freeRTOS: question about the behavior of API "vTaskPrioritySet" - embedded

In API vTaskPrioritySet:
#if ( configUSE_MUTEXES == 1 )
{
/* Only change the priority being used if the task is not
currently using an inherited priority. */
if( pxTCB->uxBasePriority == pxTCB->uxPriority )
{
pxTCB->uxPriority = uxNewPriority;
}
else
{
mtCOVERAGE_TEST_MARKER();
}
/* The base priority gets set whatever. */
pxTCB->uxBasePriority = uxNewPriority;
}
#else
......
I noticed that once priority inheritance occurs, uxPriority will not be set. My question is: If the priority set by vTaskPrioritySet is higher than the inherited priority, why not use the higher one?
like this:
if( pxTCB->uxBasePriority == pxTCB->uxPriority || uxNewPriority > pxTCB->uxPriority )
{
pxTCB->uxPriority = uxNewPriority;
}
Otherwise, the priority set by vTaskPrioritySet will not take effect until the disinheritance occurs.

Related

STM32F4 - Button GPIO input doesn't work

I'm using a STM32F469 Discovery board, and I'm trying to get an external momentary push button to work.
It is currently connected to PG11, and it is set up so than when pressed it connects the pin to +5V supplied by the MCU. Before I continue, I just want to state that I use the following code in stmf4xx_it.c to perform debounce:
#define REFdebounce 200
int In1 = 3;
int In1_0 = 0;
int In1_1 = 0;
int StatoIn1 = 3;
void SysTick_Handler(void)
{
In1 = HAL_GPIO_ReadPin( GPIOG, GPIO_PIN_11 );
if ( In1 == 0 )
{
In1_0++;
In1_1 = 0;
if ( In1_0 >= REFdebounce )
{
In1_0 = REFdebounce + 1;
StatoIn1 = 0;
}
}
else
{
In1_0 = 0;
In1_1++;
if ( In1_1 >= REFdebounce )
{
In1_1 = REFdebounce + 1;
StatoIn1 = 1;
}
}
}
I have the following code in a header file inout.h:
typedef void ( * TSelectCallback ) ( int aSelectSignal );
void ConfigSelectPin
(
TSelectCallback aSelectCallback
);
And then in inout.c I have the following code for setup of the button GPIO pin:
#define SELECT_SIGNAL_PIN GPIO_PIN_11
#define SELECT_SIGNAL_GPIO_PORT GPIOG
#define SELECT_SIGNAL_GPIO_CLK_ENABLE() __HAL_RCC_GPIOG_CLK_ENABLE()
#define SELECT_SIGNAL_GPIO_CLK_DISABLE() __HAL_RCC_GPIOG_CLK_DISABLE()
#define SELECT_SIGNAL_EXTI_IRQn EXTI15_10_IRQn
void ConfigSelectPin( TSelectCallback aSelectCallback )
{
GPIO_InitTypeDef GPIO_InitStructure;
/* Enable GPIOC clock */
SELECT_SIGNAL_GPIO_CLK_ENABLE();
/* Configure washer signal pin as input floating */
GPIO_InitStructure.Mode = GPIO_MODE_IT_RISING;
GPIO_InitStructure.Pull = GPIO_PULLDOWN;
GPIO_InitStructure.Pin = SELECT_SIGNAL_PIN;
HAL_GPIO_Init( SELECT_SIGNAL_GPIO_PORT, &GPIO_InitStructure );
/* Enable and set EXTI lines 0 Interrupt to the lowest priority */
HAL_NVIC_SetPriority( SELECT_SIGNAL_EXTI_IRQn, 8, 0 );
HAL_NVIC_EnableIRQ( SELECT_SIGNAL_EXTI_IRQn );
SelectCallback = aSelectCallback;
}
void EXTI15_10_IRQHandler( void )
{
if (__HAL_GPIO_EXTI_GET_IT( SELECT_SIGNAL_PIN ) != RESET)
{
RedLedOn();
__HAL_GPIO_EXTI_CLEAR_IT( SELECT_SIGNAL_PIN );
HAL_GPIO_EXTI_IRQHandler( SELECT_SIGNAL_PIN );
}
}
void HAL_GPIO_EXTI_Callback( uint16_t GPIO_Pin )
{
if ( GPIO_Pin == SELECT_SIGNAL_PIN )
{
YellowLedOn();
GPIO_PinState pinState;
//pinState = HAL_GPIO_ReadPin( SELECT_SIGNAL_GPIO_PORT, GPIO_Pin );
pinState = 1;
if ( SelectCallback )
SelectCallback ( pinState );
}
}
Then in my main.c file I have the following:
/* variable to detect that hardware button is pressed */
static int Select = 0;
extern int StatoIn1;
void SelectIsrCallback( int aSelectSignal )
{
if ( StatoIn1 == 1 )
{
OrangeLedOn();
Select = 1;
}
}
I then use the following code to detect if the button has been pressed and perform my required action
if ( Select )
{
BlueLedOn();
Select = 0;
}
Now EVERY time I press the button, the EXTI15_10_IRQHandler is called as acknowledged by the red led turning on.
If I keep pressing the button, many many many times, the HAL_GPIO_EXTI_Callback will eventually be called as acknowledged by the yellow led turning on.
If I then keep pressing the button even more times, then eventually the SelectIsrCallback is called and my desired action is perfomed, as acknowledged by the orange and blue led turning on.
Why do the HAL_GPIO_EXTI_Callback and SelectIsrCallback not get called on the first button press? And why does the SelectIsrCallback not get called once the HAL_GPIO_EXTI_Callback is called?
NOTE: I've just moved the YellowLedOn() call, to before the if statement in HAL_GPIO_EXTI_Callback to see if it was this function of the if statement that takes loads of button presses before it is called. It made no difference, so the issue is with the calling of the HAL_GPIO_EXTI_Callback function.
Okay, so despite spending days to figure this out, it turns out the answer is a simple one. The order of the functions called in EXTI15_10_IRQHandler need to be switched. I.e. the HAL_GPIO_EXTI_IRQHandler needs to b called first and then the flag needs to be cleared. So this:
void EXTI15_10_IRQHandler( void )
{
if (__HAL_GPIO_EXTI_GET_IT( SELECT_SIGNAL_PIN ) != RESET)
{
RedLedOn();
**__HAL_GPIO_EXTI_CLEAR_IT( SELECT_SIGNAL_PIN );
HAL_GPIO_EXTI_IRQHandler( SELECT_SIGNAL_PIN );**
}
}
Needs to be switched to this:
void EXTI15_10_IRQHandler( void )
{
if (__HAL_GPIO_EXTI_GET_IT( SELECT_SIGNAL_PIN ) != RESET)
{
RedLedOn();
HAL_GPIO_EXTI_IRQHandler( SELECT_SIGNAL_PIN );
__HAL_GPIO_EXTI_CLEAR_IT( SELECT_SIGNAL_PIN );
}
}
This seems obvious now, because you can't clear the interrupt flag before calling the interrupt function otherwise it will not execute. However, I'm sure I saw a lot of examples where it was in the order I had the functions originally.

