man/curs_threads.3x

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  31 .\" $Id: curs_threads.3x,v 1.51 2023/12/23 16:22:25 tom Exp $
  32 .TH curs_threads 3X 2023-12-23 "ncurses 6.4" "Library calls"
  33 .ie \n(.g \{\
  34 .ds `` \(lq
  35 .ds '' \(rq
  36 .\}
  37 .el \{\
  38 .ie t .ds `` ``
  39 .el   .ds `` ""
  40 .ie t .ds '' ''
  41 .el   .ds '' ""
  42 .\}
  43 .
  44 .de bP
  45 .ie n  .IP \(bu 4
  46 .el    .IP \(bu 2
  47 ..
  48 .SH NAME
  49 \fI\%NCURSES_WINDOW_CB\fP,
  50 \fI\%NCURSES_SCREEN_CB\fP,
  51 \fB\%get_escdelay\fP,
  52 \fB\%set_escdelay\fP,
  53 \fB\%set_tabsize\fP,
  54 \fB\%use_screen\fP,
  55 \fB\%use_window\fP \-
  56 \fIcurses\fR support for multi-threaded applications
  57 .SH SYNOPSIS
  58 .nf
  59 \fB#include <curses.h>
  60 .PP
  61 \fI/* data types */
  62 \fBtypedef int (*NCURSES_WINDOW_CB)(WINDOW *, void *);
  63 \fBtypedef int (*NCURSES_SCREEN_CB)(SCREEN *, void *);
  64 .PP
  65 \fBint get_escdelay(void);
  66 \fBint set_escdelay(int \fIms\fP);
  67 \fBint set_tabsize(int \fIcols\fP);
  68 .PP
  69 \fBint use_screen(SCREEN *\fIscr\fP, NCURSES_SCREEN_CB \fIfunc\fP, void *\fIdata\fP);
  70 \fBint use_window(WINDOW *\fIwin\fP, NCURSES_WINDOW_CB \fIfunc\fP, void *\fIdata\fP);
  71 .fi
  72 .SH DESCRIPTION
  73 The \fI\%ncurses\fP library can be configured to support multi-threaded
  74 applications in a rudimentary way.
  75 Such configuration produces a different set of libraries,
  76 named \fIlibncursest\fP,
  77 for example,
  78 since doing so alters \fI\%ncurses\fP's application binary interface
  79 (ABI).
  80 .PP
  81 Instead of modifying the programming interface (API) to make
  82 \fI\%ncurses\fP functions expect an additional argument specifying a
  83 thread,
  84 the library adds functions,
  85 usable in any configuration,
  86 that hide the \fImutexes\fP
  87 (mutual exclusion locks)
  88 needed to prevent concurrent access to variables shared by multiple
  89 threads of execution.
  90 .PP
  91 \fI\%ncurses\fP threading support requires the use of functions to
  92 access members of the \fI\%WINDOW\fP structure (see
  93 \fBcurs_opaque\fP(3X)).
  94 It further makes functions of the common global variables
  95 \fB\%COLORS\fP,
  96 \fB\%COLOR_PAIRS\fP,
  97 \fB\%COLS\fP,
  98 \fB\%ESCDELAY\fP,
  99 \fB\%LINES\fP,
 100 \fB\%TABSIZE\fP,
 101 \fB\%curscr\fP,
 102 \fB\%newscr\fP,
 103 and
 104 \fB\%ttytype\fP,
 105 maintaining them as as read-only values in the \fISCREEN\fP structure.
 106 .PP
 107 Even this is not enough to make an application using \fIcurses\fP
 108 thread-safe.
 109 We would expect a multi-threaded application to have threads updating
 110 separate windows (on the same device),
 111 and separate screens (on different devices).
 112 Further,
 113 applications expect a few of the global variables to be writable.
 114 The functions described here address these special situations.
 115 .PP
 116 The \fB\%ESCDELAY\fP and \fB\%TABSIZE\fP global variables are modified
 117 by some applications.
