How do you know if a particular bit is set in dart?
example how to do this?
int value = 5;
if(checkBit(value, 4)) {
print("position: 4 TRUE");
} else {
print("position: 4 FALSE");
}
The solution is the same as #MihaiBC points to but since that is in C#, I am still going to post this just so we also have a Dart example:
void main() {
const value = 5;
print(value.toRadixString(2).padLeft(64, '0'));
// 0000000000000000000000000000000000000000000000000000000000000101
print(checkBit(value, 0)); // true
print(checkBit(value, 1)); // false
print(checkBit(value, 2)); // true
print(checkBit(value, 3)); // false
}
bool checkBit(int value, int bit) => (value & (1 << bit)) != 0;
Related
I get error ":( program is free of memory errors valgrind tests failed; see log for more information."
Here is my code:
// Implements a dictionary's functionality
#include <ctype.h>
#include <stdbool.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>
#include <stdio.h>
#include "dictionary.h"
// Represents a node in a hash table
typedef struct node
{
char word[LENGTH + 1];
struct node *next;
}
node;
// TODO: Choose number of buckets in hash table
const unsigned int N = 26;
// Hash table
node *table[N];
//Declare variables
unsigned int word_count;
unsigned int hash_value;
// Returns true if word is in dictionary, else false
bool check(const char *word)
{
// TODO
hash_value = hash(word);
node *cursor = table[hash_value];
// Go in link list
while (cursor != 0)
{
if (strcasecmp(word, cursor->word) == 0)
{
return true;
}
cursor = cursor->next;
}
return false;
}
// Hashes word to a number
unsigned int hash(const char *word)
{
// TODO: Improve this hash function
unsigned long total = 0;
for (int i = 0; i < strlen(word); i++)
{
total += tolower(word[i]);
}
return total % N;
}
// Loads dictionary into memory, returning true if successful, else false
bool load(const char *dictionary)
{
// Open dictionary
FILE *file = fopen(dictionary, "r");
// it would be null if cant be open
if (file == NULL)
{
printf("Unable to open %s\n", dictionary);
return false;
}
// Declare variable words
char word[LENGTH + 1];
//Scan dictionary for strings up until EOF
while (fscanf(file, "%s", word) != EOF)
{
node *n = malloc(sizeof(node));
if (n == NULL)
{
return false;
}
//copy wordds into node
strcpy(n->word, word);
hash_value = hash(word);
n->next = table[hash_value];
table[hash_value] = n;
word_count++;
}
fclose(file);
return true;
}
// Returns number of words in dictionary if loaded, else 0 if not yet loaded
unsigned int size(void)
{
if (word_count > 0)
{
return word_count;
}
return 0;
}
// Unloads dictionary from memory, returning true if successful, else false
bool unload(void)
{
for (int i = 0; i < N; i++)
{
node *cursor = table[i];
while (cursor)
{
node *tmp = cursor;
cursor = cursor->next;
free(tmp);
}
if (cursor == NULL)
{
return true;
}
}
return false;
}
Here are the errors in valgrind check50:
program is free of memory errors valgrind tests failed; see log for more information.
Here is ERR log:
56 bytes in 1 blocks are still reachable in loss record 1 of 1: (file: dictionary.c, line: 80)
And 80th line code is:
while (fscanf(file, "%s", word) != EOF)
{
node *n = malloc(sizeof(node));
if (n == NULL)
{
return false;
}
unload will free one index and return to speller because of this if (cursor == NULL) block. The last node in an index should set cursor to NULL, so function is done. That conditional should be eliminated. There is really no condition in unload that should return false.
Everything seems fine. But EA usually opens multiple trades in the same second... The way I built it is very linear and i can't seem to spot the logical mistake. It is basically a random martingale EA to test stuff out. Any indicator (that's why I called it random, haven't decided myself) can be put in there.