How to check forwarded Packets in UDPBasicApp in Omnet

How can I modify UDPBasicApp to find duplicates in the messages recieved?
I made these changes to the class UDPBasicApp.cc to add an extra step to check recieved udp data packets like below, but I see no effect in .sca/.vec and does not even show bubbles.
Where could the error be?
void UDPBasicApp::handleMessageWhenUp(cMessage *msg)
{
if (msg->isSelfMessage()) {
ASSERT(msg == selfMsg);
switch (selfMsg->getKind()) {
case START:
processStart();
break;
case SEND:
processSend();
break;
case STOP:
processStop();
break;
default:
throw cRuntimeError("Invalid kind %d in self message", (int)selfMsg->getKind());
}
}
else if (msg->getKind() == UDP_I_DATA) {
// process incoming packet
//-----------------------------------------------------Added step
//std::string currentMsg= "" + msg->getTreeId();
std::string currentPacket= PK(msg)->getName();
if( BF->CheckBloom(currentPacket) == 1) {
numReplayed++;
getParentModule()->bubble("Replayed!!");
EV<<"----------------------WSNode "<<getParentModule()->getIndex() <<": REPLAYED! Dropping Packet\n";
delete msg;
return;
}
else
{
BF->AddToBloom(currentPacket);
numLegit++;
getParentModule()->bubble("Legit.");
EV<<"----------------------WSNode "<<getParentModule()->getIndex() <<":OK. Pass.\n";
}
//-----------------------------------------------------------------------------
processPacket(PK(msg));
}
else if (msg->getKind() == UDP_I_ERROR) {
EV_WARN << "Ignoring UDP error report\n";
delete msg;
}
else {
throw cRuntimeError("Unrecognized message (%s)%s", msg->getClassName(), msg->getName());
}
if (hasGUI()) {
char buf[40];
sprintf(buf, "rcvd: %d pks\nsent: %d pks", numReceived, numSent);
getDisplayString().setTagArg("t", 0, buf);
}
}
Since I don't have enough context about the entities participating in your overall system, I will provide the following idea:
You can add a unique ID to each message of your application by adding the following line to your applications *.msg:
int messageID = simulation.getUniqueNumber();
Now on the receiver side you can have an std::map<int, int> myMap where you store the <id,number-of-occurences>
Each time you receive a message you add the message to the std::map and increment the number-of-occurences
if(this->myMap.count(myMessage->getUniqueID) == 0) /* check whether this ID exists in the map */
{
this->myMap.insert(std::make_pair(myMessage->getUniqueID(), 1)); /* add this id to the map and set the counter to 1 */
}
else
{
this->myMap.at(myMessage->getUniqueID())++; /* add this id to the map and increment the counter */
}
This will allow you to track whether the same message has been forwarded twice, simply by doing:
if(this->myMap.at(myMessage->getUniqueID()) != 1 ) /* the counter is not 1, message has been "seen" more than once */
The tricky thing for you is how do you define whether a message has been seen twice (or more).

