I'm currently trying to convert a multithreaded LAN tic tac toe game so it compiles / works on my Windows system. I'm quite new to networking but I've managed to translate a lot of the system calls to Socket API calls however I am having trouble understanding how to convert the 'pthread' functions. Most of the questions I see online are asking how to compile it, but I want to change it instead of adding new libraries etc.
Can someone please shed some light on what exactly pthread does and how I can change it to compile in the native windows environment.
Thanks!
Main Function
pthread_mutex_t games_lock = PTHREAD_MUTEX_INITIALIZER;
int main() {
//Initialise Winsock
WSAData data;
WORD ver = MAKEWORD(2, 2);
int wsResult = WSAStartup(ver, &data);
if (wsResult != 0) {
std::cerr << "Can't start Winsock, Err #" << wsResult << endl;
}
// Signals used to kill the server gracefully
if (signal(SIGINT, sig_handler) == SIG_ERR)
{
perror("Can't catch SIGINT");
exit(1);
}
if (signal(SIGTERM, sig_handler) == SIG_ERR)
{
perror("Can't catch SIGTERM");
exit(1);
}
// Initialize the server and get the server's socket
server_sock = init_server();
int new_socket = 0;
// Infinitely accept clients and spawning threads
while (true)
{
// Wait for a client, and then accept
if ((new_socket = accept(server_sock, NULL, NULL)) < 0)
{
perror("Failed to accept client");
closesocket(server_sock);
exit(1);
}
cout << "New client connected" << endl;
// Spawn thread to handle the client
pthread_t threadid;
pthread_create(&threadid, NULL, handle_client, (void*)&new_socket);
}
return 0;
}
Client Handle Function
{
int client_sock = *(int*)arg;
char buffer[BUF_SIZE];
bool client_connected = true;
char temp = '\0';
int row = 0, col = 0;
int i = 0;
// Create the player
Player player(client_sock);
// Always handle the client
while (client_connected)
{
// Process commands or pass game data
if (player.GetMode() == COMMAND)
{
// Read a line of text or until the buffer is full
for (i = 0; (i < (BUF_SIZE - 1)) && temp != '\n' && client_connected; ++i)
{
// Receive a single character and make sure the client is still connected
if (recv(client_sock, &temp, 1, 0) == 0)
client_connected = false;
else
buffer[i] = temp;
}
// Reset temp so we don't get an infinite loop
temp = '\0';
buffer[i] = '\0';
buffer[i - 1] = '\0';
cout << "Received command \"" << buffer << "\" from " << player.GetName() << endl;
buffer[i - 1] = '\n';
// If there's an invalid command, tell the client
if (!ProcessCommand(buffer, player, client_connected))
SendStatus(player.GetSocket(), INVALID_CMD);
}
else if (player.GetMode() == INGAME)
{
// Get the game the player is a part of
pthread_mutex_lock(&games_lock);
auto game = find_if(game_list.begin(), game_list.end(),
[player](TTTGame* game) { return game->HasPlayer(player); });
auto end = game_list.end();
pthread_mutex_unlock(&games_lock);
// Something horrible has gone wrong
if (game == end)
cout << "Somehow Player " << player.GetName() << " isn't a part of a game but is INGAME" << endl;
else
{
StatusCode status;
client_connected = ReceiveStatus(player.GetSocket(), &status);
// If the player is still connected, then perform the move
if (client_connected)
{
switch (status)
{
case MOVE:
// Pass the row and column right along
ReceiveInt(player.GetSocket(), &row);
ReceiveInt(player.GetSocket(), &col);
cout << "Received moved from " << player.GetName()
<< ": row=" << row << ", col=" << col << endl;
SendStatus((*game)->GetOtherPlayer(player).GetSocket(), MOVE);
SendInt((*game)->GetOtherPlayer(player).GetSocket(), row);
client_connected = SendInt((*game)->GetOtherPlayer(player).GetSocket(), col);
cout << "Sent move to " << (*game)->GetOtherPlayer(player).GetName() << endl;
break;
case WIN:
cout << player.GetName() << " won a game against " << (*game)->GetOtherPlayer(player).GetName() << endl;
client_connected = false;
break;
case DRAW:
cout << player.GetName() << " tied against " << (*game)->GetOtherPlayer(player).GetName() << endl;
client_connected = false;
break;
default:
client_connected = SendStatus(player.GetSocket(), INVALID_CMD);
}
}
}
}
}
// The client disconnected on us D:
cout << "Player \"" << player.GetName() << "\" has disconnected" << endl;
DisconnectPlayer(player);
closesocket(client_sock);
WSACleanup();
return (void*)0;
}
These are just some examples of the code. I am happy to post more if needed.
