threads(3ncurses) [suse man page]

threads(3NCURSES)														 threads(3NCURSES)

NAME

       use_screen, use_window - curses thread support

SYNOPSIS

       #include <curses.h>

       typedef int (*NCURSES_WINDOW_CB)(WINDOW *, void *); typedef int (*NCURSES_SCREEN_CB)(SCREEN *, void *);
       int set_escdelay(int size);
       int set_tabsize(int size);
       int use_screen(SCREEN *scr, NCURSES_WINDOW_CB func, void *data);
       int use_window(WINDOW *win, NCURSES_SCREEN_CB func, void *data);

DESCRIPTION

       This  implementation  can  be configured to provide rudimentary support for multi-threaded applications.  This makes a different set of li-
       braries, e.g., libncursest since the binary interfaces are different.

       Rather than modify the interfaces to pass a thread specifier to each function, it adds a few functions which can be used in any	configura-
       tion which hide the mutex's needed to prevent concurrent use of the global variables when configured for threading.

       In  addition to forcing access to members of the WINDOW structure to be via functions (see curs_opaque(3x)), it makes functions of the com-
       mon global variables, e.g., COLORS, COLOR_PAIRS, COLS, ESCDELAY, LINES, TABSIZE curscr, newscr and ttytype.  Those variables are maintained
       as read-only values, stored in the SCREEN structure.

       Even this is not enough to make a thread-safe application using curses.	A multi-threaded application would be expected to have threads up-
       dating separate windows (within the same device), or updating on separate screens (on different devices).  Also, a few of the global  vari-
       ables are considered writable by some applications.  The functions described here address these special situations.

       The  ESCDELAY and TABSIZE global variables are modified by some applications.  To modify them in any configuration, use the set_escdelay or
       set_tabsize functions.  Other global variables are not modifiable.

       The use_window and use_screen functions provide coarse granularity mutexes for their respective WINDOW and SCREEN parameters,  and  call  a
       user-supplied function, passing it a data parameter, and returning the value from the user-supplied function to the application.

   USAGE
       All  of	the  ncurses  library functions assume that the locale is not altered during operation.  In addition, they use data which is main-
       tained within a hierarchy of scopes.

	      -  global data, e.g., used in the low-level terminfo or termcap interfaces.

	      -  terminal data, e.g., associated with a call to set_curterm.  The terminal data are initialized when screens are created.

	      -  screen data, e.g., associated with a call to newterm or initscr.

	      -  window data, e.g., associated with a call to newwin or subwin.  Windows are associated with screens.  Pads  are  not  necessarily
		 associated with a particular screen.

		 Most curses applications operate on one or more windows within a single screen.

	      -  reentrant, i.e., it uses only the data passed as parameters.

       This table lists the scope of data used for each symbol in the ncurses library when it is configured to support threading:

RETURN VALUE

       These functions all return TRUE or FALSE, except as noted.

NOTES

       Both a macro and a function are provided for each name.

PORTABILITY

       These routines are specific to ncurses.	They were not supported on Version 7, BSD or System V implementations.	It is recommended that any
       code depending on ncurses extensions be conditioned using NCURSES_VERSION.

SEE ALSO

       ncurses(3NCURSES), opaque(3NCURSES)

																 threads(3NCURSES)

threads(3NCURSES)														 threads(3NCURSES)

NAME

       use_screen, use_window - curses thread support

SYNOPSIS

       #include <curses.h>

       typedef int (*NCURSES_WINDOW_CB)(WINDOW *, void *); typedef int (*NCURSES_SCREEN_CB)(SCREEN *, void *);
       int set_escdelay(int size);
       int set_tabsize(int size);
       int use_screen(SCREEN *scr, NCURSES_WINDOW_CB func, void *data);
       int use_window(WINDOW *win, NCURSES_SCREEN_CB func, void *data);

DESCRIPTION

       This  implementation  can  be configured to provide rudimentary support for multi-threaded applications.  This makes a different set of li-
       braries, e.g., libncursest since the binary interfaces are different.

       Rather than modify the interfaces to pass a thread specifier to each function, it adds a few functions which can be used in any	configura-
       tion which hide the mutex's needed to prevent concurrent use of the global variables when configured for threading.

       In  addition to forcing access to members of the WINDOW structure to be via functions (see curs_opaque(3x)), it makes functions of the com-
       mon global variables, e.g., COLORS, COLOR_PAIRS, COLS, ESCDELAY, LINES, TABSIZE curscr, newscr and ttytype.  Those variables are maintained
       as read-only values, stored in the SCREEN structure.

       Even this is not enough to make a thread-safe application using curses.	A multi-threaded application would be expected to have threads up-
       dating separate windows (within the same device), or updating on separate screens (on different devices).  Also, a few of the global  vari-
       ables are considered writable by some applications.  The functions described here address these special situations.

       The  ESCDELAY and TABSIZE global variables are modified by some applications.  To modify them in any configuration, use the set_escdelay or
       set_tabsize functions.  Other global variables are not modifiable.

       The use_window and use_screen functions provide coarse granularity mutexes for their respective WINDOW and SCREEN parameters,  and  call  a
       user-supplied function, passing it a data parameter, and returning the value from the user-supplied function to the application.

   USAGE
       All  of	the  ncurses  library functions assume that the locale is not altered during operation.  In addition, they use data which is main-
       tained within a hierarchy of scopes.

	      -  global data, e.g., used in the low-level terminfo or termcap interfaces.

	      -  terminal data, e.g., associated with a call to set_curterm.  The terminal data are initialized when screens are created.

	      -  screen data, e.g., associated with a call to newterm or initscr.

	      -  window data, e.g., associated with a call to newwin or subwin.  Windows are associated with screens.  Pads  are  not  necessarily
		 associated with a particular screen.

		 Most curses applications operate on one or more windows within a single screen.

	      -  reentrant, i.e., it uses only the data passed as parameters.

       This table lists the scope of data used for each symbol in the ncurses library when it is configured to support threading:

RETURN VALUE

       These functions all return TRUE or FALSE, except as noted.

NOTES

       Both a macro and a function are provided for each name.

PORTABILITY

       These routines are specific to ncurses.	They were not supported on Version 7, BSD or System V implementations.	It is recommended that any
       code depending on ncurses extensions be conditioned using NCURSES_VERSION.

SEE ALSO

       ncurses(3NCURSES), opaque(3NCURSES)

																 threads(3NCURSES)