Creating/Retrieving a Cart programmatically

For a module that I'm writing I need to retrieve a cart for a certain user (not necessary registered) after that a link is called and some data are passed.
My idea was to receive back a previously id passed that can help me to identify a certain cart.
My big problem is that I've search a lot for code cart creation into prestashop. Finally I've found something into
/* Cart already exists */
if ((int)$this->context->cookie->id_cart)
{
$cart = new Cart($this->context->cookie->id_cart);
if ($cart->OrderExists())
{
unset($this->context->cookie->id_cart, $cart, $this->context->cookie->checkedTOS);
$this->context->cookie->check_cgv = false;
}
/* Delete product of cart, if user can't make an order from his country */
elseif (intval(Configuration::get('PS_GEOLOCATION_ENABLED')) &&
!in_array(strtoupper($this->context->cookie->iso_code_country), explode(';', Configuration::get('PS_ALLOWED_COUNTRIES'))) &&
$cart->nbProducts() && intval(Configuration::get('PS_GEOLOCATION_NA_BEHAVIOR')) != -1 &&
!FrontController::isInWhitelistForGeolocation() &&
!in_array($_SERVER['SERVER_NAME'], array('localhost', '127.0.0.1')))
unset($this->context->cookie->id_cart, $cart);
// update cart values
elseif ($this->context->cookie->id_customer != $cart->id_customer || $this->context->cookie->id_lang != $cart->id_lang || $currency->id != $cart->id_currency)
{
if ($this->context->cookie->id_customer)
$cart->id_customer = (int)($this->context->cookie->id_customer);
$cart->id_lang = (int)($this->context->cookie->id_lang);
$cart->id_currency = (int)$currency->id;
$cart->update();
}
/* Select an address if not set */
if (isset($cart) && (!isset($cart->id_address_delivery) || $cart->id_address_delivery == 0 ||
!isset($cart->id_address_invoice) || $cart->id_address_invoice == 0) && $this->context->cookie->id_customer)
{
$to_update = false;
if (!isset($cart->id_address_delivery) || $cart->id_address_delivery == 0)
{
$to_update = true;
$cart->id_address_delivery = (int)Address::getFirstCustomerAddressId($cart->id_customer);
}
if (!isset($cart->id_address_invoice) || $cart->id_address_invoice == 0)
{
$to_update = true;
$cart->id_address_invoice = (int)Address::getFirstCustomerAddressId($cart->id_customer);
}
if ($to_update)
$cart->update();
}
}
if (!isset($cart) || !$cart->id)
{
$cart = new Cart();
$cart->id_lang = (int)($this->context->cookie->id_lang);
$cart->id_currency = (int)($this->context->cookie->id_currency);
$cart->id_guest = (int)($this->context->cookie->id_guest);
$cart->id_shop_group = (int)$this->context->shop->id_shop_group;
$cart->id_shop = $this->context->shop->id;
if ($this->context->cookie->id_customer)
{
$cart->id_customer = (int)($this->context->cookie->id_customer);
$cart->id_address_delivery = (int)(Address::getFirstCustomerAddressId($cart->id_customer));
$cart->id_address_invoice = $cart->id_address_delivery;
}
else
{
$cart->id_address_delivery = 0;
$cart->id_address_invoice = 0;
}
// Needed if the merchant want to give a free product to every visitors
$this->context->cart = $cart;
CartRule::autoAddToCart($this->context);
}
that is contained into FrontController.php (that seems to be called in every page). So, to me, a cart should always be present during a "user session".
But - yes, there's a but - when I try to retrieve a cart (in that way, into controller of my module)
$context=Context::getContext();
$id_cart=$context->cart->id;
$id_cart isn't there, so cart seems to miss. So I'm a little bit confused.
What's goin' on here? Someone could give me some pointers?
PS.:
I've tried to replicate that function (only the else part) but it doesn't work
You can force cart generation when the user isn't logged in and there is no product in the cart:
$context = Context::getContext();
if (!$context->cart->id) {
$context->cart->add();
$context->cookie->id_cart = $context->cart->id;
}
$id_cart = $context->cart->id;
Take a look at the processChangeProductInCart method in controllers/front/CartController.php
I'm using Prestashop 1.6, and #yenshiraks answer did not work for me. I cannot use $context->cart->add();, because $context->cartis null.
This is what worked in my case:
$context = Context::getContext();
$cart_id = null
if($context->cookie->id_cart) {
$cart = new Cart($context->cookie->id_cart);
$cart_id = $cart->id; // just in case the cookie contains an invalid cart_id
}
if(empty($cart_id)) {
$cart = new Cart();
$cart->id_lang = (int)$context->cookie->id_lang;
$cart->id_currency = (int)$context->cookie->id_currency;
$cart->id_guest = (int)$context->cookie->id_guest;
$cart->id_shop_group = (int)$context->shop->id_shop_group;
$cart->id_shop = $context->shop->id;
$cart->add();
$cart_id = $cart->id;
}
$context->cookie->id_cart = $cart_id;
To answer the question at the end: Even though a cart is always generated in the FrontController, it is not saved to the database, therefore the id is null.
If you are in a context, where the FrontController is instantiated (any page of the frontend, $context->cart->add(); will suffice to save an empty cart to the database.
If on the other hand, you are in a script, that is called directly (like prestashop/modules/my_module/script.php), you have to use the above code.