I have a project where part of it is processing a video as a batch of images. I found a snippet online which helped me process a batch of images(the one attached below)
string Img_seq[] = {"flying_plane"};
int size_of_Img_seq = sizeof(Img_seq) / sizeof(Img_seq[0]);
imgpath = argv[1];
if (argc >= 3)
{
TrackingResPath = argv[2];
cout << "The image path is: " << imgpath << endl;
int Seg_num = 1; //for OPE
for (int j = 0; j < size_of_Img_seq; ++j)
{
folder = imgpath + Img_seq[j] + "/*.jpg";
string imgInFormat, imgOutFormat, imgOutFormat1, imgOutFormat2;
ofstream outBB;
imgInFormat = imgpath + Img_seq[j] + "/%05d.jpg";
if (argc >= 3)
{
//add process here
}
}
// get the total number of images in folder
glob(folder, filenames);
int Frames_per_seg = filenames.size(); // for OPE
cout << "Frames_per_seg = " << Frames_per_seg << endl;
for (int k = 1; k <= Seg_num; ++k)
{
sprintf(imgInPath, imgInFormat.c_str(), startFrame);// read image path
sprintf(imgOutPath, imgOutFormat.c_str(), startFrame);
}
I need to use this procedure to process a video from either a directory or from the webcam. I tried the one way which I've given below but it is spitting out errors
VideoCapture capture(videoFilename);
if(!capture.isOpened()){
cerr << "Unable to open video file:" << videoFilename << endl;
exit(EXIT_FAILURE);
}
while( (char)keyboard != 'q' && (char)keyboard != 27){
if(!capture.read(frame)){
cerr << "Unable to read next frame" << endl;
cerr << "Exiting" << endl;
exit(EXIT_FAILURE);
}}
stringstream ss;
rectangle(frame, cv::Point(10, 2), cv::Point(100, 20),
cv::Scalar(255, 255, 255), -1);
ss << capture.get(CV_CAP_PROP_POS_FRAMES);
string Img_seq[] = ss.str();
keyboard = waitKey( 30 );
The errors are basically because Img_seq[] is not linked properly between the above two codes.
Could anyone help me understand how I should proceed in using video for a batch processing logic.
Currently started to work with qt and found some bug in my code, and I can't understand where it comes from. Maybe you will see and explain why it happens.
Here is main.cpp code part which changes shutter from 3000 to maximum:
if (camera.test_cam->liveFrameReady())
{
camera.visualizeFrame(camera.test_cam->liveFrame());
camera.set_shutter(0, 1, 3000 + i * 200);
controlWidget->update(camera.test_cam->liveFrame());
i++;
}
The code works slowly(1 fps ), because of the camera.visuzlizeFrame() method:
void OsCam::visualizeFrame(Common::FrameHandle hFrame)
{
void* buffer_ptr = this->getFrameData(hFrame);
int width = hFrame->dataType()->width();
int height = hFrame->dataType()->height();
cv::Mat m(height, width, CV_8UC3, (int*)buffer_ptr);
cv::imshow("test image", m);
cv::waitKey(1);
}
Gui interface shows the camera frame in real time, test image from visualizeFrame at the background
Actionally, I don't need to call this method (I used it just to be sure that I can read the memory and I used opencv because I am more familiar with it).
