match with the code. It just flush the buffer, reads data from the Win_QextSerialPort and add a null terminating char. Maybe should I make a deep copy of the buffer content and store it into my QString variable buffer ? After that it processes the buffer variable and looks for a start and stop sequence char, extract the data and then update the buffer variable (it removes the extracted data). After extracting the serial data frame, it allocated some memory for a such a frame, make a copy of it and then send this frame using a custom event to the owner of the CSerialDataFrameDecoder which is the CSerialPort object. At this point should I do something else in that code ? (Other deep copy ?, mutex ?).
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