 118 To modify them in any configuration,
 119 use the \fB\%set_escdelay\fP or \fB\%set_tabsize\fP functions.
 120 Other global variables are not modifiable.
 121 \fBget_escdelay\fP retrieves \fB\%ESCDELAY\fP's value.
 122 .PP
 123 The \fBuse_window\fP and \fBuse_screen\fP functions provide
 124 coarse-grained mutexes for their respective \fI\%WINDOW\fP and
 125 \fISCREEN\fP parameters;
 126 they call a user-supplied function,
 127 pass it a \fIdata\fP parameter,
 128 and return the value from the user-supplied function to the application.
 129 .\" ***************************************************************************
 130 .SS Usage
 131 All \fI\%ncurses\fP library functions assume that the locale is not
 132 altered during operation.
 133 In addition,
 134 they use data that is maintained within a hierarchy of scopes.
 135 .bP
 136 global data used in the low-level \fIterminfo\fP or \fItermcap\fP
 137 interfaces
 138 .bP
 139 terminal data associated with a call to \fBset_curterm\fP(3X)
 140 .IP
 141 Terminal data are initialized when screens are created.
 142 .bP
 143 screen data associated with a call to \fBnewterm\fP(3X) or
 144 \fBinitscr\fP(3X)
 145 .bP
 146 window data associated with a call to \fBnewwin\fP(3X) or
 147 \fBsubwin\fP(3X)
 148 .IP
 149 Windows are associated with screens.
 150 Pads are not necessarily associated with any particular screen.
 151 .IP
 152 Most \fIcurses\fP applications operate on one or more windows within a
 153 single screen.
 154 .bP
 155 reentrant data associated with \*(``pure\*('' functions that alter no
 156 shared variables
 157 .PP
 158 The following table lists the scope of each symbol in the
 159 \fI\%ncurses\fP library when configured to support multi-threaded
 160 applications.
 161 .PP
 162 .TS
 163 center tab(/);
 164 lb lb
 165 lb l .
 166 Symbol/Scope
 167 =
 168 BC/global
 169 COLORS/screen (read-only)
 170 COLOR_PAIR/reentrant
 171 COLOR_PAIRS/screen (read-only)
 172 COLS/screen (read-only)
 173 ESCDELAY/screen (read-only; see \fBset_escdelay\fP)
 174 LINES/screen (read-only)
 175 PAIR_NUMBER/reentrant
 176 PC/global
 177 SP/global
 178 TABSIZE/screen (read-only; see \fBset_tabsize\fP)
 179 UP/global
 180 acs_map/screen (read-only)
 181 add_wch/window (\fBstdscr\fP)
 182 add_wchnstr/window (\fBstdscr\fP)
 183 add_wchstr/window (\fBstdscr\fP)
 184 addch/window (\fBstdscr\fP)
 185 addchnstr/window (\fBstdscr\fP)
 186 addchstr/window (\fBstdscr\fP)
 187 addnstr/window (\fBstdscr\fP)
 188 addnwstr/window (\fBstdscr\fP)
 189 addstr/window (\fBstdscr\fP)
 190 addwstr/window (\fBstdscr\fP)
 191 assume_default_colors/screen
 192 attr_get/window (\fBstdscr\fP)
 193 attr_off/window (\fBstdscr\fP)
 194 attr_on/window (\fBstdscr\fP)
 195 attr_set/window (\fBstdscr\fP)
 196 attroff/window (\fBstdscr\fP)
 197 attron/window (\fBstdscr\fP)
 198 attrset/window (\fBstdscr\fP)
 199 baudrate/screen
 200 beep/screen
 201 bkgd/window (\fBstdscr\fP)
 202 bkgdset/window (\fBstdscr\fP)
 203 bkgrnd/window (\fBstdscr\fP)
 204 bkgrndset/window (\fBstdscr\fP)
 205 boolcodes/global (read-only)
