Packaging a threaded program with Qt GUI

Packaging a threaded program with Qt GUI

By : user2949643
Date : November 17 2020, 01:00 AM
like below fixes the issue You do not subclass QThread to run something in a different thread. QThread is used via signals/slots.
code :
void my_function(int a, double b) {
     .... do something in another thread ....
    auto some_function = std::function<void(int, double)>(&my_function);
    QFuture<void> ret = QtConcurrent::run(some_function, 10, 20.0);
QFuture<void> ret = QtConcurrent::run(&my_function, 10, 20.0);
class Foo {
     void foo(int a) {}

Foo *foo_instance = new Foo;
QFuture<void> ret = Qtconcurrent::run(foo_instance, &Foo::foo, 10);

Share : facebook icon twitter icon
C: How can a threaded program run faster than a non-threaded on the same single core?

C: How can a threaded program run faster than a non-threaded on the same single core?

By : Luis
Date : March 29 2020, 07:55 AM
around this issue Because you are simulating the "work" by sleeping. So the scheduler need only put one thread to sleep for 5 seconds; afterwards it is free to "service" another thread.
In short, you aren't using the CPU so in theory you could service a lot of clients this way. Now if you were to do something CPU-bound for 5 seconds, you would see the difference.
Multi threaded program takes longer to execute than the Single Threaded Program

Multi threaded program takes longer to execute than the Single Threaded Program

By : user32308
Date : March 29 2020, 07:55 AM
fixed the issue. Will look into that further First of all, you are using processor-clock ticks to measure the performance, and by that measure any multi-threaded algorithm will be slower than an equivalent single-threaded algorithm. The reason is because this measure effectively counts the number of instructions that gets executed and threading always adds a little overhead to an algorithm.
To get a proper measurement of performance, you need to measure the wall-clock time. This way, the measurement can accurately reflect the work that gets done in parallel by different cores/processors.
Single Threaded Program vs Multithreaded Program (measuing time elapsed)

Single Threaded Program vs Multithreaded Program (measuing time elapsed)

By : Thomas Kgaevski
Date : March 29 2020, 07:55 AM
may help you . Your multi-threaded program likely makes all the requests at the same time which puts more strain on the server which will cause it to respond slower to all request.
As an aside, the way you are doing the update isn't threadsafe, so your count will likely be off in the multithreaded scenario given enough trials.
Multi-Threaded program runs slower than single threaded

Multi-Threaded program runs slower than single threaded

By : 지향은
Date : March 29 2020, 07:55 AM
I wish did fix the issue.
I understand that the result will not be correct but it is crawling compared to single threaded one
GDB hangs when multi-threaded python extension is used to debug multi threaded program

GDB hangs when multi-threaded python extension is used to debug multi threaded program

By : kishore dasari
Date : March 29 2020, 07:55 AM
I wish this help you From this blog post:
code :
import gdb
import threading
import pysigset, signal # Import these packages!

def plot_thread():
    import time
    while True:
        print('Placeholder for a window event loop.')

class PlotterCommand(gdb.Command):
    def __init__(self):
        super(PlotterCommand, self).__init__("plot",

    def invoke(self, arg, from_tty):
        with pysigset.suspended_signals(signal.SIGCHLD): # Disable signals here!


Related Posts Related Posts :
  • What is the purpose of name mangling in C++?
  • C++ Why the void function is not working eventhough I called it?
  • How the pointer and the pointer's adress can share the same memory adress?
  • error C2220: warning treated as error - no 'object' file generated
  • exception of strcpy function in c++ console program
  • How to access USB barcode scanner data directly from USB port using C/C++ without driver
  • Under which circumstances will std::vector.clear() call a destructor?
  • Template partial specialisation and dependent names
  • best way to share data between c codes
  • C++ ignores if statement conditions
  • How to set the argv[ ] to be case-insensitive in a Win32 Console Application?
  • How to fix error "clang: error: linker (via gcc) command failed with exit code 1 (use -v to see invocation)"?
  • C++ How do I print a .txt file verbatim?
  • Creating two dimensional array of class
  • How do I correctly use COMMTIMEOUTS with OVERLAPPED IO mode reading from a Serial port
  • An assert macro which expands to static_assert when possible?
  • How to write a copyconstructor for a class which has HANDLE as a member in win32 c++ application?
  • C++ saving info such as tree in a file
  • Transforming an expression template tree
  • How to overload an operator with multiple parameters like a + b + c?
  • C++ 11 with Raspberry Pi performances
  • Make a C++ class look like a numpy array using swig
  • Postfix incrementer overloading for nested enumerated types
  • Is there a tidy way of associating metadata with functions in C++
  • QObject::installEventFilter(): Cannot filter events for objects in a different thread
  • LNK2005 error with Zxing C++
  • C++ Doubly Linked List with Pointers: Object of class isn't constructed properly
  • Using a random string generator in c++ constructor
  • What should I use instead of void as one of the alternative types in an variant?
  • C++ return value from multithreads using reference
  • How to connect multiple TCP IP clients to same server port using c++
  • Defaul compiler generates the reference operator (In C++)?
  • Unable to change directory time stamp after using FILE_FLAG_BACKUP_SEMANTICS
  • vector handling displaying output
  • WSAGetLastError returns WSAENOTSOCK - Cause?
  • C++: How to overload pow for user type?
  • C++ using arrays as multidimensional despite initalising it as 1D with pointer
  • How negate std::is_integral for use in tag dispatch?
  • Retrieve serial number from USB memory (Windows environment c++)
  • g++ error: invalid preprocessing directive #INCLUDE
  • C++ What is the std::for_each() function parameter type?
  • C++: Read individual lines from text file, sort words alphabetically
  • Saving 'this' address into a variable
  • c++ command line arguments in ubuntu terminal
  • Convert "Cartesian coordinates" to "polar coordinates with respect to user specified origin"
  • In what order are local scoped objects destructed?
  • How to use SDL_MapRGB with SDL 2.0
  • how compiler and interpreter work in case of array declaration
  • GSL integration behaves strange
  • Cropping an image with OpenCV and C
  • Find the last line in text file and select the first 10 char and print to a new file?
  • Created many CCSprits but when triggering ccTouchBegan gives the last one allways
  • seekp and seekg don't work with fstream
  • Taking input in Sublime Text 3
  • ld: -bind_at_load and -bitcode_bundle (Xcode setting ENABLE_BITCODE=YES) cannot be used together
  • C++ storing #define as std::string would give size as zero compile time
  • How to use static linking with OpenSSL in C/C++
  • What is the difference between a trap, an error, a failure and program abortion?
  • Dynamic members allocation in qt
  • How to reduce object file size when compiling for VxWorks 5.5.1?
  • shadow
    Privacy Policy - Terms - Contact Us © ourworld-yourmove.org