[thread에서 _beginthreadex의 void *arglist로 스레드에 여러 인수 넘겨주는 방법]

February 25th, 2004, 11:40 AM

urika  Member   Join Date: Oct 2003 Posts: 204

putting values in void *arglist hi , i want to run a threads using _beginthread(...) (no MFC) inside the threadfunc i want to call a function with many variables. how do i use the void *arglist so it points to a few variables ? i hope my question makes sence  thank u

#2      February 25th, 2004, 11:47 AM

gstercken  Moderator Power Poster   Join Date: Sep 2002 Location: 14° 39'19.65"N / 121° 1'44.34"E Posts: 9,815

Re: putting values in void *arglist Quote: Originally posted by urika  how do i use the void *arglist so it points to a few variables ? Usually by creating a class or struct which contains the variables. You would then use the void* to pass the pointer to an instance of that class or struct, which you would have to cast back to the actual type before accessing the members. __________________ Guido Stercken-Sorrenti

#3      February 25th, 2004, 11:51 AM

urika  Member   Join Date: Oct 2003 Posts: 204

thanks!

#4      February 29th, 2004, 05:34 AM

urika  Member   Join Date: Oct 2003 Posts: 204

i call a function : Code: bool MapViewInit(GEO p1, GEO p2, DISPLAY Disp, CONTROL Ctrl, HINSTANCE hInst) { MapThreadArgList maparglist; ////????? maparglist.Ctrl=Ctrl; maparglist.Disp=Disp; maparglist.p1=p1; maparglist.p2=p2; maparglist.hInst=hInst; HANDLE handle1 =(HANDLE)_beginthread( MapThreadFunc,0, (void *)&maparglist); // create thread COUT << "\n >>> MapViewInit Run Successfully <<<\n"; return true; } in order to run the thread i do : Code: void MapThreadFunc( void* args ) { GEO p1; GEO p2; DISPLAY Disp; CONTROL Ctrl; HINSTANCE hInst; MapThreadArgList arglist = *((MapThreadArgList*)args); p1=arglist.p1; p2=arglist.p2; Disp=arglist.Disp; Ctrl=arglist.Ctrl; hInst=arglist.hInst; ... ... ... after i cast back to MapThreadArgList the info in arglist.p1 (and the others ) is lost. what am i doing wrong?

#5      February 29th, 2004, 06:02 AM

gstercken  Moderator Power Poster   Join Date: Sep 2002 Location: 14° 39'19.65"N / 121° 1'44.34"E Posts: 9,815

Quote: Originally posted by urika  what am i doing wrong? You are creating maparglist on the stack - it will be destroyed when it gets out of scope (when you return from MapViewInit()). Allocate it on the heap, or keep it as a member variable instead. __________________ Guido Stercken-Sorrenti

#6      February 29th, 2004, 07:55 AM

urika  Member   Join Date: Oct 2003 Posts: 204

thanks , it now works

결론
구조체를 사용하여 쓰레드에 넘겨줄 인수를 모두 넣는다. (구조체 정의를 전역변수로 해야 함)
구조체의 객체를 만든 다음 객체멤버에 값을 넣어준다.
통째로 객체를 넘겨준다.
스레드에서 구조체의 객체를 만들어 파라메터의 객체를 받는다.
쓰면된다~