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curs_threads(3X) Library calls curs_threads(3X) NAME NCURSES_WINDOW_CB, NCURSES_SCREEN_CB, get_escdelay, set_escdelay, set_tabsize, use_screen, use_window - curses support for multi-threaded applications SYNOPSIS #include <curses.h> /* data types */ typedef int (*NCURSES_WINDOW_CB)(WINDOW *, void *); typedef int (*NCURSES_SCREEN_CB)(SCREEN *, void *); int get_escdelay(void); int set_escdelay(int ms); int set_tabsize(int cols); int use_screen(SCREEN *scr, NCURSES_SCREEN_CB func, void *data); int use_window(WINDOW *win, NCURSES_WINDOW_CB func, void *data); DESCRIPTION The ncurses library can be configured to support multi-threaded appli- cations in a rudimentary way. Such configuration produces a different set of libraries, named libncursest, for example, since doing so alters ncurses's application binary interface (ABI). Instead of modifying the programming interface (API) to make ncurses functions expect an additional argument specifying a thread, the li- brary adds functions, usable in any configuration, that hide the mu- texes (mutual exclusion locks) needed to prevent concurrent access to variables shared by multiple threads of execution. ncurses threading support requires the use of functions to access mem- bers of the WINDOW structure (see curs_opaque(3X)). It further makes functions of the common global variables COLORS, COLOR_PAIRS, COLS, ESCDELAY, LINES, TABSIZE, curscr, newscr, and ttytype, maintaining them as as read-only values in the SCREEN structure. Even this is not enough to make an application using curses thread- safe. We would expect a multi-threaded application to have threads up- dating separate windows (on the same device), and separate screens (on different devices). Further, applications expect a few of the global variables to be writable. The functions described here address these special situations. The ESCDELAY and TABSIZE global variables are modified by some applica- tions. To modify them in any configuration, use the set_escdelay or set_tabsize functions. Other global variables are not modifiable. get_escdelay retrieves ESCDELAY's value. The use_window and use_screen functions provide coarse-grained mutexes for their respective WINDOW and SCREEN parameters; they call a user- supplied function, pass it a data parameter, and return the value from the user-supplied function to the application. Usage All ncurses library functions assume that the locale is not altered during operation. In addition, they use data that is maintained within a hierarchy of scopes. o global data used in the low-level terminfo or termcap interfaces o terminal data associated with a call to set_curterm(3X) Terminal data are initialized when screens are created. o screen data associated with a call to newterm(3X) or initscr(3X) o window data associated with a call to newwin(3X) or subwin(3X) Windows are associated with screens. Pads are not necessarily as- sociated with any particular screen. Most curses applications operate on one or more windows within a single screen. o reentrant data associated with "pure" functions that alter no shared variables The following table lists the scope of each symbol in the ncurses li- brary when configured to support multi-threaded applications. center; Lb2 Lb Lb2 Lx. Symbol Scope _ BC global COLORS screen (read-only) COLOR_PAIR reentrant COLOR_PAIRS screen (read-only) COLS screen (read-only) ESCDELAY screen (read-only; see set_escdelay) LINES screen (read-only) PAIR_NUMBER reentrant PC global SP global TABSIZE screen (read-only; see set_tabsize) UP global acs_map screen (read-only) add_wch window (stdscr) add_wchn- str window (stdscr) add_wchstr window (stdscr) addch window (stdscr) addchnstr window (stdscr) addchstr window (stdscr) addnstr window (stdscr) addnwstr window (stdscr) addstr window (stdscr) addwstr window (stdscr) assume_default_colors screen attr_get window (stdscr) attr_off window (stdscr) attr_on window (stdscr) attr_set window (stdscr) attroff window (stdscr) at- tron window (stdscr) attrset window (stdscr) baudrate screen beep screen bkgd window (stdscr) bkgdset window (stdscr) bkgrnd window (stdscr) bkgrndset window (stdscr) boolcodes global (read-only) boolfnames global (read-only) boolnames global (read- only) border window (stdscr) border_set window (stdscr) box window (stdscr) box_set window (stdscr) can_change_color ter- minal cbreak screen chgat window (stdscr) clear window (std- scr) clearok window clrtobot window (stdscr) clrtoeol window (std- scr) color_content screen color_set window (stdscr) copywin window (locks source, target) cur_term terminal curs_set screen curscr screen (read-only) curses_version global (read-only) def_prog_mode terminal def_shell_mode terminal define_key screen del_curterm screen delay_output screen delch window (stdscr) deleteln window (stdscr) delscreen global (locks screen list, screen) delwin global (locks window list) derwin screen doupdate screen dupwin screen (locks window) echo screen echo_wchar window (std- scr) echochar window (stdscr) endwin screen erase window (std- scr) erasechar window (stdscr) erasewchar window (stdscr) fil- ter global flash terminal flushinp screen get_wch screen (in- put operation) get_wstr screen (input operation) getattrs window get- begx window getbegy window getbkgd window getbkgrnd window getc- char reentrant getch screen (input operation) getcurx window getcury window getmaxx window getmaxy window getmouse screen (input operation) getn_wstr screen (input operation) getnstr screen (input operation) getparx window getpary window getstr screen (input operation) getwin screen (input operation) halfdelay screen has_colors terminal has_ic terminal has_il terminal has_key screen hline window (stdscr) hline_set window (stdscr) idcok window idlok window immedok window in_wch window (stdscr) in_wchnstr window (stdscr) in_wchstr window (stdscr) inch window (stdscr) inchnstr window (stdscr) inchstr window (std- scr) init_color screen init_pair screen initscr global (locks screen list) innstr window (stdscr) innwstr window (stdscr) ins_nwstr window (stdscr) ins_wch window (stdscr) ins_wstr window (stdscr) insch window (stdscr) insdelln window (stdscr) in- sertln window (stdscr) insnstr window (stdscr) insstr window (stdscr) instr window (stdscr) intrflush terminal inwstr window (stdscr) is_cleared window is_idcok window is_idlok window is_im- medok window is_keypad window is_leaveok window is_line- touched window is_nodelay window is_notimeout window is_scrol- lok window is_syncok window is_term_resized terminal is_win- touched window isendwin screen key_defined screen key_name global (static data) keybound screen keyname global (static data) keyok screen keypad window killchar terminal killwchar terminal leaveok window longname screen mcprint terminal meta screen mouse_trafo window (stdscr) mouseinterval screen mousemask screen move window (stdscr) mvadd_wch window (stdscr) mvadd_wchnstr window (stdscr) mvadd_wchstr window (stdscr) mvaddch window (stdscr) mvad- dchnstr window (stdscr) mvaddchstr window (stdscr) mvaddnstr window (stdscr) mvaddnwstr window (stdscr) mvaddstr win- dow (stdscr) mvaddwstr window (stdscr) mvchgat window (stdscr) mvcur screen mvdelch window (stdscr) mvderwin window (stdscr) mvget_wch screen (input operation) mvget_wstr screen (input opera- tion) mvgetch screen (input operation) mvgetn_wstr screen (input operation) mvgetnstr screen (input operation) mvgetstr screen (input operation) mvhline window (stdscr) mvhline_set window (stdscr) mvin_wch window (stdscr) mvin_wchnstr window (stdscr) mvin_wch- str window (stdscr) mvinch window (stdscr) mvinchnstr window (stdscr) mvinchstr window (stdscr) mvinnstr window (stdscr) mvinnw- str window (stdscr) mvins_nwstr window (stdscr) mvins_wch window (stdscr) mvins_wstr window (stdscr) mvinsch window (stdscr) mvin- snstr window (stdscr) mvinsstr window (stdscr) mvinstr window (std- scr) mvinwstr window (stdscr) mvprintw window (stdscr) mvs- canw screen mvvline window (stdscr) mvvline_set window (stdscr) mvwadd_wch window mvwadd_wchnstr window mvwadd_wchstr window mvwaddch window mvwaddchnstr window mvwaddchstr window mvwaddnstr window mvwaddnwstr window mvwaddstr window mvwaddw- str window mvwchgat window mvwdelch window mvwget_wch screen (input operation) mvwget_wstr screen (input operation) mvwgetch screen (input operation) mvwgetn_wstr screen (input opera- tion) mvwgetnstr screen (input operation) mvwgetstr screen (input operation) mvwhline window mvwhline_set window mvwin window mvwin_wch window mvwin_wchnstr window mvwin_wchstr window mvwinch window mvwinchnstr window mvwinchstr window mvwinnstr window mvwinnwstr window mvwins_nwstr window mvwins_wch window mvwins_wstr window mvwinsch window mvwin- snstr window mvwinsstr window mvwinstr window mvwinwstr window mvwprintw window mvwscanw screen mvwvline window mvwvline_set win- dow napms reentrant newpad global (locks window list) newscr screen (read-only) newterm global (locks screen list) newwin global (locks window