How to access Topic name from pdfs using poppler?

I am using poppler, and I want to access topic or headings of a particular page number using poppler, so please tell me how to do this using poppler.
Using the glib API. Don't know which API you want.
I'm pretty sure there is no topic/heading stored with a particular page.
You have to walk the index, if there is one.
Walk the index with backtracking. If you are lucky, each index node contains a PopplerActionGotoDest (check type!).
You can grab the title from the PopplerAction object (gchar *title) and get the page number from the included PopplerDest (int page_num).
page_num should be the first page of the section.
Assuming your PDF has an index containing PopplerActionGotoDest objects.
Then you simply walk it, checking for the page_num.
If page_num > searched_num, go back one step.
When you are at the correct parent, walk the childs. This should give you the best match.
I just made some code for it:
gchar* getTitle(PopplerIndexIter *iter, int num, PopplerIndexIter *last,PopplerDocument *doc)
{
int cur_num = 0;
int next;
PopplerAction * action;
PopplerDest * dest;
gchar * title = NULL;
PopplerIndexIter * last_tmp;
do
{
action = poppler_index_iter_get_action(iter);
if (action->type != POPPLER_ACTION_GOTO_DEST) {
printf("No GOTO_DEST!\n");
return NULL;
}
//get page number of current node
if (action->goto_dest.dest->type == POPPLER_DEST_NAMED) {
dest = poppler_document_find_dest (doc, action->goto_dest.dest->named_dest);
cur_num = dest->page_num;
poppler_dest_free(dest);
} else {
cur_num = action->goto_dest.dest->page_num;
}
//printf("cur_num: %d, %d\n",cur_num,num);
//free action, as we don't need it anymore
poppler_action_free(action);
//are there nodes following this one?
last_tmp = poppler_index_iter_copy(iter);
next = poppler_index_iter_next (iter);
//descend
if (!next || cur_num > num) {
if ((!next && cur_num < num) || cur_num == num) {
//descend current node
if (last) {
poppler_index_iter_free(last);
}
last = last_tmp;
}
//descend last node (backtracking)
if (last) {
/* Get the the action and do something with it */
PopplerIndexIter *child = poppler_index_iter_get_child (last);
gchar * tmp = NULL;
if (child) {
tmp = getTitle(child,num,last,doc);
poppler_index_iter_free (child);
} else {
action = poppler_index_iter_get_action(last);
if (action->type != POPPLER_ACTION_GOTO_DEST) {
tmp = NULL;
} else {
tmp = g_strdup (action->any.title);
}
poppler_action_free(action);
poppler_index_iter_free (last);
}
return tmp;
} else {
return NULL;
}
}
if (cur_num > num || (next && cur_num != 0)) {
// free last index_iter
if (last) {
poppler_index_iter_free(last);
}
last = last_tmp;
}
}
while (next);
return NULL;
}
getTitle gets called by:
for (i = 0; i < num_pages; i++) {
iter = poppler_index_iter_new (document);
title = getTitle(iter,i,NULL,document);
poppler_index_iter_free (iter);
if (title) {
printf("title of %d: %s\n",i, title);
g_free(title);
} else {
printf("%d: no title\n",i);
}
}

How to code the chess stalemate rule ?