But if I get rid of this camera.visuzlizeFrame() my gui becomes white and does not give any response.
Even if I use cv::waitKey or Sleep functions, nothing happens to the gui.
void ControlWidget::update(Common::FrameHandle hFrame)
{
try
{
QImage img((uchar*)hFrame->buffer()->data(), hFrame->dataType()->width(), hFrame->dataType()->height(), QImage::Format::Format_RGB888);
QSize standart_size = QSize(hFrame->dataType()->width() / 3, hFrame->dataType()->height() / 3);
QPixmap rectPxmp = QPixmap::fromImage(img).scaled(standart_size);
this->camera_1->setPixmap(rectPxmp);
this->camera_2->setPixmap(rectPxmp);
cv::waitKey(300);
}
catch (GeneralException& e)
{
std::cout << e.what() << std::endl;
}
}
Shall I go to QThreads? One thread for reading the buffer and another one for visualization of gui?
Thank you!
some additional code:
void* OsCam::getFrameData(Common::FrameHandle hFrame)
{
bool displayFrameData = false;
void* pFrameData = NULL;
try
{
if (hFrame)
{
if (displayFrameData)
{
// display information about the frame
cout << "Frame index: " << hFrame->frameIndex();
cout << "Frame timestamp: " << hFrame->timestamp();
// display information about the frame "data type"
DataTypeHandle hDataType = hFrame->dataType();
cout << "Frame size in bytes: " << hDataType->frameSizeInBytes() << endl;
cout << "Width in pixels: " << DataType::width(hDataType) << endl;
cout << "Height in rows: " << DataType::height(hDataType) << endl;
cout << "Bit depth: " << DataType::bitDepth(hDataType) << endl;
cout << "Bytes/line (stride): " << DataType::stride(hDataType) << endl;
// display the frame video format
VideoDataType::Format videoFormat = VideoDataType::format(hDataType);
cout << "Video format: " << VideoDataType::formatString(videoFormat).c_str() << endl;
// get a pointer to the frame data
}
pFrameData = hFrame->buffer()->data();
}
}
catch (GeneralException& e)
{
cout << e.what() << endl;
}
return pFrameData;
}
and main (I changed it a little bit) :
int main(int argc, char **argv)
{
QApplication app(argc, argv);
ControlWidget *controlWidget = new ControlWidget;
//controlWidget->show();
try
{
OsCam camera;
int i = 0;
for (int j = 0; j<10000 ; j++)
{
if ((camera.test_cam->liveFrameReady()))
{
Common::FrameHandle loaded = camera.test_cam->liveFrame()->clone();
camera.visualizeFrame(loaded);
controlWidget->update(loaded);
camera.set_shutter(0, 1, 3000 + i * 200);
loaded->~Frame();
}
i++;
}
}
catch (GeneralException& e)
{
std::cout << e.what() << std::endl;
int a;
std::cin >> a;
return 1;
}
}
After cv::named_window
I am displaying and manipulating a video with open CV as so
// looping through list of videos
for (unsigned int i = 0; i < img_loc.size(); i++)
{
string fileLoc = root_dir + "\\" + img_loc[i];
string name = img_loc[i].substr(0,img_loc[i].find("."));
cv::VideoCapture cap(fileLoc);
image_window win;
int cnt = 0;
while (!win.is_closed())
{
cv::Mat temp;
cap >> temp;
if (temp.empty())
{
break;
}
cout << "frame number ---- " << cap.get(CV_CAP_PROP_POS_FRAMES) << endl;
cv_image<bgr_pixel> cimg(temp);
// some image manipulations
win.clear_overlay();
win.set_image(cimg);
cout << cnt << endl;
// save some details
cnt++;
cout << "after cnt++ ------------ " << cnt << endl;
}
cout << endl << "finished with " << img_loc[i] << ", proceed to the next video?" << endl;
cin.get();
}
which works fine for the first for all frames except the very last. I know there are exactly 200 frames but cnt only ever reaches 198 and the frames only ever go up to 199. The final frame isn't entirely necessary but it means there's some extra data handling that I'd rather avoid. Any ideas?