list) nl screen nocbreak screen node- lay window noecho screen nofilter global nonl screen noqi- flush terminal noraw screen notimeout window numcodes global (read-only) numfnames global (read-only) numnames global (read-only) ospeed global overlay window (locks source, target) overwrite win- dow (locks source, target) pair_content screen pecho_wchar screen pechochar screen pnoutrefresh screen prefresh screen printw win- dow putp global putwin window qiflush terminal raw screen re- drawwin window refresh screen reset_prog_mode screen re- set_shell_mode screen resetty terminal resize_term screen (locks window list) resizeterm screen restartterm screen ripof- fline global (static data) savetty terminal scanw screen scr_dump screen scr_init screen scr_restore screen scr_set screen scrl window (stdscr) scroll window scrollok window set_curterm screen set_escdelay screen set_tabsize screen set_term global (locks screen list, screen) setcchar reentrant setscrreg window (stdscr) setupterm global slk_attr screen slk_attr_off screen slk_attr_on screen slk_attr_set screen slk_attroff screen slk_attron screen slk_attrset screen slk_clear screen slk_color screen slk_init screen slk_label screen slk_noutrefresh screen slk_refresh screen slk_restore screen slk_set screen slk_touch screen slk_wset screen standend window standout window start_color screen stdscr screen (read-only) strcodes global (read-only) strfnames global (read-only) str- names global (read-only) subpad window subwin window syn- cok window term_attrs screen termattrs screen termname terminal tgetent global tgetflag global tgetnum global tgetstr global tgoto global tigetflag terminal tigetnum terminal tigetstr termi- nal timeout window (stdscr) touchline window touchwin window tparm global (static data) tputs screen trace global (sta- tic data) ttytype screen (read-only) typeahead screen unc- trl screen unget_wch screen (input operation) ungetch screen (in- put operation) ungetmouse screen (input operation) untouch- win window use_default_colors screen use_env global (static data) use_extended_names global (static data) use_legacy_cod- ing screen use_screen global (locks screen list, screen) use_win- dow global (locks window list, window) vid_attr screen vid_puts screen vidattr screen vidputs screen vline window (stdscr) vline_set window (stdscr) vw_printw window vw_scanw screen vwprintw window vwscanw screen wadd_wch window wadd_wchnstr win- dow wadd_wchstr window waddch window waddchnstr window wadd- chstr window waddnstr window waddnwstr window waddstr window waddw- str window wattr_get window wattr_off window wattr_on window wattr_set window wattroff window wattron window wattrset window wbkgd window wbkgdset window wbkgrnd window wbkgrndset win- dow wborder window wborder_set window wchgat window wclear window wclrtobot window wclrtoeol window wcolor_set win- dow wcursyncup screen (affects window plus parents) wdelch win- dow wdeleteln window wecho_wchar window wechochar window wen- close window werase window wget_wch screen (input operation) wget_wstr screen (input operation) wgetbkgrnd window wgetch screen (input operation) wgetdelay window wgetn_wstr screen (input operation) wgetnstr screen (input opera- tion) wgetparent window wgetscrreg window wgetstr screen (in- put operation) whline window whline_set window win_wch window win_wchnstr window win_wchstr window winch window winchn- str window winchstr window winnstr window winnwstr window wins_nw- str window wins_wch window wins_wstr window winsch window wins- delln window winsertln window winsnstr window winsstr window win- str window winwstr window wmouse_trafo window wmove window wnoutrefresh screen wprintw window wredrawln window wre- fresh screen wresize window (locks window list) wscanw screen wscrl window wsetscrreg window wstandend window wstandout win- dow wsyncdown screen (affects window plus parents) wsyncup screen (affects window plus parents) wtimeout window wtouchln window wunc- trl global (static data) wvline window wvline_set window RETURN VALUE get_escdelay returns the value of ESCDELAY. set_escdelay and set_tabsize return ERR upon failure and OK upon successful completion. use_screen and use_window return the int returned by the user-supplied function they are called with. NOTES ncurses provides both a C function and a preprocessor macro for each function documented in this page. 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 curses(3X), curs_opaque(3X), curs_variables(3X) ncurses 6.5 2024-03-16 curs_threads(3X)