I'm trying to write a chess game and find that I cannot find solutions to find a stalemate situation. I'm trying to google, but can't find anything. Is there a well-known algorithm or something?
Your move generator will be one of two different designs;
either it checks for legality while generating the moves
or you generate all possible moves and remove those that are illegal afterwards.
The former is better as it doesn't need post-processing.
A stalemate condition is simply one where there are no legal moves and the moving-side's king is not in check. A checkmate condition is one where there are no legal moves but the moving-side's king is in check.
In other words if you've figured out how to detect check and checkmate, you've already got everything necessary to detect stalemate.
Here is an Open-source code with all the rules for the classic Chess game:
https://github.com/cjortegon/basic-chess
You can run the project right after cloning the project (Android, iOS, Desktop and Web), or you can use the main logic, which is here: https://github.com/cjortegon/basic-chess/tree/master/libgdx/core/src/com/mountainreacher/chess/model
I based my solution on a 3-moments algorithm, first moment is when the player selects a piece from the board, then when the destination of this piece has been chosen and finally when the piece reaches that position (considering that it is an animated game, if not, you can merge step 2 and 3).
The following code has been implemented in Java. From the properties of the model class:
boolean turn;
GenericPiece selected, conquest;
ClassicBoard board;
List<int[]> possibleMovements;
int checkType;
The first method will handle moments 1, 2 and the special 'conquest' moment (applied to pawn piece only):
public boolean onCellClick(int row, int column) {
if (row == -1 && conquest != null) {
checkType = 0;
conquest.changeFigure(column);
return true;
} else if (selected != null) {
if (possibleMovements != null) {
for (int[] move : possibleMovements) {
if (move[0] == row && move[1] == column) {
// Move the PieceActor to the desired position
if (selected.moveTo(row, column)) {
turn = !turn;
}
break;
}
}
}
selected = null;
possibleMovements = null;
return true;
} else {
selected = board.getSelected(turn ? Piece.WHITE_TEAM : Piece.BLACK_TEAM, row, column);
if (selected != null) {
possibleMovements = new ArrayList<>();
possibleMovements.addAll(((GenericPiece) selected).getMoves(board, false));
// Checking the movements
board.checkPossibleMovements(selected, possibleMovements);
if (possibleMovements.size() == 0) {
possibleMovements = null;
selected = null;
return false;
} else {
return true;
}
}
}
return false;
}
And the following method will handle the 3rd moment (when animation finishes):
public void movedPiece(Piece piece) {
Gdx.app.log(TAG, "movedPiece(" + piece.getType() + ")");
// Killing the enemy
Piece killed = board.getSelectedNotInTeam(piece.getTeam(),
piece.getRow(), piece.getColumn());
if (killed != null) {
killed.setAvailable(false);
}
// Checking hacks
GenericPiece[] threat = board.kingIsInDanger();
if (threat != null) {
checkType = board.hasAvailableMoves(threat[0].getTeam()) ? CHECK : CHECK_MATE;
} else {
checkType = NO_CHECK;
}
// Checking castling
if (piece.getFigure() == Piece.ROOK && ((GenericPiece) piece).getMovesCount() == 1) {
Piece king = board.getSelected(piece.getTeam(),
piece.getRow(), piece.getColumn() + 1);
if (king != null && king.getFigure() == Piece.KING && ((GenericPiece) king).getMovesCount() == 0) {
// Left Rook
if (board.getSelected(piece.getRow(), piece.getColumn() - 1) == null) {
king.moveTo(piece.getRow(), piece.getColumn() - 1);
}
} else {
king = board.getSelected(piece.getTeam(),
piece.getRow(), piece.getColumn() - 1);
if (king != null && king.getFigure() == Piece.KING && ((GenericPiece) king).getMovesCount() == 0) {
// Right Rook
if (board.getSelected(piece.getRow(), piece.getColumn() + 1) == null) {
king.moveTo(piece.getRow(), piece.getColumn() + 1);
}
}
}
}
// Conquest
else if (piece.getFigure() == Piece.PAWN && (piece.getRow() == 0 || piece.getRow() == board.getRows() - 1)) {
conquest = (GenericPiece) piece;
checkType = CONQUEST;
}
}
That code covers all the rules from the classic chess, including: regular piece movements, castling, check, check-mate and conquests of pawns.