 206 boolfnames/global (read-only)
 207 boolnames/global (read-only)
 208 border/window (\fBstdscr\fP)
 209 border_set/window (\fBstdscr\fP)
 210 box/window (\fBstdscr\fP)
 211 box_set/window (\fBstdscr\fP)
 212 can_change_color/terminal
 213 cbreak/screen
 214 chgat/window (\fBstdscr\fP)
 215 clear/window (\fBstdscr\fP)
 216 clearok/window
 217 clrtobot/window (\fBstdscr\fP)
 218 clrtoeol/window (\fBstdscr\fP)
 219 color_content/screen
 220 color_set/window (\fBstdscr\fP)
 221 copywin/window (locks source, target)
 222 cur_term/terminal
 223 curs_set/screen
 224 curscr/screen (read-only)
 225 curses_version/global (read-only)
 226 def_prog_mode/terminal
 227 def_shell_mode/terminal
 228 define_key/screen
 229 del_curterm/screen
 230 delay_output/screen
 231 delch/window (\fBstdscr\fP)
 232 deleteln/window (\fBstdscr\fP)
 233 delscreen/global (locks screen list, screen)
 234 delwin/global (locks window list)
 235 derwin/screen
 236 doupdate/screen
 237 dupwin/screen (locks window)
 238 echo/screen
 239 echo_wchar/window (\fBstdscr\fP)
 240 echochar/window (\fBstdscr\fP)
 241 endwin/screen
 242 erase/window (\fBstdscr\fP)
 243 erasechar/window (\fBstdscr\fP)
 244 erasewchar/window (\fBstdscr\fP)
 245 filter/global
 246 flash/terminal
 247 flushinp/screen
 248 get_wch/screen (input operation)
 249 get_wstr/screen (input operation)
 250 getattrs/window
 251 getbegx/window
 252 getbegy/window
 253 getbkgd/window
 254 getbkgrnd/window
 255 getcchar/reentrant
 256 getch/screen (input operation)
 257 getcurx/window
 258 getcury/window
 259 getmaxx/window
 260 getmaxy/window
 261 getmouse/screen (input operation)
 262 getn_wstr/screen (input operation)
 263 getnstr/screen (input operation)
 264 getparx/window
 265 getpary/window
 266 getstr/screen (input operation)
 267 getwin/screen (input operation)
 268 halfdelay/screen
 269 has_colors/terminal
 270 has_ic/terminal
 271 has_il/terminal
 272 has_key/screen
 273 hline/window (\fBstdscr\fP)
 274 hline_set/window (\fBstdscr\fP)
 275 idcok/window
 276 idlok/window
 277 immedok/window
 278 in_wch/window (\fBstdscr\fP)
 279 in_wchnstr/window (\fBstdscr\fP)
 280 in_wchstr/window (\fBstdscr\fP)
 281 inch/window (\fBstdscr\fP)
 282 inchnstr/window (\fBstdscr\fP)
 283 inchstr/window (\fBstdscr\fP)
 284 init_color/screen
 285 init_pair/screen
 286 initscr/global (locks screen list)
 287 innstr/window (\fBstdscr\fP)
 288 innwstr/window (\fBstdscr\fP)
 289 ins_nwstr/window (\fBstdscr\fP)
 290 ins_wch/window (\fBstdscr\fP)
 291 ins_wstr/window (\fBstdscr\fP)
 292 insch/window (\fBstdscr\fP)
 293 insdelln/window (\fBstdscr\fP)
 294 insertln/window (\fBstdscr\fP)
 295 insnstr/window (\fBstdscr\fP)
 296 insstr/window (\fBstdscr\fP)
 297 instr/window (\fBstdscr\fP)
 298 intrflush/terminal
 299 inwstr/window (\fBstdscr\fP)
 300 is_cleared/window
 301 is_idcok/window
 302 is_idlok/window
 303 is_immedok/window
 304 is_keypad/window
 305 is_leaveok/window
 306 is_linetouched/window
 307 is_nodelay/window
 308 is_notimeout/window
 309 is_scrollok/window
 310 is_syncok/window