I'm writing a tictactoe application which communicates between a server and client file. Currently, my program hangs when trying to read in the players move. The client is showing successful write to the pipe but the server is not reading the information. Any help would be appreciated. Heres the offending code from both portions. Edit: I just realized the formatting got completely buggered in the copy/paste, I am sorry.
client main() :
//used to define int holder for server read in
const int MAX = 2;
//used to define buffers to transfer information
const int BUFFERS = 10;
//path of the global pipe
const string PRIMARY = "/home/mking/GPipe";
int main() {
//variables
size_t result;
srand(time(NULL) );
int s = rand() % 10000;
if (s < 1000) { s += 1000; }
cout << s << endl;
string userWrite = "/temp/" + to_string(s);
s = rand() % 10000;
if (s < 1000) { s += 1000; }
cout << s << endl;
string serverWrite = "/temp/" + to_string(s);
cout << PRIMARY << endl;
cout << "User pipe is " << userWrite << endl;
cout << "Server pipe is " << serverWrite << endl;
// send personal pipe information through global pipe to server
FILE * comms = fopen(PRIMARY.c_str(), "w");
cout << "Comms open" << endl;
result = fwrite(userWrite.c_str(), 1, userWrite.length(), comms);
if (result < userWrite.length()) { cout << endl << endl << endl << endl << endl << "write error, userfifo" << endl; }
result = fwrite(serverWrite.c_str(), 1, serverWrite.length(), comms);
if (result < userWrite.length()) { cout << endl << endl << endl << endl << endl << "write error, serverfifo" << endl; }
cout << "Comms written to" << endl;
//done with comms so close it
fclose(comms);
// for some reason sending /tmp/ caused a hang also, so i improvised
userWrite.erase(2,1);
serverWrite.erase(2,1);
// make the personal pipes
cout << userWrite << " " << serverWrite << endl;
mkfifo(userWrite.c_str(), 0777);
mkfifo(serverWrite.c_str(), 0777);
// open the personal pipes with read or write privelege
cout << "fifos made" << endl;
FILE * pwrite = fopen(userWrite.c_str(), "w");
cout << "pwrite open" << endl;
FILE * pread = fopen(serverWrite.c_str(), "r");
cout << "pread open" << endl;
// if either pipe did not get made correctly, print an error
if (pwrite == NULL ) { cout << "pwrite is wrong" << endl; }
if (pread == NULL ) { cout << "pread is wrong" << endl; }
// used to transfer information between pipes
string buffer = "/temp/0000";
string catcher = "/temp/0000";
// initialize curses functions
initscr();
noecho();
keypad(stdscr,TRUE);
cbreak();
WINDOW * screen = newwin(LINES/2, COLS/2, 0, 0);
wclear(screen);
keypad(screen,TRUE);
//wait for input before playing the game
int c = getch();
displayOpening(screen);
c = getch();
//initialize the game data types
int row = 0;
int column = 0;
vector<pair<int, int> > userMoves;
vector<pair<int,int> > serverMoves;
int charInt[MAX];
bool invalid = 0;
//until game is over or user exits
while (1) {
// update the board
displayBoard(screen,userMoves,serverMoves, row, column, invalid);
// based on user input, do stuff, supports wsad or arrow keys
switch(c = getch() ) {
// if go up, move up a row or go back to bottom if at top
case KEY_UP:
case 'w':
if (row == 0) { row = 2; }
else { row--; }
break;
// if go down, move down a row or go back to the top if at bottom
case KEY_DOWN:
case 's':
if (row == 2) { row = 0; }
else { row++; }
break;
