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/ Power-Programmierung / CD2.mdf / gnu / djgpp / libsrc / c / go32 / go32func.c < prev    next >
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C/C++ Source or Header  |  1993-10-09  |  1.4 KB  |  70 lines
  1. #include <sys/types.h>
  2. #include <go32.h>
  3. #include <dpmi.h>
  4. #include <dos.h>
  5.  
  6. u_short _go32_my_cs()
  7. {
  8.   asm("movw %cs,%ax");
  9. }
  10.  
  11. u_short _go32_my_ds()
  12. {
  13.   asm("movw %ds,%ax");
  14. }
  15.  
  16. u_short _go32_my_ss()
  17. {
  18.   asm("movw %ss,%ax");
  19. }
  20.  
  21. u_short _go32_conventional_mem_selector()
  22. {
  23.   return _go32_info_block.selector_for_linear_memory;
  24. }
  25.  
  26. static _go32_dpmi_registers regs;
  27. static volatile u_long ctrl_break_count = 0;
  28. static int ctrl_break_hooked = 0;
  29. static _go32_dpmi_seginfo old_vector;
  30. static _go32_dpmi_seginfo new_vector;
  31.  
  32. static ctrl_break_isr(_go32_dpmi_registers *regs)
  33. {
  34.   ctrl_break_count ++;
  35. }
  36.  
  37. u_long _go32_was_ctrl_break_hit()
  38. {
  39.   u_long cnt;
  40.   _go32_want_ctrl_break(1);
  41.   cnt = ctrl_break_count;
  42.   ctrl_break_count = 0;
  43.   return cnt;
  44. }
  45.  
  46. void _go32_want_ctrl_break(int yes)
  47. {
  48.   if (yes)
  49.   {
  50.     if (ctrl_break_hooked)
  51.       return;
  52.     _go32_dpmi_get_real_mode_interrupt_vector(0x1b, &old_vector);
  53.  
  54.     new_vector.pm_offset = (int)ctrl_break_isr;
  55.     _go32_dpmi_allocate_real_mode_callback_iret(&new_vector, ®s);
  56.     _go32_dpmi_set_real_mode_interrupt_vector(0x1b, &new_vector);
  57.     ctrl_break_count = 0;
  58.     ctrl_break_hooked = 1;
  59.   }
  60.   else
  61.   {
  62.     if (!ctrl_break_hooked)
  63.       return;
  64.     _go32_dpmi_set_real_mode_interrupt_vector(0x1b, &old_vector);
  65.     _go32_dpmi_free_real_mode_callback(&new_vector);
  66.     ctrl_break_count = 0;
  67.     ctrl_break_hooked = 0;
  68.   }
  69. }
  70.