 311 is_term_resized/terminal
 312 is_wintouched/window
 313 isendwin/screen
 314 key_defined/screen
 315 key_name/global (static data)
 316 keybound/screen
 317 keyname/global (static data)
 318 keyok/screen
 319 keypad/window
 320 killchar/terminal
 321 killwchar/terminal
 322 leaveok/window
 323 longname/screen
 324 mcprint/terminal
 325 meta/screen
 326 mouse_trafo/window (\fBstdscr\fP)
 327 mouseinterval/screen
 328 mousemask/screen
 329 move/window (\fBstdscr\fP)
 330 mvadd_wch/window (\fBstdscr\fP)
 331 mvadd_wchnstr/window (\fBstdscr\fP)
 332 mvadd_wchstr/window (\fBstdscr\fP)
 333 mvaddch/window (\fBstdscr\fP)
 334 mvaddchnstr/window (\fBstdscr\fP)
 335 mvaddchstr/window (\fBstdscr\fP)
 336 mvaddnstr/window (\fBstdscr\fP)
 337 mvaddnwstr/window (\fBstdscr\fP)
 338 mvaddstr/window (\fBstdscr\fP)
 339 mvaddwstr/window (\fBstdscr\fP)
 340 mvchgat/window (\fBstdscr\fP)
 341 mvcur/screen
 342 mvdelch/window (\fBstdscr\fP)
 343 mvderwin/window (\fBstdscr\fP)
 344 mvget_wch/screen (input operation)
 345 mvget_wstr/screen (input operation)
 346 mvgetch/screen (input operation)
 347 mvgetn_wstr/screen (input operation)
 348 mvgetnstr/screen (input operation)
 349 mvgetstr/screen (input operation)
 350 mvhline/window (\fBstdscr\fP)
 351 mvhline_set/window (\fBstdscr\fP)
 352 mvin_wch/window (\fBstdscr\fP)
 353 mvin_wchnstr/window (\fBstdscr\fP)
 354 mvin_wchstr/window (\fBstdscr\fP)
 355 mvinch/window (\fBstdscr\fP)
 356 mvinchnstr/window (\fBstdscr\fP)
 357 mvinchstr/window (\fBstdscr\fP)
 358 mvinnstr/window (\fBstdscr\fP)
 359 mvinnwstr/window (\fBstdscr\fP)
 360 mvins_nwstr/window (\fBstdscr\fP)
 361 mvins_wch/window (\fBstdscr\fP)
 362 mvins_wstr/window (\fBstdscr\fP)
 363 mvinsch/window (\fBstdscr\fP)
 364 mvinsnstr/window (\fBstdscr\fP)
 365 mvinsstr/window (\fBstdscr\fP)
 366 mvinstr/window (\fBstdscr\fP)
 367 mvinwstr/window (\fBstdscr\fP)
 368 mvprintw/window (\fBstdscr\fP)
 369 mvscanw/screen
 370 mvvline/window (\fBstdscr\fP)
 371 mvvline_set/window (\fBstdscr\fP)
 372 mvwadd_wch/window
 373 mvwadd_wchnstr/window
 374 mvwadd_wchstr/window
 375 mvwaddch/window
 376 mvwaddchnstr/window
 377 mvwaddchstr/window
 378 mvwaddnstr/window
 379 mvwaddnwstr/window
 380 mvwaddstr/window
 381 mvwaddwstr/window
 382 mvwchgat/window
 383 mvwdelch/window
 384 mvwget_wch/screen (input operation)
 385 mvwget_wstr/screen (input operation)
 386 mvwgetch/screen (input operation)
 387 mvwgetn_wstr/screen (input operation)
 388 mvwgetnstr/screen (input operation)
 389 mvwgetstr/screen (input operation)
 390 mvwhline/window
 391 mvwhline_set/window
 392 mvwin/window
 393 mvwin_wch/window
 394 mvwin_wchnstr/window
 395 mvwin_wchstr/window
 396 mvwinch/window
 397 mvwinchnstr/window
 398 mvwinchstr/window
 399 mvwinnstr/window
 400 mvwinnwstr/window
 401 mvwins_nwstr/window
 402 mvwins_wch/window
 403 mvwins_wstr/window
 404 mvwinsch/window
 405 mvwinsnstr/window
 406 mvwinsstr/window
 407 mvwinstr/window
 408 mvwinwstr/window
 409 mvwprintw/window
 410 mvwscanw/screen
 411 mvwvline/window
 412 mvwvline_set/window