Basic idea is that it has an upper and lower threshold which determines when it is in buy zone and when at sell zone. Once it is in either zone, if trend goes against it (determined by indicator's value, not symbol's price) it opens another trade with the same SL/TP of the initial order. Also it checks whether initial trade still runs so it does not open other ones and once the initial trade is open. After that the criterias about the rest of the trades (that go against the trade are different).
The problem is that it opens multiple trades at times that it shouldn't, or like 3-4 trades within the same second or two. Any idea why this happens?
#property copyright "Copyright 2020, MetaQuotes Software Corp."
#property link "https://www.mql5.com"
#property version "1.00"
#property strict
input int stepValue = 5;
input double lotsize = 0.01;
input int stoploss = 2000;
input int takeprofit = 140;
input int slippage = 10;
input double upper_border = 60.0;
input double lower_border = 40.0;
const string EAComment = "Xind";
string mode = "";
bool first_trade = false;
int InitTicket = 1;
double X = 0.0;
double X_Last = 0.0;
//+------------------------------------------------------------------+
//| Expert initialization function |
//+------------------------------------------------------------------+
int OnInit()
{
//---
first_trade = false;
//---
return(INIT_SUCCEEDED);
}
//+------------------------------------------------------------------+
//| Expert deinitialization function |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
{
//---
}
//+------------------------------------------------------------------+
//| Expert tick function |
//+------------------------------------------------------------------+
void OnTick()
{
//---
SearchSignal();
if (mode == "Buy")
{
if (first_trade == false)
{
Buy();
}
if (first_trade == true)
{
MartinCheck();
CloseCheck();
}
}
if (mode == "Sell")
{
if (first_trade == false)
{
Sell();
}
if (first_trade == true)
{
MartinCheck();
CloseCheck();
}
}
}
//+------------------------------------------------------------------+
void Buy()
{
X_Last = X;
first_trade = true;
InitTicket = OrderSend(NULL,OP_BUY,lotsize,Ask,slippage,Ask-stoploss*Point,Ask+takeprofit*Point,EAComment,1,0,clrDarkBlue);
}
//---
void Sell()
{
X_Last = X;
first_trade = true;
InitTicket = OrderSend(NULL,OP_SELL,lotsize,Bid,slippage,Bid+stoploss*Point,Bid-takeprofit*Point,EAComment,1,0,clrDarkRed);
}
//---
void MartinBuy()
{
if (OrderSelect(InitTicket, SELECT_BY_TICKET) == true)
{
double new_SL = OrderStopLoss();
double new_TP = OrderTakeProfit();
int dont_care = OrderSend(NULL,OP_BUY,lotsize,Ask,slippage,new_SL,new_TP,EAComment+" martin",1,0,clrDarkBlue);
}
}
//---
void MartinSell()
{
if (OrderSelect(InitTicket, SELECT_BY_TICKET) == true)
{
double new_SL = OrderStopLoss();
double new_TP = OrderTakeProfit();
int dont_care = OrderSend(NULL,OP_SELL,lotsize,Bid,slippage,new_SL,new_TP,EAComment+" martin",1,0,clrDarkRed);
}
}
//---
void SearchSignal()
{
X = 0.0; //where 0.0, put here the iCustom for external indicators, or some built-in indicator
if (X >= upper_border)
{
mode = "Sell";
}
else if (X <= lower_border)
{
mode = "Buy";
}
else
{
mode = "";
first_trade = false;
InitTicket = 1;
X_Last = 0.0;
}
}
//---
void CloseCheck()
{
if (OrderSelect(InitTicket, SELECT_BY_TICKET))
{
if (OrderCloseTime() == 0)
{
first_trade = true;
}
else if (OrderCloseTime() != 0)
{
first_trade = false;
}
else
{
return;
}
}
}
//---
void MartinCheck()
{
if (mode == "Buy")
{
if ((X_Last - stepValue) >= X)
{
X_Last = X;
MartinBuy();
}
}
if (mode == "Sell")
{
if ((X_Last + stepValue) <= X)
{
X_Last = X;
MartinSell();
}
}
}
The layout of your code makes it possible for several processes to happen in sequence all on the same tick which I assume you do not want. Try changing your code initially to this and work from there:
void OnTick()
{
SearchSignal();
if(mode=="Buy")
{
if(!first_trade) Buy();
else
{
MartinCheck();
CloseCheck();
}
}
else if(mode=="Sell")
{
if(!first_trade) Sell();
else
{
MartinCheck();
CloseCheck();
}
}
}
Remember to use if(...) else to stop executing all functions when it should only be an either/or situation.