// if go left, move left a column or go back to the far right if at far left
case KEY_LEFT:
case 'a':
if (column == 0) { column = 2; }
else { column--; }
break;
// if go right, move right a column or go back to the far left if at far right
case KEY_RIGHT:
case 'd':
if (column == 2) { column = 0; }
else { column++; }
break;
// if spacebar is pressed, enter move if valid, otherwise tell invalid and get more input
case ' ':
if (checkX(row, column, userMoves, serverMoves)) {
invalid = 0;
// no longer used function, thought maybe was the issue
//addX(row,column,userMoves,buffer);
//catch information in buffer to send to server
buffer[8] = (row + '0');
buffer[9] = (column + '0');
//cout << "buffer 0 and 1 are " << int(buffer[0]) << " " << int(buffer[1]) << endl;
// add newest move to the list of user moves
userMoves.push_back(make_pair(row,column));
// check if the game is over, send a game over message to server if so and exit/clean up pipes
if (checkValid(userMoves,serverMoves) == 0 || (userMoves.size() + serverMoves.size() == 9) ) {
youwin(screen);
buffer[8] = (3 + '0');
buffer[9] = (3 + '0');
result = fwrite(buffer.c_str(), 1, buffer.length(), pwrite);
if (result < BUFFERS) { cout << endl << endl << endl << endl << endl << "write error, usermove" << endl; }
fclose(pread);
fclose(pwrite);
unlink(userWrite.c_str());
unlink(serverWrite.c_str());
endwin();
return 0;
}
//mvwaddch(screen, 12, 1, 'k');
//wrefresh(screen);
//cout << endl << endl << endl << endl << endl << buffer << " " << buffer.length() << endl;
// write newest move to server, currently where hangs!!!!!!
result = fwrite(buffer.c_str(),1,buffer.length(),pwrite);
if (result < BUFFERS) { cout << endl << endl << endl << endl << endl << "write error, usermove" << endl; }
//cout << endl << "written successfully" << endl;
//mvwaddch(screen,12,1,'l');
//wrefresh(screen);
// read in server counter move
result = fread(&catcher[0],1,BUFFERS,pread);
if (result < BUFFERS) { cout << endl << endl << endl << endl << endl << "read error, servermove" << endl; }
// catch newest computer move
charInt[0] = (catcher[8] - '0');
charInt[1] = (catcher[9] - '0');
// if the server says it won, clean up pipes and exit
if (charInt[0] == 3 && charInt[1] == 3) {
youlose(screen);
fclose(pread);
fclose(pwrite);
unlink(userWrite.c_str());
unlink(serverWrite.c_str());
endwin();
return 0;
}
// check if the server made a valid move
if (checkX(charInt[0], charInt[1], userMoves, serverMoves)) { invalid = 1; }
//addX(charInt[0],charInt[1],serverMoves,catcher);
// add newest server move to list of server moves
serverMoves.push_back(make_pair(charInt[0],charInt[1]));
// if server has won or a draw, tell the server and clean up pipes/exit
if (checkValid(userMoves,serverMoves) == 0) {
youlose(screen);
buffer[8] = (3 + '0');
buffer[9] = (3 + '0');
result = fwrite(&buffer[0],1,BUFFERS,pwrite);
if (result < BUFFERS) { cout << endl << endl << endl << endl << endl << "write error, usermove" << endl; }
fclose(pread);
fclose(pwrite);
unlink(userWrite.c_str());
unlink(serverWrite.c_str());
endwin();
return 0;
}
}
// if the move was invalid say so
else { invalid = 1; }
break;
// if user wants to exit, tell the server and clean up/exit
case 'q':
buffer[8] = 3 + '0';
buffer[9] = 3 + '0';
result = fwrite(&buffer[0],sizeof(char),BUFFERS,pwrite);
if (result < BUFFERS) { cout << endl << endl << endl << endl << endl << "write error, usermove" << endl; }
fclose(pread);