 413 napms/reentrant
 414 newpad/global (locks window list)
 415 newscr/screen (read-only)
 416 newterm/global (locks screen list)
 417 newwin/global (locks window list)
 418 nl/screen
 419 nocbreak/screen
 420 nodelay/window
 421 noecho/screen
 422 nofilter/global
 423 nonl/screen
 424 noqiflush/terminal
 425 noraw/screen
 426 notimeout/window
 427 numcodes/global (read-only)
 428 numfnames/global (read-only)
 429 numnames/global (read-only)
 430 ospeed/global
 431 overlay/window (locks source, target)
 432 overwrite/window (locks source, target)
 433 pair_content/screen
 434 pecho_wchar/screen
 435 pechochar/screen
 436 pnoutrefresh/screen
 437 prefresh/screen
 438 printw/window
 439 putp/global
 440 putwin/window
 441 qiflush/terminal
 442 raw/screen
 443 redrawwin/window
 444 refresh/screen
 445 reset_prog_mode/screen
 446 reset_shell_mode/screen
 447 resetty/terminal
 448 resize_term/screen (locks window list)
 449 resizeterm/screen
 450 restartterm/screen
 451 ripoffline/global (static data)
 452 savetty/terminal
 453 scanw/screen
 454 scr_dump/screen
 455 scr_init/screen
 456 scr_restore/screen
 457 scr_set/screen
 458 scrl/window (\fBstdscr\fP)
 459 scroll/window
 460 scrollok/window
 461 set_curterm/screen
 462 set_escdelay/screen
 463 set_tabsize/screen
 464 set_term/global (locks screen list, screen)
 465 setcchar/reentrant
 466 setscrreg/window (\fBstdscr\fP)
 467 setupterm/global
 468 slk_attr/screen
 469 slk_attr_off/screen
 470 slk_attr_on/screen
 471 slk_attr_set/screen
 472 slk_attroff/screen
 473 slk_attron/screen
 474 slk_attrset/screen
 475 slk_clear/screen
 476 slk_color/screen
 477 slk_init/screen
 478 slk_label/screen
 479 slk_noutrefresh/screen
 480 slk_refresh/screen
 481 slk_restore/screen
 482 slk_set/screen
 483 slk_touch/screen
 484 slk_wset/screen
 485 standend/window
 486 standout/window
 487 start_color/screen
 488 \fBstdscr\fP/screen (read-only)
 489 strcodes/global (read-only)
 490 strfnames/global (read-only)
 491 strnames/global (read-only)
 492 subpad/window
 493 subwin/window
 494 syncok/window
 495 term_attrs/screen
 496 termattrs/screen
 497 termname/terminal
 498 tgetent/global
 499 tgetflag/global
 500 tgetnum/global
 501 tgetstr/global
 502 tgoto/global
 503 tigetflag/terminal
 504 tigetnum/terminal
 505 tigetstr/terminal
 506 timeout/window (\fBstdscr\fP)
 507 touchline/window
 508 touchwin/window
 509 tparm/global (static data)
 510 tputs/screen
 511 trace/global (static data)
 512 ttytype/screen (read-only)
 513 typeahead/screen
 514 unctrl/screen
 515 unget_wch/screen (input operation)
 516 ungetch/screen (input operation)
 517 ungetmouse/screen (input operation)
 518 untouchwin/window
 519 use_default_colors/screen
 520 use_env/global (static data)
 521 use_extended_names/global (static data)
 522 use_legacy_coding/screen
 523 use_screen/global (locks screen list, screen)
 524 use_window/global (locks window list, window)
 525 vid_attr/screen
 526 vid_puts/screen
 527 vidattr/screen
 528 vidputs/screen
 529 vline/window (\fBstdscr\fP)
 530 vline_set/window (\fBstdscr\fP)