I have an indicator which gives one signal [Down Buffer]... I wish to only give signal once per day... Like after the first signal it will not paint any signal for the rest of the day! I have tested with below code it's now not painting at all?
//--- indicator buffers
double Buffer1[];
int day = 0;
int OnInit()
{
........................
}
int OnCalculate(......)
{
//--- main loop
for(int i = limit-1; i >= 0; i--)
{
//Indicator Buffer 1
if( here goes my condition )
{
if( day != Day() )
{
Buffer1[i] = High[i] + iATR(NULL, PERIOD_CURRENT, 14, i); //Set indicator value at Candlestick High + Average True Range
day = Day();
}
}
else
{
Buffer1[i] = EMPTY_VALUE;
}
}
return(rates_total);
}
What is wrong with my code? It's now not showing any signal at all...
Note : I have removed some of the code to make it simple...
Use the following function to check whether it is a new day.
It returns true if it is a new day, else returns false.
bool IsNewDay(){
static datetime prevDay = -1;
if( iTime(_Symbol, PERIOD_D1, 0) == prevDay ) return false;
prevDay = iTime(_Symbol, PERIOD_D1, 0);
return true;
}
I have absolutely no experience in programming serial communication and since I'm stuck with my code I'd really appreciate your help! Thank you already!
So now to my problem:
I got a generator on which are several different sensors who communicate over CAN with a microcontroller. This mc itself communicates with a device from USBTin again over CAN. On the USBTin, a little board, is mainly a CAN controller and a microcontroller which are precoded from its developer.
So my task now is to open my COM Port, send the right messages to the USBTin (those are "S5" for the baudrate and 'O' for Open CAN) and then receive the data.
First of all the functions and my problem:
The problem is that in my output textfield stands something like "PPPPPPPPPP,Râö". There are always these 10 P's and some random characters. I have no idea where the P's or these additional "Râö" comes from. The actual output string shoud be something like "T1E18001F8". I tested that with hTerm, which is a terminal programm for serial communication.
OPEN:
long Serial::Open()
{
if (IsOpened()) return 0;
#ifdef UNICODE
wstring wtext(port.begin(),port.end());
#else
string wtext = port;
#endif
hComm = CreateFile(wtext.c_str(),
GENERIC_READ | GENERIC_WRITE,
0,
0,
OPEN_EXISTING,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED,
0);
if (hComm == INVALID_HANDLE_VALUE) {return 1;}
if (PurgeComm(hComm, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR |
PURGE_RXCLEAR) == 0) {return 2;}//purge
//get initial state
DCB dcbOri;
bool fSuccess;
fSuccess = GetCommState(hComm, &dcbOri);
if (!fSuccess) {return 3;}
DCB dcb1 = dcbOri;
dcb1.BaudRate = baud;
if (parity == 'E') dcb1.Parity = EVENPARITY;
else if (parity == 'O') dcb1.Parity = ODDPARITY;
else if (parity == 'M') dcb1.Parity = MARKPARITY;
else if (parity == 'S') dcb1.Parity = SPACEPARITY;
else if (parity == 'N') dcb1.Parity = NOPARITY;
dcb1.ByteSize = (BYTE)dsize;
if(stopbits==2) dcb1.StopBits = TWOSTOPBITS;
else if (stopbits == 1.5) dcb1.StopBits = ONE5STOPBITS;
else if (stopbits == 1) dcb1.StopBits = ONE5STOPBITS;
dcb1.fOutxCtsFlow = false;
dcb1.fOutxDsrFlow = false;
dcb1.fOutX = false;
dcb1.fDtrControl = DTR_CONTROL_DISABLE;
dcb1.fRtsControl = RTS_CONTROL_DISABLE;
fSuccess = SetCommState(hComm, &dcb1);
delay(60);
if (!fSuccess) {return 4;}
fSuccess = GetCommState(hComm, &dcb1);
if (!fSuccess) {return 5;}
osReader = { 0 };// Create the overlapped event. Must be closed before
exiting to avoid a handle leak.