fclose(pwrite);
unlink(userWrite.c_str());
unlink(serverWrite.c_str());
endwin();
return 0;
break;
default:
break;
}
}
return 0;
}
server main() :
const int GRID = 9;
const int MAX_G = 10;
const int MAX_L = 10;
const string PRIMARY="/home/mking/GPipe";
int main() {
// variables to hold personal pipe input
char userWrite[MAX_L];
char serverWrite[MAX_L];
// open global pipe and prepare for input
cout << PRIMARY << endl;
FILE * comms = fopen(PRIMARY.c_str(), "r");
cout << "comms open" << endl;
pid_t pid;
bool valid = 1;
int charInt[MAX_G];
char prev[] = "/temp/0000";
size_t result;
// run until forced to close
while(1) {
// get the personal pipe names
//cout << "about to read user" << endl;
result = fread(&userWrite[0], sizeof(char),MAX_L,comms);
if (result < MAX_L && result > 0) { cout << "read error, user" << endl; }
//cout << "read user" << endl;
result = fread(&serverWrite[0], sizeof(char), MAX_L,comms);
if (result < MAX_L && result > 0) { cout << "read error, server" << endl; }
//cout << "read server" << endl;
//cout << "User pipe is " << userWrite << endl;
//cout << "Server pipe is " << serverWrite << endl;
// if a new pipe was detected, fork and play against a client
if (strcmp(prev, userWrite) != 0) { pid = fork(); }
strcpy(prev, userWrite);
// if a chiled, play against a client
if (pid == 0) {
//close comms and open personal pipes
cout << "In child" << endl;
fclose(comms);
string user(userWrite);
string server(serverWrite);
// was having issues with fread earlier also, roundabout fix
user.erase(2,1);
server.erase(2,1);
// set up pipes
cout << "opened pipes " << user << " " << server << endl;
FILE * userFifo = fopen(user.c_str(), "r");
cout << "opened user pipe" << endl;
FILE * serverFifo = fopen(server.c_str(), "w");
cout << "opened server pipe" << endl;
// set up data for server to check moves
pair<int,int> move;
vector<pair<int,int> > userMoves;
vector<pair<int,int> > serverMoves;
char buffer[MAX_G] = {'/','t','e','m','p','/','0','0' };
char filler[MAX_G];
vector<bool> untaken (GRID, 1);
// while game not over
while (valid) {
// get a new move, HANGS HERE!!!!!
cout << "waiting for user move" << endl;
result = fread(&filler[0], sizeof(char), MAX_G, userFifo);
if (result < MAX_G) { cout << "read error, usermove" << endl; }
cout << "move read in" << endl;
// catch user move
charInt[0] = filler[6] - '0';
charInt[1] = filler[7] - '0';
cout << charInt[0] << " " << charInt[1] << endl;
// if user says game over, close pipes
if (charInt[0] == 3 && charInt[1] == 3) {
fclose(userFifo);
fclose(serverFifo);
exit(0);
}
// add user move to list of moves
userMoves.push_back(make_pair(charInt[0], charInt[1]));
// mark location of taken moves
untaken[(userMoves.back().first * 3 + userMoves.back().second)] = 0;
// see if game can be ended and add a server move
valid = checkX(userMoves,serverMoves, untaken);
untaken[(serverMoves.back().first * 3 + serverMoves.back().second)] = 0;
//prepare server move for writing
buffer[6] = serverMoves.back().first + '0';
buffer[7] = serverMoves.back().second + '0';
//buffer[0] = -1;
//buffer[1] = -1;
// write servermove to client
//cout << buffer[0] << " " << buffer[1] << endl;
result = fwrite(&buffer[0],sizeof(char),MAX_G,serverFifo);
if (result < MAX_G) { cout << "write error, servermove" << endl; }
}
// close pipes if game is over
fclose(userFifo);
fclose(serverFifo);
exit(0);
}
}
fclose(comms);
return 0;
}