 531 vw_printw/window
 532 vw_scanw/screen
 533 vwprintw/window
 534 vwscanw/screen
 535 wadd_wch/window
 536 wadd_wchnstr/window
 537 wadd_wchstr/window
 538 waddch/window
 539 waddchnstr/window
 540 waddchstr/window
 541 waddnstr/window
 542 waddnwstr/window
 543 waddstr/window
 544 waddwstr/window
 545 wattr_get/window
 546 wattr_off/window
 547 wattr_on/window
 548 wattr_set/window
 549 wattroff/window
 550 wattron/window
 551 wattrset/window
 552 wbkgd/window
 553 wbkgdset/window
 554 wbkgrnd/window
 555 wbkgrndset/window
 556 wborder/window
 557 wborder_set/window
 558 wchgat/window
 559 wclear/window
 560 wclrtobot/window
 561 wclrtoeol/window
 562 wcolor_set/window
 563 wcursyncup/screen (affects window plus parents)
 564 wdelch/window
 565 wdeleteln/window
 566 wecho_wchar/window
 567 wechochar/window
 568 wenclose/window
 569 werase/window
 570 wget_wch/screen (input operation)
 571 wget_wstr/screen (input operation)
 572 wgetbkgrnd/window
 573 wgetch/screen (input operation)
 574 wgetdelay/window
 575 wgetn_wstr/screen (input operation)
 576 wgetnstr/screen (input operation)
 577 wgetparent/window
 578 wgetscrreg/window
 579 wgetstr/screen (input operation)
 580 whline/window
 581 whline_set/window
 582 win_wch/window
 583 win_wchnstr/window
 584 win_wchstr/window
 585 winch/window
 586 winchnstr/window
 587 winchstr/window
 588 winnstr/window
 589 winnwstr/window
 590 wins_nwstr/window
 591 wins_wch/window
 592 wins_wstr/window
 593 winsch/window
 594 winsdelln/window
 595 winsertln/window
 596 winsnstr/window
 597 winsstr/window
 598 winstr/window
 599 winwstr/window
 600 wmouse_trafo/window
 601 wmove/window
 602 wnoutrefresh/screen
 603 wprintw/window
 604 wredrawln/window
 605 wrefresh/screen
 606 wresize/window (locks window list)
 607 wscanw/screen
 608 wscrl/window
 609 wsetscrreg/window
 610 wstandend/window
 611 wstandout/window
 612 wsyncdown/screen (affects window plus parents)
 613 wsyncup/screen (affects window plus parents)
 614 wtimeout/window
 615 wtouchln/window
 616 wunctrl/global (static data)
 617 wvline/window
 618 wvline_set/window
 619 .TE
 620 .\" ***************************************************************************
 621 .SH RETURN VALUE
 622 \fB\%get_escdelay\fP returns the value of \fB\%ESCDELAY\fP.
 623 \fB\%set_escdelay\fP and \fB\%set_tabsize\fP return \fBERR\fP upon
 624 failure and \fBOK\fP upon successful completion.
 625 \fB\%use_screen\fP and \fB\%use_window\fP return the \fIint\fP returned
 626 by the user-supplied function they are called with.
 627 .SH NOTES
 628 \fI\%ncurses\fP provides both a C function and a preprocessor macro for
 629 each function documented in this page.
 630 .SH PORTABILITY
 631 These routines are specific to \fI\%ncurses\fP.
 632 They were not supported on Version 7, BSD or System V implementations.
 633 It is recommended that any code depending on \fI\%ncurses\fP extensions
 634 be conditioned using \fB\%NCURSES_VERSION\fP.
 635 .SH SEE ALSO
 636 \fB\%curses\fP(3X),
 637 \fB\%curs_opaque\fP(3X),
 638 \fB\%curs_variables\fP(3X)