osReader.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (osReader.hEvent == NULL) {return 6;}// Error creating overlapped event;
abort.
fWaitingOnRead = FALSE;
osWrite = { 0 };
osWrite.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (osWrite.hEvent == NULL) {return 7;}
if (!GetCommTimeouts(hComm, &timeouts_ori)) { return 8; } // Error getting
time-outs.
COMMTIMEOUTS timeouts;
timeouts.ReadIntervalTimeout = 20;
timeouts.ReadTotalTimeoutMultiplier = 15;
timeouts.ReadTotalTimeoutConstant = 100;
timeouts.WriteTotalTimeoutMultiplier = 15;
timeouts.WriteTotalTimeoutConstant = 100;
if (!SetCommTimeouts(hComm, &timeouts)) { return 9;} // Error setting time-
outs.
return 0;
}
WRITE:
bool Serial::Write(char *data)
{
if (!IsOpened()) {
return false;
}
BOOL fRes;
DWORD dwWritten;
long n = strlen(data);
if (n < 0) n = 0;
else if(n > 1024) n = 1024;
// Issue write.
if (!WriteFile(hComm, data, n, &dwWritten, &osWrite)) {
if (GetLastError() != ERROR_IO_PENDING) {fRes = FALSE;}// WriteFile
failed, but it isn't delayed. Report error and abort.
else {// Write is pending.
if (!GetOverlappedResult(hComm, &osWrite, &dwWritten, TRUE))
fRes = FALSE;
else fRes = TRUE;// Write operation completed successfully.
}
}
else fRes = TRUE;// WriteFile completed immediately.
return fRes;
}
READCHAR:
char Serial::ReadChar(bool& success)
{
success = false;
if (!IsOpened()) {return 0;}
DWORD dwRead;
DWORD length=1;
BYTE* data = (BYTE*)(&rxchar);
//the creation of the overlapped read operation
if (!fWaitingOnRead) {
// Issue read operation.
if (!ReadFile(hComm, data, length, &dwRead, &osReader)) {
if (GetLastError() != ERROR_IO_PENDING) { /*Error*/}
else { fWaitingOnRead = TRUE; /*Waiting*/}
}
else {if(dwRead==length) success = true;}//success
}
//detection of the completion of an overlapped read operation
DWORD dwRes;
if (fWaitingOnRead) {
dwRes = WaitForSingleObject(osReader.hEvent, READ_TIMEOUT);
switch (dwRes)
{
// Read completed.
case WAIT_OBJECT_0:
if (!GetOverlappedResult(hComm, &osReader, &dwRead, FALSE))
{/*Error*/ }
else {
if (dwRead == length) success = true;
fWaitingOnRead = FALSE;// Reset flag so that another
opertion
can be issued.
