ref: 2c23de27d5006e969106fad672399fafe6464845
dir: /DoConfig/fltk/test/threads.cxx/
// // "$Id$" // // Threading example program for the Fast Light Tool Kit (FLTK). // // Copyright 1998-2016 by Bill Spitzak and others. // // This library is free software. Distribution and use rights are outlined in // the file "COPYING" which should have been included with this file. If this // file is missing or damaged, see the license at: // // http://www.fltk.org/COPYING.php // // Please report all bugs and problems on the following page: // // http://www.fltk.org/str.php // #include <config.h> #if defined(HAVE_PTHREAD) || defined(WIN32) # include <FL/Fl.H> # include <FL/Fl_Double_Window.H> # include <FL/Fl_Browser.H> # include <FL/Fl_Value_Output.H> # include <FL/fl_ask.H> # include "threads.h" # include <stdio.h> # include <math.h> Fl_Thread prime_thread; Fl_Browser *browser1, *browser2; Fl_Value_Output *value1, *value2; int start2 = 3; void magic_number_cb(void *p) { Fl_Value_Output *w = (Fl_Value_Output*)p; w->labelcolor(FL_RED); w->redraw_label(); } extern "C" void* prime_func(void* p) { Fl_Browser* browser = (Fl_Browser*) p; Fl_Value_Output *value; int n; int step; char proud = 0; if (browser == browser2) { n = start2; start2 += 2; step = 12; value = value2; } else { n = 3; step = 2; value = value1; } // very simple prime number calculator ! // // The return at the end of this function can never be reached and thus // will generate a warning with some compilers, however we need to have // a return statement or other compilers will complain there is no return // statement. To avoid warnings on all compilers, we fool the smart ones // into beleiving that there is a chance that we reach the end by testing // n>=0, knowing that logically, n will never be negative in this context. if (n>=0) for (;;) { int pp; int hn = (int)sqrt((double)n); for (pp=3; pp<=hn; pp+=2) if ( n%pp == 0 ) break; if (pp >= hn) { char s[128]; sprintf(s, "%d", n); // Obtain a lock before we access the browser widget... Fl::lock(); browser->add(s); browser->bottomline(browser->size()); if (n > value->value()) value->value(n); n += step; // Release the lock... Fl::unlock(); // Send a message to the main thread, at which point it will // process any pending redraws for our browser widget. The // message we pass here isn't used for anything, so we could also // just pass NULL. Fl::awake(p); if (n>10000 && !proud) { proud = 1; Fl::awake(magic_number_cb, value); } } else { // This should not be necessary since "n" and "step" are local variables, // however it appears that at least MacOS X has some threading issues // that cause semi-random corruption of the (stack) variables. Fl::lock(); n += step; Fl::unlock(); } } return 0L; } int main(int argc, char **argv) { Fl_Double_Window* w = new Fl_Double_Window(200, 200, "Single Thread"); browser1 = new Fl_Browser(0, 0, 200, 175); w->resizable(browser1); value1 = new Fl_Value_Output(100, 175, 200, 25, "Max Prime:"); w->end(); w->show(argc, argv); w = new Fl_Double_Window(200, 200, "Six Threads"); browser2 = new Fl_Browser(0, 0, 200, 175); w->resizable(browser2); value2 = new Fl_Value_Output(100, 175, 200, 25, "Max Prime:"); w->end(); w->show(); browser1->add("Prime numbers:"); browser2->add("Prime numbers:"); // Enable multi-thread support by locking from the main // thread. Fl::wait() and Fl::run() call Fl::unlock() and // Fl::lock() as needed to release control to the child threads // when it is safe to do so... Fl::lock(); // Start threads... // One thread displaying in one browser fl_create_thread(prime_thread, prime_func, browser1); // Several threads displaying in another browser fl_create_thread(prime_thread, prime_func, browser2); fl_create_thread(prime_thread, prime_func, browser2); fl_create_thread(prime_thread, prime_func, browser2); fl_create_thread(prime_thread, prime_func, browser2); fl_create_thread(prime_thread, prime_func, browser2); fl_create_thread(prime_thread, prime_func, browser2); Fl::run(); return 0; } #else # include <FL/fl_ask.H> int main() { fl_alert("Sorry, threading not supported on this platform!"); } #endif // HAVE_PTHREAD || WIN32 // // End of "$Id$". //