src/apps/packageinstaller/BlockingWindow.cpp

   1 /*
   2  * Copyright (c) 2007-2014, Haiku, Inc.
   3  * Distributed under the terms of the MIT license.
   4  *
   5  * Author:
   6  *              Łukasz 'Sil2100' Zemczak <sil2100@vexillium.org>
   7  *              Stephan Aßmus <superstippi@gmx.de>
   8  */
   9
  10
  11 #include "PackageImageViewer.h"
  12
  13
  14 BlockingWindow::BlockingWindow(BRect frame, const char* title, uint32 flags)
  15         :
  16         BWindow(frame, title, B_MODAL_WINDOW,
  17                 B_NOT_ZOOMABLE | B_NOT_RESIZABLE | B_NOT_CLOSABLE | flags),
  18         fSemaphore(-1),
  19         fReturnValue(0)
  20 {
  21 }
  22
  23
  24 BlockingWindow::~BlockingWindow()
  25 {
  26 }
  27
  28
  29 bool
  30 BlockingWindow::QuitRequested()
  31 {
  32         ReleaseSem(0);
  33         return true;
  34 }
  35
  36
  37 int32
  38 BlockingWindow::Go()
  39 {
  40         int32 returnValue = 0;
  41
  42         // Since this class can be thought of as a modified BAlert window, no use
  43         // to reinvent a well fledged wheel. This concept has been borrowed from
  44         // the current BAlert implementation
  45         fSemaphore = create_sem(0, "PackageInstaller BlockingWindow");
  46         if (fSemaphore < B_OK) {
  47                 Quit();
  48                 return returnValue;
  49         }
  50
  51         thread_id callingThread = find_thread(NULL);
  52         BWindow* window = dynamic_cast<BWindow*>(BLooper::LooperForThread(
  53                 callingThread));
  54         Show();
  55
  56         if (window != NULL) {
  57                 // Make sure calling window thread, which is blocked here, is updating
  58                 // the window from time to time.
  59                 status_t ret;
  60                 for (;;) {
  61                         do {
  62                                 ret = acquire_sem_etc(fSemaphore, 1, B_RELATIVE_TIMEOUT, 50000);
  63                         } while (ret == B_INTERRUPTED);
  64
  65                         if (ret == B_BAD_SEM_ID)
  66                                 break;
  67                         window->UpdateIfNeeded();
  68                 }
  69         } else {
  70                 // Since there are no spinlocks, wait until the semaphore is free
  71                 while (acquire_sem(fSemaphore) == B_INTERRUPTED) {
  72                 }
  73         }
  74
  75         returnValue = fReturnValue;
  76
  77         if (Lock())
  78                 Quit();
  79
  80         return returnValue;
  81 }
  82
  83
  84 void
  85 BlockingWindow::ReleaseSem(int32 returnValue)
  86 {
  87         if (fSemaphore >= B_OK) {
  88                 delete_sem(fSemaphore);
  89                 fSemaphore = -1;
  90                 fReturnValue = returnValue;
  91         }
  92 }