}// Read completed successfully.
break;
case WAIT_TIMEOUT:
// Operation isn't complete yet.
break;
default:
// Error in the WaitForSingleObject;
break;
}
}
return rxchar;
}
And Finally the excerpt of the main in wxWidgets to display the received data:
void GUI_1_2Frame::OnConnectButtonClick(wxCommandEvent& (event))
{
char tempString[10] = {0};
bool ReadChar_success = true;
char temp_Char;
/* Preset Serial Port setting */
Serial com(com_x, 115200, 8, NOPARITY, 1);
char* buffer;
if(connection_flag)
{
/* Port was connected, Disconnect Button unsed*/
com.Close();
wxMessageBox(_("Port closed"),_("Info!"),wxICON_INFORMATION);
connection_flag = 0;
ConnectButton->SetLabel("Connect");
TextCtrl1->SetValue("");
}
else
{
/* If open() == true -> INVALID HANDLE */
if(com.Open())
{
wxMessageBox(_("Port not available"),_("ERROR!"),wxICON_ERROR);
}
else /* Port Opened */
{
TextCtrl1->SetValue(com.GetPort());
ConnectButton->SetLabel("Disconnect");
connection_flag = 1;
}
if(com.Write("S5"))
{
TextCtrl1->SetValue("Baudrate sent!\n");
delay(100);
if(com.WriteChar('O'))
{
TextCtrl1->SetValue("Baudrate & Open Command sent!");
int i =0;
while(i<10)
{
temp_Char = com.ReadChar(ReadChar_success);
tempString[i] = temp_Char;
i++;
}
com.WriteChar('C');
com.Close();
//com.readSerialPort(data, MAX_DATA_LENGTH);
TextCtrl2->SetValue(tempString);
//wxMessageOutput::Get()->Printf("%s", tempString);
}
else
{
TextCtrl1->SetValue("Open Command Error!"); }
}
else
{
TextCtrl1->SetValue("Error!");
}
}
}
Since I am not native speaking englisch I say sorry for my language mistakes.
Thank everybody a lot and again I really appreciate every single hint!
Greetings,
MSol
I found a way to enumerate other programs handles, but I have problem now. I can not see Process type threads. I need to check which programs open handles for my process.
When I check the output, it is "unnamed", I don't know how to fix it.
Should I do this via dirver? or any other way to do this without driver?
pid = _wtoi(argv[1]);
if (!(processHandle = OpenProcess(PROCESS_DUP_HANDLE, FALSE, pid)))
{
printf("Could not open PID %d! (Don't try to open a system process.)\n", pid);
return 1;
}
handleInfo = (PSYSTEM_HANDLE_INFORMATION)malloc(handleInfoSize);
/* NtQuerySystemInformation won't give us the correct buffer size,
so we guess by doubling the buffer size. */
while ((status = NtQuerySystemInformation(
SystemHandleInformation,
handleInfo,
handleInfoSize,
NULL
)) == STATUS_INFO_LENGTH_MISMATCH)
handleInfo = (PSYSTEM_HANDLE_INFORMATION)realloc(handleInfo, handleInfoSize *= 2);
/* NtQuerySystemInformation stopped giving us STATUS_INFO_LENGTH_MISMATCH. */
if (!NT_SUCCESS(status))
{
printf("NtQuerySystemInformation failed!\n");
return 1;
}
for (i = 0; i < handleInfo->HandleCount; i++)
{
SYSTEM_HANDLE handle = handleInfo->Handles[i];
HANDLE dupHandle = NULL;
POBJECT_TYPE_INFORMATION objectTypeInfo;
PVOID objectNameInfo;
UNICODE_STRING objectName;
ULONG returnLength;
/* Check if this handle belongs to the PID the user specified. */
if (handle.ProcessId != pid)
continue;
/* Duplicate the handle so we can query it. */
if (!NT_SUCCESS(NtDuplicateObject(
processHandle,
handle.Handle,
GetCurrentProcess(),
&dupHandle,
0,
0,
0
)))
{
printf("[%#x] Error!\n", handle.Handle);
continue;
}
/* Query the object type. */
objectTypeInfo = (POBJECT_TYPE_INFORMATION)malloc(0x1000);
if (!NT_SUCCESS(NtQueryObject(
dupHandle,
ObjectTypeInformation,
objectTypeInfo,
0x1000,
NULL
)))
{
printf("[%#x] Error!\n", handle.Handle);
CloseHandle(dupHandle);
continue;
}
/* Query the object name (unless it has an access of
0x0012019f, on which NtQueryObject could hang. */
if (handle.GrantedAccess == 0x0012019f)
{
/* We have the type, so display that. */
printf(
"[%#x] %.*S: (did not get name)\n",
handle.Handle,
objectTypeInfo->Name.Length / 2,
objectTypeInfo->Name.Buffer
);
free(objectTypeInfo);
CloseHandle(dupHandle);
continue;
}
objectNameInfo = malloc(0x1000);
if (!NT_SUCCESS(NtQueryObject(
dupHandle,
ObjectNameInformation,
objectNameInfo,
0x1000,
&returnLength
)))
{
/* Reallocate the buffer and try again. */
objectNameInfo = realloc(objectNameInfo, returnLength);
if (!NT_SUCCESS(NtQueryObject(
dupHandle,
ObjectNameInformation,
objectNameInfo,
returnLength,
NULL
)))
{
/* We have the type name, so just display that. */
printf(
"[%#x] %.*S: (could not get name)\n",
handle.Handle,
objectTypeInfo->Name.Length / 2,
objectTypeInfo->Name.Buffer
);
free(objectTypeInfo);
free(objectNameInfo);
CloseHandle(dupHandle);
continue;
}
}
/* Cast our buffer into an UNICODE_STRING. */
objectName = *(PUNICODE_STRING)objectNameInfo;
/* Print the information! */
if (objectName.Length)
{
/* The object has a name. */
printf(
"[%#x] %.*S: %.*S\n",
handle.Handle,
objectTypeInfo->Name.Length / 2,
objectTypeInfo->Name.Buffer,
objectName.Length / 2,
objectName.Buffer
);
}
else
{
/* Print something else. */
printf(
"[%#x] %.*S: (unnamed)\n",
handle.Handle,
objectTypeInfo->Name.Length / 2,
objectTypeInfo->Name.Buffer
);
}
free(objectTypeInfo);
free(objectNameInfo);
CloseHandle(dupHandle);
}
free(handleInfo);
CloseHandle(processHandle);
return 0;
void SearchMyProcessHandles()
{
ULONG UniqueProcessId = GetCurrentProcessId();
if (HANDLE hProcess = OpenProcess(MAXIMUM_ALLOWED, FALSE, UniqueProcessId))
{
NTSTATUS status;
union {
PSYSTEM_HANDLE_INFORMATION_EX pshi;
PVOID buf;
};
ULONG cb = 0x10000;
do
{
status = STATUS_INSUFFICIENT_RESOURCES;
if (buf = new UCHAR[cb += PAGE_SIZE])
{
if (0 <= (status = ZwQuerySystemInformation(SystemExtendedHandleInformation, buf, cb, &cb)))
{
if (ULONG_PTR NumberOfHandles = pshi->NumberOfHandles)
{
SYSTEM_HANDLE_TABLE_ENTRY_INFO_EX* Handles = pshi->Handles;
do
{
if (Handles->UniqueProcessId == UniqueProcessId &&
Handles->HandleValue == (ULONG_PTR)hProcess)
{
PVOID Object = Handles->Object;
Handles = pshi->Handles;
NumberOfHandles = pshi->NumberOfHandles;
do
{
if (Handles->Object == Object &&
Handles->UniqueProcessId != UniqueProcessId)
{
DbgPrint("%p %p %08x\n",
Handles->UniqueProcessId,
Handles->HandleValue,
Handles->GrantedAccess);
}
} while (Handles++, --NumberOfHandles);
break;
}
} while (Handles++, --NumberOfHandles);
}
}
delete [] buf;
}
} while (status == STATUS_INFO_LENGTH_MISMATCH);
CloseHandle(hProcess);
}
}